JP2003275164A - Insertion part position detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insertion part position detection device that can precisely detect the position of an insertion part. <P>SOLUTION: The insertion part position detection device comprises an insertion body with either magnetic field generating elements or magnetic field detecting elements, a bed with at least three of the other magnetic field generating elements or magnetic field detecting elements, and a means for estimating the positions of the magnetic field generating elements or magnetic field detecting elements in the insertion part of the insertion body relative to the magnetic field generating elements or magnetic field detecting elements on the bed from magnetic field detection signals detected by the magnetic field detecting elements. The bed does not affect magnetic fields generated by the magnetic field generating elements, and carries at least three magnetic field generating elements or magnetic field detecting elements so as to form a detected target area in a region where a subject lies. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insertion portion position detecting device for detecting the position of an insertion portion using a magnetic field generating element and a magnetic field detecting element.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used in medical fields and industrial fields. This endoscope, especially if it has a soft insertion part, can be inserted into a bent body cavity to diagnose an organ deep inside the body cavity without incision or to insert a treatment instrument into the channel as necessary. It is possible to carry out therapeutic treatment such as excision of polyps and the like.

In this case, some skill may be required to smoothly insert the insertion portion into the bent body cavity, for example, when examining the lower digestive tract from the anus side.

That is, when the insertion work is being performed, a work such as bending the bending portion provided in the insertion portion in accordance with the bending of the conduit is necessary for smooth insertion. For that purpose, the insertion portion is required. It is convenient to know where in the body cavity the position of the tip of the body is, and the current bending state of the insertion part.

Therefore, for example, Japanese Patent Laid-Open No. 3-295530
There is one disclosed in Japanese Patent Laid-Open Publication No. 2003-242242 in which the receiving antenna (coil) provided in the insertion portion is scanned with a transmitting antenna (antenna coil) provided outside the insertion portion to detect the insertion state of the insertion portion.

Further, Japanese Patent Laid-Open No. 5-177000 discloses a catheter guide device in which a transmitting means is attached to the tip of a catheter or the like and the signal thereof is received to determine the position of the transmitting means.

US Pat. No. 4,176,662 discloses a method in which a burst wave is emitted from a transducer at the tip of an endoscope and detected by a plurality of surrounding antennas or transducers to plot the position of the tip on a CRT. Has been done.

Further, US Pat. No. 4,821,731 discloses a technique in which a quadrature coil outside the body is rotated to detect the tip position of the catheter from the output of a sensor provided on the catheter inside the body.

Further, in PCT application GB91 / 01431 publication, an XY is arranged around an object into which an endoscope is inserted.
There is disclosed a conventional example in which a large number of dipole antennas are arranged in a grid pattern in a direction and AC-driven, and the position of the endoscope is derived from a signal obtained by a coil built in the endoscope side.

[0010]

However, it is desired to further improve the accuracy of detecting the position of the insertion portion.

An object of the present invention is to provide an insertion portion position detecting device which enables highly accurate insertion portion position detection.

[0012]

[MEANS FOR SOLVING THE PROBLEMS] Of a magnetic field generation element which has a flexible insertion part which can be inserted into a subject and which generates a magnetic field in the insertion part, and a magnetic field detection element which detects the generated magnetic field, An insertion tool provided with one, a mounting table on which the subject can be placed and at least three other ones of the magnetic field generation element and the magnetic field detection element are provided; and the magnetic field generation element. From the detection signal of the generated magnetic field detected by the magnetic field detection element, the magnetic field detection element or the magnetic field detection provided in the insertion part of the insertion tool for the magnetic field generation element or the magnetic field detection element provided on the mounting table And a position estimating means for estimating the position of the element, wherein the mounting table is formed of a member that does not affect a magnetic field generated by driving the magnetic field generating element, and the subject is mounted on the mounting table. By arranging the at least three magnetic field generating elements or magnetic field detecting elements so that the detection target area is formed at the position, it is possible to set an environment where the generated magnetic field is not affected on the mounting table, and A detection target region formed by three magnetic field generation elements or magnetic field detection elements can be set on the mounting table, and the position of the insertion portion can be detected with higher accuracy.

Further, at least the magnetic field detecting element is a triaxial coil having three coils wound so as to have directivity in three orthogonal axial directions, and the position estimating means is the triaxial coil. By providing the correction means for correcting the difference in each output characteristic due to the difference in the diameter of each coil of the coil, it is possible to prevent the difference in each output characteristic due to the difference in the diameter of each coil, and to improve the accuracy. The position of the insertion part can be detected.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 43 show a first embodiment of the present invention. As shown in FIG. 1, an endoscope system 1
Is equipped with an endoscope apparatus 2 that performs an inspection or the like using the endoscope 6, and the function of the first embodiment that is used together with the endoscope apparatus 2 and that detects the position of the insertion portion 7 of the endoscope 6. Further, the endoscope shape detecting device 3 that estimates the shape of the insertion portion 7 and displays an image corresponding to the shape is configured.

A patient 5 as a subject is placed on the bed 4 (for endoscopy), and is placed in the body cavity of the patient 5 as shown in FIG.
The insertion portion 7 of the endoscope 6 shown in is inserted. This endoscope 6
Has an elongated and flexible insertion portion 7, a wide operation portion 8 formed at the rear end thereof, and a universal cable 9 extending from a side portion of the operation portion 8. A connector 9A is provided at the end of the connector, and the connector 9A can be detachably connected to the light source unit 36 in the video processor 11.

A signal cable 9B is further extended from the connector 9A, and the signal connector 9C provided at the end of the signal cable 9B can be detachably connected to the signal processing section 37 in the video processor 11.

As shown in FIG. 4, a light guide 38 for transmitting illumination light is inserted through the insertion portion 7, and the light guide 38 is further inserted through the universal cable 9 extended from the operation portion 8 and at the end. It reaches the connector 9A. Illumination light is supplied from the lamp 36A in the light source unit 36 to the end surface of the connector 9A, transmitted by the light guide 38, and attached to the illumination window at the tip of the insertion unit 7 (which forms illumination light emitting means). The illumination light transmitted from the front end face is emitted forward.

A subject such as an inner wall or a diseased part in the body cavity illuminated by the illumination light emitted from the illumination window is focused by an objective lens 39 attached to an observation window formed adjacent to the illumination window at the tip. An image is formed on the CCD 29 as a solid-state image sensor arranged on the surface.

The CCD 29 is a CC in the signal processing unit 37.
By applying the CCD drive signal output from the D drive circuit 37A, the image signal photoelectrically converted (by the CCD 29) is read out, and the signal processing circuit 37B is passed through the signal line inserted through the insertion portion 7 or the like. Is subjected to signal processing in order to be converted into a standard video signal, output to the color monitor 12, and the endoscope image formed on the photoelectric conversion surface of the CCD 29 by the objective lens 39 is displayed in color.

Further, a bending operation knob 8A is provided on the operation section 8, and the bending section 7A is formed near the tip of the insertion section 7 by rotating the knob 8A.
The distal end side is curved so that it can be smoothly inserted into a body cavity path that has been curved so that it can be curved.

Further, as shown in FIG. 4, a hollow channel 13 is formed in the insertion portion 7 of the endoscope 6.
By inserting a treatment tool such as forceps through the insertion opening 13a at the proximal end of the channel 13, the distal end side of the treatment tool is projected from the channel outlet of the distal end surface of the insertion section 7 to perform biopsy or treatment on the affected area or the like. Treatment can be performed.

Further, a probe 15 for detecting the position and shape (of the insertion portion 7 inserted into the body cavity) is inserted into the channel 13, and the tip side of the probe 15 is set at a predetermined position in the channel 13. can do. FIG. 5 shows an example of the tip side of the probe 15 when the probe 15 is fixed in the channel 13.

As shown in FIG. 5, the probe 15 has a plurality of source coils 16a, 16b, ... It is fixed to the inner wall of the tube 19 with an insulative adhesive 20 in the tube 19 of the cross section at a constant interval d, for example.

Each source coil 16i is composed of, for example, a solenoid-shaped coil in which a conductive wire wound around an insulating and hard cylindrical core 10 is wound, and an insulating adhesive 20 is applied to the outer peripheral surface of the coil. Coated core 10
It is also fixed to the inner wall of the tube 19 while being fixed to the inner wall of the tube 19 while being insulated.

Even if the tube 19 is bent and deformed, each source coil 16i has a rigid core 10.
Since the conducting wire is wound around and fixed with the adhesive 20,
The source coil 16i itself has a structure in which its shape is not deformed, and the function of generating a magnetic field is kept unchanged even when the tube 19 is deformed.

Further, for example, the position of the source coil 16a at the end (tip) is installed so as to coincide with the surface of the outlet of the channel 13 (its tip surface), and therefore the position of the source coil 16a at the most tip should be detected. Allows the endoscope 6
Position of the tip surface of the insertion portion 7 (more accurately, 1 / l of the length of the source coil 16a (in the axial direction of the insertion portion 7)
It is designed to be able to detect 2 positions backward).

Since the position of the source coil 16a at the tip is a known position of the endoscope 6 and the source coils 16i are provided at regular intervals d, each source coil 1
The position of 6i is set to a known position in the insertion portion 7 of the endoscope 6, and by detecting the position of each source coil 16i, the position of 6i of the insertion portion 7 of the endoscope 6 becomes discrete. The position (more precisely, the position of each source coil 16i) can be detected.

By detecting these discrete positions, the positions between them can also be roughly estimated. Therefore, by detecting the discrete positions, the shape of the insertion portion 7 of the endoscope 6 inserted into the body cavity. It becomes possible to ask.

The outer diameter near the tip of the probe 15 may be made slightly larger than the other portions so that the probe 15 can be positioned and installed in close contact with the inner wall near the outlet of the channel 13. Then, when it becomes unnecessary to display the endoscope shape (for example, the endoscope shape is displayed so that the operation of inserting the distal end side of the insertion portion 6 to the vicinity of the target site on the deep side of the body cavity can be smoothly performed. Alternatively, the proximal side of the probe 15 may be pulled, the probe 15 may be removed toward the proximal side, and the treatment instrument or the like may be inserted through the channel 13.

The lead wire 17 connected to each source coil 16i is provided at the rear end of the probe 15 or the probe 1
5 is connected to a connector 18 provided at the rear end of the cable extending from the rear end of the cable 5, and the connector 18 is connected to the connector receiver of the (endoscope) shape detection device main body 21. Then, as will be described later, a drive signal is applied to each source coil 16i to generate a magnetic field used for position detection.

FIG. 6 shows the structure of a modified probe 15 '. The probe 15 'is an insulating member and has a flexible sheath tube 19' in which a source coil 16i is attached to a flexible supporting member 46 at a constant distance d. The support member 46 is formed of a member that does not have elasticity in the longitudinal direction (the axial direction of the insertion portion 7 when arranged in the insertion portion 7), and when the sheath tube 19 ′ is bent. Also, the source coils 16i are arranged so that the distance between them is constant.

Each source coil 16i is formed by a coil in which a copper wire 48 is wound around a magnetic material 47, and one of the wound two terminals has a common copper wire, and is extended, for example, along the support member 46. The copper wire 48 extending from the other terminal extends rearward from each source coil 16i and is connected to a contact point of a connector 49 (see FIG. 3) at the proximal end of the sheath tube 19 '. It should be noted that one of the two terminals of each coil forming each source coil 16i is not shared,
You may make it respectively extend to the back side with two copper wires.

A through hole is provided in the magnetic material 47 of each source coil 16i, a support member 46 is passed through the through hole, and is fixed with an insulating adhesive 20 at a constant interval d. When the sheath tube 19 'is made thin, it may be crushed by an external force and buckled to make it difficult to insert the sheath tube 19' inside the source coil 16i. The bonding material 50 is filled.

A substantially spherical tip 55 is attached to the tip of the sheath tube 19 'to improve slippage when it is inserted into the channel 13. A break stop 56 is provided between the rear end of the tube 19 'and the connector 49. Further, the connector 49 is covered with a connector cap 57 in order to facilitate handling by an operator and in consideration of disinfection and sterilization processing.

FIG. 3 shows how the probe 15 'is attached to the channel 13. In FIG. 3, in addition to the probe 15 ', a structure in which forceps or the like can be further inserted from the insertion port 14.

The source coil 16i may be composed of a uniaxial coil as shown in FIG. 5 or FIG. 6, or a triaxial structure having a structure similar to that of a triaxial sense coil 22j (described later) as shown in FIG. The source coil 16i may be used.

When the triaxial source coil 16i is used, the three coils are wound around a hard core 10 formed of a non-magnetic material or a magnetic material and having a cubic shape, for example. By using the non-magnetic core 10, it is possible not to affect the magnetic field distribution generated in other source coils adjacent to each other, or the magnetic substance may be used when it is not very close to the adjacent source coil. A source coil as a magnetic field generating element may be configured by a coil in which the core 10 is wound and a conductive wire is wound.

Further, as shown in FIG. 7, a hole is formed in a portion of the core 10 where the coil is not wound so that the lead wires 17 connected to both ends of each coil are passed through (one end of each coil). Can be common). The core 10 may be omitted, and three coils including the hollow portions of the three coils may be bonded and fixed with an insulating adhesive. In addition, as shown in FIG. 1, the known position of the bed 4,
For example, three-axis sense coils 22a, 22b, 22c as magnetic field detecting elements for detecting magnetic fields are respectively provided at three corners.
(Represented by 22j) is attached, and these three-axis sense coils 22j are connected to the shape detection device main body 21 via a cable extended from the bed 4.

As shown in FIG. 7, the triaxial sense coil 22j is wound in three directions so that the respective coil surfaces are orthogonal to each other, and each coil is proportional to the strength of the magnetic field of the axial component orthogonal to the coil surface. Detected signal.

The shape detecting device main body 21 detects the position of each source coil 16i based on the output of the triaxial sense coil 22j and determines the shape of the insertion portion 7 of the endoscope 6 inserted into the patient 5. An estimated computer graphic image corresponding to the estimated shape is displayed on the monitor 23.

Since the endoscope shape detecting device 3 uses magnetism, if a metal that is not transparent to magnetism exists, it will be affected by iron loss and the like, and the source coil 16i for generating a magnetic field and the detecting coil will be used. Influences mutual inductance between the three-axis sense coils 22j. In general, when the mutual inductance is expressed by R + jX, both R and X are affected (metals that are not transparent to magnetism).

In this case, the amplitude and phase of the signal measured by the quadrature detection which is generally used for detecting the minute magnetic field are changed. Therefore, in order to detect signals accurately, it is desirable to set up an environment in which the generated magnetic field is not affected.

In order to realize this, the bed 4 may be made of a magnetically transparent material (in other words, a material that does not affect the magnetic field). The magnetically transparent material may be, for example, resin such as Delrin, wood, or non-magnetic material metal.

Since an AC magnetic field is actually used to detect the position of the source coil 16i, the source coil 16i may be formed of a material that does not magnetically affect the frequency of the drive signal. Therefore, the endoscopic examination bed 4 shown in FIG. 1 used together with the present endoscope shape detecting device 3 is made of a non-magnetic material that is magnetically transparent at least at the frequency of the magnetic field generated.

FIG. 2 is a block diagram showing a schematic configuration of the endoscope shape detecting device 3. A drive signal from the source coil drive unit 24 is supplied to the source coil 16i in the probe 15 set in the channel 13 of the endoscope 6, and a magnetic field is generated around the source coil 16i to which the drive signal is applied.

The source coil driving section 24 amplifies the AC signal supplied from the (magnetic field generating) oscillating section 25,
A drive signal for generating a required magnetic field is output. The AC signal of the oscillator 25 is sent as a reference signal to the (mutual inductance) detector 26 for detecting a minute magnetic field detected by the triaxial sense coil 22j provided in the bed 4.

The minute magnetic field detection signal detected by the triaxial sense coil 22j is amplified by the (sense coil) output amplifier 27 and then input to the detector 26. The detection unit 26 performs amplification and quadrature detection (coherent detection) with the reference signal as a reference, and obtains a signal related to the mutual inductance between the coils.

Since there are a plurality of source coils 16i, the distributor 28 serving as a switching means (source coil driving current) serving as a switching means for switching to sequentially supply the driving signal to the lead wire connected to each source coil 16i drives the source coil. It exists between the portion 24 and the source coil 16i.

The signal obtained by the detection section 26 is input to the (source coil) position detection section (or position estimation section) 31 which constitutes the shape calculation section 30, and the input analog signal is converted into a digital signal. Then, the position detection calculation or the position estimation calculation is performed to obtain the estimated position information for each source coil 16i. This position information is used as the shape image generation unit 32.
The image of the endoscope 6 (the insertion part 7 of the endoscope 6) is estimated by performing a graphic process such as an interpolation process for interpolating between the obtained discrete position information, and the image corresponding to the estimated form is obtained. Is generated and sent to the monitor signal generator 33.

The monitor signal generator 33 generates a video signal of RGB or NTSC or PAL system representing an image corresponding to the shape, outputs it to the monitor 23, and inserts the endoscope 6 on the display surface of the monitor 23. Display the image corresponding to the shape.

The position detecting section 31 sends a switching signal to the distributor 28 after completing the calculation of one position detection and supplies a drive current to the next source coil 16i to calculate the position detection. (Before the calculation of each position detection is completed, a switching signal may be sent to the distributor 28 to sequentially store the signals detected by the sense coil 22j in the memory).

The system control unit 34 is composed of a CPU or the like, and controls the operations of the position detection unit 31, the shape image generation unit 32, and the monitor signal generation unit 33. An operation panel 35 is connected to the system control unit 34, and a keyboard, a switch, or the like of the operation panel 35 is operated to select an endoscope-shaped drawing model or monitor 2.
It is possible to change the endoscope shape displayed in 3 to a display state for the selected visual field direction.

The shape calculation unit 30 shown by the dotted line in FIG. 2 includes software. Further, the endoscope shape detecting device 3 of FIG. 2 includes the endoscope position detecting device of the first embodiment, and this endoscope position detecting device is denoted by reference numerals 16i, 22j, 24 in FIG.
˜28,31.

The configuration of the endoscope shape detecting device 3 is more specifically shown in FIG. That is, the oscillating unit 25 is composed of the oscillator 25a, and the oscillated output is amplified by the amplifier 24a forming the driving unit 24 and switched by the source coil switching circuit 28a forming the distributor 28 to sequentially output to the plurality of source coils 16i. A magnetic field is generated around the applied source coil 16i.

Each magnetic field is detected by each sense coil 22j, amplified by an amplifier 27, and then detected by a synchronous detection circuit 26d having a bandpass filter 26a, a phase detection circuit 26b, and a lowpass filter 26c which constitute an inductance detection section 26. A signal including the magnetic field strength and the phase difference from the oscillation output is detected.

The phase detection circuit 26b refers to the output signal of the oscillator 25a and performs phase detection (quadrature detection). The output signal of the synchronous detection circuit 26d is an A / D signal that constitutes the shape calculation unit 30.
After being converted into a digital signal through each channel of the converter 30a, the detection data storage unit 30 of the RAM 30b.
Once stored in b ', the data in this storage section 30b' is C
The data is transferred to the PU 30c, and the CPU 30c performs calculations such as position estimation and shape calculation. A / D converter 30
The timing control circuit 30d is used to switch the channels of a
Done by.

In this case, for example, one source coil 16
When the calculation for i is completed, the CPU 30c sends an end signal to the timing control circuit 30d, and when the timing control circuit 30d receives this end signal, it sends a switching control signal to the source coil switching circuit 28a and sends it to the next source coil 16i. Apply a drive signal.

The CPU 30c estimates the position of the source coil 16i by referring to the reference information stored in the reference information storage section 30b "of the RAM 30b, and interpolates between the positions by using the information of each position obtained by the estimation. The shape of the endoscope is estimated, an image corresponding to the estimated shape is also generated, and the monitor 2 is generated via the monitor signal generation unit 33 as in FIG.
The image corresponding to the estimated endoscope shape is displayed on the display unit 3. The reference information storage unit 30b ″ stores data of two curves Cu and Cd in FIG. 16 described later.

FIG. 9 shows a flow of driving operation of the source coil for shape detection and signal detection by the sense coil.
First, after setting the parameter i to 1 (step S1),
The i-th source coil 16 according to the source coil switching signal
i is selected and a drive current is passed through the source coil 16i (step S2).

Next, the transient response time Δt is waited (step S3), and after this time Δt, the detection signal detected by the sense coil 22j is sampled (step S4). Then, it is judged whether or not the i-th source coil that is driven next is the last source coil (step S5), and if it is not the last one, i is incremented to i + 1 (step S6) and the i-th source coil is restarted. Returning to the step of passing the drive current to the source coil 16i, on the other hand, in the case of the last source coil, it ends.

FIG. 10 is an explanatory diagram showing the reason why the detection signal from the sense coil 22j is sampled after the transient response time Δt. When the source coil 16i is selected by the source coil switching signal shown in FIG. 10A and a drive current is passed through the source coil 16i, the source coil 16i is selected.
Depending on the resistance component and the inductance component of i, the drive current actually flowing in the source coil 16i exhibits a transient response characteristic during the time Δt as shown in FIG.

Therefore, the detection signal detected by the sense coil 22j becomes a signal affected by the transient response characteristic as shown in FIG. 10 (c). Therefore, the timing control circuit 3
0d controls the A / D converter 30a to read after this time Δt. In this way, the detection signal that is not affected by the transient response is used. FIG. 7 shows a state in which a triaxial source coil is used as the source coil 16i and the position of a certain source coil 16i is detected by the triaxial sense coil 22j.

Three mutually orthogonal coils in the triaxial source coil 16i are respectively 16x, 16y, 16
z, the three coils of the three-axis sense coil 22j are set to 22
Consider as X, 22Y, 22Z. Further, it is assumed that there is no variation in each coil. Then, the signal output detected by (the three coils 22X, 22Y, 22Z of) the three-axis sense coil 22j when the coils 16x, 16y, 16z of the three-axis source coil 16i are respectively driven is defined as follows. .

Of the three-axis source coils 16i, the sense coil output when driving the coil 16x is X
x, Yx, Zx The sense coil output when driving the coil 16y is expressed as X
y, Yy, Zy The sense coil output when driving the coil 16z is X
Let z, Yz, and Zz.

Detection signal outputs Xx ^ 2 + Yx ^ 2 + Zx ^ 2, Xy ^ 2 + Yy ^ 2 corresponding to the square of the magnetic field strength formed by the three coils 16x, 16y, 16z, respectively.
Eight positions determined by the values of + Zy ^ 2, Xz ^ 2 + Yz ^ 2 + Zz ^ 2 are obtained as candidates for the detection position of the source coil 16i.

Further, X obtained by the synchronous detection of the detection unit 26
x, Yx, Zx, Xy, Yy, Zy, Xz, Yz, Zz
From the phase information of (1), one quadrant (of the eight quadrants) in which the source coil 16i exists at the coordinates with the sensor (the triaxial sense coil 22j) as the origin is determined. As a result, the existence position of the source coil 16i is determined (in this embodiment, the existence position of the source coil 16i is not directly calculated by using a signal corresponding to the detected magnetic field strength, as described later. , (Existing position is calculated (estimated) with reference to reference data obtained by measurement in advance).

Thus, the triaxial source coil 16i
With the use of the triaxial sense coil 22j, the discrete position of the source coil 16i can be detected. Further, by disposing the triaxial sense coils 22j at a plurality of locations on the bed 4 as shown in FIG. 1, the position of each source coil 16i can be detected more accurately.

FIG. 11 shows how the position detection is performed by the triaxial sense coil 22j using the uniaxial source coil 16i (expressed as a coreless solenoid). In the case of endoscopy, the patient 5 is on the bed 4, so the endoscope 6
The position of is always on the bed 4.

That is, the sensors 3 are provided at the four corners of the bed 4.
If the axis sense coil 22j is provided, the endoscope 6 (the source coil 16i therein) exists in the area surrounded by the sensor group, so that the installed three-axis sense coil 2
The quadrant in which the source coil 16i exists is limited for each 2j.

When the output of one triaxial sense coil 22 when the source coil 16i is driven is Xi, Yi, and Zi, the triaxial sense coil 22 having the magnetic field strength associated with Xi ^ 2 + Yi ^ 2 + Zi ^ 2. The source coil 16i is present at the distance.

However, the uniaxial coil is generally expressed as a dipole, and its equal magnetic field surface does not become a sphere but becomes an ellipse as shown in FIG. Therefore, the position of the source coil 16i whose orientation is unknown is set to the equal magnetic field surface Xi ^ 2 + Yi ^ 2 + by the single triaxial sense coil 22.
It cannot be identified only from Zi ^ 2.

Therefore, Xj ^ 2 + measured for each of the three-axis sense coils 22j provided in the bed 4
Use the distance associated with Yj ^ 2 + Zj ^ 2. In this case, since the installation position of each triaxial sense coil 22j is known, it can be represented by, for example, one coordinate system fixed to the bed 4. Consider that the sense coil 22j detects the magnetic field strength in which the equal magnetic field surface generated by the source coil 16i is expressed as Xs ^ 2 + Ys ^ 2 + Zs ^ 2 and estimates the distance therebetween.

Then, assuming an equal magnetic field surface including the magnetic field strength from the magnetic field strength detected by the sense coil 22j, the sense coil 22j exists on the same magnetic field surface with respect to the center source coil 16i. Therefore, the maximum value and the minimum value of the distance from the center to the equal magnetic field surface are Rmaxj and Rminj, respectively, and the sense coil 22j and the source coil 16i are present at the distance between them.

That is, when the sense coil 22j at a known position is used as a reference, the maximum distance Rmaxj as shown in FIG.
The source coil 16i is present inside the distance r and outside the minimum distance Rminj.

Xj, Yj, and Zj measured by the three-axis sense coils 22j and different for each three-axis sense coil 22j.
Since the source coil 16i exists in the overlap of the spherical shells represented by Rmaxj and Rminj corresponding to, the center of gravity of the region can be detected as the coil position.

With this, the position is obtained, and Rmax,
If the difference in Rmin is large, an error may occur.

Therefore, the inclination in the previously obtained volume is obtained by utilizing the fact that the inclination of the source coil 16i is represented in the phase information included in Xj, Yj, and Zj. As a result, the previous position is corrected so that the position becomes more accurate. Further, since the mutual distance between the source coils 16i is known, it may be further corrected by this value.

In this case, as shown in FIG.
Is continuous, the calculated discrete source coil 16
Gradient (dx / dl, dy / d) of i position (marked with x)
l, dz / dl) should be equal to or approximate to the tangential direction of the curve 1 interpolated based on the source coil position at the source coil position, so the position may be further corrected.

An image 100 in which the shape of the insertion portion 7 of the endoscope 6 estimated by a plurality of position information thus detected is modeled as described later is displayed on the display surface of the monitor 23, for example, as shown in FIG. As shown in the graphics output area on the left. The area on the right side is a user interface area in which the user sets a viewpoint (distance between the position and the origin), a rotation angle, an elevation angle formed by the viewpoint position and the z-axis, and the like by a key input from the operation panel 35.

FIG. 15 shows the source coil 16i in the scope.
The magnetic field generated by the external coil is detected by the external three-axis sense coil 22j, the position of the source coil 16i is obtained from the relationship between the magnetic field strength and the distance between the two points, and the insertion state is set based on the detection of each position of the plurality of source coils 16i. The flow which displays a certain insertion part shape (it describes simply as a scope shape) on a monitor (it describes also as CRT) is shown. The overall structure of this flow can be divided into the following four blocks B1 to B4 according to the processing contents.

B1: Initialize Bloc
k) This block completes the initialization work for all functions of this program. Specifically, when calculating the existing position of the source coil 16i from the setting of the initial parameters based on the method of outputting the scope shape on the CRT, and the phase information and the amplitude information obtained from the magnetic field strength detected by the hardware. Memory reading of basic data used for the above, initialization of various boards for controlling hardware, etc. are performed. Note that the detailed processing contents will be described later for each block.

B2: Hardware control block (Hardwa
re Control Block) In this system, the position coordinates of the source coil 16i arranged and fixed in the insertion portion 7 of the endoscope 6 are set to the source coil 16i.
Is calculated from the intensity of the magnetic field generated by, and the shape of the insertion portion 7 of the endoscope 6 in the inserted state is estimated based on this. This block is responsible for switching the drive of the source coil 16i to generate a magnetic field, detecting the generated magnetic field intensity by the sense coil 22j, converting the detected output into a form in which the source coil position coordinates can be calculated, and outputting the converted position. .

The drive switching of the source coil 16i is such that the position of the source coil on the endoscope 6 can be known, and the sense coil 22j for detecting the magnetic field strength of the source coil 16i is as shown in FIG. It is manufactured so that the planes of the respective coils are parallel to the three axes that are orthogonal to each other, and the magnetic field strength components in the directions of the three axes that are orthogonal to one sense coil 22j can be detected. The detected magnetic field strength data is separated and output into amplitude data and phase data required when calculating the source coil position.

B3: Source position calculation block (Sourcr P
osition Calculate Block) Based on the amplitude data and phase data obtained by the magnetic field detection in the previous block, the relationship between the magnetic field strength and the distance between the two points is used to calculate the position coordinates of the source coil 16i. Carry. First, the amplitude data and the phase data are corrected for the difference in the diameter of the sense coil 22j in the respective axial directions and the positional relationship between the source coil 16i and the sense coil 22j, and the sense coil 22j is corrected. Calculate the magnetic field strength considered to be detected at the installation position.

From the magnetic field strength thus calculated, the distance between the source coil 16i and the sense coil 22j is obtained.
However, since the attitude of the source coil 16i in the inserted state (direction of the solenoid coil) is unknown, the position of the source coil 16i can be limited to within a certain spherical shell. Therefore, three or more sense coils 22j are prepared, the overlap of the regions where the source coil 16i can exist is obtained, and the position of the center of gravity of the regions is output as the position coordinates of the source coil 16i.

B4: Image display block (Image Display
Block) Builds the scope shape based on the data obtained as the position coordinates of the source coil and outputs the image on the CRT. On the basis of data, one or more coordinates obtained as the source coil position coordinates are used to construct smooth continuous coordinates as a whole. Modeling processing is performed to make the scope shape look like this continuous coordinate (polygonal column, color gradation,
Saturation, utilization of brightness, hidden line processing, perspective, etc.).

Further, the scope image model displayed on the CRT can be rotated and enlarged or reduced in any direction,
It can also display body markers that show the viewpoint position of the current display and the head direction of the patient at a glance. The viewpoint position at the end is automatically saved and becomes the next initial viewpoint position. There is also a hot key to remember the viewpoint direction that the surgeon thinks is easy to see. Next, detailed contents of each block will be described.

B1: Initialization block In the first step S11, initialization of the graphic page (V
Initialize RAM). Also, when updating the scope image displayed on the CRT, if a new image is overwritten,
Gives the viewer the impression of a flickering image that is rewritten,
It disappears with a smooth image. Therefore, by constantly switching a plurality of graphic pages to display an image, smoothness like a moving image is realized. In addition, the colors and gradations used are set as follows.

The number of colors that can be used is limited for each hardware, and is assigned in the form of a palette number. However, with the default settings, there are only two gradations. Therefore, in order to realize richer gradation within the range of available colors, we set the palette. For example, in FIG. 14, the frame F1, the markers m1 and m2, and the display model name (not shown) have three colors, and the rest are all used for gradation display of the modeled image 100 of the insertion unit 7.

As a result, the image can be displayed brighter as it is closer to the viewpoint and darker as it is further away, and it is possible to express the insertion portion 7 in a two-dimensional manner with a stereoscopic effect and depth. . Of course, increasing or decreasing the number of gradations is arbitrary. In addition to the gradation, the colors adopted are also made up of R, G, and B configurations, making it possible to express subtle saturation and brightness.

In the next step S12, image parameters such as automatic reading of the initial viewpoint position are initialized. The way in which it looks easy to see the scope image depends largely on the operator's preference. If the initial viewpoint position is fixed, the operator has to purposely reset the viewpoint position where the scope image is easy to see, which reduces usability.

Therefore, the desired viewpoint position is saved in the form of a file (parameter file), and the file is read at the time of starting the program so that the scope image can be viewed from the viewpoint position that is easy for the operator to see immediately after the program starts. The means to do this are provided.

Further, in this embodiment, the scope image and the text screen are displayed separately. By dividing the scope image from the text screen, the degree of rotation and enlargement / reduction of the scope image can be confirmed visually and numerically.
In the next step S13, the principle source data storing the principle for deriving the source coil position is loaded. This data is reference data or reference information having the following relationship.

Relationship between magnetic field strength and distance between two points The measurement principle is that the output of the uniaxial source coil 16i is orthogonal to 3
Detecting with the sense coil 22j manufactured on the axis, the distance between the source coil 16i and the sense coil 22j is obtained from the magnetic field strength. To get the distance between both coils,
The maximum magnetic field strength output and the minimum magnetic field strength output due to the difference in the orientation (axial direction) of the source coil 16i are used, instead of directly solving from the function showing the magnetic field distribution created by the uniaxial source coil 16i. Introduced a new distance calculation method.

The graph shown in FIG. 16 is the basic data of this distance deriving principle. This is a graph of the data actually measured in the shielded room. That is, the uniaxial source coil 16i and the triaxial sense coil 22
The value of the maximum magnetic field strength detected at the position of the triaxial sense coil 22j (maximum magnetic field strength) when the axial direction of the source coil 16i is changed at each distance value when the distance to j is set to various values. Value) and the value of the smallest magnetic field strength (minimum magnetic field strength value) are plotted and made into a graph, and the upper curve Cu is the maximum magnetic field strength curve and the lower curve Cd is The minimum magnetic field strength curve is shown.

When the distance between the two coils Cu and Cd is small, there is a difference in the value detected depending on the orientation of the source coil 16i, but the distance between the coils is larger than that of the large source coil 16i. Becomes larger, the difference between the detected values becomes smaller. This is because the magnetic field formed by the dipole does not become a spherical surface when the distance is small, but at a distance sufficiently large with respect to the size of the dipole, it becomes almost spherical without depending on the size of the dipole. This result is consistent with qualitative physical phenomena.

Further, when a certain magnetic field strength H is detected,
It is possible to add a limitation that the source coil 16i can exist only in the spherical shell sandwiched between the minimum radius r_min and the maximum radius r_max. Then, in the measurement range of FIG. 16, the distance within this spherical shell (= r_max-r_min)
Is approximately 60 mm without much depending on the value of the magnetic field strength H.
It can be seen from the two curves Cu and Cd that it is about the same.

FIG. 17A shows a measuring method for obtaining the data of FIG. As shown in FIG. 17A, for example, the uniaxial source coil 16 is arranged at a known distance r1 with respect to the triaxial sense coil 22 (the center of the cube is aligned with the origin) arranged at the origin, and this position Change the direction of the source coil 16 (the axial direction) and place it at the origin 3
The magnetic field strength is measured by the axis sense coil 22, and the maximum value H1 and the minimum value H1 'thereof are measured.

That is, when the direction of the source coil 16 is changed, the magnetic field strength detected by the triaxial sense coil 22 changes accordingly, and the maximum value H1 and the minimum value H1 'of those measured values are obtained.

In general, the axial direction of the source coil 16 is the center of the sense coil 22 and the source coil 16.
The state of being coincident with the line connecting (center of) (Fig. 17 (a)
The maximum value H1 is obtained in the case of the direction of the source coil 16 shown by the solid line), and the minimum value H1 'is obtained in the state shown by the chain double-dashed line orthogonal to the source coil 16 shown by the solid line.

Similarly, the value of the distance r1 is changed to r2, and the triaxial sense coil 22 is similarly measured at the distance r2 to obtain the maximum value H2 and the minimum value H2 '. Further, the same measurement is performed by changing the distance, the maximum value and the minimum value obtained at each distance are plotted, and the maximum value and the minimum value are connected by a line so as to interpolate, respectively, as shown in FIG. 17 (b). A curve Cu of the maximum magnetic field strength and a curve Cd of the minimum magnetic field strength are obtained. The data of these curves Cu and Cd are stored in a data storage means such as a hard disk, and when the operation of displaying the endoscope shape is started, they are transferred and stored in the reference information storage unit 30b ″ of the RAM 30 of FIG. CPU3
0c is referred to when necessary.

The actual measured values proportional to the magnetic field strength detected by the triaxial sense coil 22 are the signals 22X, 22Y and 22Z respectively detected by the three coils constituting the triaxial sense coil 22. Squared value and summed, 22X ・ 22X + 22Y ・ 22Y + 22Z ・ 22
It is a value obtained by obtaining the square root of Z, and by calibrating (calibrating) the obtained value with a standard magnetic field measuring device (for example, a Gauss meter), an accurate measured value of the magnetic field strength can be obtained. The data shown in FIG. 16 is a detailed result of such measurement in a magnetically shielded shielded room.

By referring to the two curves Cu and Cd in FIG. 17B, from the magnetic field strength detected by the triaxial sense coil 22, the source coil 16 exists for the triaxial sense coil 22. The dimensional area can be estimated.

For example, when a certain magnetic field strength Ha is obtained by measurement, the distance corresponding to this magnetic field strength Ha is shown in FIG.
From (b), it can be estimated that the value of the magnetic field strength Ha is a three-dimensional region in which the source coil 16 exists in the distance range between the distances ra and ra 'where the curves Cd and Cu respectively intersect. That is, when a certain magnetic field strength is obtained, the values are the minimum magnetic field strength curve Cd and the maximum magnetic field strength curve Cu.
Minimum distance r_min and maximum distance r_m that intersect with
It can be estimated that it is between ax.

Further, FIG. 18 shows a comparison between the measured value in the shield room and the measured value of the magnetic field strength in other places (specifically, the living room) for the case of r_max (maximum magnetic field strength). Therefore, the measured value in the shielded room and the measured value in the living room almost coincide with each other. That is, the measured value in the living room is almost the same as the measured value in the shielded room, and the characteristic of the magnetic field strength with respect to the distance of the measured value is almost the same as the measured value in the shielded room. (Although not shown, the same characteristics were exhibited at the minimum magnetic field strength).

Therefore, if the shape of the function of the curve of the measured value in the shielded room is obtained in advance, the maximum magnetic field strength curve and the minimum magnetic field strength curve in that environment can be accurately used in other environments. Can be determined.

That is, even in a situation where the environment of endoscopy changes, by measuring the magnetic field in advance by a measuring device capable of measuring the magnetic field strengths in the max and min directions at several places in the environment, It becomes possible to obtain the curve data of the maximum magnetic field strength and the minimum magnetic field strength in that environment, and it is possible to save the trouble of obtaining detailed data for each environment by measurement. Thus, FIG. 18 shows that the data is very universal.

The file (max_min data file) in which the data of the maximum magnetic field strength and the minimum magnetic field strength are recorded is loaded, and the correction data is also loaded from the correction data file to perform the following correction.

Correction of Sense Coil Diameter How accurately the magnetic field strength at the installation position of the sense coil 22j can be obtained is a very important issue. It is almost impossible to manufacture the sense coil 22j having three orthogonal axes with the same core and the same diameter, and the output detection value differs due to the difference in diameter. Also, the source coil 1
The output value also changes depending on the direction and direction of 6i.

Therefore, the magnetic field was actually detected, and the arrangement of the source coil 16i and the sense coil 22j and the change in the magnetic field detection value were examined. As a result, with respect to the diameters of the respective sizes, the difference in the size of the diameters and the arrangement of both coils 16i and 22j can be obtained only by multiplying the two sets of correction coefficients according to the signs of the phase data obtained when the magnetic field is detected. We have found that the relationship can be corrected.

Therefore, the correction coefficient for each sign of the phase data for each axis measured in advance is fetched by the initialization block B1. The result is described in the source position calculation block B3 for calculating the magnetic field strength.

After loading the above-mentioned data, the hardware is initialized in the next step S14. This step S
14, the source coil switching circuit 28a shown in FIG.
Reset the setting contents of to the initial state. Also, A /
The setting contents of the D converter 30a are reset to a setting state corresponding to the usage environment. In this way, the hardware is set to the shape calculation enabled state, and the next block B2 is operated.

B2: Hardware Control Block First, in step S21, a switching signal is applied to the source coil switching circuit 28a to select the source coil 16i and the source coil 16i is driven, as described with reference to FIG. The magnetic field generated in the source coil 16i is detected by the sense coil 22j.

Therefore, as shown in step S22, the phase detection circuit 2 detects the detection signal detected by the sense coil 22j.
After 6, the data is sampled by the A / D converter 30a.
The sampled data is once written in the RAM 30b. As shown in step S23 (CPU 30c
Is the timing control circuit 30d determines whether or not the driving for all the source coils 16i incorporated in the probe 15 has been completed. If not completed, the timing control circuit 30d drives the next source coil 16i. 30d
To control.

When all the source coils 16i are driven, the amplitude data and the phase data are calculated from the data in the RAM 30b (that is, the PSD data passed through the phase detection circuit 26d) (the PSD in step S24 in FIG. 15).
Calculation, see amplitude data and phase data in step S25).

From the above amplitude data and phase data, the processing of the next block B3 is started. First, the calculation of the magnetic field strength in step S31 is performed using the correction coefficient. The concrete contents of the flow relating to the calculation of the magnetic field strength are shown in FIG. Here, a description of the flow will be added. (A1) First, in step S31_1, the sign of the phase data is determined.

The sense coil 22j has three uniaxial coils having different diameters. Therefore, when the signs of the phase data are classified for each uniaxial coil, there are eight cases. This is done as follows.

A1_1. To judge the sign at high speed, +
Create a conditional operator that outputs 1 if 0, 0 if negative (S
IG (x) → (x <0)? 0: 1). a1_2. The sign of the phase data of the minimum diameter is checked, and the result is substituted for the parameter x (x + = SIG (ph
i)).

A1_3. Shift the bits of x left. a1_4. The sign of the phase data of the next diameter is checked, and the result is added to the parameter x. a1_5. Shift the bits of x left.

A1_6. The sign of the phase data with the largest diameter is examined and the result is added to the parameter x. By doing so, the code set of the phase data for each diameter can be replaced with eight kinds of x values, and the processing can be performed at a higher speed than the case of individually judging the code.

(A2) In the next step S31_2, the influence of the difference in diameter and arrangement included in the amplitude data is corrected. In (a1), since the combination of the phase data is replaced with the value of the parameter x, eight conversion equations are written according to the value of x. This makes it possible to multiply each amplitude data by an appropriate correction coefficient at high speed.

By the processing up to this point, the correction of data for the difference in diameter and the difference in arrangement is completed. (A3) The magnetic field strength is calculated in the next step S31_3.

In (a2), the influence of the difference in the diameter of each direction component and the difference in the coil arrangement on the output can be corrected. Therefore, by calculating the square root of the sum of squares of each component, the magnetic field strength can be calculated. Can be calculated. By the above procedure,
From the output of the sense coil 22j manufactured with three orthogonal axes,
The magnetic field strength can be calculated more accurately and at high speed.

Next, the maximum distance and the minimum distance (between the source coil 16i and the sense coil 22j) in step S32 of FIG. 15 are calculated using the maximum and minimum distance data (data of FIG. 16). This step S32 uses the magnetic field strength obtained in the previous step S31 to detect the sense coil 2
The process of calculating the maximum distance and the minimum distance between 2j and the source coil 16i is performed.

The fact that there is a proportional relationship between the distance between two points and the magnetic field strength is a very generally known physical phenomenon. However, at one point in a certain space, the l-axis source coil 1
Since the magnetic field strength generated by 6i is generally expressed by a super function, even if the direction of the source coil 16i is known and the magnetic field strength is measured, it is not easy to calculate the direction and distance in which the source coil 16i exists.

Therefore, when a certain magnetic field strength can be detected,
Let R_max be the distance when it is assumed that the source coil 16i is oriented in the direction in which its output is strongest, and R_min be the distance when it is assumed that the source coil 16i is oriented in the direction in which its output is weakest. Distance R_true between source coil 16i and sense coil 22j
Can be limited within the range of R_min ≦ R_true ≦ R_max.

Magnetic field strength M obtained in the previous step S31
And the already read magnetic field strength data m of the R_max curve are compared, and a point where mb ≦ M ≦ mt is picked up. Assuming that there is a linear change between mb and mt,
R_max is the distance corresponding to the magnetic field strength M at the midpoint.
And

The same applies to R_min. Here, the reason why the mb and mt are linearly changed is because the calculation is simplified, and there is no problem in curve approximation. Further, it is of course possible to derive the function form f (x) of the R_max curve and calculate it as R_max = f (M).

The means or method for calculating the distance adopted here is an extremely simple means or method which does not require the solution of a complicated super function, although the value of the distance R_true cannot be obtained with certainty. Upper 1-axis source coil 1
Even if the direction of 6i is unknown, the source coil 16i
It is a means or method with a wide range of application that can limit the range of existence.

Next, the source coil 16i in step S33.
Position coordinates are calculated. In this step S33, processing from the distance between the sense coil 22j and the source coil 16i to the calculation of the coordinates of the source coil 16i is performed. Source coil 16 when viewed from a certain sense coil 22j
The possible range of i is the R obtained in the previous step S32.
It is within a spherical shell surrounded by _max and R_min. In order to limit the range in which the sword coil 16i can exist to a smaller space, superposition of the possible regions of the source coil 16i found from the plurality of sense coils 22j is used. Each sense coil 22
For j, the existing region of the source coil 16i obtained from the same source coil 16i always has a region where all of them overlap unless the position of the source coil 16i moves.

The boundaries of such regions are radii R_max and R_mi centered on the respective positions of the sense coils 22j.
It is the intersection of n balls. Since it is the intersection of spheres,
If there are at least three sense coils 22j, the source coil 16i is R_max, R_ of each sense coil 22j.
Its existence can be limited to a minute region surrounded by eight intersections of a sphere having a radius of min.

The three sense coils 22j are connected to Sa, Sb,
Sc, and Ra_max, Ra_min, Rb, respectively
_Max, Rb_min, Rc_max, Rc_min
Assuming that the distance is obtained, the existence of the source coil 16i is restricted in a minute space having the following eight points as vertices.

Ra-max, Rb_max, Rc_ma
Intersection points Ra_min, Rb_max, Rc_max of spheres having radius x, respectively. Intersection points Ra_max, Rb_min, Rc_max of spheres, respectively. The intersection points Ra_min, Rb_min, and Rc_min of the spheres have radiuses Ra_min, Rb_max, and Rc_min, respectively. The intersection of the spheres and the center of gravity of the minute area surrounded by these eight points are output as the position coordinates of the source coil 16i. Further, as the number of sense coils 22j increases, the source coil 16i
Can be limited to a smaller area, and the position of the source coil 16i can be obtained more accurately.

Since this source coil position limiting method is a simple arithmetic calculation of calculating the intersection of three spheres,
It is an extremely excellent method that does not require the processing time and can limit the existence region of the source coil 16i to a very small region.

In this way, the position coordinates of each source coil 16i are calculated, and the source coil 1 of step S34 is calculated.
The position coordinate data of 6i is obtained. The processing of the next block B4 is performed using these data.

B4: Image display block This block B4 is based on the position coordinate data of the source coil 16i.
Responsible for processing up to drawing on RT. Source coil 16
The position coordinate of i is the locus that the inserted scope has passed. Therefore, based on this, the scope shape in the inserted state is estimated. When the insertion shape of the scope can be estimated, the result is drawn on the CRT. At that time, because the 3D scope shape must be displayed on the 2D CRT screen,
It is necessary to devise so that the image can be expressed more three-dimensionally.

Further, if the scope image can be rotated in an arbitrary direction and the direction from which the scope image is viewed now can be instantly judged, the usability thereof is further improved. In view of this,
In this system, it is classified by function as follows,
We have realized a display method that combines the features of each module.

S41 Keyboard input processing S42 Scope image depiction processing S43 Reference plane display processing S44 Marker display processing Not all of these are necessary for depiction of a scope image, so functions can be selected as necessary.

This method is excellent in that a more three-dimensional scope shape image can be reproduced on the CRT by incorporating a scope shape display auxiliary means that can be selected. Therefore, the features of each module will be described below.

S41: Keyboard input process Here, when a key input corresponding to a given user command is made, it is up to changing setting parameters and the like according to the contents.

The fact that an additional function, which is considered to be highly demanded by the user, is equipped determines the usability of the system. Further, function selection is a simple task, and it is necessary for the user to be able to operate it whenever he or she desires, and to promptly realize the content of the user's request.

This step S41 specifically performs the processing shown in FIG. First, as shown in step S41_1, input is obtained from the keyboard. When a key is input, the input content is substituted into the input key variable KB.

Next, in step S41_2, a command erroneous input is checked. Here, it is determined whether the entered key is incorrect. Specifically, it is performed by checking the command erroneous input flag. When this flag is ON, it is further determined in step S41_4 of the next determination process whether the input key is correct. On the other hand, if it is OFF, the process proceeds to step S41_3 of the next command processing. In step S41_4, it is confirmed whether the input key is really correct. The three judgment results are processed.

In the case of Yes: the command is processed according to the key input. After substituting the contents of the variable dumy, which temporarily stores the contents of the key input, into the input key variable KB (S41_5), the process proceeds to step S41_3 of the command processing. In the case of No: The contents of the key input are discarded. The contents of the input key variable KB are discarded and the command error input flag is set to OF.
It is set to F (S41_6).

In case of no input: It may be delayed for the user to notice an erroneous input. However, at such times, the scope image still needs to be updated. This is a process for dealing with this, and does not perform any process until it is determined whether the command is correct, and prohibits other command processes.

By this procedure, even if the user makes a mistake in the key operation, the command can be safely canceled. Next, the contents of step S41_3 of the command processing will be described.

In the processing here, the input command is processed and reflected in the creation of the scope image. The specific contents of this command processing are 13 processings 3_1 to 3_13 as shown in FIG.

3_1. Rotation of image image around x-axis An image image obtained when the viewpoint position is rotated around the x-axis is output. For example, when the x key is input, the viewpoint rotates in the x axis direction. The rotation angle is calculated from the viewpoint position coordinates thus moved. This rotation angle is substituted into the variable pitch. This variable is referred to in the affine transformation when creating the scope image, and the output image rotated around the x axis is obtained.

3_2. Rotation of image image around y-axis The image image obtained when the viewpoint position is rotated around the y-axis is output. For example, when the y key is input, the viewpoint rotates in the y axis direction. The rotation angle is calculated from the viewpoint position coordinates thus moved. This rotation angle is substituted into the variable head. This variable is referred to in the affine transformation when creating the scope image, and the output image rotated around the y axis is obtained.

3_3. Rotation of image image around z axis The image image obtained when the viewpoint position is rotated around the z axis is output. For example, when the z key is input, the viewpoint rotates in the z axis direction. The rotation angle is calculated from the viewpoint position coordinates thus moved. This rotation angle is substituted into the conversion bank. This variable is referred to in the affine transformation when creating the scope image, and the output image rotated around the z axis is obtained.

3_4. Enlargement / reduction of image image Outputs an image image when the distance between the origin and the viewpoint position is increased or decreased. For example, when the E key identified by the notation of E is input, the distance between the viewpoint position and the origin is imaged without changing the direction. The distance between the new viewpoint position and the origin at this time is substituted into the variable viewpoint.

Also, in response to this change in the viewpoint position, 3
The position of the plane (project screen) for projecting the two-dimensional image onto the two-dimensional image is also changed and assigned to the variable screen.
This is to adjust the perspective associated with the change in the viewpoint position. These variables are referred to in a three-dimensional to two-dimensional projection (abbreviated as 3D → 2D projection) conversion, and an output image obtained by enlarging or reducing the image is obtained.

3_5. The viewpoint position changed by rotating, enlarging or reducing the image image display from the initial viewpoint position is returned to the initial viewpoint position defined by the apparatus side, and the image image viewed from that position is output.

For example, if the initial viewpoint position is (0, 0, 10
0) and the viewpoint position is set when the R key identified by the R notation is pressed, the variables key, head, bank, and view are input by the R key input.
The values calculated from the initial viewpoint position are collectively assigned to the variables of wpoint and screen. These variables are referred to in the same manner as 3_1 to 4 and the output image from the initial viewpoint position is obtained. Thereby, the viewpoint position can be reset without knowing in which direction the viewpoint is turned.

3_6. Image display from user registered viewpoint position This function is the same as 3_5. The major difference is that the viewpoint position is not the initial value defined by the device, but the viewpoint position registered by the user. The user registration method for a certain viewpoint position is shown in the following 3_7. Any number of viewpoint positions can be registered. This function makes it possible to instantly obtain an output image from the viewpoint position preferred by the user, regardless of how the viewpoint position is changed.

3_7. User registration of viewpoint position The user can register this viewpoint position so that the image image output from a certain viewpoint position can be viewed at any time. Here, if the viewpoint position is registered, the function of 3_6 can be used.

For example, when the U key identified by the notation U is pressed, the viewpoint position coordinates at that time are saved as data. Alternatively, the variable pitc calculated from the viewpoint position coordinates
h, head, bank, viewpoint, scr
You may store een etc. A plurality of registration keys are prepared, and a plurality of viewpoint positions can be stored. It is also possible to update the once saved viewpoint position coordinate data.

3_8. The image output screen is divided into a plurality of images, which is usually one screen. However, this is divided into a plurality of images to enable simultaneous output of scope images from a plurality of viewpoint positions.

For example, when the 2 or 4 key identified by the notation of 2 or 4 is pressed, the screen is divided into 2 or 4 parts. At this time, coordinate conversion is performed according to the screen division amount so that the scope image image fits on the divided screen. By pressing the 0 key identified by the notation of 0, the active screen of the screens divided into a plurality can be selected.

3_9. Screen display of comment input Switch the text output screen to the comment input screen regarding the patient list and system usage. For example, when the T key identified by the notation of T is input, the comment input text screen is overlapped with the screen outputting the viewpoint position coordinates and the like, and the cursor is output to prompt the comment input.

3_10. Change the background color When the scope image is difficult to see due to the influence of the surroundings,
You can change the tint of the background color by changing the palette. For example, when the B key identified by the notation B is input, the parameter value relating to B of the RGB palette that determines the background color can be changed, and the delicate hue can be changed.

3_11. Marker Display ON / OFF This system has a function of displaying the position of a single coil (hereinafter, marker) attached to a finger or the like, independently of the scope image in the inserted state. When the marker is used during the operation, the position of the marker is displayed on the CRT by, for example, pressing the M key identified by the M notation.

When the M key is input, the marker is C
A status flag for outputting on RT is set. If set, the program routine displaying the marker is executed and the marker is displayed. After using the marker, press the M key again. The status flag is cleared, the routine for outputting the marker is prohibited, and the marker display is canceled.

With this function, the marker and the image output image can be compared, and the marker can be provided as an auxiliary means for knowing the position of the imaged scope image.

3_12. Numerical display of source coil coordinates O
N / OFF Normally, the image image that is output is only its shape, but if the N key identified by the notation of N is input, for example, the numerical value of the source coil coordinates detected simultaneously with the image image can be output. The ON / OFF means is the same as in the case of 3_11. For example, by inputting the N key, a status flag for displaying a numerical value is set. When the numerical value display becomes unnecessary, the N key is pressed again to cancel the status flag and cancel the numerical value display.

From this, in addition to the visual positional relationship, a numerical positional relationship can be obtained. 3_13. Program termination The program can be terminated more safely.

For example, the program can be terminated by pressing the Q key. However, in order to prevent the program from ending when the Q key is erroneously input, the following measures are taken.

(3_a) Check the command erroneous input flag. (3_b) If the flag is off, turn it on
Then, the contents of the input key variable KB are substituted into the variable dumy.

If the (3_c) flag is ON, the command is executed according to the input key variable KB. This procedure avoids the risk of accidentally terminating the program while using the system.

Since one key is assigned to each command as described above, the operation is extremely easy. Then, when a certain key is pressed, only the parameters necessary for realizing the change of the function are set, and therefore the flow of the program is not disturbed.

Further, the parameters for realizing the functions of these commands are the same as the one-time processing (the source coil is driven, the magnetic field is detected, the source coil position is detected, and then the scope shape is CRT output. Since it is always referenced somewhere between (), the time lag until the function is realized as requested by the command is extremely small.

This method is an excellent means in which the influence on the drawing of the scope shape is extremely small although it is possible to respond to the user's key input instantaneously. After the processing of this step S41_3, the next step S42
Proceed to the scope image rendering process.

S42: Scope image depiction processing Here, it is responsible for creating a scope shape from the source coil position coordinates obtained from the magnetic field detection and displaying the image image three-dimensionally on the CRT. The obtained position coordinates of the source coil are scattered data of the number of source coils inserted in the scope. Therefore, the shape of the scope in the inserted state must be estimated based on these data. Furthermore, how the scope shape data obtained in this way can be output as a three-dimensional shape on the CRT is the greatest point of this system.

The processing flow of this scope image depiction processing is as shown in FIG. Detailed processing contents of each
Each block will be touched, and in order to realize a more realistic display, the reason why it is essential will be touched step by step.

S42_a: Calculated three-dimensional interpolation between source coils Step S42_a In the three-dimensional interpolation process between source coils, the source coil position coordinates calculated by magnetic field strength detection are discrete, so this calculation Even if only the data is connected, the trajectory becomes angular and it does not correspond to the scope shape whose position changes continuously. In order to create a smooth overall scope shape, three-dimensional interpolation is performed on the source coil position coordinate data.

S42_b: Construction of three-dimensional model Since a real scope has a thickness, no matter how smooth data points are obtained, it is realistic to connect with a straight line without a thickness. It cannot be said that the scope is depicted. Therefore, in the process of constructing the three-dimensional model in step S42_b, the connection between the catch data is made into a cylinder or
The polygonal column model is used so that the thickness can be displayed in correspondence with the actual scope shape.

S42_c: The affine transformation scope shape is output as an image viewed from the designated viewpoint position. Therefore, in the affine transformation process in step S42_c, the scope shape model data obtained in the world coordinate system as the reference coordinate system for deriving the source coil position is transformed into the viewpoint coordinate system for screen display. The viewpoint position can be changed by the user. The changed contents are referred to here.

S42_d: 3D → 2D projection Although the scope shape is originally three-dimensional, it must be converted into two-dimensional in order to output the image on the CRT screen. Therefore, the projection conversion from the three-dimensional image to the two-dimensional image in step S42_d is performed. At this time, perspective may be used to emphasize perspective.

S42_e: Rendering The scope shape image obtained by the above processing is drawn on the CRT. In rendering, in the rendering processing in step S42_e, side processing of n polygons and hidden line processing for expressing before and after the loop of the scope are performed. It is also possible to perform processing such as gradation display in shading processing by perspective and adjusting the brightness and saturation of the scope model side surface according to the curvature of the scope, etc., to further emphasize the space between solids.

Note that it is not necessary to carry out some of the items described above. Of course, if implemented, the image can be reproduced on the CRT including the effect of the improvement item. Further, it is not necessary to perform in the order shown in FIG. 22, and the same processing may be performed in a shorter time by changing the order according to the model displaying the insertion portion shape. .

Through these processes, the inserted three-dimensional scope shape can be reproduced on the CRT from only the position coordinates of several source coils. Further, in this embodiment, an n-gonal prism model and an n-gonal connection model can be selected as the display of the scope as follows. Therefore, the three-dimensional model construction and the like will be described along the following specific examples.

First, the case of the n-gonal prism model will be described.
In this model, for example, as shown in FIG. 14, the cross section of the insertion portion is modeled as a regular n-gon and displayed as an n-gonal column (n = 5 in FIG. 14). If the number of n is increased, it becomes almost a circle, and in this case, it is displayed as a cylinder.

The flow of display processing contents in this model is shown in FIG. In FIG. 23A, the process of interpolation & construction of a three-dimensional model in step S42_1 is the process shown in FIG. 23B.

Here, first, the three-dimensional B-spline interpolation of step S42_1 is carried out. This interpolation is not a type of interpolation that always passes through the interpolation point, but creates a smooth curve while passing through the neighborhood of the interpolation point. It is easy to process. Of course, a natural spline, another interpolation method, or an approximation function may be used.

The B-spline, which is relatively easy to calculate,
It is excellent in that the processing speed is fast even if three-dimensional catching is performed. Next, as a three-dimensional model construction in step S42_12, n-prism model construction is performed.

Here, from the catching data of the source coil position coordinates, an n polygonal column model (hereinafter, including a cylinder,
And)) constructs a three-dimensional scope image. The actual processing is as shown in the flow chart of FIG. Consider the case of creating an n-polygonal medium model for the i-th and i + 1-th data obtained by interpolating the source coil position coordinates.

First, as in step S51, i to i +
The direction vector P toward the point 1 and its magnitude | P | Next, as in step S52, the vector P is translated so that the origin becomes the starting point. Let K be the vector that is translated, and let its magnitude be | K |. This vector K is shown in FIG.

Then, as in step S53, the vector K
To match the axial direction of the coordinate axis, for example, the y-axis (here, first rotate around the y-axis (FIG. 25 (b)), and then x
By rotating around the axis (Fig. 25 (c)), the vector K
In the y-axis direction).

Next, as in step S54, two points y1 and y2 on the vector K pointing in the y-axis direction are determined. However,
Let a ≦ y1 <y2 ≦ | K | −a, 2a <| K | (FIG. 26 (a)). Next, as in step S55, 2 points y
Vectors A1 and A2 having a size a and perpendicular to the vector K are created from 1, y2 (FIG. 26B).

Next, as in step S56, the vector A
1 and A2 are rotated in steps of (360 / n) °, A1, A
The coordinates of 2 are obtained and used as the basic data of the n polygonal column (FIG. 26 (c)). Next, basic model data is created by adding or subtracting the y-axis values of the top surface and bottom surface of the data obtained as in step S57.

Next, the basic model data obtained in step S58 is subjected to the inverse of the conversion performed when the vectors P are aligned in the y-axis direction, and n-square column model data can be created around the vectors P. (FIG. 27 (a)). Next, by returning to step S51 again in the judgment of step S59 and performing the same processing on all the interpolation data, the n polygonal column model data of the scope shape is completed (FIG. 27 (b)).

Here, a ≦ y1 <y2 ≦ | K |
“A” under the condition of −a, 2a <| K | will be described. If model data for the vector K is created around the point i without considering this condition, the model data will overlap as shown in FIG.
The scope shape cannot be displayed smoothly. Under the above conditions, the n-polygonal column model data do not overlap each other, so that a smooth n-gonal column model can be created by connecting the model data as shown by the dotted line in FIG. 28 (b).

For the calculation of the model data, the work of aligning the vector P in the direction of a certain axis and performing the inverse transformation again seems to be troublesome, but since it is represented by a simple rotation around each axis, The calculation is extremely easy. This method is an excellent means in that the n-prism model data can be calculated only by rotating around the axis.

Of course, calculating the conversion formula for creating a prism model around the vector P is
Since the orientation of is not constant, it is a difficult expression, but you can use this to create a prism model.

Next, step S42_13 of FIG. 23B.
Affine transformation of. This affine transformation is one of the methods used when performing coordinate transformation of a figure in computer graphics, and is generally performed when handling coordinate transformation. Simple linear coordinate transformations such as translation, rotation, enlargement, reduction, etc. are all included in the affine transformation. FIG. 29 shows a state of affine transformation by a rotation angle around the x-axis (pitch angle), a rotation angle around the y-axis (head angle), and a rotation angle around the z-axis (bank angle). In this process, the scope model data represented by the above-mentioned world coordinates is converted into model data viewed from a certain viewpoint position.

The viewpoint position can be set in any direction. Therefore, tracking in which direction the viewpoint position has moved and moving the model data so as to follow that direction requires extremely difficult processing. Therefore, it is assumed that the viewpoint is fixed, and the world coordinate system that should not move originally is rotated for convenience. This gives a result similar to obtaining an image with shifted viewpoint, as seen in FIG.

This method is an excellent means in that the time lag with respect to the movement of the viewpoint can be made extremely small because it can be dealt with in which direction the viewpoint moves by rotating the world coordinate system for convenience.

Next, step S42_14 of FIG. 23 (b).
3D-2D projection (3D → 2D projection) is performed. This 3D that performs projection conversion from 3D image to 2D image
→ In the 2D projection process, the following projection method is performed, so that the display can be realized by perspective or the like according to the purpose.

A) In the case of adding perspective, the three-dimensional shape looks larger as it is closer to the viewpoint and smaller as it is further away. This can be realized by a process of converting three-dimensional model data into two-dimensional data.

In order to project the three-dimensional coordinates onto the two-dimensional plane, the screen is virtually perpendicular to the viewpoint, and
It is arranged on the opposite side of the three-dimensional image (3D image obtained up to S42_13) (see FIG. 31 (a)). The projection plane of the object viewed from the viewpoint in such a state is as shown in FIG.
The projection image P1 on the side closer to the viewpoint becomes larger than the projection image P2 on the side far away. It is also easy to change the degree of perspective enhancement by moving the position of the projection screen back and forth.

This method is excellent in that a three-dimensional depth can be easily added to the two-dimensional projection image and the degree of emphasis can be easily changed.

When the projection screen is provided at a position facing the viewpoint, it may be angled. This makes it possible to see how the projected image changes depending on how the screen is tilted, so that the degree of emphasis of the perspective can be confirmed.

B) When no perspective is attached, instead of attaching a perspective, as shown in FIG.
A projection method such as (c) is also conceivable. The projected image at this time is represented by an image having the same thickness P3 regardless of the viewpoint position. Since there is no perspective, the sense of depth is somewhat poor, but it is excellent in that the image does not become extremely large when the viewpoint is brought close to it due to the effect of perspective, or it becomes too small when it is moved away.

Next, the rendering process of step S42_15 is performed. In this embodiment, as shown in FIG. 23B, the paste model display PM and the wire frame model display WM can be selected.

FIG. 32 shows a coordinate system such as the above-mentioned world coordinate system before moving on to the description of the display by these models. Figure 32
(A) shows the world coordinate system fixed to the bed 4, and FIG.
2 (b) shows a visual field coordinate system set by the user,
Its origin coincides with the origin of the world coordinate system. In addition, FIG.
(C) shows a model coordinate system used for displaying the scope shape, which coincides with the world coordinate system.

FIG. 33 shows that a coordinate system suitable for each process is adopted during the process of displaying the scope shape. For example, the source coil coordinates are in the world coordinate system, and after the source coil coordinates are rotated to obtain the source coil coordinates (that is, the visual field coordinate system) viewed from the "viewpoint", the discrete source coil coordinates are calculated. On the other hand, data interpolation is performed to obtain the source coil coordinates viewed from the "viewpoint" in which data interpolation has been completed.

Next, in a three-dimensional model construction process, after a scope model is generated by a wire frame or the like, a three-dimensional to two-dimensional conversion (perspective projection conversion) process is performed to display the two-dimensional screen on the two-dimensional screen. Data, three-dimensional data is generated, and a pseudo three-dimensional image is rendered and displayed.

Next, the paste model display P of FIG.
M will be described. This model fills each surface of the n-polygonal prism and is called a paste model. Scope shape image is C
An explanation will be given of the side processing of n polygons when drawn on the RT, the hidden line processing or hidden surface processing of 1_a described below for expressing the front and back of the scope when the scope becomes a loop, and then the other processing. A process for emphasizing a stereoscopic effect will be described.

1_a: When the hidden line or hidden surface processing scope model is displayed by n polygonal columns, it has n side surfaces. Of these, what is actually visible is only the side face on the side of the viewpoint, and therefore the process is performed so that only the side face on the side of the viewpoint is visible and the side or side that is not visible is hidden, that is, hidden lines or hidden lines. Surface treatment (hereinafter,
Simply referred to as hidden line processing).

Therefore, a parameter indicating how close each side surface is to the viewpoint position (referred to as a z-buffer, which is derived from the z-value (distance from the viewpoint) of the object stored in the buffer memory) is sorted. , Start writing from the side where the z-buffer is small (that is, far from the viewpoint). Overwrite the side sticking method. In this method, since the area to be rewritten is overwritten on the small surface of the z buffer and the area to be rewritten is drawn, only the area to be rewritten is drawn.
The processing speed is improved.

Furthermore, this method can also be used to determine which is the upper side when the scope model is in a twisted position. Generally, when the scope model is in a twisted position, check which is the upper one,
You have to decide whether you want to overwrite or go under.

Although this method is reliable, it takes a little processing time. Therefore, if all z buffers of the entire model are sorted and rendering is started from the smallest one, the upper model is always drawn afterward even if it is in a twisted position, so it is necessary to judge the condition. Disappears. In the z-buffer method, before-and-after judgment is actually made in units of pixels inside polygon processing.
This is an excellent method in that the entire shape of the scope model can be created in a shorter time.

Specifically, the hidden line processing is performed according to the flow shown in FIG. First, stereoscopic image data such as scope shape coordinate data is fetched, and in step S61, a parameter indicating how close each side surface is to the viewpoint viewpoint position (z buffer value of z buffer method for processing for each polygon forming each object). Are sorted, and the z buffer values are sorted in ascending order. In the next step S62, a bidirectional vector that defines the surface is obtained from the polygon data, and a normal vector N of the surface is obtained.

In the next step S63, the light ray vector I is set, and in order to obtain the angle formed by the normal vector N and the light ray vector I in the next step S64, the magnitudes of the normal vector N and the light ray vector I are set. To 0.0005
The added value is the diffuse reflection light value of each value.

At the next step S65, the normal vector N,
Lambert (Lam) from the ray vector I and the diffuse reflection value
Bert's law (incident light diffuses equally in all directions) to obtain the light intensity t.

In the next step S66, it is determined whether or not the light intensity value is 0 or more. If it is 0 or more, the polygon surface far from the viewpoint is painted in the next step S67, and the process proceeds to step S68 of the next determination. . On the other hand, if it is less than 0, it means that the light is not shining, so the process proceeds to step S68, it is judged whether or not all the surface data are finished, the above-mentioned processing is performed for all the surface data, and the processing is finished. To do.

[0218] Since the time required to draw one screen of the scope shape on the display device is long in this device, the moving image of the scope displayed on the same screen flickers when repeated drawing and erasing. I can see it. Therefore,
A screen (hereinafter referred to as a back screen) that is not displayed is provided separately from the screen displayed as shown in FIG. 35A (hereinafter referred to as a front screen), and the screen next to the current front screen is a back screen. After drawing on the screen, switch to the front screen. Figure 3
A display method using a back screen for preventing flicker will be described below with reference to the flow shown in FIG.

First, as shown in step S71, the screen to be drawn is designated as the back screen, and in step S72 the graphic on the back screen is erased. That is, the VRAM as the video display memory used for display is prepared for the front screen and the back screen, and the target screen for drawing is not displayed at that time while the front screen is being displayed. , And erase the figure written in the VRAM on the back screen.

In the next step S73, necessary images of the scope, reference plane, markers, etc. are drawn on the back screen which has been erased. When this drawing is completed, as shown in step S74, the front screen that has been displayed up to this point and the back screen on which the latest image has been drawn are replaced, and the image for which drawing has been completed is displayed. During this display, the back screen replaced from the front screen is used for the next drawing.

By this work, the process of drawing one screen is not visible to the user, and the screen is momentarily replaced with the next screen, so that the moving image seen by the user does not flicker.

1_b: Stereoscopic effect emphasizing process Here, a process for emphasizing the stereoscopic effect and depth to the image image of the n-square prism model constructed as the scope shape model in the inserted state is performed. The scope shape in the inserted state is a three-dimensional shape. However, since the medium (CRT) that displays images is two-dimensional,
How to display a three-dimensional image on a CRT greatly affects the usability of the system. The following is an example of processing for emphasizing the stereoscopic effect and depth.

1_c: Shading processing Since the scope shape is three-dimensional, bright and dark can be created depending on how the light rays hit. This is a means for reproducing such light and dark by gradation display. Brightness and darkness vary depending on the curvature of the scope. The number of colors that can be used is limited to 16 colors of 4096 colors for each hardware, and if the number of colors that can be used is small, the default gradation is also small. Therefore, the palette is changed so that this gradation can be effectively used. The hue was set by the angle formed by the light source vector and the normal vector to the side of each scope modeling.

This process is performed as shown in FIG. The scope image is displayed as n polygonal columns. First, in step S81, the parameter i is set to 1, and in the next step S82, the normal vector N of the i-th side surface of the n-square prism is obtained.

At the next step S83, the inner product of the light source vector I and the normal vector N for the quadrangle forming the side surface is calculated. The light source vector I is assumed to face the origin from the viewpoint position.

In the next step S84, the side surface is colored with the brightness corresponding to the value of the inner product. In this case, when the inner product is 0, the darkest color is displayed, and when the inner product = 1, the brightest color is displayed. Other than that, it is equally divided by the amount of usable gradation. Of course, the wider the gradation can be set, the smoother the three-dimensional effect can be expressed.

Next, the parameter i is incremented by 1 (step S85), it is determined whether i is equal to n (step S86), and the same processing is repeated up to the nth side surface.

According to this method, since the light source direction and the viewpoint direction coincide with each other, the viewpoint direction is always displayed brightest and
The gradation display is excellent in that the stereoscopic effect of the scope image can be further emphasized. Of course, the light source position and the viewpoint position may be different. At this time, depending on the position of the light source, the display may be dark even in the front direction of the viewpoint, which is a particularly excellent means for enhancing the depth of the scope image. The background color may be colored in order to clearly distinguish the darkest gradation color and the background color.

1_d: Utilization of luminance and saturation of color When the number of colors available is abundant, for example, 256 colors out of 16384 colors, the shading processing can be performed by colors. The processing content is shown in FIG. The shading process is basically the same as that in step S of FIG.
The "brightness" at 84 is step S84 'in this flow.
The only difference is that it has been changed to "color" in. Therefore, the description of the flow is omitted.

Since a wide variety of colors can be used, for example, it is possible to display the side of the scope model facing the light source direction in warm color and the side in the opposite direction in cold color. Of course, the color setting is not limited to this.

Since the light and shade of the scope can be displayed in rich colors, the stereoscopic effect of the scope can be emphasized as compared with the case of simply displaying the light and dark. In addition, even when the contrast of the CRT has to be suppressed due to the influence of the installation environment of the CRT, the scope image does not become difficult to see.
It is excellent in that respect.

Furthermore, by combining with the use of brightness,
More diverse displays are possible. For example, the ray direction is displayed in saturation and the distance from the viewpoint is displayed in brightness. By doing so, it becomes possible to display the depth from the viewpoint direction with different brightness, and the three-dimensional image can be realized, because the stereoscopic effect of the scope has different colors. Of course, the stereoscopic effect may be expressed by brightness and the depth may be expressed by saturation, and the depth may be expressed not only from the viewpoint direction but also from any direction. For example, if the shades are made different in the height direction from the bet surface, it is possible to confirm whether or not the insertion state of the scope is good with the shades.

The processing using this saturation and luminance is shown in the flow of FIG. This flow is the same as the flow of FIG. 37 and step S.
The process up to 83 is the same, and instead of the next step S84, the process of calculating the distance from the start point to the side face is performed in step S84a, and in the next step S84b, the brightness according to the distance and the color according to the value of the inner product are performed. The color is applied to the sides depending on the degree.

This method is an excellent means in that the stereoscopic effect and the depth of the scope image can be realized with a more three-dimensional image, and the relative position from a certain position can be predicted.

Next, the processing of the wire frame model display WM will be described. The result is the same as when the part excluding the sides of the n-prism model is filled with the background color, but this stretches the surface of the n-prism model (paint).
In order to reduce the processing time, it can be used selectively.

In this model, if the z buffers are written in the ascending order, the wires behind the scope model will be visible. Therefore, a hidden line processed model can be constructed by appropriately performing hidden line processing to remove it or drawing a wire frame up to the (n / 2) th model data in descending order of z buffer.

The flow of this display is shown in FIG. First, n-gonal modeling is performed in step S91, and the vertices obtained by modeling are connected by a straight line in step S92. In this state, the wire on the back side of the scope model is visible, and therefore, the hidden image processing is performed in the next step S93 to obtain the scope image by the wire frame model display WM.

Next, in FIG. 23 (a), step S42_2 for displaying the reference surface and two-point marker display S42_3 are performed.
The processes of steps S42_2 and S42_3 are additional processes. The process of displaying the reference plane plays an auxiliary role of making the three-dimensional display of the scope shape easy to visually understand by displaying the reference plane such as the bet plane.

In this embodiment, the image displayed on the CRT is only the scope-shaped image, and the positional relationship between the image and the internal organs in the body is unknown. Then, when the viewpoint position is rotated, the information about which direction the scope shape is viewed from, the direction of the head direction, and the like are only numerical information of the angle displayed in text. This is not suitable for sensory judgment. Therefore, an auxiliary means has been provided so that such a judgment can be performed sensuously.

Here, it is realized as shown in FIG. First, the affine transformation of step S42_21 is performed. In this process, the reference display symbol in the world coordinate system is converted into the viewpoint coordinate system. Next, step S42_22-3
D → -2D projection is performed. Conversion processing is performed to project the reference display symbol transferred to the viewpoint coordinate system in two dimensions so that it can be displayed on the CRT.

Next, a symbol such as a bed is displayed as the reference surface in step S42_23. Scope image 3
Display symbols that aid the three-dimensional picture. Specific examples of symbols will be described below.

By doing so, it is excellent in that it is possible to visually judge the reference plane position, the distance of the scope shape from the reference plane, and the head direction of the patient, and to provide a reference for judging the position of the scope shape and the like. ing. Next, a bed surface display of 2_a and the like will be described as a specific example of the reference display symbol.

2_a: Bet plane display A reference plane parallel to the xy plane of the world coordinate system and perpendicular to the z axis is displayed. The z coordinate may be at any position on the bet surface (z = 0) as long as it can be used as a reference.
This plane does not move with the viewpoint coordinates. That is, when the viewpoint position rotates in the x-axis direction and the y-direction, the bet surface is displayed as a line. A rectangle like a pillow so that you can see the head direction,
Markers may be attached to the right shoulder, the left shoulder, or both directions.
Since this is represented by a simple single plate, it is excellent in that it does not interfere with the scope image and the viewpoint rotation can be recognized.

2_b: Reference marker display This is a display typified by FIG. 40 (a). Here, two markers m3 and m4 in both shoulder directions and a marker m5 in the foot direction.
Exists. Since the shoulder markers m3 and m4 are oriented in the direction perpendicular to the z coordinate and the leg marker m5 is oriented in the direction perpendicular to the x coordinate, when viewed from the z direction, they are displayed as line segments as shown in FIG. 40 (a). To be done.

Therefore, when the viewpoint position rotates in the x-axis direction, the markers m3 and m4 on both shoulders change to be displayed as line segments, and the marker m5 in the foot direction faces the front and becomes a circular marker. I know the direction. The difference in the number of markers between the top and the bottom is to make the description easy to identify the head direction. The number and shape of the markers may be arbitrary, and which marker is associated with which axis is also arbitrary. It is also possible to make the marker three-dimensional and add gradation or luminance saturation. This method is excellent in that the scope shape is easy to see because the scope shape and the marker do not overlap.

2_c: rectangular parallelepiped display. It is a symbol displayed as a rectangular parallelepiped by adding a frame in the z direction to the bet display of 2_a. The size of the rectangular parallelepiped is arbitrary, but if it is within the detection range of the system or larger, the scope shape is displayed inside the rectangular parallelepiped, and the sense that the scope is in the inserted state increases. Further, the height of the box in the z direction also facilitates the estimation of the z coordinate of the model.

This method is excellent in that it gives a sense of reality that the scope is in the inserted state, so that the scope shape can be easily connected to the scope in the actually inserted state. Conversely, a block may be displayed in one corner of the scope image and rotated in association with the movement of the viewpoint.

2_d: Mixed display The reference symbols mentioned above may be combined.
FIG. 40B shows a case where the bed surface display of 2_a and the reference marker display of 2_b are combined. In this case, the reference for the z-axis is the surface display, and the information about the rotation and the head direction when rotated can be recognized by the mark. Other displays may be combined in any way.

Such a means is excellent in that the effects of the respective symbols can be shared. Next, FIG.
The marker display process of step S42_3 of (a) is performed.

In this marker display processing, a single source coil position is calculated and displayed separately from the source coil 16i inserted in the scope. A means for displaying one or more markers that can be moved separately from the source coil 16i in the scope is provided as means for confirming the position of the inserted position in the scope.

On the actual device, the position calculating means is exactly the same as that used for the source coil 16i inserted in the scope, and the display means is the same as before, and FIG.
As shown in (d), the process is affine transformation in step S42_31 → 3D in step S42_32 → 2D projection → marker display in step S42_33. Therefore,
Here, as a specific example of the marker shape output, display by an n-sided polygon (including a circle) will be described. If the marker is displayed in such a form, many colors cannot be used, and in the case of a device configuration in which the same color as the scope shape cannot be used, it is possible to distinguish even if it overlaps with the scope shape.

By changing the shape of this marker display according to the rotation of the viewpoint, it is possible to recognize from which direction the user is looking. Further, it may be associated such that it is always in front of the viewpoint. At this time, the viewpoint direction cannot be recognized from the marker, but it is excellent in that a marker of a constant size is always output.

This is similar to the case where the marker has a spherical shape. If the marker has a spherical shape, it is possible to display the direction and depth of the viewpoint by giving information such as gradation and saturation / luminance.

By moving the marker outside the body using such a means, it becomes possible to confirm the position of the scope shape in the inserted state in association with the marker, and the position of inserting the scope is compared with the actual position of the patient. It is possible to provide a means of assistance that is associated and known. Up to now, the display in the n-prism model has been described, but next, the display in the n-gon connection model will be described.

Although the scope shape of the n-square prism model can be displayed realistically, it takes some processing time. Therefore, the model configuration has been simplified to enable high-speed display.
A rectangular connection model was constructed so that it could be selected and used (displayed). The processing flow is as shown in FIG. The basic processing contents of the processing described here are the same as those used in the n-prism model. Therefore, the difference will be described.

The contents of the interpolation & construction of the three-dimensional model in step S42_1 'of FIG. 41 (a) are shown in FIG. 41 (b). In this model, first step S42_11 '
Affine transformation.

Conversion from the world coordinate system to the viewpoint coordinate system, processing by the n-prism model (step S in FIG. 23B)
42_13)). However, in the n-square prism model, conversion was performed on the interpolation data, but here,
The source coil position data is converted first. By doing this, the amount of affine transformation is small,
Improve the processing speed of the program.

In the next step S42_12 ', three-dimensional interpolation is performed. This processing is also similar to the above. The difference is the data in the world coordinate system in the n-prism model, but here is the data in the viewpoint coordinate system.

In the next step S42_13 ', 3D → 2D
Project. This processing is also similar to the above. However, this time it is a projection of a point without size. Next step S42
In _14 ', an n-gon connection model is constructed.

FIG. 42 shows the processing contents of this n-gon connection model.
Shown in. In FIG. 42, the rendering step S42_15 ′ in FIG. 41 (b) is also included.

First, in step S101, the distances from the target point to the viewpoint and the light source are calculated. In the next step S102, it is determined whether or not shading processing is performed. In the case of performing the shading process, in the next step S103, the process of determining the brightness according to the distance to the light source is performed, and then in the next step S104, it is determined whether or not the perspective process is performed. The process moves to this determination even when the process is not performed.

In the case of performing the perspective processing, in the next step S105, the size is determined according to the distance to the viewpoint, and then in the next step S106, the process proceeds to the n-sided polygon drawing process. In the processing of (1), each point is made to coincide with the center of the n-sided polygon, and drawing is performed by simply connecting the n-sided polygons to form an image in which the n-sided sides are connected. Also, when the perspective process is not performed, the process shifts to this drawing process.

Further, in the next step S107, it is determined whether or not the wire frame display WM is performed (that is,
Perform paste model display PM or wireframe display W
If it is not the wire frame display WM, the process proceeds to the display process of the paste model in the next step S108, and the inside is filled with the brightness determined in step S103. On the other hand, when performing wireframe display, hidden line processing is performed in the next step S109, and a wireframe model is displayed.

Up to this point, a scope image is created in a form in which n-gons are connected. Also, make the obtained points coincide with the center of the n-sided model shape, and "flesh" around the interpolation data points.
You may output the image in the style that was done. In the above process, when NO is selected in the determination process, the n-gonal concatenation model having the minimum function is output.

This method eliminates the processing time of the n-square prism model as much as possible, and can display at a very high speed (1/2 or less of the processing time of the n-square prism model). Is excellent at.

It should be noted that, in the flow of FIG. 42, YES may be selected in the determination process, and additional processing similar to that in the case of the n-polygonal column model may be added to further emphasize the stereoscopic effect. Since the basic processing is the same, a brief description will be given so that only the differences can be seen. As an additional function to the n-sided concatenated model, there are the following 4_a perspective processing and the like.

4_a: Perspective This is not possible because the target for 3D → 2D conversion is a point having no size. If the target of conversion is not a point but a shape having a size, the same effect as that described above can be obtained. This shape may be any shape, but since this model was devised to realize high-speed display, it is desirable to have a symmetrical shape centering on the point at which conversion is originally performed.

4_b: Hidden line processing For the version in which the inside of the n-gon is filled, the modeling itself also serves as the hidden line processing, which is advantageous in that no special processing is required. When the hidden line processing is performed in the wireframe version, it can be achieved by adding processing to erase the overlapping portion or by once painting the inside of the n-sided polygon with the background color and then overwriting the wireframe.

4_c: Shading processing In this model, since the surface of the scope does not exist, the depth of the scope model may be represented by shading processing. Specifically, the side closest to the light source is displayed brightly, and the side farthest from the light source is displayed darkly, and a gray scale display corresponding to the number of available colors is displayed during that time.

At this time, the depth of the model can be expressed.

As an application, it is possible to give a slight difference in gradation between the center and the end of the model. This way
Although the gradation for indicating the entire depth is reduced, the stereoscopic effect of the scope can be emphasized because the Scope model is displayed as if it is swollen due to the gradation difference.

4_d: Utilizes color saturation and luminance This is similar to the n-prism model, and similar effects are expected. 4_e: Wireframe display Here, a simple and convenient display method including a hidden line processing function is provided for the wireframe display.

First, not all wireframes are represented by n-gons, but only the root data is represented by n-gons, and a half-n-gon is added from there to the tip (FIG. 43 ( See a)). This method is an excellent means in that it is possible to create the same wireframe shape as when the hidden line processing is performed without performing the hidden line processing.

Further, instead of overlapping the same n-sided polygons, a shape including angular distortion set according to the curvature of the orientation of the scope may be stacked (see FIG. 43 (b)). In addition to the effect of the above means, this method emphasizes curvature information,
It is excellent in that it approaches a more realistic scope image.

As described above, according to the first embodiment, the source coil 16i as a magnetic field generating element for generating a magnetic field is provided in each flexible insertion portion 7 of the endoscope 6. 16i is fixed to the inner wall of the probe 15 via an insulating adhesive 20 or the like so that the shape of 16i does not change, and the source coil 16i is placed at a known position around the subject into which the insertion section 7 is inserted. A triaxial sense coil 22j is arranged as a magnetic field detecting element for detecting the magnetic field generated in 1., and the magnetic field generated in each source coil 16i is arranged at the known position from the detection signal detected by the triaxial sense coil 22j. Since the position calculation unit 31 calculates the position of each source coil 16i in the insertion unit 7 with respect to the three-axis sense coil 22j, When inserting the parts, the insertion portion 7
Since the source coils 16i inside the insertion portion 7 are fixed by the fixing means so that their shapes do not change even when the insertion portion 7 is bent, the insertion portion 7 of the endoscope 6 is calculated from the position of each source coil 16i. The position of can be detected accurately. Further, by providing the shape estimating means so as to estimate the shape of the insertion section 6 with respect to the output of the position calculation section 31, it is possible to perform the shape estimation of the insertion section 6 with high accuracy, and to correspond to the estimated shape. By displaying the image, the shape of the insertion portion can be easily visually determined.

Further, a plurality of triaxial sense coils 22 constituting the magnetic field detecting means respectively arranged at the above-mentioned known positions.
In consideration of the strength of the magnetic field generated by the uniaxial or triaxial source coil 16i constituting the magnetic field generating means, the phase information when AC driving, and the shape of the equal magnetic field surface by the magnetic field generating means. Since the area where each magnetic field generating means is present is detected or estimated and the three-dimensional position thereof is calculated or estimated, if the magnetic field detecting means is installed at a known position such as a corner of the bed 4, With respect to a subject such as a patient on the bed 4, it is possible to accurately calculate or estimate the position within a required position detection range.

That is, by arranging several (three or four) three-axis sense coils 22j in the bed 4, etc.
The three-dimensional region in which the source coil 16i exists is estimated from the magnetic field strength detected by the axis sense coil 22j, and the existing region of the source coil 16i is determined from the overlapping portion of the three-dimensional regions estimated by the respective three-axis sense coils 22j. Presumed. In this case, if the phase information is used, it is possible to exclude a region such as outside the detection range.

Further, in the first embodiment, reference information serving as a reference is used from the signal corresponding to the detected magnetic field strength,
Since the area in which the source coil 16i exists is estimated, the area can be calculated in a very short time as compared with the distance calculation.

Further, if the number of the three-axis sense coils 22j arranged is increased, the position of the source coil 16i can be detected with higher accuracy, and the shape of the endoscope can be estimated with higher accuracy.

Further, the obtained endoscope shape can be displayed in a shape as viewed from the viewpoint direction desired by the user, and setting the viewpoint to perform the insertion operation facilitates the insertion work. It has many advantages mentioned in the first embodiment.

Next, a first modified example of the first embodiment will be described with reference to FIG. In the first embodiment, for example, as shown in FIG. 10, the timing of capturing the signal detected by the sense coil 22j is delayed in consideration of the transient characteristic of the source coil 16i.

On the other hand, in this modification, as shown in FIG. 44, the signal of the oscillator 25a is compared between the oscillator 25a and the amplifier 24a by comparing with the reference voltage which is the reference from the reference voltage generator 58. A phase detector 59 is arranged to detect that the phase angle is suitable for driving the source coil 16i. The reference voltage generator 58 outputs the voltage value of the sine wave corresponding to the power factor angle of each source coil 16i as the reference voltage to the phase detector 59, and the phase detector 59 makes the sine wave of the oscillator 25a coincide with the reference voltage. At the same time, the phase detection signal is output and the sine wave of the oscillator 25a is passed to the amplifier 24a side.

Each source coil 16i is supplied with a drive current from the oscillator 25a which generates a sine wave, after the power is amplified through the phase detector 59 and the contact selected by the switching circuit 28a. The timing of supplying the drive current is synchronized with the rising edge of the phase detection signal transmitted from the phase detector 59 to the timing control circuit 30d. Further, the A / D converter 30 for the detection signal obtained by amplifying the voltage excited at both ends of the sense coil 22j and performing synchronous detection
The timing of reading to the CPU 30c side via a is also synchronized with the rising edge of this phase detection signal.

Here, the phase detection signal is generated as follows. Oscillator 2 that generates a sine wave that is the source of the drive signal
The signal e from 5a can be expressed as e = Em sin (ωt + θ) [V]. Here, Em: maximum amplitude voltage [V], θ: initial phase [rad], ω = 2πf, f: drive frequency [Hz], t: time [s].

If the power factor angle φi obtained from the pure resistance components Ri [Ω] and Li [H] held for each source coil 16i is φi = arc tan (ωLi / Ri), the reference voltage Vref = Em sin A phase detection signal can be obtained when φi [V] and the signal e [V] of the transmission source are compared by a comparator.

The drive current i [A] supplied is i = Asin (ωt + θ−φ) −Asin (θ−φ) · exp (−a
t) where A = Em / (R · R + ωL · ωL), a = R /
It becomes L. In the above equation representing the drive current i, when θ = φ, it is indicated that the second term on the right side becomes 0, so that the transient DC component does not occur. That is, the coil can be driven in a steady state from the moment of switching.

Therefore, it is possible to read the detection signal of the sense coil 22j to the CPU side at the same time as the coil switching. Actually, the voltage excited in the sense coil 22j is read in consideration of the delay time until it becomes the output of the synchronous detector 26d.

Even if a large number of source coils are switched by driving the source coil 16i in this way, the time from the start of driving to the start of fetching the detection signal is greatly shortened, so the operation of the entire system You can speed up the time.

FIG. 45 is a timing chart for explaining the operation of driving the source coil and reading the detection signal by the sense coil according to this modification. As can be seen from the comparison with FIG. 9, reading can be performed within a short time Δt ′ after driving the source coil.

Further, in this modification, means for shielding the signal relay line for precision measurement is provided. As shown in FIG. 46, the signal line for supplying the drive current to the source coil 16i and the signal line for transmitting the detection signal of the sense coil are formed by twisting two connected to each coil. It reduces the radiation from and superposition of disturbances.

However, even in this twisted signal line, the above influence exists to some extent. Therefore, when the drive signal cable of the source coil approaches the sense coil, the influence of the weak electromagnetic wave radiated from the cable causes the influence of the sense coil. If the detection signal is swung around 2 to 3 times, or if the stray capacitance of the human body approaches the detection signal cable of the sense coil, disturbance will be superimposed on the signal line via the stray capacitance. A phenomenon occurs that makes it impossible to perform accurate measurements. We will solve such problems and enable stable and accurate measurement. A specific method will be described below.

First, the drive signal cable 60a for the source coil 16i will be described. This cable 60a includes a probe 15 (FIG. 4) having a plurality of source coils 16i built therein.
6 shows two source coils for simplification)
And a sine wave current for driving each source coil 16i sequentially is supplied.

At this time, a component of the electromagnetic wave radiated from each signal line connected to each source coil 16i, which has the same frequency as the driving current, is superimposed on the signal line of another source coil 16i and is not desired to be driven. Since a current flows up to generate an unnecessary magnetic field, each cable twisted to absorb such an unnecessary electromagnetic wave is covered with a shield 60b to the root of the coil as much as possible, and a driving means (for example, the switching circuit 28 and The connection end with the (including the amplifier circuit 24 etc.) side is connected to the reference potential of the driving means.

Next, the detection signal cable 40a of the sense coil 22j will be described. This cable 40a has one end connected to each of the three coils forming the triaxial sense coil 22j (only one pair of cables is shown in FIG. 46 for simplification), and the other end of each sense coil 22j. Is connected to the input terminals of the synchronous detection means (the amplifier 27 and the synchronous detection circuit 26d in FIG. 8).

The voltage transmitted by this cable 40a is
The signal is a weak signal of about several tens of μV to 1 mV, and the AC magnetic field from the source coil 16i may be buried in the fluctuation component superimposed on the cable 40a via the stray capacitance of the human body or the like. Therefore, in order to absorb such undesired superimposed noise, the shield 40b is covered as much as possible to the root of each coil for each cable twisted, and the connection terminal on the side of the synchronous detection means is connected to the reference potential of the synchronous detection means. To do.

Further, the reference potential points of the drive means and the synchronous detection means are connected to each other so that they have the same potential. With such a configuration, the influence of the leak signal due to the interference and radiation between the drive signal lines of the source coil 16i on the sense coil 22j is almost eliminated, and the influence of the sense coil 22j on the detection signal by the human body or the like is extremely small. It will be a little.

Therefore, since the noise included in the signal detected by the sense coil 22j can be almost eliminated, the signal component excited in the sense coil 22j by the AC magnetic field generated by the source coil 16i can be measured stably and accurately. become.

Next, a second modification of the first embodiment will be described. The second modification is for improving the accuracy of position derivation. In order to obtain a narrow closed space (closed region) when the three-dimensional position is calculated by accurately limiting the region where the source coil exists from the magnetic field strength obtained by the sense coil located at a certain distance from the source coil, At least three (or three sets) sense coils 22j are required.

However, the sense coil 22j is actually 3
In the case of only a pair, 3 is set when the distance between the source coil 16i and the sense coil 22j is too short or too far.
There is a possibility that the detection signal cannot be obtained even with one of the pairs, and in that case, the closed space in which the source coil 16i exists cannot be limited to a narrow range, so that the position of the source coil 16i can be derived. It becomes virtually impossible.

Therefore, in this modification, the position of the source coil can always be derived in a stable state regardless of the level of the detection signal. Therefore, as shown in FIG. 47, four sets of three-axis sense coils 22j are used.

Let us assume that the detectable range of the sense coil 22j is a radius of 30 to 100 cm, and the required detection area width is (x, y, z) = (40, 60, 40) [cm].
And four triaxial sense coils 22j on the endoscopic examination bed 4 of size (200 × 70 cm), each coordinate being Q.
a (0,0,0), Qb (60,0,0), Qc (6
It is assumed that they are installed at positions of 0, 100, 0) and Qd (0, 100, 0) [unit is cm]. Then this 4
The required detection area width is included in the rectangular column whose bottom is a rectangle with the point as the apex. In this setting, when the source coil 16i moves within the detection area,
The distances from the four sets of sense coils 22j are 30 to 1 respectively.
If it is within 00 cm, the position can be reliably derived. If the distance from one of the four sets of sense coils 22j is less than 30 cm, the position is derived using the detection signals of the other three sets of sense coils 22j.

In the above setting, when the distance to one sense coil 22j is less than 30 cm, the other three pairs always have a distance of 30 cm or more.
This makes it possible to reliably obtain three sets of detection signals, and position detection (or position estimation) can be performed with high accuracy.
Furthermore, when the combination of the distance between the source coil 16i and the sense coil 22j is larger than 100 cm, the combination is the same as when the distance is less than 30 cm.

However, there may be two or more combinations in which the distance between the source coil 16i and the sense coil 22j is larger than 100 cm. At this time, the drive current of the source coil 16i is increased or the sensitivity of the output of the sense coil 22j is increased. After that, measurement is performed again so that the detectable distance becomes longer, and this process is repeated until three or more pairs are within the detectable range. As a result, the position of the source coil 22j can be derived.

The size of the bed 4 or the sense coil 2
In the case where two of the four sets cannot be used for position detection due to the condition that the detection range of 2j is different from the above value or the range, almost the same method can be dealt with. For example, if you want to secure a wider detection area, the sense coil 2
This can be achieved by widening the interval between 2j and increasing the drive current of the source coil 16i and increasing the sensitivity of the output of the sense coil 22j as described above.
The width of the bed cannot be expanded as it is.

Therefore, the detection range is shifted closer to the sense coil 22j by decreasing the drive current of the source coil 16i and decreasing the sensitivity of the output of the sense coil 22j so that three or more sets are within the detection range. Can be derived.

By the method as described above, the position of the source coil can be always derived in a stable state regardless of the level of the detection signal. Further, in the position derivation of the source coil in all the cases described above, the size of the closed space becomes smaller as the number of sense coil sets increases from three, so that the position derivation accuracy improves. Therefore, it is possible to obtain the required accuracy by using all the detection signals of the sense coil in which the source coil exists in the detectable area for deriving the position.

FIG. 48 shows an explanatory diagram of the above method. Figure 4
A curve C1 in 8 indicates a graph on the maximum magnetic field strength side of the measured data of the magnetic field strength with respect to the relative distance for calculating the relative distance described in FIG. When a certain magnetic field strength value is actually detected from the detection signal by the sense coil 22j, the distance between the source coil 16i and the sense coil 22j from the magnetic field strength value is a curve C intersecting with the strength value.
It exists in the range between 1 and the graph on the minimum magnetic field strength side not shown. The signal detected by the sense coil 22j is limited in the range in which it can be detected accurately due to the dynamic range of an amplifier or the like.

Therefore, in the normal setting state (such as sensitivity), the detection range D in the normal state shown in the horizontal axis corresponds to the output value of the measurable band MR shown in the vertical axis with respect to the curve C1.
1 is the detectable distance range (corresponding to a radius of 30 to 100 cm by the sense coil 22j). In this case, if the gain of the amplifier is lowered (that is, the sensitivity is lowered), the detectable range can be shifted to the smaller range side, and even if the drive current value for driving the source coil 16i is lowered, it is shifted to the smaller radius side. can do. That is, when the drive current is reduced or the gain of the amplifier is reduced, the range detectable by the output value of the sense coil 22j is the curve C.
The curve C2 is obtained by relatively lowering the value of 1 in the vertical axis direction. In this case, the detection range is D2, and detection can be performed on the smaller distance side.

Conversely, when the drive current or the sensitivity is increased, the range that can be detected by the output value from the sense coil 22j becomes a curve C3 in which the value in the vertical direction of the curve C1 is relatively increased. In this case, Has a detection range of D3, which enables detection on a large distance side.

Next, a second embodiment of the present invention will be described with reference to FIG. The endoscope shape detection device 41 of FIG. 49 has a configuration in which the distributor 28 of FIG. 2 is omitted by changing the frequency of the drive signal.

Therefore, the source coil drive section 24 outputs a drive signal of a frequency fi different for each source coil 16i. By applying a drive signal having a different frequency fi to each source coil 16i, a plurality of source coils 16i can be driven simultaneously and high-speed processing can be realized.

In the endoscope shape detecting apparatus 3 of the first embodiment, the plurality of source coils 16i are sequentially driven by the sinusoidal current having a specific frequency from the one arranged on the distal end side, and the sense at that time is sensed. A detection signal for detecting the position coordinate of the source coil 16i is obtained one by one according to the detection signal level of the coil 22j. However, in this method, as the number of source coils 16i increases, the time required for one shape detection also increases, so that it becomes difficult to capture the shape data in real time.

Therefore, in this embodiment, the source coil 1
The shape calculation data can be taken in in real time without being affected by the number of 6i. Next, a specific configuration is shown in FIG.

For example, the case of detecting the shape of a probe having twelve source coils 16i will be described.
As shown in FIG. 50, the oscillating unit 25 has oscillators 25a, 25b, ... 25l that oscillate at different frequencies, and after being current-amplified by the amplifiers 24a, 24b ,. Coil 16
, 16l are simultaneously applied to generate magnetic fields of different frequencies.

On the other hand, each sense coil 22j generates a detection signal proportional to these magnetic field strengths, and each of the amplifiers 2j
After being amplified by 7, the synchronous detection circuit 2 constituting the detection unit 26
6di performs synchronous detection by referring to the signal of the oscillator 25i, and the source coil 16i senses the coil 22j.
Only the signal component proportional to the magnetic field strength at the position is extracted.
The bandpass filter 2 of each synchronous detection circuit 26di
6ai is set to a band through which only the signal of the frequency of the oscillator 25i passes.

Each signal synchronously detected by each synchronous detection circuit 26di is sampled at high speed by, for example, a 12-channel A / D converter 30aj, temporarily stored in the RAM 30b connected to the A / D converter 30aj, and further stored in the RAM 30b. Data is read by the CPU 30c, and position calculation and shape estimation processing is performed. The other configuration is similar to that of FIG. 8, and the description thereof is omitted.

FIG. 51 is a flow chart showing the processing contents of driving the source coil 16i and fetching data in the sense coil in this embodiment. In step S111, each oscillator 2
5i are driven at different frequencies, and a drive current is supplied to each source coil 16i. Next, the detection signal of each sense coil 22j is sampled. In this case, since the drive current can be applied to each source coil 16i (the condition where the drive current is kept flowing), the detection signal of each sense coil 22j can be sampled without delay by the transient response time. Of course, immediately after the drive current is first applied,
Consider the transient response.

As can be seen from the comparison with FIG. 9, it is possible to take in data for position detection or shape detection in a short time. Further, in this embodiment, since data for position detection or shape detection can be taken in in a short time, it is possible to perform highly accurate shape estimation and the like even when the movement of the insertion portion is fast. become.

Note that, for example, 12 source coils 16i
Are different frequencies that are not integer multiples (for example, 10.
0, 10.5, 11.0, 11.5, 12.0, 12.
5, 13.0, 13.5, 14.0, 14.5, 15.
An alternating magnetic field is simultaneously generated with a drive current of 0,15.5 [KHz].

According to this structure, a plurality of (for example, 12
The position of each source coil can be derived. Further, in this embodiment, when the endoscope shape is displayed on the monitor screen, the endoscope shape is output by being superimposed on the model pattern of the patient as shown in FIG. In FIG. 52, the left area is the graphics output area, and the right area is the user interface area in which the user sets the viewpoint, the rotation angle, the elevation angle formed by the viewpoint position and the z-axis, etc. by key input from the operation panel 35. Other effects are almost the same as those of the first embodiment.

FIG. 53 shows an endoscope system 70 including the third embodiment of the present invention. This system 70 is the system 1 shown in FIG. 1 in which a sensor 75 formed by magnetoresistive elements (abbreviated as MR elements) 76a, 76b, 76c as shown in FIG. 55A instead of the triaxial sense coil 22j.
j is used, and the sensors 75j are attached to three known positions (or four positions) at the corners of the bed 4, respectively.

FIG. 54 shows the configuration of the endoscope shape detecting device 3'in this system 70. This device 3'is shown in FIG.
A sensor 75j composed of elements 76a, 76b and 76c is used. Further, the sense coil output amplifier 27 becomes a sensor output amplifier 27 ', and the mutual inductance detection unit 26
A magnetic field strength detection unit 26 'is used instead of. Also,
The source coil position detection unit 31 refers to the data of the table 31b storing the reference data to perform position detection or position estimation.

As shown in FIG. 55 (a), each of the sensors 75j has three MR elements 7 whose resistance value changes according to the magnetic field strength.
6a, 76b, and 76c are vertically adjacent to each other in a cube and are 3
These three MR elements 76 are attached to each of the three surfaces.
Sensor 7 formed by connecting a, 76b, and 76c in series
Two terminals 5 are used as output terminals of the magnetic field strength detection signal. In this case, the MR elements 76a, 76b, 76c are provided so that the respective resistance values change from the reference values due to the magnetic field strength components in the X, Y, Z directions, respectively.

Since the resistance change amount ΔRq of each MR element 76q changes in proportion to the square of the magnetic field Hq as shown in FIG. 55 (c), the resistance change amount ΔR of the two terminals of the sensor 75j is
As shown in FIG. 55 (b), the magnetic field component H in the x, y, z directions
It is the sum of the squares of x, Hy, and Hz.

This embodiment has the advantage that a signal proportional to the sum of squares of the magnetic field strength can be directly detected from the output of the sensor 75j. The magnetic field strength of this signal is detected by calculating the square root in the magnetic field strength detection unit 26 '. Further, the source coil position detector 31 refers to the data in the table 31b to calculate the position of each source coil 16i.

The data of this table 31b is obtained in the same manner as in the first embodiment. That is, in FIG. 17A, the sensor 75j is arranged instead of the triaxial sense coil 22, and the reference data of the curve Cu of the maximum magnetic field strength and the curve Cd of the minimum magnetic field strength as shown in FIG. It is a table.

In FIG. 56, the sensors A, B, C (corresponding to 75a, 75b, 75c) are arranged at three known positions, and a plurality of sources (specifically, for example, the source coil 1) are arranged.
When one of 6i) is driven, an output corresponding to the positional relationship with the source is generated in the sensors A, B and C.

The outputs of the sensors A, B, and C at that time are defined as νa, νb, and νc, respectively. Further, for each sensor, the sensor output and the data of the spatial coordinate group that should be the output are secured in a memory or the like in advance.

FIG. 57 shows a data table for the sensor A, for example. Sensor output ν obtained when one source is present at a certain position and a magnetic field is generated
a is compared with νa1 to νaL in the table of FIG. 57, and νa
An integer l that satisfies l ≦ νa <νak (k = 1 + 1) is obtained. Similarly, the integers m and n satisfying the conditions are obtained for the other sensor outputs νb and νc.

At this time, output data νa satisfying the condition
Spatial coordinate groups Pai, Pb corresponding to l, νbm, νcn
j and Pck exist, and their relationship is as shown in FIG. Therefore, the three-dimensional area that is the common area of these becomes the spatial coordinate area of the source. Further, the barycentric position of the area may be obtained and used as the three-dimensional position of the source.

It is possible to obtain the insertion shape of the endoscope by performing processing such as connecting the spatial coordinate areas (or the spatial coordinate positions obtained from the center of gravity) of the plurality of sources thus obtained and further estimating the shape. it can. The three-dimensional positions or regions obtained by FIG. 58 are connected by a line passing through the barycentric position of each region, etc., the shape of the insertion portion is estimated, and a model display of the insertion portion shape is displayed on the monitor screen. In the case of more simplified display, as shown in FIG. 59, only the three-dimensional region or the three-dimensional position of the source coil estimated as shown in FIG. 58 is displayed on the monitor screen by 3D-2D projection or the like and inserted. It is also possible to omit the model display of the partial shape (the dotted line in FIG. 59 shows the line in the case of interpolation, and this interpolation may be omitted and displayed).

In this third embodiment, since position detection is performed using a table, as in the first embodiment, processing time for position detection or position estimation can be shortened. In addition, since the sum of the signals proportional to the square of the magnetic field strength in the three directions can be directly detected by the MR element, there is an advantage that the magnetic field strength calculation process can be performed at high speed. Further, by omitting the process of drawing the shape of the insertion portion as a model, the outline of the insertion shape of the insertion portion can be displayed very quickly. Further, as shown in FIG. 59, after first displaying, it may be drawn by a model that is more visually recognizable (such as the above-described n-square prism model).

FIG. 60A shows an endoscope shape detecting device 42 of the fourth embodiment. In FIG. 2, the third embodiment has a configuration in which a plurality of sensors, that is, a plurality of sense coils 43i are built in on the probe 15 side, and a magnetic field generation source, that is, a plurality of triaxial source coils 44j are arranged on the bed side. As in the first embodiment, the endoscope and the bed 4 are installed at known positions.

Therefore, the drive signals passed through the distributor 28 are 3 each.
The signal sequentially applied to the axial source coil 44j and detected by the sense coil 43i on the probe 15 side is amplified by the amplifier 27 and passed through the detection unit 26 to the (sense coil) position detection unit 31 'constituting the shape calculation unit 30. Is entered.

The position detector 31 'relatively detects the position of the sense coil 43i with the triaxial source coil 44j as a reference. Other configurations are similar to those of the first embodiment. The effect of this modification is also almost the same as that of the first embodiment.

FIG. 60 (b) shows an endoscope shape detecting device 42 'according to a modification of the fourth embodiment. This modification is shown in FIG.
In (a), the triaxial sense coil 43i is changed to a uniaxial sense coil 43i ', and the uniaxial source coil 44j is changed to a triaxial source coil 44j'.
The configuration is similar to that of the embodiment. Also, the effect is almost the same.

FIG. 61 (a) shows an endoscope shape detecting device 45 according to the fifth embodiment of the present invention. This fifth embodiment is shown in FIG.
By changing the frequency of the drive signal at 0 (a),
The configuration is such that the distributor 28 of FIG. 60 (a) is omitted.

Therefore, the drive unit 24 is controlled by the source coil 44j.
A drive signal having a frequency fj different for each is output. The other configurations are the same as those in the fourth embodiment. The effect of the fifth embodiment is almost the same as that of the second embodiment.

In the first to fifth embodiments or the modifications, the signal from the sense coil may be amplified, digitally converted, and the subsequent detection may be performed by digital signal processing.

Further, one source coil or sense coil may be incorporated only in the tip portion of the endoscope, which is the position of maximum interest. In this case, it functions as an endoscope tip position detecting device that detects the position of the tip of the endoscope. Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 62 is an endoscope system 51 including the sixth embodiment.
Indicates.

In the above-described embodiment and modification, the estimated endoscope shape is drawn on the monitor 23 as a dedicated display device. However, in this embodiment, the video signal output to the monitor 23 is viewed internally. The monitor 12 for displaying the mirror image is switched and displayed. Therefore, the output of the detection device main body 21 is input to the external video signal input end of the video processor 11 via the connection cable 52, and by operating the changeover switch 53, the color monitor 1
The endoscopic image and the endoscopic shape can be selectively displayed on the second display surface.

Further, in this embodiment, the reference signal on the video processor 11 side (which determines the timing of the drive signal for CCD reading) is sent to the shape detecting device main body 21 via the cable 54. Then, in order to detect the shape of the endoscope, the timing for applying the drive signal to the source coil 16i is adjusted such that it is performed during the period when the drive signal is not output.

FIG. 63 shows how the system 51 operates during an operation period. The light source unit in the video processor 11 sequentially illuminates with R, G, B field sequential light as shown in FIG. Then, a CC (not shown) built in the endoscope 6
As shown in FIG. 63 (b), a CCD drive period is set in D while a CCD drive period is set, and a CCD drive signal for driving the CCD is applied within this CCD drive period, and the CCD performs photoelectric conversion. The captured image signal (imaging signal) is read.

On the other hand, the drive signal period is set so that the drive signal period during which the drive signal is output is within the period other than the CCD drive period during which the CCD drive signal is output, that is, during the illumination (exposure) period. This prevents the CCD drive signal from affecting the detection signal from the sense coil.
In other words, we are building a means to eliminate mutual interference of each function. Other configurations are the same as those of the first embodiment shown in FIG.

According to this embodiment, the driving signal for detecting the shape of the endoscope can be prevented from becoming noise in the endoscope image signal, and the CCD drive signal becomes noise in the detection signal by the sense coil. Can be prevented. Other actions and effects are almost the same as those of the first embodiment.

In the sixth embodiment, the endoscopic image may be displayed as the endoscopic image or the endoscopic image may be displayed as the endoscopic image by the picture-in-picture method. Further, in the sixth embodiment, when the endoscope shape is detected so as not to interfere with the image pickup signal, the endoscope observation image may be frozen so that noise is not mixed in the image. (Add a setting function to the operation panel 35 of FIG. 1).

Further, the observation image acquisition is automatically interrupted and the magnetic field for shape detection is automatically interrupted for each field of image acquisition, each frame, every few frames, every few fields, and every time the endoscopic shape drawing processing is completed. Generation and magnetic field strength acquisition may be performed.

Next, an endoscope system 61 including the seventh embodiment of the present invention will be described with reference to FIG. This system 61 is different from the endoscope system 51 of FIG. 62 in that a head mounted display (hereinafter, abbreviated as HMD).
62, a TV camera 63 for confirming the position of the patient 5, a computer 64 for extracting the contour of the body of the patient 5 from the TV camera 63, and an image processing device 65 for performing image processing for virtual reality.

The image processing device 65 is the shape detection device main body 21.
Connected to, for example, the shape image generation unit 32 (see FIG. 2),
The shape image generated by the shape image generation unit 32 is subjected to image processing to generate a shape image for right eye (or left eye) observation at a position where the viewpoint is slightly changed, and the shape image generated by the shape image generation unit 32. As the shape image for the left eye together with the monitor signal generation unit 3
Then, the data is output to the liquid crystal display of the HMD 62 (for right eye observation and left eye observation) via 3, and the operator wearing the HMD 62 on the head can stereoscopically observe the endoscope shape in virtual reality.

Also, in this embodiment, the TV camera 63 detects the position of the patient 5 on the bed 4 and generates a video signal of the body shape of the patient 5 so as to overlap the body shape. The shape of the endoscope can be observed with virtual reality. In this way, by displaying the shape of the body in an overlapping manner, the insertion portion 7 of the endoscope 6 is
It is designed so that you can see up to what part is actually inserted. As in the case of FIG. 62, one of the endoscopic image and the endoscopic shape displayed on one of the liquid crystal displays of the HMD 62 (overlapped with the body shape) is selected on the color monitor 12. Can be displayed.

FIG. 65 shows the bed 4 with the TV camera 63.
The explanatory view of the method of detecting the position of the patient 5 above is shown. In FIG. 65, the image captured by the TV camera 63 is the image of the arrow indicated by the dotted line below the cable, and the image obtained by the endoscope shape detection device 3 is the image shown below the outline of the image by the computer 64. Extraction is performed and (as through the monitor signal generation unit 33, etc.) is displayed in an overlapping manner as shown in the figure. A body marker 67 for detecting the position and direction is attached to the body of the patient 5. This may be singular or plural.

The body marker 67 has a built-in coil for position detection. The installation position of the body marker may be provided at a reference point such as the lateral position of the pelvis of the patient 5, and when the endoscope shape is displayed, the body marker may be displayed so as to overlap with the reference body shape graphic model.

When the patient sleeps on the endoscopic examination bed 4, a TV camera 63 for confirming the position, which is provided above the bed 4, uses the computer 6 including the body marker 67.
Capture the image in 4. Since the body marker 67 attached to the body of the patient 5 is the contour line portion of the patient 5, only the contour image of the patient 5 is extracted based on this, and is superimposed on the shape display and drawn on the color monitor 12 or the like. To do.

The superimposed image is
The direction of the patient 5 may be derived from an image based on the image of the entire circumference of the body of the patient 5 that has been captured in advance, or the position of the body marker 67 obtained magnetically, and the computer 64 may synthesize and form the displayed direction. . If the color (bed, etc.) on the image actually captured by the TV camera 63 or the like is similar to the color of the endoscope which is combined and displayed by the shape detection device, the shape is difficult to discriminate on the color monitor 12. Become.

Therefore, the user may change the color of the displayed endoscope shape. Further, the thickness of the endoscope displayed on the color monitor 12 may be changed.

By detecting the body direction of the patient 5, the image displayed on the color monitor 12 may always be the image from the front direction of the body of the patient 5. Of course, the obtained image may be rotated. By doing so, the image can be converted from the same position as the user's viewpoint, and thus the user can be prevented from erroneously recognizing the shape of the endoscope.

In the above example, the user rotates the image obtained according to his / her own viewpoint, but if the user also mounts the position detecting sensor in the same manner as the body marker 67, the The image can be transformed such as rotated. In the case of the user, the endoscope 6 is inserted, so that the endoscope 6 is mounted at a position where the movement of the endoscope 6 is large and the movement of the user is not hindered. Also, the position of the sensor cannot be physically the same as the user's viewpoint. (It is necessary to install the sensor in the skull.) Therefore, when using, an adjusting means for adjusting the sensor position and the viewpoint may be provided.

For example, a probe for shape detection is placed on the endoscopic examination bed 4, and the probe is rotated and scaled so that the displayed probe shape is the same as the actual appearance.
In that state, by pressing the viewpoint correction switch, the offset between the viewpoint and the sensor position is adjusted.

This also needs to be done in the same way when using the HMD 62 described above. HMD62 sensor 68
May be fixed. In this case, since there is not much difference between the line of sight and the sensor position, it can be used with almost no correction. When the user's position is detected using a magnetic sensor, magnetic coupling is used as in the endoscope shape detection, but the position of the source coil 16i in the endoscope shape detection probe 15 is detected. Mutual magnetic interference may be reduced by driving them in a time division manner instead of driving them simultaneously. FIG. 66 shows an explanatory diagram in the case of driving in this time division.

The narrow pulse period indicates the period for driving the fixed magnetic sensor of the HMD 62, and the long pulse period indicates the source coil 16i for endoscope shape detection.
Shows the period for driving.

According to this embodiment, the shape of the endoscope can be stereoscopically observed with virtual reality. Therefore, when performing an inspection by the endoscope 6 or a treatment using the endoscope 6, the endoscope 6 There is an advantage that the work of introducing the distal end portion of the insertion portion 7 to the vicinity of the target site can be performed more easily and in a shorter time. Others have the same effects as the first embodiment.

When the magnetic sensor fixed to the HMD 62 and the source coil for detecting the shape of the endoscope are driven, instead of time-division driving, the respective frequencies are changed and detection is completed. You may drive simultaneously. In this case, all sensor positions are obtained simultaneously, so
Even if the position, shape, or user position of the endoscope changes rapidly, the position and shape can be quickly obtained by following the change.
Well-known quadrature detection can be used for these processes, but it may be analog or may be digitally processed by A / D conversion.

The magnetic field generating coil and the magnetic field detecting coil used for position detection are generated even if the same current is supplied due to variations in characteristics of cores, variations in windings, differences in ambient temperature, and the like. Of the detected magnetic field strength, and even in the field of the same magnetic field strength, the obtained detection signal strength varies.

Therefore, the variation is corrected beforehand by measuring the current value for generating the same magnetic field strength. For example, a current value for obtaining a strength of 2 Gauss from the source coil at a position of 30 cm in the axial direction is measured, a ratio with a reference current value is stored as a table value, and driving is performed with the ratio. To do. Similarly, for the sense coil, the signal output with a magnetic field strength of 2 gauss is measured in advance, and the ratio with the reference value is used as a table, and the detection signal is multiplied to perform correction.

Since this correction coefficient needs to be set for each coil, it may be set by a keyboard provided in the apparatus. Further, the value may be stored in the ROM provided in the connector of the probe 15 and automatically read. Further, the stored value or the set value may be compressed and coded. The combination of the coil installed in the endoscopic examination bed 4 with the device does not change except when there is a failure, so a correction amount for the variation may be set when the device is assembled.

The bed-side coil is thus basically always combined with the same device. The intervals between the coils in the probe 15 for shape detection are pre-assembled with known values. Therefore, the probe 15 may be placed on a straight line in the center of the bed and the variation correction switch may be pressed to correct the variation of each coil in the probe 15. Further, the correction coefficient may be set or the drive current may be adjusted so that the detected positions are lined up on a straight line or the interval is a known value. In this way, the expensive R
There is no need to incorporate an OM (these are the same in the case of a special endoscope for shape detection).

Next, an eighth embodiment of the present invention will be described. Generally, the detectable range of the sense coil used for position detection depends on the dynamic range of the device. Therefore, from the small distance when the source coil and the sense coil are close to each other where the level of the detection signal is high, to the case where the distance between the two is long where the signal level that can be detected is minute, the dynamic range that can be sufficiently covered is sufficient. Required.

However, in the actual endoscopic examination, the examination bed is used, and since the patient is present on the bed, it is sufficient to detect only the area on the bed, and in addition to the general case. If the patient is a physique, the position of the endoscope that can be considered when inserting the endoscope is a very limited area.

That is, it suffices to have a practically limited dynamic range. On the other hand, considering the image to be displayed, if only the endoscopic image is displayed, it is generally difficult to determine from which viewpoint the drawing is performed. Therefore, in this embodiment, the display of the detectable area is prepared for the operator to confirm the viewpoint direction.

Since sufficient detection accuracy can be obtained within this area, the shape of the endoscope is displayed only for objects existing within this area. The flow of this processing is shown in FIG.

A reference rectangular parallelepiped value or the like is set in advance as a detection range (detection region), and this detection range is acquired in step S121. That is, the detection range from the visual field coordinate system is actually taken in as reference data. Next step S
At 122, construction of the scope image drawing begins. In this case, the position coordinates of the endoscope obtained by interpolating the coil position are compared with the surface surrounding the detection area to determine whether or not it is within the detection area (step S123).

By comparison, the image data is stored in the video RAM only when it is determined to be inside the area (step S1).
24) If it is out of the range, the data is discarded (step S125). The image data stored in the video RAM is displayed on the CRT (step S126), it is determined whether the image construction process is completed (step S126), and the process is repeated.

In this embodiment, if the detection range is within the detection range, the display is performed. If the detection range is outside, the display is not performed and the process ends. The endoscope shape existing outside this detection area is not displayed because its positional accuracy is not sufficient.

However, if the shapes existing outside the area are not displayed at all, when most of the endoscopes are out of the area due to patient movement or the like, the shapes are hardly displayed. Can also be considered. Therefore, for example, as shown in FIG. 68, the display may be performed differently inside and outside the area. In FIG. 68, in the process of determining whether it is within the detection range (step S123), if it is within the range, it is stored in the first RAM (step S124).
a) If it is out of the range, it is stored in the second RAM (step S125a). The image data stored in the first RAM and the second RAM are displayed on the CRT by changing the display method such as different display density (step S126a). The other processing contents are the same as those in FIG. 66.

The present invention is not limited to changing the shading of the display density within and outside the detection range. For example, outside the area (inside the area), a different color system (endoscope) is used. It may be displayed in cold color if is a warm color system (for example, such an LUT is prepared). Further, the pixels used for drawing are thinned to roughen the displayed image. (A display mask is prepared and EXOR is performed, OR is performed, or the like) may be performed. Since the continuous endoscope shape is displayed together with the detection accuracy, the endoscope shape can be reliably obtained.

That is, the position coordinates of the endoscope obtained by interpolating the position of the source coil are compared with the surface surrounding the area, and normal drawing is performed only when it is determined to be inside the area by this comparison. According to the drawing method of the endoscope shape detection device, accurate shape display can be performed. The process of FIG. 67 or FIG. 68 is performed by the process of FIG.
It may be performed in step S42 of 5.

Next, a ninth embodiment of the present invention will be described. In the above-described embodiments and the like, when the endoscope shape is displayed, it is displayed as a computer graphic, whereas in this embodiment, for example, an endoscope real image is displayed.

The detected or estimated endoscopic shape is
It has been described that the drawing is performed by a wire frame or the like inside the computer, the light source is set, and the set surface is shaded and displayed.

However, in general, this image processing requires high-speed calculation and drawing ability, and it is difficult to obtain a comfortable drawing speed with little waiting time due to the processing speed of the computer and the capacity of the built-in memory. There can be cases. In this case, a model that is easy to process is desired in order to improve the drawing speed. However, a model that is too simplified is very different from an actual endoscope image, and even if the endoscope is drawn, it may be difficult to think of the endoscope itself.

In such a case, by adopting this embodiment, it becomes possible to display the shape of the endoscope at a high speed and in a shape that is easier to grasp even by a computer having a small processing capacity. Therefore, in this embodiment, means for displaying the endoscope shape by pasting a texture is configured, and an image of an actual endoscope is captured in advance by a scanner as a texture to be pasted and stored in a ROM, and various images are stored. Prepare a texture as an image pattern. That is, as a texture, a pattern is prepared in advance on a high-speed semiconductor memory. Then, as shown in FIG. 69, the texture is pasted so that the coordinates corresponding to the detected position of the endoscope and the coordinates of the pattern center of the corresponding texture match.

When the texture to be pasted is basically a square as shown in FIG. 69, a step is generated in the displayed image depending on the state of the endoscope, so
The outline may be connected by a Peget curve or a spline curve.
Alternatively, known anti-aliasing may be applied.

The texture to be used corresponds to the light source direction from A to H as shown in FIG. 70 (a) and is prepared by capturing the image of the endoscope insertion section 7. It goes without saying that the direction of the light source can be appropriately increased or decreased according to the size of the storage area and the quality of the displayed image to prepare the texture.

It is also possible to separately prepare images 7a when the endoscope insertion portion 7 is tilted as shown in FIGS. 70 (b) and 70 (c). The more the textures that match the inclination of the endoscope insertion portion 7 itself and the light source direction are stored, the less the calculation for image display becomes, and the faster the drawing becomes possible.

Known edge enhancement may be performed in order to distinguish the image of the endoscope from the background. According to this embodiment, the image of the ROM in which the image pattern is written in advance is written in the video RAM as the display memory for forming the image of the endoscope.

This means that after the coordinates at which the endoscope is present are obtained, the corresponding patterns are simply sorted and written, so that data transfer between the memories can be performed, resulting in complicated arithmetic processing. Is unnecessary, and the drawing speed can be very high.

Further, since the texture to be used is the one using an actual endoscope, it is easy to intuitively form an endoscope-shaped image. In addition, since it can be displayed in the same color as the existing endoscope, it is very easy to reconstruct the actual shape of the endoscope in the operator's head.

Next, a tenth embodiment of the present invention will be described.
In this embodiment, the display color is switched every fixed length. The shape of the inserted endoscope insertion portion is displayed on a monitor by computer graphics, but unlike the actual exterior of the endoscope insertion portion, the display indicating the insertion length was not displayed.

Therefore, the position of the built-in coil is displayed by using a color different from that of the endoscope shape. How much length is actually inserted into the patient's body? To confirm this, the operator had to judge from the image on the monitor.

Especially, the installation intervals of the coils for position detection are made constant, and the positions of the coils are distinguished from other pseudo endoscopic display (for example, the endoscope is gray scale, the coil position is a red dot). If it is set, the insertion length can be obtained depending on how many coils are displayed. However, in the case of actually performing an endoscopic examination, the insertion of the endoscope is not the purpose, but the observation and treatment of the internal tissue is the purpose, and the extra counting work is a burden on the operator.

Therefore, the endoscope shape displayed by computer graphics is displayed by changing the basic color for each fixed length. For example, on a straight line drawn on a color chart of colors that can be displayed by the device, colors that are apart to some extent are set as basic colors.

By repeating this according to the drawing length, the color can be changed at a constant distance. The fixed distance may be set by the user.

Since a larger drawing area can be obtained than when only the coil position is represented by another color, the insertion length can be easily understood visually. It may be expressed by repeating gradation changes. The pattern to be pasted may be changed on the monochrome binary screen.

For the sake of simplicity, an image when the endoscope insertion portion is a straight line is shown in FIG. 71 (a). The colors are displayed such that Ca, Cb, Cc, Cd, and Ce change at regular intervals from the tip.

Such a display can be realized by storing the data of the colors Ca, ..., Ch to be pasted at predetermined address positions in the texture area and sequentially reading them as shown in FIG. 71 (b). . Each pattern may be freely set by the user.

FIG. 72 shows the basic flow of drawing. First, in step S131, the parameter n is initialized to 0. In the next step S132, the insertion is performed from the distal end portion, so the position of the distal end is detected, this position is set to Psn (here, n = 0), and the endoscope having the distance 1 set by the user from this position Psn The position Psn + 1 on the position is searched.

In the next step S133, it is judged whether or not the parameter n is equal to or smaller than the detected insertion portion length / l (that is, n ≦ detected insertion portion length / l),
If this condition is satisfied, n is set to n + 1 (step S134), the process returns to step S132 again, and the same processing is repeated.

On the other hand, if the condition is not satisfied, the process proceeds to the next step S135, and the color is displayed in a different color for each distance l searched from the tip side, that is, as shown in FIG. To finish.

Next, an eleventh embodiment of the present invention will be described with reference to FIG. In this embodiment, peripheral images are captured and displayed. When the shape of the endoscope detected by magnetism is displayed by computer graphics, it is difficult to detect living tissue and the like, so only the endoscope is displayed. Therefore, it is difficult to intuitively understand the positional relationship between the living body and the endoscope.

In order to solve this, in the first embodiment, the reference plane such as the plane of the bed is displayed. In this case, since the texture is created by a computer, it may be difficult to immediately recognize the shape by associating it with the actual endoscope unlike the actual scene of the endoscope room. To prevent this, peripheral images may be captured and displayed as in this embodiment.

In the endoscope shape detecting apparatus 101 of the eleventh embodiment shown in FIG. 73, a video camera 102 as a video input device is connected to the shape detecting apparatus main body 21, and this video camera 102 is used in an endoscopic examination room. 103 is imaged.

The bed 4 and the like are arranged in the endoscopy room 103, the image of the bed 4 and the like is picked up by the video camera 102, and the shape detection device main body 2 is taken as the picked-up image signal.
It is output to 1. The shape detection device main body 21 converts an input image signal into a digital signal by an A / D converter in the image processing unit 21a and stores the digital signal in a memory. The image in this memory is reproduced on the monitor 23 via the monitor signal generation unit.

The operator operates the keyboard 35a and the mouse 35b on the image displayed on the monitor 23 to display the image shown in FIG.
The process shown in FIG. 4 is performed so that it can be displayed as a background image when the endoscope shape is displayed.

Next, the flow of FIG. 74 will be described. First, in step S141, an image is captured by the video camera 102. That is, the image signal from the video camera 102 is A / D converted and stored in the memory.

In the next step S142, the image stored is reproduced on the monitor, and the reproduced image is corrected. That is, an unnecessary image portion or a noise portion is corrected by photo retouching software or the like, and a necessary area of the corrected image is selected by the mouse 35b and stored in the memory as a sticking image.

In the next step S143, the endoscope shape detection control program is called, the pasting image stored in the memory is also read, and the area to be pasted as the background screen is designated.

In the next step S144, deformation, enlargement, and reduction are performed to fit (mix) with the shape display image of the shape detection device, and then the pasted data is fixed in step S145 to determine the background image. Is confirmed. As a result, the shape of the endoscope detected in the actual background of the endoscope room is expressed, so that the shape of the endoscope inside the patient's body can be easily understood.

Next, a twelfth embodiment of the present invention will be described.
In this embodiment, the cable for driving the source coil is not used, and the source coil is wirelessly driven. In the first embodiment and the like, in order to detect the position of the source coil, the sense coil obtains a detection signal corresponding to the magnetic field strength. In this case, synchronous detection is performed in order to detect a minute signal. Then, in order to extract a signal having the same frequency as the drive signal of the source coil, the detector uses a reference signal based on the drive signal to perform quadrature detection on the received signal to determine the amplitude of the received signal and the phase of the received signal. Trying to get.

In this case, the drive signal is transmitted to the detection section on the side of the shape detecting device via a cable, but the cable limits the operator's free movement, and the patient is provided with a source coil as a marker. This may limit the patient's freedom of movement. Therefore, in this embodiment, an apparatus capable of wirelessly transmitting a signal for generating a reference signal and performing wireless position detection will be described.

FIG. 75 shows a probe 1 provided with a source coil.
The structure of the 31st side is shown. A power supply unit 132 configured by a battery or an antenna coil that generates an AC signal by an electromagnetic field from the outside supplies power to a power supply unit 133, and this power supply unit 133 generates a stabilized DC power supply and oscillates. The voltage necessary for operation is supplied to the means 134 and the like.

The oscillating means 134 oscillates at a predetermined frequency,
This oscillating signal is applied to the radiation means 135, and the radiation means 13
The signal 5 is amplified so as to be a drive signal of a constant level and applied to the internal source coil 136i to generate a magnetic field around it.

The reference signal generating means 137 for generating a reference pulse for external synchronization generates a reference pulse as a reference from the oscillation signal of the oscillating means 134, and the radiating means 138.
To radiate from the radiating means 138.

The radiating means 138 is provided with an AGC circuit for keeping the amplitude of the drive signal constant, and sends out a reference pulse for external synchronization using the spread spectrum method. Figure 7
Reference numeral 6 shows a more specific configuration of FIG. The AC signal generated in the antenna coil 132a that constitutes the power supply means 132 is rectified and converted into direct current by the DC conversion circuit 133a that is composed of the rectifier and the condenser that configures the power supply means 133, and further the constant DC power supply voltage is generated by the stabilization circuit 133b. To be

This DC power supply voltage is applied to the oscillator 134a constituting the oscillating means 134, oscillates at a predetermined frequency, is amplified to a certain level by the AGC circuit 135a constituting the radiating means 135, and is further changed over.
It is sequentially applied to the source coil 136i via 5b.

Further, the spread code generator 137a constituting the reference signal generating means 137 monitors the oscillation signal output level so that it becomes 0 when the output of the oscillator 134a becomes zero and becomes 1 at the next zero cross point, Form a pulse signal. This pulse signal is output from the modulator 138a, for example, F
It is SK-modulated and further spread-modulated by a spread modulator 138b using a PN code. The spread-modulated signal is amplified as necessary and radiated from the reference pulse transmitting coil 138c. This signal spectrum becomes broad.

The changeover switch 135b is changed over by the changeover controller 135c formed by using a counter or the like for counting the output of the spread code generator 137a.
On the other hand, FIG. 77A shows the configuration of the reference signal generating circuit 141 on the body side of the shape detecting device provided with the sense coil 22j.

The main body of the shape detector is the reference signal generation circuit 14
1 and the signal radiated from the coil 138c is received by the antenna coil 142. The received signal is despread by the despreading circuit 144 with reference to the PN code of the spreading code generator 143 similar to that on the transmitting side, filtered by the BPF 145, and then returned to the original signal by the demodulation circuit 146. .

Therefore, this demodulated signal is used as a pulse signal as a reference drive signal, so that a PLL loop is formed and the PLL loop performs phase lock on the reference frequency. The signal that is phase-locked and tuned to the reference frequency becomes a reference wave (reference signal) with the reference phase aligned,
This reference wave is output to the synchronous detection circuit and used for synchronous detection with respect to the detection signal detected by the sense coil.

If the PN code on the receiving side does not match the PN code on the transmitting side, spreading is performed and the signal is not reproduced. That is, if the PN codes of all the coils whose positions are to be detected are changed, there will be no interference, and a large number of reference waves can be obtained at the same time without a connecting cable. That is, if applied to FIG. 50, the driving of the source coil and the detection by the sense coil can be simultaneously performed wirelessly. Note that any known method may be used for the modulation and demodulation.

When the antenna coil 132a is adopted as the power supply means 132 as shown in FIG. 76, an electromagnetic field or the like is generated on the side of the shape detecting device or separately from this device to generate the energy in the antenna coil 132a. An energy supply means for supplying is required, and this energy supply means is
Reference numeral 47 designates an oscillator 148, a coil 149 for radiating its oscillation output, and a DC power supply 15 as shown in FIG.
The DC power source 150 may be a battery or a power source generated by rectification from a commercial power source.

The oscillator 149 is, for example, the oscillator 134a.
Much higher than the frequency of (for example, several tens of MH)
z to several 100) and has almost no effect on the magnetic field generated at the frequency of the oscillator 134a. The modulated wave on the transmission side may be the drive signal (oscillation signal) itself.

Also, this embodiment can be used for displaying a marker. FIG. 78 (a) shows a wireless type magnetic field generation unit 159 of a modification of the twelfth embodiment. This wireless magnetic field generation unit 159 is a coil unit 15
2 and a drive unit 156.

For example, as shown in FIG. 78 (a), a connector 153 is provided on a coil unit 152 mounted on an object whose position is to be known and having a source coil 151 used for generating a magnetic field for detecting the position. By connecting the drive circuit 154 for driving the source coil 151 and the connector receiver 157 of the drive unit 156 containing the battery 155, the wireless magnetic field generation means used for the position detection for the marker is constituted. .

In the drive circuit 154 and the battery 155 shown in FIG. 76, a connector receiver 157 is connected to the output end of the AGC circuit 135a, and one source coil 151 connected to the connector receiver 157 via the connector 153.
It will be configured to drive only.

Further, as shown in FIG. 78 (b), the cable 15 is moved to a position where the drive unit 156 can be installed without difficulty.
Separated by 8 Coil unit 152 and drive unit 156
And may be connected. Connector means for connecting to the connector 153 and the connector receiver 157 is provided at both ends of the cable 158. The connector 15
Coil unit 15 with cable 158 without providing 3 etc.
2 and the drive unit 156 may be connected.

With such a structure, the cable between the shape detecting device side and the coil side used for the marker can be omitted, so that when it is attached to the patient, the movement of the patient is hardly restricted and the operator does not have to do so. When used, it is hardly restricted by the movement of the operator.

Next, a thirteenth embodiment of the present invention will be described.
In this embodiment, for example, the position of the palm is displayed as a marker display that is visually easy to understand. In order to realize this, at least one of the source coil and the sense coil is detachably attached, and means for fixing it to an arbitrary place such as a palm is provided.

In the twelfth embodiment, for example, the palm position detecting device 111 shown in FIG. 79A in FIG. 2 of the first embodiment is further provided as a magnetic field generating means for displaying a marker.

As shown in the exploded view of FIG. 79 (b), this device 111 has two source coils 116a and 116b for detecting the position of the palm, and these are provided with flexible thin plates 112a and 112b (for example, styrene). It is fixed with an adhesive between flexible materials such as polymers such as resin,
In addition, the outer surface (front surface) of one plate 112a is shown in FIG.
As shown in (a), an indicator 114 that indicates the directionality of fixation.
Is provided, and the back surface of the other plate 112b is coated with an adhesive 113 as a detachable fixing means.

Then, as shown in FIG. 79 (c), the palm (or glove) 11 of the operator or the caregiver is provided by the adhesive 113.
I am trying to stick to 5. The adhesive 113
Can be covered with a release paper before use, and the release paper can be peeled off immediately before and stuck and fixed at a desired place. It may be fixed with a surgical tape or the like without applying an adhesive agent. It may also be used as a body marker to identify the position of the patient's body.

The index 114 is shown in FIG. 79, for example.
As shown in (a), the fingertip side and the wrist side are displayed, and the operator or the like can confirm the fixing direction. Even if the source coils 116a and 116b used for the detection are connected to the shape detection device by a cable 117 in a wired manner, FIG.
As in (b), it may be connected to the drive unit (not connected to the shape detection device) to allow wireless generation of the alternating magnetic field. Of course, the AC magnetic field may be generated by itself as shown in FIG.

Source coil 1 detected by the shape detection device
The positions of 16a and 116b are respectively P0 (x0, y0,
z0) and P1 (x1, y1, z1). P01 =
With (P1-P0), one vector can be set. The operator sticks it on the palm so that the vector overlaps with the palm in the direction from the wrist to the fingertip.

As shown in FIG. 80 (a), the detected palm position may be displayed on the monitor screen together with the endoscope-shaped image 118 by a graphic 119 simulating the palm. The arrow 120 may be displayed as shown in b). Further, in practice, since it is a means for confirming the endoscope from outside the body, the distance between the endoscope and the operator's palm may be displayed as auxiliary information.

FIG. 81 shows an endoscope shape detecting device 121 of a modified example of the thirteenth embodiment. This device 121 is, for example, in the first embodiment shown in FIG. 2, further includes coil units 122a, 122b, 122c (represented by 122q) each having a built-in source coil that can be used for marker display or the like.
Is provided. A keyboard 35b and a mouse 35c are connected to the shape detection device main body 21.

As shown in an enlarged view, the operation panel 35 has a user-defined marker switch 123a, a body marker switch 123b, a marker setting mode ON / OFF switch 123c, an instrument marker switch 123d, a hand marker switch 123e, and a marker setting switch 123f.
(Represented by 123k) and the like are provided so that the operator can specify the coil arbitrarily used in the coil unit 122q by operating these switches 123k.

Each coil unit 122q is shown in FIG.
As in the case of 9, a means for attaching and fixing to the operator is provided. In addition, the operation panel 35 has a cursor key 1
A display / coil switching key 125 is provided together with 24.

Next, a process of setting an arbitrary desired coil unit to the user-defined marker, body marker, instrument marker, etc. by operating the operation panel 35 will be described with reference to the flow of FIG. This process is performed, for example, in step S of FIG.
Incorporated into the scope image rendering process of 42.

During the operation of this step S42 (referred to as main in FIG. 82), the CPU sets the marker setting mode switch 1
ON / OFF of 23c is monitored (step S15
1), turn on the marker setting mode switch 123c,
In the setting mode, the display unit corresponding to the coil unit 122q that can be set as a marker blinks or is displayed on the screen of the monitor 23 in a color different from that of other coil units.

As in step S152, the display of, for example, the unit number N corresponding to the coil unit 123q blinks. Therefore, the blinking coil unit 123q
Then, the marker switch to be set such as the body marker switch 123b is turned on (step S153).

The blinking coil unit 122q indicates that the operator wants to set the coil unit 123p (p = a, b,
To know whether or not it is c), when the coil unit 123p is held and moved above the position detecting device, the display mark corresponding to the coil unit 123p moves on the monitor screen.

Therefore, when the desired coil unit 123p is not selected, the desired coil unit is selected (by selecting with a pointing device such as a mouse cursor, or with the cursor keys). (Reverse display) (step S154), set the coil unit 123p corresponding to the unit number M,
Further, the display format is set (step S155).

Next, the marker setting switch 123f is turned on to set the marker, and the desired coil unit 123p is set.
Register the marker. (Steps S156, 157). In this way, the operator sequentially sets the necessary markers (for example, registers as a body marker indicating the position on the right side of the patient, a body marker indicating the left side of the patient, a body marker indicating the position of the anus, etc.).

Since the pattern candidates for marker display are also displayed on the monitor screen, selection is made with the displayed mouse or cursor in the same manner as selection of the coil unit. The function of coil unit selection and display selection can be switched with the display / coil switching key at the center of the cursor to switch the display format.

Here, the case where only the position can be detected has been described, but the detected signal includes the influence of the change due to the inclination between the source coil and the sense coil. Therefore, it is possible to detect the inclination. When the position derivation method capable of detecting even the inclination is used, only one source coil or sense coil may be installed on the palm.

As described above, the coil units to be installed are displayed so as to respectively show the direction corresponding to the fingertip and the direction corresponding to the wrist. (It can also be applied to a structure in which a plurality of coils are integrated.) A method of deriving only the position of the source coil or the sense coil. For example, when two source coils are used, or even the direction of the source coil is derived. Method, 1 source coil
When using one, the direction in which the palm is facing cannot be specified.
To determine the direction, three parameters are required, and FIG. 83 shows a palm position detecting device 161 used when detecting and drawing the palm direction as well.

A palm position detecting device 161 shown in FIG.
79 has one source coil 11 in the device 111 of FIG.
6c is added. Since one plane including the three source coils 116a, 116b, and 116c can be defined by adding one source coil 116c in this way, the direction of the palm can be determined.

As a result, it is possible to detect a change in the direction of the palm and change the drawing pattern of the marker to be displayed, and it becomes easy for the operator to grasp the three-dimensional positional relationship. As shown in FIG. 84, the three source coils 116a, 11a
Position vectors of positions P0, P1 and P2 of 6b and 116c are vP0, vP1 and vP2. The origin O is set to the center of the bed.

At this time, P1P0 = vP1-vP0 (1) P2P0 = vP2-vP0 (2) Here, for example, P1P0 has a length from the position P0 to the position P1, and represents a vector pointing in the direction from the position P0 to the position P1.

Now, assuming that the position vector on this plane is r, the plane including three points for detecting the palm to be displayed is generally r = vP0 + s (vP1-vP0) + t (vP2-vP0) (3 ).

By substituting r = vP0, vP1 and vP2 and solving (3), the unit vectors in the x-, y-, and z-axis directions are a. b. As c, the expression (3) can be rewritten as la + mb + nc = 0 (4) (at least one of l, m, and n is an integer that is not 0).

At this time, u = (l, m, n) is P0, P
A direction vector perpendicular to the plane including the three points 1 and P2 will be determined. When the position vector of the viewpoint is q, the inner product of u and q takes a value of negative, positive, or 0 depending on whether the angle is an obtuse angle, an acute angle, or a right angle (in the case of an acute angle, positive, and the obtuse angle is negative). Whether the palm is facing the viewpoint direction with the sign of this value,
It is possible to judge whether the back of the hand is facing the viewpoint.

Therefore, the colors displayed on the screen are changed for the palm and the instep. This device 161 is used for the endoscope shape detection device (for example, the coil unit 1 in the device 121 of FIG. 81).
This device 161 as 22a, 122b, 122c
FIG. 85 shows the marker display processing when the marker display is performed by adopting the above three (3).

It is judged from the main state whether or not the marker is set (step S161). If set, the positions of the three source coils of each set coil unit are detected, and the drawing position of the marker is acquired (step S161).

Next, in the pattern corresponding to the marker setting mode, the image of the marker is displayed at the detected position in different colors on the palm and the back (step S163), and after this display processing, the process returns to the main.

[0454] When the marker is displayed in this way, the color is gradually changed according to the inclination angle from the surface of the palm or the instep (for example, from the color table to change from warm color to cold color). The display color may be selected). Further, the displayed shape may be deformed according to the angle and the position.

FIG. 86 shows a palm position detecting device 171 which makes it possible to detect the position and direction of the palm using two source coils. This device 171 is the same as the device 111 of FIG.
The a and 116b are provided at the positions P0 and P1 so that they are not in the same direction, and these can be attached to the palm.

As shown in FIG. 87, the source coil 116
If the direction vectors of a and 116b are a and b, then a. b
The vector c representing a plane parallel to is c = ga + hb (g and h are at least one non-zero integer), and the perpendicular of this plane is the outer product of a and b.

That is, a vector determined by i = a × b is obtained, and as in the case of FIG. 83, the palm direction is determined by the positive or negative value of the inner product value w of i and the vector indicating the viewpoint direction, or 0. it can.

FIG. 88 is a flow chart showing the processing contents of marker display. The process up to step S162 is the same as in FIG. In the next step S173, a vector c parallel to the plane is calculated, and a vector i perpendicular to this vector c is calculated.

Next, this vector i and the viewpoint direction vector q
A value w of the inner product of and is calculated (step S174). Then, the sign of this value w is determined (step S175), and if it is positive, the instep side pattern of the graphic of this marker is drawn (step S176a). If it is negative, the palm side pattern of this marker graphic is drawn. Draw (step S
176b), if 0, the side pattern pattern of the graphic of this marker is drawn (step S176c).

Further, when additional drawing is performed, when the instep side pattern is drawn, the vectors i and q
The side pattern is rotated according to the angle formed by and (which can be seen from the value of w), and the process returns to the main (step S177).
a). Also, when the palm side pattern is drawn, the side pattern is rotated according to the angle and the process returns to the main (step S177b).

In the embodiment shown in FIG. 53, three MR elements (connected in series) are used as the sensor 75j for detecting magnetic field strengths in three directions, but as shown in FIG.
Two MR elements 71 and 72 whose detection axes are orthogonal to each other are set on two surfaces forming a degree, and these MR elements 71 and 72 are reciprocated by a step motor 74 or a solenoid to rotate 90 degrees, and the 90 degrees It is also possible to measure the magnetic field strength at each place by measuring the magnetic field strength for each rotation. A Hall element may be used instead of the MR element.

When a plurality of coils or MR elements are used as the position detecting sensor, holes are formed in the core material and connected to each other so that the distance between the elongated probe 15 and the endoscope 6 becomes a known length. It is possible to improve the accuracy of the obtained sensor position.

In the case of the probe 15 to be inserted into a narrow tubular space such as the channel 13 of the endoscope 6, it may be difficult to provide a position regulating member outside the sensor because it is desired to make the diameter as thin as possible. .

Therefore, a hole for connection may be formed in the detection portion on the surface to be connected, and for example, an MR element may be formed avoiding this hole. FIG. 90 (a) shows such a sensor. Each sensor 80 has MR elements 82a, 82b, and MR elements 82a, 82b on three surfaces of a cubic sensor support member 81, respectively.
82c is fixed by adhesion or the like, and is fixed to the connecting cord 83 at regular intervals.

In this case, in the center of the MR element 82a, as shown in FIG.
As shown in 0 (b), a hole 84 for inserting a cord is formed, and the connecting cord 83 allows the hole 84 to pass through. The cubic sensor support member 81 is also formed with a cord insertion hole 84 '(see FIG. 91). On the other hand, instead of forming the connecting hole 84 in the MR element 82a, the structure shown in FIG. 91 may be used.

In the sensor 80 'shown in FIG. 91, the sensor shown in FIG.
The MR element 82a and the MR element 82c of (a) are integrated to form an MR element 82c '. This MR element 8
2c 'is MR element parts 85a and 85c whose detection directions are orthogonal to each other.
Are formed on the same plane to form an MR element sensor for two-direction detection.

The surface adjacent to the surface provided with the MR element 82c 'and having no hole 84' is shown in FIG. 89 (a).
Similarly, the MR element 82b for detecting in one direction is attached. As described above, the MR element may not be provided on the surface of the sensor support member 81 required for connection.

Further, in FIG. 91, the MR element 82c '
Although the MR elements whose detection directions are orthogonal to each other are integrally formed on the same plane, it is obvious that two MR elements may be attached.

In order to position the sensor having such a structure, each sensor (80 or the like) is adhered to a fixing member such as the cord 83 with an adhesive as shown in FIG. good. Then, the tube is inserted into the tube 87 having a length shorter than the entire length of the fixing member, and for example, tension is applied to the fixing member to ensure the positioning, and FIG.
As shown in FIG.
It is only necessary to fill and harden the resin that has been cured to the state of having elasticity.

In order to perform the positioning, as shown in FIG. 93, the sensors 80 are placed at respective positions at predetermined intervals on cylindrical split molds 91 and 92, the split molds are closed, and an insulating resin (not shown) is poured. You may make it harden | cure by. In this case, the lead wire may be fixed to the cord 83, and the cord 83 may be slightly slackened, and a resin may be poured and cured so that the lead wire is not easily broken even when bent. .

Once cured, it is inserted into an extended mantle member or heat-shrinkable mantle member. In this way, by inserting into the jacket member, the strength as a probe can be secured, and the slippage when inserting into the channel can be secured by the surface treatment of the jacket member. Further, since the inside is filled with resin, buckling does not occur.

In the above-described embodiments and the like, the probe is inserted into the channel of the endoscope and the magnetic field generation source or the magnetic field detection sensor is arranged at a known position in the endoscope. The invention is not limited to this, and a magnetic field generation source or a magnetic field detection sensor may be built in the endoscope (for example, in the tip portion) or attached to the outer peripheral surface.

The endoscope is not limited to one having an image pickup device such as a CCD built therein, and may be an optical endoscope (for example, a fiberscope). Further, the magnetic field generation source or the magnetic field detection sensor is not limited to be arranged at a corner of the bed 4, but may be arranged around the bed 4 or at a position above the bed 4.

Further, the invention is not limited to the one in which the source coil or the sense coil is formed by using the uniaxial or triaxial coil, and the biaxial coil (one coil is removed from the triaxial coil is removed. Thing) may be used.

Also, a flexible printed circuit board or the like on which a coil is printed and formed into a tube shape so that it can be installed in a channel may be used as a probe for position detection or shape detection. Further, the coil thus formed by printing may be formed into a tube shape and applied to a tube forming a channel.

Further, a flexible printed circuit board or the like on which a coil is printed may be attached to the insertion portion by spirally winding it around the insertion portion of the endoscope and used for position and shape detection.

In the above-described embodiments and the like, the source coil as a magnetic field generating element is arranged so as to be flexible so as not to change its shape in the endoscope insertion portion to be inserted into the subject. Place the fixed one or the magnetic field generating element side at a known position outside the subject, and place a sense coil or magnetic resistance element as a magnetic field detecting element inside the insertion part so that its shape does not change. I explained the fixed one. The present invention is not limited to these, and can be applied to a rigid endoscope having a rigid insertion portion as described below.

When performing surgery or examination using a plurality of rigid endoscopes such as laparoscopic surgery, it is important to know the positional relationship of the tips of the rigid endoscopes accurately for smooth work. Play a role. Therefore, a probe with one source coil is fixed at two locations on a known portion near the eyepiece of the rigid endoscope existing within the position detection range, or two source coils are arranged at a known distance. The probe is fixed parallel to the central axis of the rigid endoscope.

When changing the direction of the distal end of a rigid endoscope, the vicinity of the eyepiece moves considerably, so the fixed portion of the probe needs to be resistant to bending, and the source coil needs to be solidified with an insulating member. However, other parts are made of a flexible material so that unnecessary tension is not applied when the rigid endoscope is moved.

Since the distance from the position of the source coil thus arranged to the tip of the rigid endoscope is known in advance, when the positions of the two source coils are detected,
It can be seen that the tip portion is located at the known distance on the straight line connecting the two source coils. In this case, since the source coil does not have to be provided inside the rigid endoscope, the rigid endoscope can be used for any rigid endoscope.

Furthermore, the present invention is not limited to the one inserted into a living body such as a human body, and is inserted into a lumen other than the living body, and to a test part (object) to be inspected, One of the magnetic field generating element and the magnetic field detecting element is arranged in a flexible probe, and the shape of the magnetic field generating element and the magnetic field detecting element are fixed by an insulating member so that the shape is not deformed. Also, it can be applied to a device arranged at a known position outside the test part. In addition, a magnetic field generating element and a magnetic field detecting element may be provided at a known position such as an insertion tool such as a medical instrument or device, or an insertion tool that is industrially inserted into a lumen such as the inside of a plant for inspection. One of them is fixed or attached with an insulating member, etc. so that the position of the flexible insertion part or the rigid insertion part inserted in the lumen or the position on the proximal side of the insertion tool can be detected or estimated. You can

In these cases as well, the magnetic field generated by the magnetic field generating element is detected by the magnetic field detecting element, and the magnetic field generating element or the magnetic field detecting element arranged at a known position is used as a reference to detect a portion to be inspected or a lumen. Detecting the position of the magnetic field generating element or the magnetic field detecting element in the probe or the insertion tool inside,
Furthermore, at least one or more positions of the probe or insertion tool can be detected, or the shape of the probe or insertion part can be estimated.
The estimated shape can be displayed. In the above-described embodiments and the like, a signal corresponding to the magnetic field strength is obtained by measurement, the reference data obtained in advance by measurement or the like is referred to, and the region in which the source coil 16i or the like exists inside the insertion portion 7 is present. Alternatively, the position is calculated, but the source coil 16 arranged in the insertion portion 6 or the like is calculated.
The position and inclination of i or the like may be derived.

Further, in the first embodiment, as the triaxial sense coil 22j, coils orthogonal to the triaxial are used to correct the variations in size and the like, but the same is applied to the source coil 16i and the like. You may do it. The entire shape of the endoscope may be displayed, but a portion of high interest (for example, only the tip portion) may be selected and displayed. Also, only the direction of the tip may be represented by an arrow or the like. Only the position of the coil for detection may be expressed by distinguishing it from the other interpolated and expressed endoscope shape.
A symbol such as x may be attached only to that portion. Set the threshold by the distance from the bed, and when it is far from that position, warm color,
When they are close to each other, they may be represented by cold colors, or vice versa, by changing saturation, lightness, hue, or the like.

Since the shape detected by this shape detecting device represents the process of inserting the endoscope, its time series data may be stored in a disk or the like. When one of the magnetic field generating element and the magnetic field detecting element is fixed to the flexible insertion portion of the endoscope, it may be fixed to a hard tip hard member at the tip of the insertion portion, or it can be bent freely. An insulating member or the like may be fixed to the hard bending piece that constitutes the part so that the shape thereof is not deformed. Further, the magnetic field detecting element or the magnetic field generating element arranged in the insertion portion may be formed so that at least a part of the outer surface forms a curved surface.

When the magnetic field generating element is an element which generates a magnetic field having a strong directivity in one axial direction in the space near the periphery, the magnetic field detecting element is a magnetic field in three orthogonal axial directions. It is desirable to use one that can detect the intensity component. When only one or two magnetic field strength components in the axial direction can be detected, this greatly depends on the relative orientation of the magnetic field generation element and the magnetic field detection element, and the detected magnetic field strength becomes extremely small. The level difference between the case and the case of increasing becomes large. Therefore, it is almost impossible to limit the range of the distance between the two elements from the detected signal to a narrow range.

On the other hand, if the magnetic field strength components in the three orthogonal axis directions can be detected, the dependence of the direction is smaller than that in the above case even in the case of a magnetic field having a strong directivity, and The range of the distance between the two elements can be limited to a relatively narrow range.

In the case of an element capable of detecting magnetic field strength components in three orthogonal directions as the magnetic field detection element, it is desirable that the detection sensitivity in each direction is as equal as possible. This is because in this case, the magnetic field strength can be obtained by the square root of the sum of squares of the magnetic field strength components. On the other hand, if the detection sensitivities in the respective directions are different, a correction is required to calculate the magnetic field strength, but the correction can be used. In addition,
Embodiments and the like formed by partially combining the above-described embodiments and the like also belong to the present invention. In addition to the above-described embodiments and the like, the present invention also includes the following supplementary notes (claims, objects, actions, effects, etc.).

[Additional Notes] 1. A flexible insertion part that can be inserted into the test part, and a magnetic field generation element that is disposed at a known position outside the test part and that generates a magnetic field in the surroundings by applying a drive signal and a magnetic field detection that detects the magnetic field. Used in combination with one of the elements, the other of the magnetic field generating element and the magnetic field detecting element, which is arranged in the insertion portion, and the other of the magnetic field generation element and the magnetic field detection element, An insertion part position detection probe having a fixing means for fixing the shape of the magnetic field generation element or the magnetic field detection element by an insulating member so that the position is known. While claim 1 is an apparatus for detecting the position of the insertion portion of an endoscope, claim 1 (hereinafter, simply abbreviated as 1) of this appendix is not limited to an endoscope, and The purpose is to accurately detect the position of a flexible insertion portion to be inserted into the inspection portion. In order to detect the position of the insertion part, the magnetic field generation element or magnetic field detection element is fixed in the insertion part with an insulating member, so the magnetic field generation element or magnetic field detection element is not deformed even if it is bent and inserted. To be done. The position of the magnetic field generation element or the magnetic field detection element in the insertion portion can be accurately detected by the magnetic field detection element or the magnetic field generation element arranged at a known position outside the inspected portion, and the position of the insertion portion can be detected by this detection. Can be accurately detected (estimated).

2. A flexible tube, a magnetic field generating element that is disposed in the tube and generates a magnetic field around by applying a drive signal, and a magnetic field detecting element that detects a magnetic field, and the shape of the magnetic field generating element or the magnetic field detecting element. A position detecting probe having a fixing means for fixing with an insulating member so as not to be deformed. 1 has an insertion part to be inserted into the test part, this probe may be inserted into the test part, or may be attached to a device or other device inserted into the test part or the like. The purpose is to accurately detect the position of the device or other device. Since it is a flexible tube, it can be easily attached to instruments and other devices. As in the case of 1, the position of the instrument or other device can be accurately detected. Also, since the magnetic field generating element or magnetic field detecting element is fixed in the tube,
It is easy to wash and disinfect after use.

3. The probe for position detection according to claim 2, wherein at least the magnetic field generating element of the magnetic field generating element and the magnetic field detecting element is composed of a coil. 4. The position detecting probe according to claim 2, wherein the tube can be inserted into a human body.

5. An insertion tool having a flexible insertion part that can be inserted into the test part, a magnetic field generation means having a magnetic field generation element that generates a magnetic field around by applying a drive signal, and a magnetic field generated by the magnetic field generation element. Magnetic field detecting means having a magnetic field detecting element for detecting, and one of the magnetic field generating element and the magnetic field detecting element arranged in the insertion part, via an insulating member, the shape of the magnetic field generating element or the magnetic field detecting element Fixing means for fixing so as not to deform, setting means for setting the other of the magnetic field generating element and the magnetic field detecting element to a known position outside the portion to be inspected, and outside the portion to be inspected or inside the insertion portion. Position estimating means for estimating the position of the magnetic field generating element or the magnetic field detecting element arranged in the insertion part with respect to a known position outside the portion to be inspected from the detection signal detected by the magnetic field detecting element of Equipped with a insertion portion position detecting device. The object of the present invention is to detect the position of the insertion part of the insertion tool of the endoscope including the endoscope to be inspected. And The action and effect are almost the same as those of the endoscope according to claim 1 replaced with the insertion tool.

6. In the insertion portion position detection device according to claim 5, the magnetic field generating means has a plurality of the magnetic field generating elements. 7. In the insertion portion position detecting device of claim 5, the magnetic field detecting means includes a plurality of magnetic field detecting elements. 8. The insertion portion position detecting device according to claim 5, wherein the one has a plurality of the magnetic field generating elements or the magnetic field detecting elements. 9. The insertion portion position detection device according to claim 8, wherein the position estimation means estimates a plurality of the positions, and further estimates a shape of the insertion portion to be inserted into the subject from the plurality of estimated positions. It has a shape estimating means. 10. The insertion portion position detection device according to claim 9, further comprising display means for displaying an image corresponding to the estimated shape of the insertion portion.

11. In the insertion portion position detecting device according to claim 7, the magnetic field generating element includes a coil formed by winding a conductive wire. 12. In the insertion portion position detecting device according to claim 7, the magnetic field detecting element includes a coil around which a conductive wire is wound or a magnetoresistive element whose resistance value changes depending on the magnetic field strength. 13. In the insertion portion position detecting device according to claim 7, the magnetic field generating element is composed of a coil in which a conductive wire is wound around a hard core member. 14. In the insertion portion position detecting device according to claim 7, the magnetic field detecting element is composed of a coil in which a conductive wire is wound around a hard core member. 15. In the insertion portion position detecting device of claim 7, the fixing means is an insulating adhesive that fixes the magnetic field generating element or the magnetic field detecting element.

16. In the insertion portion position detection device according to claim 7, the magnetic field detection element or the magnetic field generation element arranged in the insertion portion are connected by a fixing member having no elasticity in the axial direction of the insertion portion. 17. In the insertion portion position detection device according to claim 7, the magnetic field detection element or the magnetic field generation element arranged in the insertion portion is formed such that at least a part of the outer surface forms a curved surface. 18. In the insertion portion position detecting device according to claim 7, the magnetic field detecting element or the magnetic field generating element transmits a signal via a shielded cable. 19. In the insertion portion position detecting device of claim 6, the plurality of magnetic field generating elements are driven at different timings. 20. In the insertion portion position detection device of claim 6, the plurality of magnetic field generation elements are driven at different frequencies.

21. In the insertion portion position detection device according to claim 6, the plurality of magnetic field generation elements are driven simultaneously. 22. In the insertion portion position detecting device according to claim 20, the frequencies are set to frequencies that are not in an integral multiple relationship. 23. In the insertion portion position detecting device of claim 7, when the magnetic field generating element exhibits a transient response when driven by the drive signal, the transient response is set to the timing at which the detection signal detected by the magnetic field detecting element is taken in. Take in after delaying about the time. 24. In the insertion portion position detecting device according to claim 7, when the magnetic field generating element is driven, the magnetic field generating element is driven by a drive signal having a phase angle that reduces transient response characteristics to the drive signal of the magnetic field generating element. 25. The insertion part position detection device according to claim 7, wherein at least the magnetic field detection element of the magnetic field generation element and the magnetic field detection element are three coils wound so as to respectively have directivity in three orthogonal axial directions. Is a three-axis coil.

26. The insertion portion position detection device according to claim 25, wherein the position estimation means calculates the position of the magnetic field generation element or the magnetic field detection element in the insertion portion in consideration of the diameter of each coil of the triaxial coil. Have means. 27. The insertion part position detection device according to claim 7, wherein the position estimation means uses position information of at least three or more magnetic field detection elements or three or more magnetic field generation elements installed at known positions outside the subject. Then, a three-dimensional area in which the presence of each magnetic field generating element or magnetic field detecting element in the insertion portion is predicted is calculated. 28. The insertion portion position detecting device according to claim 25, wherein the position estimating means responds to a detection signal of the magnetic field detecting element,
It has reference information serving as a reference for estimating a distance range in which the distance between the magnetic field generation element and the magnetic field detection element exists, with reference to reference reference information. 29. The insertion portion position detection device according to claim 28, wherein the position estimation means considers the orientation of the magnetic field generation element and outputs a signal corresponding to the magnetic field strength that can be detected by the magnetic field detection element at a known distance from the magnetic field generation element. The data obtained by changing the known distance value for the maximum value and the minimum value of is set as the reference information. 30. In the insertion portion position detection device of claim 7, the magnetic field generation element or the magnetic field detection element in the insertion portion is connected to the position estimation means side by wire.

31. In the insertion portion position detection device according to claim 7, the magnetic field generation element or the magnetic field detection element is wirelessly connected to the position estimation means side. 32. The insertion portion position detection device according to claim 7, wherein the magnetic field detection element or the magnetic field generation element in the insertion portion is wirelessly connected to the position estimation means side, and DC power is generated from energy supplied wirelessly from outside. Have the means to do. 33. The insertion portion position detection device according to claim 10, further comprising marker display means for displaying a marker including a reference position on the display means. 34. The insertion part position detection device according to claim 33, wherein the marker display means is settable at an arbitrary position outside the subject, and the magnetic field generation element or the magnetic field detection device that forms the one provided in the insertion part is formed. It has a magnetic field generation element or a magnetic field detection element of the same type as the element. 35. The insertion portion position detection device according to claim 34, wherein the marker display means has the magnetic field generation element or the magnetic field detection element that can be installed in the operator's hand, and the marker display means is set at a set point set by the movement of the hand. Accordingly, a mark corresponding to the set point is displayed on the display means.

36. The insertion part position detecting device according to claim 10, wherein the display means has first and second image memories for displaying the shape of the insertion part, and image data stored in the first image memory. While outputting to the display means, the insertion portion shape estimation means stores in the second image memory image data during the calculation for estimating the shape of the insertion portion. 37. The insertion portion position detection device according to claim 10, wherein the display means has an image pattern storage means that stores a plurality of different image patterns for displaying an image corresponding to the insertion portion, and the display means An image pattern corresponding to the shape of the insertion portion estimated by the insertion portion shape estimation means is read from the image pattern storage means and displayed. 38. In the insertion portion position detecting device according to claim 6, the display means displays a rough shape of the subject by superimposing it on the image. 39. In the insertion portion position detecting device according to claim 7, the magnetic field detecting means extracts a signal component obtained by synchronous detection from a detection signal detected by the magnetic field detecting element using a reference signal based on the drive signal. To do. 40. In the insertion portion position detecting device according to claim 7, the insertion portion is formed of a member that does not affect a magnetic field generated by driving the magnetic field generation element. 41. The insertion portion position detection device according to claim 7, further comprising a mounting table on which the subject is mounted, wherein the mounting table is formed of a member that does not affect a magnetic field generated by driving the magnetic field generating element. To be done.

42. An insertion tool having a flexible insertion section that can be inserted into the lumen, a magnetic field generation unit having a magnetic field generation element that generates a magnetic field around by applying a drive signal, and a magnetic field generated by the magnetic field generation element. A magnetic field detecting means having a magnetic field detecting element for detecting, and one of the magnetic field generating element and the magnetic field detecting element arranged in the insertion tool, with an insulating member interposed between the magnetic field generating element or the magnetic field detecting element. Fixing means for fixing the shape so as not to deform, setting means for setting the other of the magnetic field generating element and the magnetic field detecting element at a known position outside the lumen, and outside the lumen or inside the insertion tool. Position estimating means for estimating the position of the magnetic field generating element or the magnetic field detecting element arranged in the insertion tool with respect to a known position outside the lumen from the detection signal detected by the magnetic field detecting element. Position detecting device. An object of the present invention is to accurately detect the position of an insertion tool that has an insertion portion that is inserted into a lumen. The position of the insertion tool can be accurately detected or estimated by accurately detecting the position of the magnetic field generation element or the magnetic field detection element in the insertion tool.

43. An endoscope having a flexible insertion part that can be inserted into a subject, and having an illumination light emitting means for emitting illumination light to the distal end side of the insertion part and an objective optical system for observing an illuminated subject. A magnetic field generating means having a magnetic field generating element for generating a magnetic field around by applying a drive signal, a magnetic field detecting means having a magnetic field detecting element for detecting a magnetic field generated by the magnetic field generating element, and arranged in the insertion portion. Fixing means for fixing one of the magnetic field generation element and the magnetic field detection element with an insulating member so that the shape of the magnetic field generation element or the magnetic field detection element is not deformed, the magnetic field generation element and the magnetic field detection element Installation means for setting the other of the two to a known position outside the subject, and to a known position outside the subject from the detection signal detected by the magnetic field detection element outside the subject or inside the insertion part The endoscope position detecting device having a position estimation means for estimating the position of the said magnetic field generator disposed in the insertion portion or the magnetic field detecting element. Although the configuration of the endoscope is described more specifically,
It has substantially the same purpose, action, and effect as the first aspect.

44. The endoscope insertion portion position detecting device according to claim 43, wherein the one has a plurality of magnetic field generating elements or magnetic field detecting elements, and is inserted into the subject from a plurality of positions estimated by the position estimating means. The insertion portion shape estimating means for estimating the shape of the insertion portion. 45. The endoscope insertion portion position detection device according to claim 44, further comprising display means for displaying an image corresponding to the shape of the insertion portion estimated by the insertion portion shape estimation means. 46. In the endoscope insertion portion position detection device according to claim 43, the magnetic field generation element or the magnetic field detection element is fixed to a hard tip hard member provided at the tip of the insertion portion. 47. The endoscope insertion portion position detection device according to claim 43, wherein the insertion portion has a bendable bending portion, and the magnetic field generation element or the magnetic field detection element is a hard bending piece forming the bending portion. Fixed. 48. The endoscope insertion portion position detection device according to claim 43, wherein the endoscope includes an image pickup device having a function of photoelectric conversion, and the magnetic field generation device is included in a non-image pickup device drive period in which the image pickup device is not driven. To drive. 49. The endoscope insertion portion position detection device according to claim 43, wherein the endoscope includes an image pickup device having a photoelectric conversion function, and drives the magnetic field generation device during an exposure period during which the image pickup device is exposed. . 50. The endoscope insertion portion position detection device according to claim 43, wherein the endoscope has a channel through which a treatment tool can be inserted, and one of the magnetic field generation element and the magnetic field detection element is in the channel. Is installed.

51. Generating the magnetic field by applying a drive signal for driving the magnetic field generating element to a magnetic field generating element installed in a flexible insertion part that can be inserted into the object or at a known position outside the object. A driving step of generating a magnetic field around the element, and a magnetic field detection element installed at a known position outside the subject or installed in the insertion section, the strength of which changes according to the distance from the magnetic field generation element. A magnetic field detection step of detecting a detection signal corresponding to the magnetic field, and the magnetic field generation element installed in the insertion portion from each known position of the magnetic field generation element outside the subject or the magnetic field detection element from the detection signal Or a position estimation step of estimating a three-dimensional position where the magnetic field detection element exists, the insertion portion position detection method. A method for detecting the position of the insertion portion to be inserted into the subject is claimed. 52. The insertion portion position detection method according to claim 51, wherein a plurality of the magnetic field generation elements or the magnetic field detection elements are arranged in the insertion portion, and the three-dimensional position estimated in the position estimation step is referred to in the subject. A shape estimating step of estimating the shape of the insertion portion inserted into the body, and a display step of displaying an image corresponding to the estimated insertion portion shape. The object is to display an image corresponding to the shape of the insertion part inserted into the subject. The shape of the insertion part inserted in the subject is estimated with reference to each three-dimensional position estimated in the position estimation step, and an image corresponding to the estimated insertion part shape is displayed. Therefore, the user can visually recognize the state of the insertion portion, and can easily perform work such as insertion of the insertion portion and other treatments.

53. In the insertion portion position detecting method of claim 51, when a plurality of the magnetic field detecting elements are arranged, the driving step applies the driving signal to each magnetic field generating element at different timings. 54. In the insertion portion position detecting method according to claim 51, wherein a plurality of magnetic field detecting elements are arranged, the magnetic field detecting step includes detecting signals corresponding to the strengths of the magnetic fields detected by the magnetic field detecting elements at different timings. Take in. 55. The insertion portion position detecting method according to claim 51, wherein the magnetic field detecting element has a function of detecting magnetic field strength components in three orthogonal axial directions, and the position estimating step is prepared in advance corresponding to the detection signal. It is calculated with reference to the reference data that the magnetic field detection element or the magnetic field generation element in the insertion portion exists at a three-dimensional position within a three-dimensional area between the minimum distance and the maximum distance.

56. The insertion portion position detection method according to claim 55, wherein the reference data can be detected at a known distance from the magnetic field generation element with respect to the magnetic field generated by the magnetic field generation element, in consideration of the orientation of the magnetic field generation element. It is data obtained by changing the known distance with respect to the maximum value and the minimum value of the detection signal of the magnetic field detecting element. 57. The method for detecting the position of an insertion portion according to claim 55, wherein the position estimating step comprises the three-dimensional region in which the magnetic field detection element or the magnetic field generation element in the insertion portion is present at a known position outside the subject. By performing the detection element or the magnetic field generation element respectively, a plurality of 3
It is calculated that there is a three-dimensional position in the common area of the dimensional area. 58. The insertion portion position detecting method according to claim 51, wherein the shape estimating step includes a connecting step of connecting each three-dimensional position corresponding to each magnetic field detection element or each magnetic field generation element in the insertion portion. 59. The insertion portion position detecting method according to claim 58, wherein the shape estimating step interpolates and connects the respective three-dimensional positions. 60. In the insertion portion position detecting method of claim 51, in the displaying step, an image corresponding to a projection shape obtained by pseudo-projecting the shape of the insertion portion onto a virtual screen facing a viewpoint is displayed.

61. It is the insertion part position detection method of Claim 60, Comprising: The said display step can set the position of the said viewpoint arbitrarily. 62. In the insertion portion position detecting method according to claim 60, the display step performs a hidden surface or hidden line processing that does not display a portion of the image corresponding to the projection shape pseudo-projected on the screen that is not visible from the viewpoint side. 63. The insertion portion position detection method according to claim 60, wherein the displaying step displays the image perspectively according to a distance value from a viewpoint. 64. In the insertion portion position detection method of claim 60, the display step performs a stereoscopic effect enhancement process for enhancing a stereoscopic effect when displaying the projected shape. 65. The insertion portion position detection method according to claim 64, wherein the stereoscopic effect enhancement processing is at least one of a color gradation, a brightness gradation, a saturation, and a hue according to a reflection model by a pseudo light ray.
Change the one to emphasize the three-dimensional effect.

66. In the insertion portion position detecting method of claim 51, when the image corresponding to the shape of the insertion portion is displayed, the display step displays the insertion portion in a pseudo manner as a polygonal column having a polygonal cross section. 67. The insertion portion position detecting method according to claim 66, wherein the displaying step paints the surface of the polygonal prism. 68. The insertion portion position detecting method according to claim 66, wherein the displaying step displays the polygonal column in a wire frame. 69. In the insertion portion position detection method of claim 51, when the image corresponding to the shape of the insertion portion is displayed in the display step, the insertion portion is pseudo-displayed as a connected polygon in which polygons are connected. 70. The insertion portion position detecting method according to claim 51, wherein the displaying step displays the image by performing a process corresponding to a designated command.

71. The method for detecting the position of an insertion portion in claim 70, wherein the command performs an affine transformation process. 72. The method for detecting the insertion portion position according to claim 71, wherein the command using the affine transformation rotates the image around at least one coordinate axis of three-dimensional Cartesian coordinates, or
The image is enlarged or reduced. 73. The method for detecting the position of an insertion portion in claim 72, wherein the command is displayed in a state corresponding to a case where the image is viewed from a predefined viewpoint position, and corresponds to a case when viewed from a viewpoint position registered by the user. Displayed in a state of being displayed, in a state corresponding to each of the divided screens when viewed from a designated viewpoint position, display of a comment input screen, changing the background color of the image, together with the image It corresponds to an instruction to perform at least one process of turning on / off the display of the marker, turning on / off the numerical value display of the three-dimensional position, and ending the program to be displayed. 74. In the insertion portion position detecting method of claim 52, in the case of displaying the image, the display step changes the display color of the image for each predetermined length of the insertion portion. 75. The insertion portion position detecting method according to claim 52, wherein the displaying step displays a reference surface such as an upper surface of a bed on which the subject is placed.

76. An insertion tool having a flexible insertion part that can be inserted into the subject, a first coil element provided in the insertion part, the shape of which is fixed by an insulating member, and a known position outside the subject. A second coil element arranged and a drive signal generating means for applying a drive signal to one of the first and second coil elements to generate a magnetic field around the one of the first and second coil elements; Magnetic field detection means for detecting a detection signal corresponding to a magnetic field formed at the other position of the other of the second coil elements, and the insertion based on a known position outside the subject from the detection signal. An insertion part position detection device, comprising: a position calculation means for calculating a three-dimensional position or a three-dimensional region in which the first coil element exists. 1 is a more specific configuration, and its purpose, action, and effect are almost the same as 1. 77. The insertion portion position detection device according to claim 76, comprising shape estimating means for estimating the shape of the insertion portion using information on the three-dimensional position or three-dimensional area, and an image corresponding to the estimated shape of the insertion portion. And image display means for displaying.

[0509]

As described above, according to the present invention, it is possible to set the environment on the mounting table so that the generated magnetic field is not affected, and the three magnetic field generating elements or magnetic field detecting elements are provided on the mounting table. The detection target area to be formed can be set, and the position of the insertion portion can be detected with higher accuracy.
Further, it is possible to correct the difference in the output characteristics due to the difference in the diameter of each coil of the triaxial coil, and to detect the position of the insertion portion with higher accuracy.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an endoscope system having a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an endoscope shape detection device.

FIG. 3 is an external view of an endoscope.

FIG. 4 is an overall configuration diagram of an endoscope device.

FIG. 5 is a cross-sectional view showing the configuration of the tip side of the probe.

FIG. 6 is a cross-sectional view showing the structure of a probe.

FIG. 7 is an explanatory diagram showing how the position of the source coil of the probe is detected using a sense coil.

FIG. 8 is a block diagram showing a specific configuration of the endoscope shape detection device.

FIG. 9 is a flowchart for explaining the operation of driving a source coil and detecting a signal by a sense coil.

FIG. 10 is a timing chart for explaining an operation of driving a source coil and detecting a signal by a sense coil.

FIG. 11 is an explanatory diagram showing how a plurality of sense coils provided around the bed detect the existence range of one source coil in the endoscope.

FIG. 12 is an explanatory diagram showing the shape of an equal magnetic field surface formed by a uniaxial coil.

FIG. 13 is an explanatory diagram showing how position correction is performed based on inclination.

FIG. 14 is an explanatory diagram showing an endoscope-shaped output image displayed on the monitor screen.

FIG. 15 is a flowchart showing the processing contents of the endoscope shape detection device.

FIG. 16 is a characteristic diagram showing a graph in which the values of the maximum magnetic field strength and the minimum magnetic field strength detected by the sense coil at a known distance between the sense coil and the source coil in the shield room are measured by changing the distance.

17 is an explanatory diagram of a measuring method and the like for obtaining the data of FIG.

FIG. 18 is a comparative diagram showing that the measured values in the shielded room and in the living room are almost the same.

FIG. 19 is a flowchart of magnetic field strength calculation processing.

FIG. 20 is a flowchart of keyboard input processing.

FIG. 21 is a flowchart of command processing.

FIG. 22 is a flowchart of scope image depiction processing.

FIG. 23 is a flowchart of a scope image depiction process in an n-square prism model.

FIG. 24 is a flow chart of n-prism model construction.

FIG. 25 is an explanatory diagram of origin movement and the like in constructing an n-square prism model.

FIG. 26 is an explanatory diagram of a process in which a vector perpendicular to a vector parallel to the y-axis in the n-prism model construction is rotated by a constant angle to create n-prism data.

FIG. 27 is an explanatory diagram showing a state in which n-prism model data is generated by inversely converting the original vector.

FIG. 28 is an explanatory diagram showing restrictions when generating n-square prism model data.

FIG. 29 is an explanatory diagram showing shaft rotation by affine transformation.

FIG. 30 is an explanatory diagram of changing the viewpoint change to the rotation of the world coordinate system.

FIG. 31 is an explanatory diagram showing how projection conversion is performed from three-dimensional coordinates to two-dimensional coordinates.

FIG. 32 is an explanatory diagram of a world coordinate system and the like.

FIG. 33 is an explanatory diagram of processing for displaying a stereoscopic image and a coordinate system adopted.

FIG. 34 is a flowchart of hidden line processing in an n-square prism model.

FIG. 35 is an explanatory diagram of flicker prevention processing.

FIG. 36 is a flowchart showing a shading process using colors.

FIG. 37 is a flowchart of shading processing using colors.

FIG. 38 is a flow chart of shading processing using luminance and saturation.

FIG. 39 is a flow chart of an n-square prism model using a wire frame.

FIG. 40 is an explanatory view showing a display example of an endoscope shape.

FIG. 41 is a flow chart in the case of displaying by an n-sided polygon connection model.

FIG. 42 is a flow chart of drawing processing in the n-sided polygon connection model.

FIG. 43 is an explanatory diagram showing an example of display by wire frame display.

FIG. 44 is a block diagram showing the overall configuration of an endoscope shape detection device of a first modified example of the first embodiment.

FIG. 45 is a timing chart for explaining the operation.

FIG. 46 is an explanatory diagram in which each cable of the source coil and the sense coil is shielded.

FIG. 47 is an explanatory diagram showing a state in which sense coils are arranged at four positions on the bed.

FIG. 48 is an explanatory view of the action of changing the detection range by increasing or decreasing the drive current in the second modified example of the first embodiment.

FIG. 49 is a block diagram showing the overall configuration of an endoscope shape detection device according to a second embodiment of the present invention.

FIG. 50 is a block diagram showing a more specific configuration of the endoscope shape detection device according to the second embodiment.

FIG. 51 is a flowchart showing processing of magnetic field generation and magnetic field detection according to the second embodiment.

FIG. 52 is an explanatory diagram showing a monitor screen that displays the shape of an endoscope and the like.

FIG. 53 is an overall configuration diagram of an endoscope system including a third embodiment of the present invention.

FIG. 54 is a block diagram showing a configuration of an endoscope shape detecting device according to a third embodiment.

FIG. 55 is a diagram showing a sensor formed of a magnetoresistive element, its equivalent circuit, and characteristics.

FIG. 56 is an explanatory diagram showing a relationship between a sensor and a source according to the third embodiment of the present invention.

57 is an explanatory diagram showing a data table of sensor A. FIG.

FIG. 58 is an explanatory diagram showing that the source position is determined from the spatial coordinate group corresponding to the output data.

59 is an explanatory diagram showing a state in which the source position determined in FIG. 58 is displayed.

FIG. 60 is a block diagram showing the configuration of an endoscope shape detection device according to a fourth embodiment of the present invention.

FIG. 61 is a block diagram showing the configuration of an endoscope shape detection device according to a fifth embodiment of the present invention.

FIG. 62 is an overall configuration diagram of an endoscope system including a sixth embodiment of the present invention.

FIG. 63 is an explanatory diagram in which the CCD drive signal period and the drive signal period do not overlap each other.

FIG. 64 is an overall configuration diagram of an endoscope system including a seventh embodiment of the present invention.

FIG. 65 is an explanatory diagram for detecting the position of a patient.

FIG. 66 is an explanatory diagram for performing position detection and shape detection driving in time division.

FIG. 67 is a flowchart showing the contents of processing in the eighth embodiment of the present invention.

FIG. 68 is a flowchart showing the contents of processing in a modification of the eighth embodiment.

FIG. 69 is an explanatory diagram of a processing operation according to the ninth embodiment of the present invention.

FIG. 70 is an explanatory diagram of a texture to be pasted.

FIG. 71 is an explanatory diagram of an image and the like displayed according to the tenth embodiment of the present invention.

FIG. 72 is a flowchart of a process of displaying a color by changing the color for each constant length according to the tenth embodiment.

FIG. 73 is a configuration diagram of an endoscope shape detection device according to an eleventh embodiment of the present invention.

FIG. 74 is a flowchart showing the processing contents of generating a background image according to the eleventh embodiment.

FIG. 75 is a block diagram showing the configuration on the probe side in the twelfth embodiment of the present invention.

FIG. 76 is a more specific configuration diagram of FIG. 75.

FIG. 77 is a configuration diagram of a reference signal generation circuit and the like.

FIG. 78 is a configuration diagram of a magnetic field generation unit according to a modification of the twelfth embodiment.

FIG. 79 is a view showing a device for detecting a palm position according to the thirteenth embodiment of the present invention.

FIG. 80 is an explanatory diagram showing a display example of a monitor screen.

FIG. 81 is a configuration diagram of an endoscope shape detection device according to a first modified example of the thirteenth embodiment.

FIG. 82 is a flowchart showing the processing contents of marker setting by operating the operation panel of the first modification.

FIG. 83 is a view showing a device for detecting a palm position according to a second modification of the thirteenth embodiment.

FIG. 84 is an explanatory view showing a plane or the like formed by three source coils of the second modification.

FIG. 85 is a flowchart showing the operation of marker display in the second modification.

FIG. 86 is a view showing a palm position detecting device according to a third modified example of the thirteenth embodiment.

FIG. 87 is an explanatory view showing a plane and the like formed by two source coils of a third modification.

FIG. 88 is a flowchart showing the operation of marker display in the third modification.

FIG. 89 is a perspective view showing an example in which a magnetic resistance element and a step motor are used to form means for detecting a magnetic field in three axial directions.

FIG. 90 is a view showing a sensor in which magnetoresistive elements are connected and a magnetoresistive element in which holes for connection are formed.

FIG. 91 is a view showing a sensor in which magnetoresistive element portions having different detection directions are provided on the same surface.

FIG. 92 is an explanatory diagram showing a method of positioning a sensor and the like.

FIG. 93 is an explanatory view showing a state of performing positioning using a cylindrical split mold.

[Explanation of symbols]

1 ... Endoscope system 2 ... Endoscopic device 3 ... Endoscope shape detection device 4 ... bed 5 ... Patient 6 ... Endoscope 7 ... insertion part 11 ... Video processor 12 ... Color monitor 13 ... Channel 15 ... probe 16i ... Source coil 20 ... Adhesive 21 ... Shape detection device body 22j ... 3-axis sense coil 23 ... Monitor 24 ... Source coil drive unit 26 ... Detector 30 ... Shape calculation unit 31 ... Position detection unit 32 ... Shape image generation unit 33 ... Monitor signal generator 34 ... System control unit 35 ... Operation panel

Continued front page    (72) Inventor Tsukasa Ishii             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Masanao Hara             6-53, 1-53, Hatsudai, Shibuya-ku, Tokyo             Within Npas Systems Co., Ltd.

Claims (2)

[Claims] 1. A flexible magnetic insertion part that can be inserted into a subject, and one of a magnetic field generation element for generating a magnetic field and a magnetic field detection element for detecting the generated magnetic field is provided inside the outer insertion part. An insertion tool, a mounting table on which the subject can be placed, and at least three other ones of the magnetic field generation element and the magnetic field detection element are provided; and a magnetic field generated by the magnetic field generation element. The position of the magnetic field generation element or the magnetic field detection element provided in the insertion part of the insertion tool for the magnetic field generation element or the magnetic field detection element provided on the mounting table from the detection signal detected by the magnetic field detection element And a position estimating means for estimating, wherein the mounting table is formed of a member that does not affect a magnetic field generated by driving the magnetic field generating element, and is detected at a site where the subject is mounted. Insertion portion position detecting device, wherein said at least three magnetic field generator or the magnetic field detection element be disposed so as elephants region. 2. At least the magnetic field detecting element is a triaxial coil having three coils wound so as to have directivity in three orthogonal axis directions, and the position estimating means is the triaxial coil. The insertion portion position detection device according to claim 1, further comprising a correction unit that corrects a difference in output characteristics due to a difference in diameter of each coil.