JP2001299718A - Method and instrument for imaging localization of nerve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of imaging the localization of a nerve that helps very easily keep track of the localization of the nerve in a biological tissue and an inexpensive and compact device for imaging the localization of the nerve. SOLUTION: A stimulating current is generated by stimulating a nerve from a skin surface A by passing electricity thereto, the amount of current attenuated by the electrical resistance of somatic tissues is measured by three or more reception electrodes 7, 8 and 9 on a body slice W arranged in a contacted state on a skin surface B at a site to be examined of a subject, actual measurement data of the amount of current attenuated are converted to the distance or the direction from the positions X, Y and Z of the reception electrodes 7, 8 and 9 to the never on the basis of the positions X, Y and Z of the reception electrodes 7, 8 and 9 on the measurement skin surface B after correction for determining the relation between the value of the amount of current measured and the localization N of the nerve, the localization N of the nerve is computed and specified, and the localization N of the nerve can be displayed in real time on the screen 4a of a monitor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for imaging nerve positions for accurately grasping the positions of internal nerves before performing incision surgery on a body such as an arm or a leg.

[0002]

2. Description of the Related Art At present, a computer tomography apparatus (CT) is used.
Scanner) is provided and used. Depending on the purpose of diagnosis, MRI (magnetic resonance imaging), X-ray CT,
Ultrasound diagnostic devices and the like are used. In these devices, the difference in the transmittance of X-rays such as bones, muscles, and adipose tissue in X-ray CT, and the emitted ultrasonic waves hit the bones, muscles, etc. This is a system that analyzes the difference between the returning reflected waves with a computer and visualizes it. Further, in an ultrasonic diagnostic apparatus, a technique of capturing the flow of blood flowing in a blood vessel by using the Doppler effect has been implemented.

[0003] However, it is difficult to distinguish nerves like bones and muscles with an ultrasonic diagnostic apparatus, and since there is nothing flowing like blood vessels, it is difficult to distinguish them from surrounding physical tissues. Because there was no sensing means,
It was extremely difficult to capture that position on the tomographic image from the outer surface. In MRI and CT, a thick nerve can be displayed as a shadow, but it cannot be mechanically identified whether or not the nerve is a nerve. Actually, from the projected image, it is determined whether it is a nerve,
Specialized doctors will do this based on the shape and position.

[0004] Although it is considered that the sensitivity of MRI can be increased and the position of nerves can be grasped to some extent from the accumulation of anatomical data, the MRI itself is extremely large-scale and dedicated to hospitals. However, there was a problem that a large space was required to secure one room, and the installation cost was huge.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a method of imaging a nerve position, in which only a nerve existence position in a living tissue can be grasped as an image very easily, It provides a compact device for performing the method.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for stimulating the same nerve at a position considerably distant from a nerve at a desired body position from a skin surface A at a position distant from the same nerve. To generate a stimulation current in the nerve, and attenuated by the electrical resistance of the body tissue at three or more receiving electrodes 7, 8, and 9 on the body ring section W arranged in contact with the skin surface B of the body part to be obtained. The decay current amount is measured, and the data of the actual measurement value of the decay current amount is calculated in advance based on experiments based on the positions X, Y, and Z of the receiving electrodes 7, 8, and 9 on the measured skin surface B. Correction is performed to determine the relationship between the value of the measured current amount and the nerve existence position N, and the distance or direction from the position X, Y, Z of each receiving electrode 7, 8, 9 to the nerve is converted to the nerve existence position N. Is calculated in one place, and the screen 4 of the monitor 4
A neural position imaging method characterized in that the positions X, Y, and Z of the respective receiving electrodes on the sliced body plane W and the nerve presence position N can be simultaneously displayed on a.

Further, in the method having the above configuration, the specification of the nerve existence position N is converted into distances a, b, and c and is derived from only the distance ratio by a three-point survey method.

Further, in the method having the above-mentioned configuration, the positions of the receiving electrodes X, Y, and Z are moved while being in contact with the skin surface B, and the movement is continuously measured. The nerve presence position N is displayed as a continuous line in a three-dimensional stereoscopic image of the body.

Further, in the method having the above configuration, a correction method for determining the relationship between the value of the measured current amount and the nerve existence position N calculated in advance based on an experiment is a method of correcting the measured value from the reference correction value. It is characterized in that it is a correction by back calculation.

Further, in order to carry out the nerve position imaging method of each of the above constitutions, the same nerve at a position considerably apart from the nerve at the body position desired to be obtained is applied to the skin surface A at a position far from the nerve by the stimulation electrode. An energizing stimulator 1 for generating a stimulating current to the nerve by energizing the stimulus, and three or more receiving electrodes 7, 8, 9 that can be placed in contact with the skin section B of the body part to be obtained on the sliced surface W of the body. Receiving terminal device 2 and each receiving electrode attenuated by the amount of electrical resistance of the body tissue with reference to the fixed position X, Y, Z of each receiving electrode on the skin surface B on the sliced body surface W taken in earlier. The data of the currents sent from 7, 8, and 9 are processed and processed, and the fixed positions X, Y, and Z of each receiving electrode are processed.
Specifying operation device 3 for specifying a nerve existence position N with respect to
And a monitor 4 for displaying the processed data from the position specifying arithmetic unit 3, wherein the nerve existing position N in the figure of the body cross section W can be graphically displayed on the monitor 4 screen. Is a nerve position imaging device.

Further, in the apparatus having the above configuration, the scanner 11 of the ultrasonic diagnostic apparatus 11
And the ultrasonic transmitting / receiving surface 1 of the scanner 12
2a is provided with receiving electrodes 7, 8, 9 so that a tomographic image and a nerve existence position N are simultaneously displayed on the screen of the dual-purpose monitor 4 with the ultrasonic diagnostic apparatus 11. Things.

Still further, in the apparatus having the above-mentioned configuration, three or more of the receiving electrodes 7, 8, and 9 are of a desktop type 5.

Still further, in the apparatus having the above-mentioned structure, three or more of the receiving electrodes 7, 8, and 9 are provided with a handy type 6.
It is characterized by being.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to a conceptual diagram shown in FIG. According to the present invention, a stimulation current is generated in the nerve n by stimulating electricity from the skin surface A of the same nerve at a position considerably separated from the nerve N at the desired body position. The electrical resistance of the body tissue is determined by three or more receiving electrodes 7, 8, and 9 on the body ring-shaped surface W (indicated by a two-dot chain line substantially ellipse) arranged in contact with the skin surface B of the body part to be obtained. The amount of each decay current attenuated by is measured.

[0015] The position of the body position to be obtained, which is far away from the nerve, is a distance that can measure the amount of each attenuation current and grasp the difference in distance. Although it depends on the sensitivity of the receiving electrodes 7, 8, and 9, in order to avoid interference between the stimulating current and the receiving current, a distance equal to or longer than the distance to a position where there is a possibility of existence, that is, a width corresponding to the width of the measurement site. It is preferable that the distance is longer than the distance. Further, in order to avoid interference between the stimulation current and the reception current, a method in which a band-shaped conductive material 14 is arranged in contact with and connected to the ground 13 so as to separate them, as shown in FIG.

Then, based on the fixed positions X, Y, Z of the receiving electrodes 7, 8, 9 on the measured skin surface B, data of the actually measured value of the attenuation current is calculated in advance based on an experiment. Correction is performed to determine the relationship between the value of the current amount and the nerve presence position N, and the positions X, Y,
The distance or the direction from Z to the nerve n is converted to specify the nerve existence position N at one location, and the respective receiving electrodes on the (cross-sectional plane) body slice plane W captured on the screen 4a of the monitor 4 are displayed. , And the nerve existence position N can be displayed simultaneously.

In this method, there is a method of specifying the nerve existence position N by converting the distances into distances a, b, and c and deriving the distances only from the distance ratios by a three-point survey method. It is also possible to use a three-point survey method based only on the angle ratio.

The positions of the receiving electrodes X, Y, and Z are moved while being in contact with the skin surface B, and the movement is continuously measured, and the nerve existence position N specified by the measurement is continuously measured. The position can be displayed in the three-dimensional stereoscopic image of the body as the drawn line.

In the above method, the correction method for determining the relationship between the value of the measured current amount and the nerve existence position N, which is calculated in advance based on an experiment, is a correction method by back-calculating the actually measured value from the reference correction value. Is possible.

Further, in order to carry out the nerve position imaging method of each of the above constitutions, as shown in FIG. 2, a skin surface A corresponding to the same nerve at a position considerably apart from the nerve n at the body position to be obtained. A current stimulating device 1 for generating a stimulating current to the nerve n by stimulating the current with a stimulating electrode;

Three or more receiving electrodes 7, which can be placed in contact with the skin surface B of the body part to be obtained on the sliced surface W of the body,
A receiving terminal device 2 provided with 8, 9;

The body slice section (tomographic plane) W taken in earlier
Fixed position X, Y, Z of each receiving electrode on upper skin surface B
The data of the current sent from each of the receiving electrodes 7, 8, and 9 attenuated by the amount of electrical resistance of the body tissue is processed based on the data to specify the nerve existence position N for the positions X, Y, and Z of each receiving electrode. A position specifying arithmetic device 3

A monitor 4 for displaying the processed data from the position specifying arithmetic unit 3 is provided. Then, on the monitor 4 screen, the nerve existence position N in the figure of the body cross section W can be graphically displayed.

In addition, the scanner 11 of the ultrasonic diagnostic apparatus 11 is integrated with the receiving terminal device 2, and the receiving electrodes 7, 8, 9 are provided on the ultrasonic transmitting / receiving surface 12a of the scanner 12.
May be provided. Then, the tomographic image and the nerve location N are simultaneously displayed on the screen of the dual-purpose monitor 4 with the ultrasonic diagnostic apparatus 11. Then, the position can be more reliably specified by superimposing the tomographic images obtained by the ultrasonic diagnostic apparatus 11.

Also, three or more receiving electrodes 7, 8, 9
Can be a desktop type 5 (shown in FIG. 3) and a handy type 6 (shown in FIG. 2) having a grip portion 10. The figure shows the case where the number of the receiving electrodes 7, 8, and 9 is three, but even if the number of the receiving electrodes is more than three, the nerve existing position N
Is possible because it matches at one point of (N) in the sign section shown in FIG. Rather, the more the number of receiving electrodes,
If a numerical value that is far apart is generated, the numerical value can be excluded from the calculation and specified, so that the accuracy can be improved.

[0026]

[Experimental Example 1] In the reception of the stimulation current, an experiment was conducted to confirm that an attenuation difference appeared as an energy amount of the current in the measured value depending on the transmission distance of the body tissue. 4, 5, and 6
Shows the experimental results, and shows the measured values (shown on the right side of the figure) and the actually measured waveforms (shown on the left side of the figure). The distance of the receiving electrode from the nerve was measured just above the nerve (shown in FIG. 4), 50 mm (shown in FIG. 5), 150 mm
(Shown in FIG. 6).

The average value of the actually measured values of the energy amount (unit: μVms) is calculated as follows. 0 mm 12.179 μVms directly above the nerve 50 mm 11.926 μVms 150 mm 11.226 μVms When it is graphed, it becomes FIG. 7. As can be seen from FIG. 7, it can be confirmed that the energy amount (unit: μVms) appears in inverse proportion to the distance from the nerve.

Then, based on this, for example, the major axis 7
In a human arm with a short diameter of 6 cm and a short diameter of 6 cm,
When the amount of energy obtained at each receiving electrode is: receiving electrode 7 = 1.210 μVms, receiving electrode 8 = 1.205 μVms, receiving electrode 9 = 1.200 μVms, the distance from the receiving electrode to the nerve β the distance from the receiving electrode to the nerve Distance from the receiving electrode to the nerve

Α = 30 mm β = 35 mm γ = 40 mm This calculation is performed by the position specifying arithmetic unit 3 (an arithmetic unit of a computer). That is, as shown in FIG. 1, the X points having the same distance are specified and output and displayed on the screen of the monitor 4.

[0030]

[Experimental example 2] Separately, the distance of the receiving electrode from the nerve was
0mm, 10mm, 20mm and 30m just above the nerve
m was set at intervals. As a result, the average value of the actually measured energy amounts was as follows.

[0031] Immediately above the nerve 0mm 1.244μVms 10mm 0.721μVms 20mm 0.490μVms 30mm 0.286μVms FIG. Also in FIG. 8, it can be confirmed that the energy amount (unit: μVms) appears in inverse proportion to the distance from the nerve.

Then, on the basis of this, for example,
In a human arm having a major axis of 6 cm and a minor axis of 5 cm, when measured, the amount of energy obtained at the receiving electrode was as follows: receiving electrode 7 = 0.50 μVms, receiving electrode 8 = 0.40 μVms, and receiving electrode 9 = 0.20 μVms. If

Α = 20 mm β = 24 mm γ = 35 mm This calculation is performed by the position specifying arithmetic unit 3 (an arithmetic unit of a computer). That is, as shown in FIG. 1, the X points having the same distance are specified and output and displayed on the screen of the monitor 4.

In the above experimental example, the method of replacing the received energy amount (μVms) with the distance has been described. However, the X point corresponding to the angle (direction) of each receiving electrode from the position X, Y, Z is converted. Is also possible.

[0035]

As described above, the present invention focuses on the fact that nerves in living tissue are current-carrying bodies, and utilizes the fact that the current flowing through a living body is attenuated with distance, and the amount of the current is reduced. By correcting the actually measured value using the position specifying arithmetic unit 3, each of the receiving electrodes 7, 8, and 8 on the measured skin surface B is corrected.
It is possible to specify the nerve existence position N on the screen 4a of the monitor 4 based on the positions X, Y, and Z of the nine. The overall apparatus of the present invention is extremely compact as compared with MRI, and can be easily carried. Another advantage is that it can be provided at extremely low cost as compared with such a large-scale device.

And, until now, in surgery,
It was said that the location of the nerve with a large individual difference could not be known unless it was actually opened.However, this makes it possible to easily confirm the location of the nerve in real time before inserting a scalpel, so treatment before incision He was able to make decisions and doctors could start the surgery with confidence.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is a perspective view showing the device of the present invention.

FIG. 3 is a perspective view showing another form of the apparatus.

FIG. 4 is an actual measurement diagram in which the distance to the nerve is directly above and an explanatory diagram of the actual measurement values.

FIG. 5 is an actual measurement diagram in which the distance to the nerve is 50 mm and an explanatory diagram of the actual measurement values.

FIG. 6 is an actual measurement diagram in which the distance to the nerve is 150 mm and an explanatory diagram of the actual measurement values.

FIG. 7 is a graph showing experimental results of Experimental Example 1.

FIG. 8 is a graph showing experimental results of Experimental Example 2.

FIG. 9 is a block diagram of another embodiment of the device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conduction stimulating device 2 receiving terminal device 3 current receiving arithmetic measuring device 4 monitor 5 desktop-type receiving terminal device 6 handy type receiving terminal device 7 receiving electrode 8 receiving electrode 9 receiving electrode 10 grip section 11 ultrasonic diagnostic apparatus 12 scanner 12a The ultrasonic transmitting and receiving surface of the scanner 13 Ground 14 Conductive material α Distance from receiving electrode to nerve β Distance from receiving electrode to nerve γ Distance from receiving electrode to nerve

Claims (8)

[Claims] 1. A skin surface at a position far away from the same nerve at a position considerably away from a nerve at a body position to be obtained (A)
To stimulate the nerves to generate a stimulation current, and to receive the body with three or more receiving electrodes (7,8,9) on the body ring section (W) placed in contact with the skin surface (B) of the body part to be obtained The amount of each attenuated current attenuated by the electrical resistance of the tissue was measured, and each receiving electrode (7,
The relationship between the value of the measured current amount and the nerve existence position (N) calculated based on experiments in advance, based on the actual measured value of the attenuation current amount based on the position (X, Y, Z) of (8, 9). Is corrected, and the position (X, Y, Z) of each receiving electrode (7, 8, 9) is converted into the distance or direction to the nerve, and the nerve existence position (N) is calculated and specified at one place. Then, on the screen (4a) of the monitor (4), the position (X, Y, Z) of each receiving electrode and the nerve existence position (N) on the sliced body plane (W) can be simultaneously displayed. A nerve position imaging method, characterized in that: 2. The nerve position image according to claim 1, wherein the specification of the nerve existence position (N) is converted into a distance (a, b, c) and is derived from only the distance ratio by a three-point survey method. Method. 3. The position of the receiving electrode (X, Y, Z) is moved while keeping it in contact with the skin surface (B), the movement is continuously measured, and the nerve existence position specified by the measurement is measured. 3. The method according to claim 1, wherein (N) is displayed as a continuous line in a three-dimensional image of the body. 4. The nerve position imaging method according to claim 1, wherein the correction method is a correction by back calculation of an actually measured value from a reference correction value. 5. A skin surface at a position far away from the same nerve at a position considerably away from a nerve at a body position to be obtained (A)
Stimulating device (1) for generating a stimulating current to nerves by stimulating current from the stimulation electrode with stimulating electrodes, and three points that can be placed in contact with the skin surface (B) of the body part to be obtained on the sliced surface (W) of the body A receiving terminal device (2) having the above-mentioned receiving electrodes (7, 8, 9), and a fixing position (X, Y) of each receiving electrode on the skin surface (B) on the body slice surface (W) taken in earlier. ,
The data of the current sent from each of the receiving electrodes (7, 8, 9) attenuated by the amount of electrical resistance of the body tissue with reference to Z) is processed and processed, and the fixed position (X, Y, Z) of each receiving electrode is calculated. And a monitor (4) for displaying processed data from the position specifying processor (3) for specifying the nerve existence position (N) with respect to the monitor (4). The nerve position according to any one of claims 1 to 4, wherein the position (N) of the nerve in the figure of the cross-section of the body (W) can be displayed graphically. Position imaging device. 6. A scanner (12) of an ultrasonic diagnostic device (11) is integrated with a receiving terminal device (2), and receiving electrodes (7, 8) are provided on an ultrasonic transmitting / receiving surface (12a) of the scanner (12). , 9), and the ultrasonic diagnostic apparatus (1)
6. The nerve position imaging apparatus according to claim 5, wherein the tomographic image and the nerve existence position (N) are simultaneously displayed in the screen of the monitor (4) which is combined with (1). 7. The receiving electrodes (7, 8, 9) of three or more points,
The nerve position imaging device according to claim 5 or 6, wherein the device is a desktop type (5). 8. The receiving electrode (7, 8, 9) of three or more points,
6. A handy type (6).
Or the nerve position imaging device according to 7.