JP6961862B2 - In-vivo magnetic substance detector - Google Patents

Description

The present invention mainly relates to an in-vivo magnetic substance detecting device for searching for the presence or absence of a magnetic substance in the human body and an in-vivo magnetic substance detecting method.

Conventionally, there is an in-vivo magnetic substance detecting device capable of detecting the presence or absence of a magnetic substance in the body during surgery. For example, Patent Document 1 below discloses a magnetic fluid detection device that detects a magnetic fluid in a lymph node by using the difference between two magnetic sensors.

Japanese Unexamined Patent Publication No. 2004-121667

However, in the above-mentioned magnetic fluid detection device, the change in the magnetic field around the probe is detected and notified even before the probe is placed in the portion where the magnetic fluid is detected in order to detect the change in the extremely small magnetic field (magnetic flux density). Therefore, there is a problem that the reliability of detection of magnetic fluid is low.

The present invention has been made to address the above problems, and an object of the present invention is to provide an in-vivo magnetic substance detecting device and an in-vivo magnetic substance detecting method capable of improving the reliability of the detection accuracy of the magnetic substance.

In order to achieve the above object, the feature of the present invention is from a detection rod formed in a rod shape and inserted into the body, and an electric signal provided at the tip of the detection rod and corresponding to a change in surrounding magnetic energy. The first magnetic sensor that outputs the first detection signal and the first magnetic sensor in the detection rod are arranged at positions separated from each other so as not to be affected by the magnetic energy of the first magnetic sensor. The second magnetic sensor that outputs the second detection signal consisting of the electric signal according to the change, and the difference between the first detection signal and the second detection signal are eliminated to eliminate the difference between the first detection signal and the second detection signal. The total detection value is calculated using the detection correction value calculation means for calculating and storing the detection correction value for correcting the above values to substantially the same value, the first detection signal, the second detection signal, and the detection correction value. A magnetic substance detecting means for detecting the presence or absence of a magnetic substance around the tip of the detection rod based on this comprehensive detection value, a notifying means for notifying the detection of the magnetic substance by the magnetic substance detecting means, and a manual operation by the user. The purpose is to provide an operator for operating the magnetic material detecting means and the notifying means, respectively.

In this case, when the operator puts the magnetic body detecting means and the notifying means in the operating state, the other is in the operating state when one of the magnetic body detecting means and the notifying means is in the operating state and the other is in the stopped state. Or, when both the magnetic substance detecting means and the notification means are in the stopped state, both are put into the operating state.

According to the feature of the present invention configured as described above, the in-vivo magnetic substance detection device corrects the difference between the first detection signal output from the first magnetic sensor and the second detection signal output from the second magnetic sensor. It is provided with an operator for acquiring the detection correction value to be used and for operating the magnetic substance detecting means and the notification means in the acquired state of the detection correction value. For this reason, the magnetic substance detection device in the body detects the magnetic substance only when the operator is operated. Therefore, when the detection of the magnetic substance is unnecessary, the magnetic substance is not detected and the detection accuracy of the magnetic substance is reliable. Can be improved. Further, in this in-body magnetic substance detection device, a detection correction value for correcting the difference between the first detection signal output from the first magnetic sensor and the second detection signal output from the second magnetic sensor is acquired. Therefore, it is possible to correct the variation and error in the detection accuracy between the first magnetic sensor and the second magnetic sensor, and it is possible to improve the reliability of the detection accuracy of the magnetic material.

Another feature of the present invention is that in the in-vivo magnetic substance detecting device, the magnetic substance detecting means stores the comprehensive detection value when the operator is operated as a reference comprehensive detection value and subsequently acquires the comprehensive detection value. The purpose is to detect the presence or absence of a magnetic substance around the tip of the detection rod using the value and the reference comprehensive detection value.

According to another feature of the present invention configured in this way, the in-vivo magnetic material detection device stores the total detection value when the operator is operated as the reference total detection value, and the reference total detection value and thereafter. Since the presence or absence of the magnetic material is detected using the acquired comprehensive detection value, when there is a difference between the magnetic field state at the time when the correction value calculation means calculates the detection correction value and the current magnetic field state, that is, Even when the detection correction value does not match the current magnetic field state over time and proper correction cannot be performed, the detection accuracy of the magnetic material can be maintained with reference to the reference comprehensive detection value.

Further, the present invention can be implemented not only as an in-vivo magnetic substance detecting device but also as a method for detecting an in-vivo magnetic substance.

Specifically, the method for detecting a magnetic substance in the body consists of a detection rod formed in a rod shape and inserted into the body, and an electric signal provided at the tip of the detection rod and corresponding to a change in surrounding magnetic energy. A first magnetic sensor that outputs a first detection signal and a second magnet that outputs a second detection signal composed of an electric signal arranged at a position separated from the first magnetic sensor in the detection rod and corresponding to a change in magnetic energy. A sensor, a control means for detecting the presence or absence of a magnetic substance around the tip of the detection rod using the first detection signal and the second detection signal, and a detection of the presence or absence of a magnetic material around the tip of the detection rod. The control means is provided with a notification means for notifying, and an operator for instructing the control means to execute a detection process for the presence or absence of a magnetic substance around the tip of the detection rod by a manual operation by the user. The detection correction value calculation step for calculating and storing the detection correction value for correcting this difference from the difference between the first detection signal and the second detection signal, and the first detection signal, the second detection signal, and the detection correction value are stored. A magnetic body detection step that calculates the total detection value using the total detection value and detects the presence or absence of a magnetic material around the tip of the detection rod based on this comprehensive detection value, and a notification that notifies the detection of the magnetic material by the magnetic body detection step. The magnetic substance detection step and the notification step, including the step, may be executed by being operated by the user.

In this case, in the method for detecting a magnetic substance in the body, in the magnetic substance detection step, the total detection value when the operator is operated is stored as the reference total detection value, and the total detection value and the reference total detection value to be acquired thereafter are stored. It can be used to detect the presence or absence of a magnetic substance around the tip of the detection rod. In these methods for detecting an in-vivo magnetic substance, the same effects as those in the above-mentioned in-vivo magnetic substance detecting device can be expected.

It is a perspective view which shows the outline of the appearance structure of the in-body magnetic substance detection apparatus which concerns on one Embodiment of this invention. It is an internal configuration sectional view schematically showing the internal configuration and the system configuration of the internal magnetic substance detection device shown in FIG. 1. It is a block diagram which shows the system structure of the in-body magnetic substance detection apparatus shown in FIG. 2 in more detail. It is a partial perspective view which enlarges and shows the state in which the magnetic material M made up of suture needles is magnetically adsorbed to the tip end part of the detection rod body in the in-body magnetic material detection apparatus shown in FIG. It is a partially cutout front view for demonstrating the internal structure of the detection rod body in the body magnetic substance detection apparatus shown in FIG. FIG. 5 is a flowchart showing a work process of detecting a magnetic substance in a patient's body using the in-vivo magnetic substance detecting device shown in FIG. It is a flowchart which shows the processing process of the detection correction value calculation program executed by the control device shown in FIG. The principle of calculating the detection correction value will be described using the maximum value and the minimum value of the first detection signal value in the detection correction value calculation program shown in FIG. 7 and the two corresponding detection values corresponding to the second detection signal value. Therefore, it is an explanatory diagram showing the relationship between the two. It is a flowchart which shows the processing process of the magnetic material detection program executed by the control device shown in FIG. It is a perspective view which shows the outline of the appearance structure of the in-body magnetic substance detection apparatus which concerns on the modification of this invention.

Hereinafter, an embodiment of an in-vivo magnetic substance detecting device and an in-vivo magnetic substance detecting method according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an outline of an external configuration of the in-vivo magnetic substance detection device 100 according to the present invention. Further, FIG. 2 is a cross-sectional view of the internal configuration schematically showing the internal configuration and the system configuration of the internal magnetic substance detection device 100 shown in FIG. Further, FIG. 3 is a block diagram showing the system configuration of the in-vivo magnetic substance detection device 100 shown in FIG. 2 in more detail. It should be noted that each of the figures referred to in the present specification is schematically shown by exaggerating some of the components in order to facilitate the understanding of the present invention. Therefore, the dimensions and ratios between the components may be different. The in-vivo magnetic substance detection device 100 is a device for examining whether or not a metal piece such as a suture needle is placed in the body during human surgery.

(Structure of magnetic substance detection device 100 in the body)
The internal magnetic substance detection device 100 includes a main body case 101. The main body case 101 is a hollow component that houses various components of the internal magnetic substance detection device 100 and constitutes a housing of the internal magnetic substance detection device 100. The main body case 101 is formed by molding a resin material into a size and shape that can be held and operated by the user of the in-vivo magnetic substance detection device 100. More specifically, the main body case 101 is configured by integrally forming a storage portion 101a extending in the horizontal direction shown in the drawing and a grip portion 101b extending diagonally downward in the drawing from the lower portion shown in the storage portion 101a. .. Further, the main body case 101 constitutes one main body case 101 by combining two halves divided into two in the thickness direction.

A control board 120, which will be described later, is provided at the center of the storage portion 101a. Further, the storage portion 101a is provided with a detection rod body connecting portion 102 at one end (left side in the drawing) and a power switch 103 at the other end (right side in the drawing). The detection rod body connecting portion 102 is a component that detachably connects the detection rod body 110 described later, and is formed in a cylindrical shape into which the detection rod body 110 can insert the resin material. In this case, the detection rod body connecting portion 102 also electrically connects the detection rod body 110 and the control board 120. One end (left side in the drawing) of the detection rod connecting portion 102 is exposed to the outside of the storage portion 101a, and the other end (right side in the drawing) is located in the storage portion 101a and is electrically connected to the control board 120. ing.

The power switch 103 is an electric component for controlling the start-up or stop of the start-up of the magnetic substance detection device 100 in the body by supplying or shutting off the power to the control board 120 according to the manual operation of the user. In the present embodiment, the power switch 103 is composed of a rocker switch. The power switch 103 is provided in a state where the portion operated by the user is exposed at a position that can be operated by the thumb of the user who holds the grip portion 101b on the outer surface of the storage portion 101a.

The grip portion 101b is a portion that is gripped by the user of the internal magnetic substance detection device 100 and holds the entire internal magnetic substance detection device 100, and is formed to have a thickness that can be grasped by the user with one hand. The grip portion 101b is configured so that a part of the outer surface thereof can be detachably removed, and the battery case 104 is provided inside the removable portion. The battery case 104 is a portion that detachably holds the battery 105, which is a power source for the electric power supplied to the control device 122, and is electrically connected to the control board 120 via the power switch 103.

Further, the grip portion 101b is provided with an operator 106 on the end side on the storage portion 101a side. The operator 106 is a push-button type input device for operating when detecting a magnetic substance in the body by the magnetic substance detecting device 100 in the body and giving an instruction to a control device 122 described later. The operator 106 is provided at a position where it can be operated by the index finger or the middle finger of the user who holds the grip portion 101b while being electrically connected to the control device 122.

As shown in FIGS. 4 and 5, the detection rod 110 is a component that is inserted into the body of a patient (not shown) undergoing surgery to detect the magnetic substance M, and is mainly connected to a casing 111. A unit 112, a first magnetic sensor 113, and a second magnetic sensor 115 are provided, respectively. The casing 111 is a portion that houses the first magnetic sensor 113 and the second magnetic sensor 115 and is inserted into the patient's body, respectively, and is magnetically neutral (with a magnetic permeability of “1”) and is non-magnetic (for example, the magnetic permeability is “1”). (Resin material, aluminum material, stainless steel material, ceramic material, etc.) It is formed in the shape of an elongated hollow rod.

More specifically, the casing 111 is formed in a bottomed cylindrical shape in which one end (left side in the drawing) of the cylinder is closed and the other end (right side in the drawing) is open. In this case, in the casing 111, the tip portion 111b that closes the one end portion of the side surface portion 111a formed in a cylindrical shape is formed in a flat shape, and the thickness of the tip portion 111b is the thickness of the side surface portion 111a. It is formed thinner than the one. In the present embodiment, the casing 111 is formed to have an outer diameter of 10 mm and a length of 130 mm.

The connecting portion 112 is a component for detachably connecting the casing 111 to the detection rod body connecting portion 102 in the main body case 101, and is formed in a shaft shape having a thickness that can be inserted into the detection rod body connecting portion 102. Has been done. In this case, the connecting portion 112 is formed with a hooking portion 112a that is elastically hooked on the inner peripheral surface of the detection rod body connecting portion 102 on the outer peripheral surface, and the detection rod is not pulled strongly by the user. It is configured so as not to come off from the body connecting portion 102. The connecting portion 112 is also electrically connected to the detection rod body connecting portion 102.

The first magnetic sensor 113 is a component for detecting the magnetic body M placed in the patient's body, and is provided at a position adjacent to the tip portion 111b in the casing 111. The first magnetic sensor 113 is mainly configured to include a detection element 113a, a substrate 113b, and a permanent magnet 113c, respectively.

The detection element 113a is composed of an element that converts magnetic energy into electrical energy and outputs it. In the present embodiment, the detection element 113a is composed of a magnetoresistive element whose resistance value changes depending on the strength of the magnetic field. In this case, the detection element 113a may be configured by connecting two magnetoresistive elements in series, but may be configured by connecting four magnetoresistive elements in a bridge shape. In the present embodiment, the detection element 113a is formed in a chip shape having a size of 0.7 mm × 0.7 mm in length and width, and is configured to have a sensitivity of 15.0 kA / m. The detection element 113a is electrically connected to the control device 122 via the signal line 114a.

The substrate 113b is a component that supports the detection element 113a and the permanent magnet 113c, respectively, and is configured by forming an epoxy resin material into a plate-like body. The substrate 113b fixedly supports the detection element 113a on one surface (upper surface in the drawing) via an adhesive (not shown), and attaches a permanent magnet 113c on the other surface (lower surface in the drawing) (FIG. It is fixed to the inner peripheral surface of the casing 111 with an adhesive (not shown) in a state of being fixedly supported via (not shown).

The permanent magnet 113c applies a magnetic bias to the detection element 113a to shift the operating point of the detection element 113a to a linear region of resistance change, and magnetically magnetizes the magnetic body M existing around the tip portion 111b of the detection rod 110. It is a magnet for attracting magnetically. In the present embodiment, the permanent magnet 113c is formed in a plate shape having a length and width of 6 mm × 6 mm and a thickness of 4 mm, and is composed of a neodymium magnet having a surface magnetic flux density of 350 mT and an attractive force (adhesive force) of 0.9 kgf. Has been done. The permanent magnet 113c is arranged to face the detection element 113a via the substrate 113b. In this case, the permanent magnet 113c is positioned at a position where the resistance value changes linearly with respect to the change in the strength of the magnetic field and the output signal does not saturate.

The second magnetic sensor 115 is a component for canceling the influence of terrestrial magnetism, the detecting element 113a, the substrate 113b and the permanent magnets 113c and similar detection elements 115a, it is configured to include a substrate 115b and the permanent magnets 115c .. Like the detection element 113a, the detection element 115a is composed of an element that converts magnetic energy into electrical energy and outputs it. In the present embodiment, the detection element 115a is composed of a magnetoresistive element whose resistance value changes depending on the strength of the magnetic field. In this case, the detection element 115a may be configured by connecting two magnetoresistive elements in series, but may be configured by connecting four magnetoresistive elements in a bridge shape. In the present embodiment, the detection element 115a is formed in a chip shape having a size of 0.7 mm × 0.7 mm in length and width, and is configured to have a sensitivity of 15.0 kA / m. The detection element 115a is electrically connected to the control device 122 via the signal line 114b.

Like the substrate 113b, the substrate 115b is a component that supports the detection element 115a and the permanent magnet 115c, respectively, and is configured by forming an epoxy resin material into a plate-like body. The substrate 115b fixedly supports the detection element 115a on one surface (upper surface in the figure) via an adhesive (not shown), and attaches a permanent magnet 115c on the other surface (lower surface in the figure) (FIG. It is fixed to the inner peripheral surface of the casing 111 with an adhesive (not shown) in a state of being fixedly supported via (not shown).

Similar to the permanent magnet 113c, the permanent magnet 115c is a magnet for applying a magnetic bias to the detection element 115a to shift the operating point of the detection element 115a to a linear region of resistance change. In the present embodiment, the permanent magnet 115c is formed in a plate shape having a length and width of 6 mm × 6 mm and a thickness of 4 mm, and is composed of a neodymium magnet having a surface magnetic flux density of 350 mT and an attractive force (adhesive force) of 0.9 kgf. Has been done. The permanent magnet 115c is arranged to face the detection element 115a via the substrate 115b.

In this case, the permanent magnet 115c is positioned at a position where the resistance value changes linearly with respect to the change in the strength of the magnetic field and the output signal does not saturate. The permanent magnet 115c does not necessarily have to be composed of a magnet having the same magnetic force as the permanent magnet 113c as long as the operating point of the detection element 115a can be changed, but in the present embodiment, it is the same as the permanent magnet 113c. It is composed of magnets with characteristics.

The second magnetic sensor 115 is provided at a position separated from the first magnetic sensor 113 in order to cancel the influence of the geomagnetism. In the present embodiment, the second magnetic sensor 115 is provided in the casing 111 at a position about 80 mm away from the first magnetic sensor 113.

The control board 120 includes amplifiers 121a and 121b, a control device 122, and a drive circuit 124 for executing detection processing of the magnetic body M using detection signals output from the first magnetic sensor 113 and the second magnetic sensor 115, respectively. It is an electronic circuit board provided with a display device 125 and a buzzer 126, respectively, and is mounted in a storage portion 101a of the main body case 101.

The amplifiers 121a and 121b amplify the first detection signal composed of the electric signal output from the first magnetic sensor 113 and the second detection signal composed of the electric signal output from the second magnetic sensor 115 to the control device 122, respectively. It is an electric circuit that outputs each.

The control device 122 is composed of a microcomputer including a CPU, a ROM, a RAM, and the like, and has a detection correction value calculation program and a detection correction value calculation program stored in advance in a storage device such as the ROM according to an instruction from the user via the operator 106. By executing each of the magnetic material detection programs, the magnetic material M around the tip portion 111b of the detection rod 110 is detected.

In this case, the control device 122 controls the operation of the first magnetic sensor 113 and the second magnetic sensor 115 via the drive circuit 124, respectively. Further, the control device 122 has a built-in A / D converter 123, and converts the first detection signal and the second detection signal, which are analog signals input via the amplifiers 121a and 121b, into digital signals for detection. The magnetic material M around the tip portion 111b of the rod body 110 is used for detection. Further, the control device 122 outputs the detection status of the magnetic body M around the tip portion 111b of the detection rod 110 to the outside via the display device 125 and the buzzer 126, respectively.

Here, the drive circuit 124 is an electric circuit whose operation is controlled by the control device 122 to apply a predetermined constant voltage (for example, 5 V) to the first magnetic sensor 113 and the second magnetic sensor 115. Further, the display device 125 is a light emitting element whose operation is controlled by the control device 122 to notify the outside of the detection state of the magnetic body M around the tip end portion 111b of the detection rod 110 by lighting light, and is a light emitting element of the main body case 101. It is provided in a state of being exposed on the outer surface. In the present embodiment, the display device 125 is composed of four LED light emitting elements (Light Emitting Diodes). The buzzer 126 is a sounding device whose operation is controlled by the control device 122 to notify the outside of the detection state of the magnetic body M around the tip 111b of the detection rod 110 by generating a sound.

(Operation of magnetic substance detection device 100 in the body)
Next, the operation of the in-vivo magnetic substance detection device 100 configured as described above will be described with reference to FIG. First, the user (for example, a doctor) of the in-vivo magnetic substance detection device 100 prepares the in-vivo magnetic substance detection device 100 during the operation of the patient (not shown) as the first step. Specifically, the user prepares the main body case 101 and the detection rod 110, respectively.

Next, the user attaches the detection rod 110 to the main body case 101 as a second step. Specifically, the user inserts the connecting portion 112 of the detection rod body 110 into the detection rod body connecting portion 102 of the main body case 101. As a result, the detection rod body 110 is integrated with the main body case 101 by hooking the hooking portion 112a on the inner peripheral surface of the detection rod body connecting portion 102. Further, in this case, the first magnetic sensor 113 and the second magnetic sensor 115 in the detection rod 110 are electrically connected to the control board 120.

Next, as a third step, the user operates the power switch 103 of the internal magnetic substance detection device 100 to turn on the power of the control device 122 of the internal magnetic substance detection device 100. As a result, the control device 122 is in a standby state waiting for an instruction from the user by executing a control program (not shown).

Next, the user performs the work of acquiring the detection correction value as the fourth step. In this detection correction value acquisition step, the detection correction value for eliminating the variation in the detection characteristics (output characteristics) of the first magnetic sensor 113 and the second magnetic sensor 115 in the same magnetic field is acquired, that is, , This is a calibration for eliminating individual differences in the detection sensitivities of the first magnetic sensor 113 and the second magnetic sensor 115. Specifically, the user instructs the control device 122 to acquire the detection correction value by performing a predetermined operation (for example, double-clicking) on the operator 106.

In response to this instruction, the control device 122 acquires the detection correction value by executing the detection correction value calculation program shown in FIG. 7. Specifically, the control device 122 starts the execution of the detection correction value calculation program in step S100, and starts the operation of the first magnetic sensor 113 and the second magnetic sensor 115 in step S102. Specifically, the control device 122 controls the operation of the drive circuit 124 and applies the same voltage to the first magnetic sensor 113 and the second magnetic sensor 115, respectively, to apply the same voltage to the first magnetic sensor 113 and the second magnetic sensor 115. Each of the operations is started. As a result, the first magnetic sensor 113 and the second magnetic sensor 115 generate the first detection signal and the second detection signal according to the strength of the magnetic field around each of the first magnetic sensor 113 and the second magnetic sensor 115, respectively. Output.

Next, in step S104, the control device 122 stores a predetermined amount of each of the first detection signal and the second detection signal. Specifically, the control device 122 acquires the values of the first detection signal and the second detection signal output from the first magnetic sensor 113 and the second magnetic sensor 115, respectively, at predetermined time intervals during a predetermined time. It is stored as the first detection signal value and the second detection signal value, respectively. For example, the control device 122 keeps storing each value of the first detection signal and the second detection signal as a pair every 0.01 seconds for several seconds to several tens of seconds.

In this case, the control device 122 stores the values of the first detection signal and the second detection signal in the temporary storage device built in the control device 122, respectively. In each storage process of the first detection signal and the second detection signal, the user responded to the magnetic environment around the user by greatly changing the position and orientation of the gripped internal magnetic substance detection device 100. The first detection signal value and the second detection signal value can be acquired, respectively.

Next, the control device 122 calculates the detection correction value in step S106. Specifically, the control device 122 extracts the maximum value and the minimum value of each value of the first detection signal value stored in the step S104, and acquires the maximum value and the minimum value at the same timing as the maximum value and the minimum value. Each value of the second detection signal value is extracted as a corresponding detection value.

Next, the control device 122 uses the maximum value and the minimum value of the first detection signal and the corresponding detection values paired with them to set the second detection signal value as the first detection signal value as shown in the following equation 1. Specify the correction count α and the offset value β to match the same values as. In this case, as shown in FIG. 8, the correction count α is the slope of the straight line L1 connecting the maximum value and the minimum value of the first detection signal and the straight line L2 connecting the two corresponding detection values of the second detection signal. It is a count for correcting the inclination of. The offset value β is a correction value for the difference in the magnitude of the detection signal between the straight line L1 and the straight line L2.
<Number 1>
1st detection signal value = 2nd detection signal value x correction count α + offset value β

The interval between the maximum value and the minimum value of the first detection signal on the horizontal axis of FIG. 8 may be determined in advance as an appropriate value, or the timing at which the maximum value is acquired and the timing at which the minimum value is acquired. It may be the time of. Further, to match the second detection signal value with the first detection signal value means that the second detection signal value may be exactly the same as the first detection signal value in a strict sense, but the second detection signal value is the first detection. It is also possible to keep the signal value within a predetermined range and make it substantially the same value. That is, these correction count α and offset value β correspond to the detection correction value.

Further, the detection correction value may be any value as long as the first detection signal value and the second detection signal value can be made substantially the same value, and does not necessarily have to be composed of the correction count α and the offset value β. .. Therefore, the detection correction value can be configured only by the offset value β, for example. Specifically, the control device 122 uses the average value of the differences between each value of the first detection signal value and each value of the second detection signal value corresponding to each value of the first detection signal value as the offset value β. It can also be a detection correction value. Further, the detection correction value may be configured by, for example, only the correction count α.

Next, in step S108, the control device 122 records the detection correction value calculated in step S106 in the temporary storage device built in the control device 122. Then, in step S110, the control device 122 controls the operation of the drive circuit 124 to stop the application of the voltage to the first magnetic sensor 113 and the second magnetic sensor 115, and stops the application of the voltage to the first magnetic sensor 113 and the second magnetic sensor 113. After stopping each operation of the sensor 115, the execution of the detection correction value calculation program ends in step S112. As a result, the control device 122 acquires the detection correction value.

The execution of the detection correction value calculation program corresponds to the detection correction value calculation step according to the present invention, and the control device 122 that executes the detection correction value calculation program corresponds to the detection correction value calculation means according to the present invention. Further, the execution of the detection correction value calculation program for acquiring the detection correction value is configured to be automatically executed when the power switch 103 of the internal magnetic material detection device 100 is operated to turn on the power. You can also do it.

Next, as the fifth step, the user performs a work of detecting the magnetic substance M in the patient's body. Specifically, the user instructs the control device 122 to detect the magnetic material M by performing a predetermined operation (for example, continuing to press) on the operator 106. In response to this instruction, the control device 122 executes the magnetic material detection program shown in FIG.

Specifically, the control device 122 starts the execution of the magnetic material detection program in step S200, and determines in step S202 whether or not the detection correction value has been acquired. In this case, when the detection correction value is acquired (stored), the control device 122 determines "Yes" in this determination process and proceeds to step S204. On the other hand, if the detection correction value is not acquired (stored), the control device 122 determines "No" in this determination process, proceeds to step S212, and ends the execution of the magnetic material detection program. .. That is, the control device 122 does not perform the detection process of the magnetic material M unless the detection correction value is acquired.

Next, the control device 122 acquires the reference comprehensive detection value in step S204. Here, the reference comprehensive detection value is a value used as a reference (threshold value) when determining the presence or absence of the magnetic material M. The acquisition process of the reference comprehensive detection value is configured by each process of the following sub-steps 1 to 3.

Sub-step 1: First, the control device 122 acquires one value each of the first detection signal and the second detection signal output from the first magnetic sensor 113 and the second magnetic sensor 115, respectively.

Sub-step 2: Next, the control device 122 substitutes the detection correction value and the second detection signal value acquired in the sub-step 1 into the following equation 2 to obtain a correction second detection signal value.
<Number 2>
Corrected second detection signal value = second detection signal value x correction count α + offset value β

Sub-step 3: Next, the control device 122 calculates the reference comprehensive detection value by substituting the first detection signal value acquired in the sub-step 1 and the calculated correction second detection signal value into the following number 3. And record it in the temporary storage device. As a result, the control device 122 can acquire one reference comprehensive detection value. The process of acquiring the reference comprehensive detection value in step S204 may be executed immediately before the user inserts the detection rod 110 into the patient's body. That is, the user may instruct the control device 122 to execute the magnetic material detection program by operating the operator 106 immediately before inserting the detection rod 110 into the patient's body.
<Number 3>
Reference comprehensive detection value = 1st detection signal value-correction 2nd detection signal value

Next, the control device 122 executes the detection process of the magnetic material M in step S206. Here, the detection process of the magnetic body M is a process of detecting the presence or absence of the magnetic body M in the vicinity of the tip portion 111b of the detection rod body 110. Therefore, the user operates the gripped internal magnetic substance detecting device 100 to insert the tip end portion 111b of the detection rod 110 into the patient's body and move it to search for the magnetic substance M. The detection process of the magnetic material M is composed of the following processes of sub-steps 1 to 5.

Sub-step 1: First, the control device 122 starts the operation of the first magnetic sensor 113 and the second magnetic sensor 115. Specifically, the control device 122 controls the operation of the drive circuit 124 and applies the same voltage to the first magnetic sensor 113 and the second magnetic sensor 115, respectively, to apply the same voltage to the first magnetic sensor 113 and the second magnetic sensor 115. Each of the operations is started. As a result, the first magnetic sensor 113 and the second magnetic sensor 115 generate the first detection signal and the second detection signal according to the strength of the magnetic field around each of the first magnetic sensor 113 and the second magnetic sensor 115, respectively. Output.

Sub-step 2: Next, the control device 122 acquires one value each of the first detection signal and the second detection signal output from the first magnetic sensor 113 and the second magnetic sensor 115, respectively.

Sub-step 3: Next, the control device 122 substitutes the detection correction value and the second detection signal value acquired in the sub-step 1 into the above number 2 to obtain a correction second detection signal value. As a result, the control device 122 can obtain the corrected second detection signal value in which the variation in the detection accuracy between the first magnetic sensor 113 and the second magnetic sensor 115 is cancelled.

Sub-step 4: Next, the control device 122 substitutes the first detection signal value acquired in the sub-step 1 and the calculated corrected second detection signal value into the following number 3 to obtain a total detection value. As a result, the control device 122 can obtain a comprehensive detection value that cancels the influence of the geomagnetism around the detection rod 110.
<Number 4>
Comprehensive detection value = 1st detection signal value-correction 2nd detection signal value

Substep 5: Next, the control device 122 determines the detection of the magnetic material M. Specifically, the control device 122 calculates the difference between the reference total detection value and the total detection value calculated in the sub-step 3 as a detection difference value, and this detection difference value is preset in the control device 122. It is determined whether or not the value exceeds the predetermined range.

In this case, if the detection difference value is a value outside the predetermined range, the control device 122 determines “Yes” in this determination process and proceeds to step S208. On the other hand, when the detection difference value is within a predetermined range, the control device 122 determines "No" in this determination process and proceeds to step S210. That is, when a magnetic material M such as a suture needle is present in the vicinity of the tip end portion 111b of the detection rod 110, the magnetic field state around the first magnetic sensor 113 changes, so that the first detection signal value and the second detection signal value There is a difference from the detection signal value (corrected second detection signal value).

Therefore, the control device 122 is the tip of the detection rod 110 when the detection difference value, which is the difference between the first detection signal value and the second detection signal value (corrected second detection signal value), is out of the predetermined range. Assuming that some magnetic material M such as a suture needle is present in the vicinity of the portion 111b, it is determined as "Yes" and the process proceeds to step S210.

In this way, by using the reference comprehensive detection value, the control device 122 uses the reference comprehensive detection value even when there is a difference between the magnetic field state at the time when the detection correction value is calculated and the current magnetic field state. The detection accuracy of the magnetic material M can be maintained with reference to. The magnetic material M detection process according to step S206 corresponds to the magnetic material detection step according to the present invention, and the control device 122 that executes this step S206 corresponds to the magnetic material detection means according to the present invention.

Next, the control device 122 operates the display device 125 and the buzzer 126 in step S208. In this case, the control device 122 may turn on all four LEDs constituting the display device 125 at the same time, but the number of LEDs to be turned on is gradually increased according to the magnitude of the detection difference value. It may be. Further, the control device 122 may make the buzzer 126 sound as a continuous sound having a constant volume, but the volume is gradually increased or the intermittent sound is changed to a continuous sound according to the magnitude of the detection difference value. You may pronounce it. Thereby, the user can visually grasp that some magnetic material M such as a suture needle is present in the vicinity of the tip end portion 111b of the detection rod body 110.

Further, in this case, the in-body magnetic body detection device 100 detects the magnetic body M in which the permanent magnet 113c constituting the first magnetic sensor 113 exists around the tip portion 111b of the detection rod 110 (for example, within a range of 10 mm). Since it has a magnetic force that can be magnetically attracted, a magnetic material M such as a suture needle can be magnetically attracted to the tip portion 111b. Therefore, the control device 122 stores in advance the magnitude of the detection difference value when the magnetic body M is adsorbed on the tip portion 111b of the detection rod body 110, so that the detection difference value is stored in advance. When the above is achieved, the user can be notified of the adsorption of the magnetic material M on the tip portion 111b by operating or changing the operation of the display device 125 and the buzzer 126.

As a result, the user can recover the magnetic material M such as the suture needle placed in the body by operating the in-body magnetic material detection device 100 to separate the detection rod 110 from the body (see FIG. 4). ). The operation processing of the display device 125 and the buzzer 126 according to step S206 corresponds to the notification step according to the present invention, and the display device 125 and the buzzer 126 correspond to the notification means according to the present invention. Note that FIG. 4 shows a state in which the magnetic body M is adsorbed on the tip portion 111b of the casing 111, but the magnetic body M is other than the tip portion 111b if it is the surface of the casing 111 around the permanent magnet 113c. It may also be adsorbed on the side surface portion 111a.

Next, in step S210, the control device 122 determines whether or not to end the execution of the detection process of the magnetic material M. Specifically, the control device 122 determines whether or not the operator 106 has been operated (for example, the pressed state is released). In this case, the control device 122 continues to determine "No" in this determination process until the operator 106 is operated (for example, the pressed state is released), and returns to step S206. Then, the control device 122 again executes the process of detecting the presence / absence of the magnetic material M in step S206. That is, in the present embodiment, the control device 122 executes the detection process of the magnetic body M while the operator 106 is pressed.

On the other hand, when the operator 106 is operated (for example, the pressed state is released), the control device 122 determines "Yes" in this determination process and executes the magnetic material detection program in step S212. To finish. In this case, the control device 122 controls the operation of the drive circuit 124 to stop the application of the voltage to the first magnetic sensor 113 and the second magnetic sensor 115, and each of the first magnetic sensor 113 and the second magnetic sensor 115. The operation is stopped, and when the display device 125 and the buzzer 126 are operating, the operation of each of these devices is stopped.

Next, the user performs the finishing work as the sixth step. Specifically, the user operates the power switch 103 of the internal magnetic substance detection device 100 to turn off the power of the control device 122 of the internal magnetic substance detection device 100, and then removes the detection rod 110 from the main body case 101. Remove. In this case, the user can remove the detection rod 110 from the main body case 101 by pulling the detection rod 110 axially with respect to the main body case 101. In this case, the user can use the detection rod 110 again by cleaning and disinfecting it, but in consideration of the detection accuracy of the first magnetic sensor 113 and the second magnetic sensor 115 and the hygiene aspect of the casing 111. It can also be discarded without being reused.

As can be understood from the above operation description, according to the above embodiment, the in-body magnetic substance detection device 100 has a first detection signal output from the first magnetic sensor 113 and a second detection signal output from the second magnetic sensor 115. A detection correction value for correcting the difference from the detection signal is acquired, and an operator 106 for operating the control device 122, the display device 125, and the buzzer 126 in the acquired state of the detection correction value is provided. .. Therefore, since the magnetic body detection device 100 detects the magnetic body M only when the operator 106 is operated, the magnetic body M is not detected when the detection of the magnetic body M is unnecessary, and the magnetic body M is not detected. It is possible to improve the reliability of the detection accuracy of. Further, in the internal magnetic substance detection device 100, a detection correction value for correcting the difference between the first detection signal output from the first magnetic sensor 113 and the second detection signal output from the second magnetic sensor 115 is acquired. Therefore, it is possible to correct the variation and error in the detection accuracy between the first magnetic sensor 113 and the second magnetic sensor 115, and it is possible to improve the reliability of the detection accuracy of the magnetic body M.

Furthermore, the practice of the present invention is not limited to the above-described embodiment, and various modifications can be made as long as the object of the present invention is not deviated. In each of the following modifications, the same components as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

For example, in the above embodiment, the first magnetic sensor 113 and the second magnetic sensor 115 are composed of magnetoresistive elements. However, the first magnetic sensor 113 and the second magnetic sensor 115 are not necessarily limited to the above embodiments as long as they are elements capable of converting changes in magnetic energy around the detection rod 110 into electrical energy and outputting them. It is not something that is done. Therefore, the first magnetic sensor 113 and the second magnetic sensor 115 can be composed of, for example, a Hall element, a GMR sensor, or an MI sensor.

Further, in the above embodiment, the permanent magnet 113c constituting the first magnetic sensor 113 is composed of a neodymium magnet having a magnetic force capable of attracting the magnetic body M existing around the detection rod 110. However, the permanent magnet 113c only needs to be able to attract the magnetic material M existing around the detection rod 110, and magnets other than neodymium magnets, for example, various magnets such as ferrite, samarium cobalt, and alnico can be used. .. In this case, the periphery of the detection rod 110 is a range of 10 mm or less, preferably 20 mm or less, and more preferably 30 mm or less with respect to the tip end portion 111b of the detection rod 110. Further, when it is not necessary for the permanent magnet 113c to attract the magnetic body M existing around the detection rod 110, at least the detection element 113a is magnetically biased to linearize the operating point of the detection element 113a with a resistance change. It suffices if it is composed of a magnet having a magnetic force capable of shifting to a certain region. In this case, the permanent magnet 115c is also composed of a magnet having a magnetic force capable of at least applying a magnetic bias to the detection element 115a to shift the operating point of the detection element 115a to a linear region of resistance change. Just do it. That is, the in-body magnetic substance detection device 100 does not necessarily have to adsorb the detected magnetic substance M to the tip portion 111b of the detection rod 110, and does not adsorb the detected magnetic substance M, that is, it only detects. You can also do it. Therefore, as the permanent magnets 113c and 115c, in addition to neodymium magnets, various magnets such as ferrite, samarium cobalt, and alnico can be used.

Further, in the above embodiment, the control device 122 executes the detection correction value calculation program by double-clicking the operator 106 (the operation of pressing the operator 106 quickly twice in a row without a gap), and the operator 106. It is configured to execute the magnetic substance detection program by continuously pressing. However, the instruction to the control device 122 for each execution of the detection correction value calculation program and the magnetic material detection program may be instructed by another operation method of the operator 106 (for example, a so-called long press that maintains the pressed state for a predetermined time). It's natural that it's good. Further, the control device 122 can be configured to automatically execute the detection correction value calculation program once or a plurality of times every predetermined time elapses after the power is turned on. Further, the in-body magnetic substance detection device 100 may separately provide an operator 106 for instructing the execution of the detection correction value calculation program and an operator 106 for instructing the execution of the magnetic substance detection program. ..

Further, in the above embodiment, the magnetic substance detection program acquires the reference comprehensive detection value in step S204, and then executes the detection process of the magnetic substance M using the reference comprehensive detection value in step S206. However, the magnetic substance detection program can also determine the presence or absence of the magnetic substance M without using the reference comprehensive detection value. For example, the magnetic material detection program can determine the presence or absence of the magnetic material M based on the comprehensive detection value acquired in substep 4 in step S206.

Specifically, the magnetic material detection program determines in sub-step 5 in step S206 whether or not the total detection value itself exceeds a predetermined range preset in the control device 122. do. In this case, if the total detection value is out of the predetermined range, the control device 122 determines "Yes" in this determination process and proceeds to step S208. On the other hand, when the total detection value is within a predetermined range, the control device 122 determines "No" in this determination process and proceeds to step S210. According to this, the acquisition process of the reference comprehensive detection value in step S204 becomes unnecessary.

Further, in the above embodiment, the control device 122 executes the operation of the first magnetic sensor 113 and the second magnetic sensor 115 each time the detection correction value calculation program and the magnetic body detection program are executed. It was configured in. However, the first magnetic sensor 113 and the second magnetic sensor 115 can be configured to start operation when the power of the internal magnetic substance detection device 100 is turned on and to stop operation when the power is turned off. In this case, the control device 122 may be configured to ignore the inputs of the first detection signal and the second detection signal continuously output from the first magnetic sensor 113 and the second magnetic sensor 115 except when necessary.

Further, in the above embodiment, the control device 122 detects the magnetic body M and the magnetic body M detection process (step S206) by executing each of the detection correction value calculation program and the magnetic body detection program based on the operation of the operator 106. It is configured to execute the notification process (step S208) at the time of each execution. However, the control device 122 may execute the detection process (step S206) and the notification process (step S208) of the magnetic body M as a result based on the operation of the operator 106, respectively.

Therefore, for example, the control device 122 is configured to automatically start the execution of the magnetic body M detection process (step S206) after the power of the internal magnetic body detection device 100 is turned on, and the notification process (step). S208) can be configured to start execution based on the operation of the operator 106. In this case, the control device 122 executes the detection process of the magnetic material M (step S206) until the notification process (step S208) is executed based on the operation of the operator 106, but the detection result is It may be configured to be ignored.

Further, for example, the control device 122 is configured to automatically start the notification process (step S208) after the power of the internal magnetic substance detection device 100 is turned on, and the detection process of the magnetic body M (step). S206) can also be configured to start execution based on the operation of the operator 106.

Further, in the above embodiment, the in-body magnetic substance detection device 100 is configured so that the detection rod body 110 can be detachably attached to the main body case 101. However, the in-body magnetic substance detection device 100 can also integrally form the detection rod 110 and the main body case 101 so that they do not need to be separated from each other.

Further, in the above embodiment, the detection rod body 110 is formed so that the wall thickness of the tip portion 111b is thinner than the wall thickness of the side surface portion 111a. As a result, the detection rod 110 can easily magnetically attract the detected magnetic body M to the tip portion 111b while maintaining the rigidity of the long detection rod 110. However, in the detection rod body 110, the wall thickness of the side surface portion 111a and the wall thickness of the tip portion 111b may be formed to be the same thickness, or the wall thickness of the tip portion 111b may be set to be larger than the wall thickness of the side surface portion 111a. It can also be formed thick.

Further, in the above embodiment, the main body case 101 is composed of a storage portion 101a and a grip portion 101b. However, the main body case 101 may be formed in a size and shape that can be gripped by the user, and is not necessarily limited to the above embodiment. Therefore, for example, as shown in FIG. 10, the main body case 101 may be composed of only the thin box-shaped storage portion 101a extending in the axial direction of the detection rod body 110. In this case, the storage portion 101a also serves as the grip portion 101b in the above embodiment. In the in-vivo magnetic substance detecting device 100 formed in such a shape, the main body case 101 can be easily inserted and operated in a narrow place such as a human head by grasping the main body case 101 like a knife or a pencil.

Further, in the above embodiment, the notification means according to the present invention is composed of the display device 125 and the buzzer 126. However, the notification means may be configured so that the user can recognize the detection state of the magnetic material M. Therefore, the notification means can be configured to, for example, be configured to include a vibrator so that the user can recognize the detection state of the magnetic body M by vibration.

Further, in the above embodiment, it is assumed that the in-body magnetic substance detection device 100 is inserted into the human body and used for detecting a foreign substance made of a magnetic substance such as a suture needle. However, the in-vivo magnetic substance detection device 100 can be inserted into the body of an animal other than a human being, machinery / equipment, various devices, a container, or the like and used for detecting a foreign substance made of a magnetic substance.

M ... Magnetic material,
100 ... Internal magnetic substance detection device, 101 ... Main body case, 101a ... Storage part, 101b ... Grip part, 102 ... Detection rod body connection part, 103 ... Power switch, 104 ... Battery case, 105 ... Battery, 106 ... Operator,
110 ... Detection rod, 111 ... Casing, 111a ... Side surface, 111b ... Tip, 112 ... Connecting part, 112a ... Hooking part, 113 ... First magnetic sensor, 113a ... Detection element, 113b ... Substrate, 113c ... Permanent Magnet, 114a, 114b ... signal line, 115 ... second magnetic sensor, 115a ... detection element, 115b ... substrate, 115c ... permanent magnet,
120 ... Control board, 121a, 121b ... Amplifier, 122 ... Control device, 123 ... A / D converter, 124 ... Drive circuit, 125 ... Display device, 126 ... Buzzer.

Claims (2)

A detection rod that is formed in a rod shape and inserted into the body,
A first magnetic sensor provided at the tip of the detection rod and outputting a first detection signal composed of an electric signal corresponding to a change in the surrounding magnetic energy.
A second detection signal composed of an electric signal arranged at a position separated from the first magnetic sensor in the detection rod body so as not to be affected by the magnetic energy of the first magnetic sensor and corresponding to a change in the magnetic energy. The second magnetic sensor that outputs
A detection correction value for eliminating this difference from the difference between the first detection signal and the second detection signal and correcting the first detection signal and the second detection signal to substantially the same value is calculated. Detection correction value calculation means to be stored and stored
The total detection value is calculated using the first detection signal, the second detection signal, and the detection correction value, and the presence or absence of a magnetic material around the tip of the detection rod is detected based on the total detection value. Body detection means and
A notification means for notifying the detection of the magnetic material by the magnetic material detecting means, and
An in-body magnetic substance detecting device including an operator for setting the magnetic substance detecting means and the notifying means into an operating state by manual operation by a user. In the in-vivo magnetic substance detection device according to claim 1,
The magnetic substance detecting means is
The total detection value when the operator is operated is stored as a reference total detection value, and the total detection value and the reference total detection value acquired thereafter are used to describe the vicinity of the tip of the detection rod. An in-vivo magnetic substance detection device characterized by detecting the presence or absence of a magnetic substance.

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