JP2009118969A - System for supporting diagnosis of intraoperative evoked potential - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for supporting the diagnosis of intraoperative evoked potential which accurately analyses waveforms of evoked potential pulses displayed by an oscilloscope and gives an alarm when spinal cord ischemia occurs. <P>SOLUTION: The system for supporting diagnosis of intraoperative evoked potential is provided with: evoked potential electrode devices 2 including electrodes 14 and arranged respectively on the exposed intercostal nerves located on the upper and lower parts of the aorta blocked during an operation; a determination device which detects and stores a spinal evoked potential before the operation and also a spinal evoked potential during the operation, sets an arbitrary level as a threshold on the basis of an amount of change from the stored spinal evoked potential before the operation to the stored spinal evoked potential after the operation, and determines a spinal cord ischemia state by comparing the spinal evoked potentials fluctuating periodically and the threshold; and an alarm device that gives an alarm on the basis of directions of the determination device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intraoperative evoked potential diagnosis support system based on intercostal nerve stimulation and recording, and more specifically, an intraoperative evoked potential diagnosis support that determines whether spinal cord ischemia has occurred in the vicinity of the spinal cord region during the operation and generates an alarm. About the system.

  In thoracoabdominal aortic surgery, descending thoracic aortic aneurysm surgery, and spinal cord injury surgery, paraplegia due to spinal cord ischemia (lower body paralysis) is a complication that significantly impairs the patient's quality of life (QOL).

  Various spinal protection methods have been developed to date but have not yet completely prevented paraplegia.

  One method for monitoring spinal cord ischemia during surgery is spinal cord evoked potential. This is to monitor the current generated in the spinal cord by electrical stimulation as a signal waveform, and when the spinal cord is exposed to ischemia, the electrical conduction deteriorates, so observe changes such as a decrease in the amplitude of the signal waveform, This is a method for monitoring spinal cord ischemia during surgery.

  Conventionally, stimulation electrodes are attached to the scalp, cervical spinal epidural and peripheral nerves, and signal waveforms for monitoring spinal cord ischemia are obtained from recording electrodes attached to the thoracolumbar epidural, leg muscles, and spinal cord. It was.

However, the conventional spinal cord evoked potential measurement method has various problems as described below.
(1) When an electrode is placed outside the dura mater, heparin is used during the operation on the day of the operation. Therefore, in order to avoid bleeding complications, it is necessary to insert and place the electrode outside the dura mater the day before the operation.
(2) It cannot be used during emergency surgery.
(3) When recording a potential from the leg muscle, if a muscle relaxant is used during the operation, the potential cannot be recorded.
(4) The spinal cord evoked potential measurement method has been used to eliminate obstacles such as paralysis in spinal cord surgery. However, due to the lack of human resources, the need for machines has increased.

  Due to the above drawbacks, the anesthesia method and the potential measurement method are very difficult.

  Accordingly, the present inventor has proposed an intraoperative evoked potential diagnosis support system that monitors spinal cord ischemia during surgery using electrodes having a specific structure, including a conventional spinal cord evoked potential measurement method.

  The system includes an evoked potential electrode device, a pulse generator that generates a stimulation pulse as an electrical stimulus applied to the spinal cord, and a digital oscilloscope that detects a signal waveform of the spinal evoked potential generated in the spinal cord by the application of the stimulation pulse. The measurement unit and a processing unit for processing the measurement result of the spinal evoked potential obtained by the measurement unit are provided as main components, and the exposed upper intercostal nerve is positioned above the aorta to be blocked during the operation. Wearing one evoked potential electrode device and exposing the exposed lower intercostal nerve located below the aorta to be blocked during surgery, wearing a second evoked potential electrode device to monitor spinal cord ischemia during surgery Is.

  That is, a stimulation pulse is generated by a pulse generator, and this stimulation pulse is applied to the upper intercostal nerve via the first evoked potential electrode device. The applied stimulation pulse stimulates the nerve cells of the intercostal nerve, thereby generating a spinal cord evoked potential (evoked potential pulse) in the spinal cord. The evoked potential pulse is propagated through a nerve transmission path formed in the nerve tissue constituting the spinal cord, and the second evoked potential electrode device attached to the lower intercostal nerve in response to the propagation of the evoked potential pulse. An electrical signal is detected in the measuring device via

  The detected electrical signal is output to the digital oscilloscope via the wiring. The digital oscilloscope acquires the waveform of the evoked potential pulse from the electrical signal.

  In this way, the evoked potential electrode device is attached to each of the exposed intercostal nerves above and below the aorta to be blocked during the operation to monitor spinal cord ischemia during the operation.

  However, this intraoperative evoked potential diagnosis support system requires a high degree of expertise and experience in order to determine whether spinal cord ischemia has occurred from the waveform of the evoked potential pulse displayed by the oscilloscope.

  Therefore, there is a need for an intraoperative evoked potential diagnosis support system that is easy to operate and can accurately check spinal cord ischemia without advanced expertise or experience.

  The present invention has been made to solve the above-mentioned drawbacks, and the object of the present invention is to provide an intraoperative evoked potential diagnosis support that does not require preoperative preparation, can cope with sudden illnesses, and is not easily affected by anesthesia. To provide a system.

  Another object of the present invention is to provide an intraoperative evoked potential diagnosis support system that generates an alarm when a spinal cord ischemia occurs by accurately analyzing a waveform of an evoked potential pulse displayed by an oscilloscope. There is.

  Still another object of the present invention is to provide an intraoperative evoked potential diagnosis support system that is easy to operate and can accurately check spinal cord ischemia without a high level of expertise or experience.

  Still another object of the present invention is to monitor an intraoperative spinal cord ischemia by measuring a spinal cord evoked potential and setting a threshold value, and to generate an alarm when a spinal cord ischemic state occurs. Is to provide.

  The intraoperative evoked potential diagnostic support system of the present invention is an intraoperative evoked potential diagnostic support system that supports intraoperative diagnosis based on spinal cord evoked potential, and is electrically connected to the upper intercostal nerve located above the aorta to be blocked during the operation. A first electrode connected to the second intercostal nerve, a second electrode electrically connected to the lower intercostal nerve located below the aorta to be blocked during the operation, and the two electrodes connected to the corresponding intercostal nerve On the other hand, a stimulation application unit that applies a stimulation signal so that the intercostal nerve is stimulated, and a spinal cord evoked potential generated by the intercostal nerve stimulation is transmitted via the other of the two electrodes connected to the corresponding intercostal nerve. A potential detection unit for detecting, a spinal cord ischemia detection unit for detecting spinal cord ischemia based on the spinal cord evoked potential, and a detection output of the spinal cord ischemia detection unit; Generated alarm With the door, the objects can be achieved.

  In one embodiment, each of the first and second electrodes is attached by an electrode holding member so that the corresponding intercostal nerve can be attached to the electrode, and a fixed position where the corresponding intercostal nerve is fixed by the electrode. The potential detector has a signal amplifier that amplifies the electrical signal captured by the electrode, and the spinal cord ischemia detector is amplified by the signal amplifier. An arithmetic processing unit that obtains signal waveform data of spinal cord evoked potentials, a storage unit that stores and stores preoperative signal waveform data of spinal evoked potentials as standard data, and is stored in the storage unit A comparator that compares the standard data with the signal waveform data of the spinal evoked potential obtained by the arithmetic processing in the arithmetic processing unit at the time of measurement, and as a result of comparison by the comparator, the difference between the two data is within an allowable range. Beyond and a whether the determination unit the presence or absence of abnormality is, the alarm unit, when it is determined there is an abnormality by the determining unit, with an alarm annunciator to give an alarm.

  In one embodiment, the standard data stored in the storage unit stores, as the measurement preparation operation, the signal waveform data of the average spinal cord evoked potential before the operation, which is arithmetically processed by the arithmetic processing unit, in the storage unit. Previously stored in the unit.

  In one embodiment, the alarm notification device is at least one of an acoustic alarm notification unit using sound, an optical alarm notification unit using light, and an information transmission type alarm notification unit using character information or image information. is there.

  Another intraoperative evoked potential diagnosis support system according to the present invention includes an evoked potential electrode device including electrodes attached to the exposed intercostal nerves above and below the aorta to be blocked during surgery, and spinal evoked potentials from the electrodes. An evoked potential detecting device for detecting the preoperative spinal cord evoked potential, and detecting and storing the spinal evoked potential during operation, and storing the preoperative spinal cord evoked potential from the stored preoperative spinal evoked potential A threshold value is set to an arbitrary level from the amount of change leading to the evoked potential, and the spinal cord evoked potential that changes over time is compared with the threshold value to determine a spinal cord ischemia state, And an alarm device for generating an alarm based on the alarm device.

  In one embodiment, the evoked potential electrode device includes a pair of electrodes and a holding portion that holds the pair of electrodes, and a tip portion of the electrode protrudes outward from an end portion of the holding portion, The electrode and the holding part are relatively movable, and a hook part capable of engaging with the intercostal nerve is provided at the distal end part of the electrode, and the electrode or holding is performed with the intercostal nerve engaged with the hook part. The intercostal nerve can be clamped between the hook part and the holding part by moving the part.

  In one embodiment, the holding portion is a case, and the pair of electrodes are disposed in the case so as to protrude and immerse, and an elastic body is interposed between the electrode and the case so as to immerse the pair of electrodes into the case. The intercostal nerve can be clamped between the hook portion of the electrode and the tip portion of the case.

  In one embodiment, electrical connection means to the electrodes is provided in the case.

  In one embodiment, the electrical connection means includes a stereo jack and an electrode cable that connects the stereo jack and the electrode.

  In one embodiment, the holding part is provided with a fixing claw that can be pierced into the tissue.

  In one embodiment, the holding portion is a cylindrical body that accommodates the electrode, a pair of electrodes are arranged in the cylindrical body so as to be movable in the axial direction of the cylindrical body, and a supporting portion that supports the electrode is the cylindrical body And an elastic body that biases the electrode so as to be immersed in the cylindrical body is disposed between the cylindrical body and the support portion.

  In one embodiment, the holding portion is a tube that wraps the electrode, the tube is configured to be movable in the axial direction of the electrode, and a support portion that supports the electrode is movably fitted to the tube, and the support A spring for urging the tube in the direction of the hook portion of the electrode is disposed between the portion and the tube.

  In one embodiment, each of the electrodes is surrounded by the tube, and the pair of tubes are connected by a connecting member.

  In one embodiment, the interval between the pair of electrodes is 2 to 3 mm.

  The spinal cord evoked potential measurement method of the present invention detects the spinal cord evoked potential from the intercostal nerve, detects and stores the preoperative spinal cord evoked potential, and detects and stores the spinal cord evoked potential during the operation, and stores the preoperatively stored state. The threshold value is set to an arbitrary level from the amount of change from the spinal cord evoked potential to the spinal cord evoked potential during surgery, and the spinal cord evoked potential that varies over time is compared with the threshold value to determine the spinal cord ischemic state during surgery. Judgment is made, and an alarm is generated based on the judgment result, whereby the above object is achieved.

  According to the intraoperative evoked potential diagnosis support system for monitoring spinal cord ischemia during surgery according to the present invention, by having an evoked potential electrode device attached to each of the upper and lower exposed intercostal nerves, The upper intercostal nerve is electrically stimulated from the attached evoked potential electrode device, and the evoked potential electrode device attached to the lower intercostal nerve records the electric signal transmitted through the spinal cord and transmitted to the lower intercostal nerve as a waveform. Here, since the evoked potential electrode device has the above-described configuration, the electrode can be reliably and stably brought into contact with the intercostal nerve. In addition, the function of the spinal cord as a nerve transmission path can be evaluated in detail, and the position of the spinal cord where ischemia, damage, etc. can be accurately grasped.

  The patent applicant has already used this method in animal experiments and demonstrated its effectiveness.

  Since the evoked potential electrode device of the present invention can be used in the surgical field, it can also be applied to emergency surgery cases. In addition, the influence of anesthesia such as a muscle relaxant is small, the spinal cord can be monitored corresponding to the position of the aorta to be operated, and a localized diagnosis of spinal cord ischemia is possible.

  Moreover, according to spinal cord evoked potential measurement using an evoked potential electrode device, it is possible to evaluate the function of the spinal cord as a nerve transmission path in detail by continuously analyzing the detection results, and ischemic, injured, etc. It is possible to grasp the position of the spinal cord where is occurring.

  In addition, the intercostal nerve stimulation and recording electrodes necessary for performing this method can efficiently stimulate and record without damaging the intercostal nerve. This is because the current flowing through the spinal cord by electrical stimulation is recorded as an electromagnetic waveform, and when the spinal cord is exposed to ischemia, the conduction of electricity deteriorates, and this is a method of observing changes such as a decrease in the amplitude of the waveform. . In addition, if the electrode for measuring spinal cord evoked potential is minute, lightweight, and flexible, it can be appropriately placed on the surface with an appropriate pressure without damaging the nerve even if it is in direct contact with the nerve.

  In addition to spinal cord ischemia monitoring in thoracoabdominal aortic surgery, descending thoracic aortic aneurysm surgery and spinal cord injury surgery, spinal cord injury due to traffic accidents, falling over high places, falls, bruises, underlays, etc., spinal cord injury due to metastasis, tumors, etc. The present invention can also be applied to the diagnosis.

  In addition, since the spinal cord evoked potential (Tic-ESCP) due to intercostal nerve stimulation is monitored, first, the waveform of Tic-ESCP is simple and reflects activation over a short segment of the spinal cord, so it is less susceptible to external noise. . Second, it does not require pre-operative preparation such as electrode placement outside the dura mater and is not only available in an emergency, but also used in patients undergoing anticoagulation or antiplatelet treatment Is possible. Third, muscle relaxants can be used and the nerve potential can be evaluated without muscle interference. Although the electrodes are small, the waveform is simple and clear, so the analysis of the waveform is easy. Fourth, because of direct stimulation to the nerve, less stimulation is needed.

  In particular, since the holding portion is provided with a fixing claw that can be pierced into the tissue, the holding claw can be pierced into the tissue and the holding portion can be fixed at an arbitrary position in the tissue.

  It can also be comprised with a case as a holding | maintenance part. In that case, since the pair of electrodes arranged in the case is projecting and retracting from the case (movable in the front-rear direction), the electrode slides from the case and projects, and a hook provided at the tip of the electrode By engaging the part with the intercostal nerve and moving the electrode into the case in that state, the electrode can be reliably and stably brought into contact with the intercostal nerve.

  According to the intraoperative evoked potential diagnosis support system of the present invention, the spinal cord evoked potential is detected from the intercostal nerve, and the spinal evoked potential before and during the operation is detected and stored. A threshold is set to an arbitrary level of change from the stored preoperative spinal evoked potential to the intraoperative spinal evoked potential, and the spinal evoked potential that varies with time is compared with the set threshold to determine the spinal cord ischemic state. judge. Based on the determination result, an alarm is generated. Therefore, information on the patient's spinal cord ischemia can be easily and reliably obtained at the time of surgery or examination.

  Furthermore, according to the evoked potential electrode device, a hook portion that can be engaged with the intercostal nerve is provided at the tip portion of the electrode, and the electrode or the holding portion is moved in a state where the intercostal nerve is engaged with the hook portion, The intercostal nerve can be sandwiched between the hook part and the end part of the holding part.

  Therefore, the electrode is moved from the holding part and the hook part formed at the tip of the electrode protrudes outward from the holding part, the hook part is engaged with the intercostal nerve, and the electrode is moved to the holding part side in this state ( Alternatively, the intercostal nerve is sandwiched between the hook portion and the tip of the holding portion by moving the holding portion while the hook portion is engaged with the intercostal nerve. As a result, the electrode can be reliably and stably brought into contact with the intercostal nerve.

  In this way, the electrodes of the evoked potential electrode device are respectively attached to the upper and lower exposed intercostal nerves of the aorta that are blocked during the operation, and the upper intercostal nerves by the evoked potential electrode device attached to the upper intercostal nerve The electrical signal transmitted to the lower intercostal nerve through the spinal cord from the evoked potential electrode device attached to the lower intercostal nerve is recorded as a waveform.

  In this way, since an intraoperative evoked potential diagnosis support system based on intercostal nerve stimulation and intercostal nerve recording is obtained, preoperative preparation is unnecessary, it is possible to cope with emergency cases, and it is difficult to be affected by anesthesia.

  Since the case is provided with means for electrical connection to the electrodes (for example, a stereo jack and an electrode cable), the electrodes can be easily pushed forward or stored in the case with respect to the case. Manufacture is also easy.

Embodiments of the present invention will be described below.
(Evoked potential electrode device)
As shown in FIGS. 1 to 5, the evoked potential electrode device 2 of the present invention includes a case 12 as a holding portion, a pair of electrodes 14 disposed so as to protrude and immerse in the case 12, and both electrodes 14. Fixing means 26 that can be fixed to the case 12 in a state of protruding from the opening 18 of the case 12.

  The case 12 is formed in a flat box shape using an electrically insulating resin or the like, and electrodes 14 are respectively disposed on both sides of the case 12.

  An opening 18 is provided at the front end of the case 12, and the tip of each electrode 14 disposed in the housing part of the case 12 can protrude forward from the opening 18. Both electrodes 14 are configured to be slidable so as to protrude forward from the housing portion through the opening 18 or to be immersed and housed in the case 12.

  The shape of the electrode 14 is not limited as long as it does not damage the intercostal nerve, but in this embodiment, the electrode 14 is formed of a strip-shaped conductive metal piece as shown in FIG.

  As the material of the electrode, conventionally known materials can be used. For example, platinum, silver, copper, stainless steel, gold, or a conductor plated with gold can be used. In particular, gold and gold-plated ones are preferable. The thickness of the electrode is preferably 0.8 to 1.2 mm.

  Moreover, a conductive polymer can also be used as a material of the electrode. Examples of such a conductive polymer include polyacetylene, polypyrrole, polythiophene, poly p-phenylene, polyphenylene vinylene, and the like.

  The distance between the pair of electrodes 14 is preferably 2 to 3 mm from the viewpoint of the stability of the potential difference.

  The electrode 14 may be formed in a wire shape. The electrode 14 preferably has some elasticity. The opening 18 may be formed over the entire width of the case 12.

  A hook portion 15 that is curved downward is formed at the tip of both electrodes 14. The hook portion 15 has a shape that can engage with the intercostal nerve. The shape of the hook portion 15 can be semicircular when viewed from the side.

  A long hole 20 that is long in the front-rear direction is formed on the upper surface of the case 12, and an operation portion 26 connected to each electrode 14 projects outside through the long hole 20. Both electrode levers 22 are connected to each other by an electrically insulating connecting member.

  When the operation unit 26 is moved in the front-rear direction of the case 12 by hand or the like, both electrodes 14 slide in the front-rear direction within the case 12. The operation unit 26 may be constituted by a screw as a fixing means. The connection member (and the electrode 14) may be fixed to the case 12 by turning the screw 26 by hand, or the connection member and the electrode may be loosened by loosening the screw 26. 14 can be moved in the front-rear direction of the case 12 along the long hole 20.

  A pair of fixing claws 28 that can pierce the tissue are provided on the left and right sides of the rear surface of the rear portion of the case 12. The case 12 can be fixed at a desired position of the tissue by piercing the fixed claw 28 into the tissue at an arbitrary position.

  As shown in FIG. 2, an electrical connection means 30 to the electrode 14 is provided in the case 12. This electrical connection means 30 exposes the upper and lower intercostal nerves of the aorta that are blocked during the operation, attaches electrodes 14 to the respective intercostal nerves, electrically stimulates the upper intercostal nerves, and conducts the spinal cord. It is for receiving signals transmitted to the lower intercostal nerve.

  Specifically, the electrical connection means 30 includes a stereo jack 32 disposed in the case 12 and an electrode cable 34 connected from the stereo jack 32 to the electrode 14.

  The anode portion of the stereo jack 32 is connected to the rear end portion of one anode-side electrode 14 by an electrode cable 34, and the cathode portion of the stereo jack 32 is connected to the rear end portion of the other cathode-side electrode 14 by an electrode cable 34. Has been.

  Note that an elastic body 27 such as a spring may be provided as a fixing means in the case 12 to bias each electrode 14 in a direction in which it is accommodated in the case 12 (FIG. 10). When the elastic body 27 is provided, the screw 26 may be unnecessary.

  When the elastic body 27 is disposed in the case 12, the electrode 14 is protruded from the case 12 by operating the connecting member 24 by hand, and the intercostal nerve N is engaged with the hook portion 15 of the electrode 14. By releasing the hand from the connecting member 24, both electrodes 14 move to the case 12 side by the tensile force of the elastic body 27. The intercostal nerve N is sandwiched between the hook portion 15 and the front end surface 12 a of the case 12.

  As the elastic body 27, for example, a coil spring or the like can be used.

  FIG. 11 is a diagram showing another embodiment.

  In this embodiment, the holding member is constituted by a cylindrical case 12.

  An insertion hole 19 through which the electrode 14 passes is formed at the tip of the case 12.

  The pair of electrodes 14 are inserted into a cylindrical support portion 52. A base portion of the electrode 14 is fixed to the support portion 52. The support portion 52 is inserted into the case 12 so as to be movable in the axial direction of the case 12.

  A coil spring 27 is disposed between the support portion 52 and the case 12 and biases the hook portion 15 formed at the tip of the electrode 14 in a direction to move toward the case 12 side.

  An operation projection 54 is formed on the outer surface of the support portion 52 so that the support portion 52 or the case 12 can be easily operated in the axial direction by hand. In the figure, 66 is an electric cord.

  When the operation protrusion 54 is operated to move the support portion 52 in the longitudinal direction with respect to the case 12, the hook portion 15 of the electrode 14 protrudes from the case 12 or moves to the case 12 side.

  Therefore, as shown in FIG. 12, the intercostal nerve is engaged with the tip of the hook portion 15 in a state where the hook portion 15 is projected. When the hand is released from the operation projection again in the engaged state, the support portion 52 moves in a direction away from the case 12, so that the hook portion 15 moves toward the case 12. As a result, the intercostal nerve N engaged with the hook portion 15 is sandwiched between the distal end surface of the case 12 and the hook portion 15.

  FIG. 13 shows still another embodiment.

  In this embodiment, the evoked potential electrode device 2 includes a pair of electrodes 14 and a tube 56 as a holding portion that wraps each of the electrodes 14.

  The electrode 14 is inserted into the support portion 52, and the base portion of the support portion 52 is connected by a connecting member 58.

  The tube 56 covers the support portion 52 and the electrode 14 through a gap, and the tube 56 is configured to be movable in the axial direction of the electrode 14. The pair of tubes 56 are connected by an operation member 60.

  A compression spring 62 is disposed between the base of the tube 56 and the connecting member 58, and biases the tube 56 away from the connecting member 58. A flange 57 extending outward is formed at the tip of the tube 56.

Therefore, when the operating member 60 is operated by hand and the tube 56 is moved in the direction of the connecting member 58 against the spring 62, a space is formed between the hook portion 15 of the electrode 14 and the flange 57 at the tip of the tube 56. The When the intercostal nerve is positioned in this space and then the hand is released from the operation member 60, the tube 56 is pushed by the spring 62 and moves toward the hook portion 15 of the electrode 14. The intercostal nerve is sandwiched between the hook portion 15 and the flange 57.
(Evoked potential diagnosis support system)
As shown in FIGS. 6 and 7, the intraoperative evoked potential diagnosis support system 100 according to the present invention includes the evoked potential electrode device 2 configured as described above, which is attached to each of the upper and lower exposed intercostal nerves. Monitoring spinal cord ischemia. FIG. 6 shows an actual potential measurement in a dog, in which 4 indicates the aorta, 6 indicates the 11th intercostal nerve, 8 indicates the 12th intercostal nerve, and 10 indicates the spinal cord.

  In addition to the evoked potential electrode device 2, the intraoperative evoked potential diagnosis support system 100 of the present invention is generated in the spinal cord 10 by applying a pulse generator 40 that generates a stimulation pulse as an electrical stimulus to be applied to the spinal cord 10 and applying the stimulation pulse. A measurement unit 44 including a digital oscilloscope 42 that detects a signal waveform of the spinal cord evoked potential and a processing unit 46 that processes the measurement result of the spinal evoked potential obtained by the measurement unit 44 are provided as main components.

  The pulse generator 40 is configured to be able to output information on the generated stimulation pulse to the processing unit 46. The digital oscilloscope 42 is connected to the electrical connection means 30 disposed in the evoked potential electrode device 2 at the signal extraction side end, detects the signal waveform of the spinal cord evoked potential input through the wiring, and processes the result. The unit 46 can be output.

  The processing unit 46 is configured by, for example, a personal computer. In this case, the processing unit 46 can include an arithmetic processing unit (CPU) 48, a storage unit 49 including a semiconductor storage unit and the like, and a display 50 including a CRT and the like. The display device 50 visualizes and displays the processing result acquired by the arithmetic processing unit 48. The spinal cord evoked potential device 2 may be provided with an amplifier or the like.

  In order to measure the spinal cord evoked potential, a stimulation pulse is generated by the pulse generator 40 (for example, a current of 10 mA or less, particularly 2 mA to 3 mA), and this stimulation pulse is applied from the evoked potential electrode device 2 to the upper intercostal nerve 6. At this time, information on the stimulation pulse is output from the pulse generator 40 to the processing unit 46. Information on the stimulation pulse input to the processing unit 46 is processed by the arithmetic processing unit 48. Here, a current pulse is used as the stimulation pulse, but a voltage from the pulse generator 40 may be applied as the stimulation.

  In other words, the nerve cells of the intercostal nerve 6 are stimulated by the applied stimulation pulse, whereby a spinal cord evoked potential (evoked potential pulse) is generated in the spinal cord 10. The evoked potential pulse is propagated through a nerve transmission path formed in the nerve tissue constituting the spinal cord 10. The evoked potential pulse is input as an electrical signal to the digital oscilloscope 42 of the measuring unit 40 via the evoked potential electrode device 2 attached to the lower intercostal nerve 8. The digital oscilloscope 42 acquires the waveform of the evoked potential pulse from the input electrical signal as follows.

  FIG. 8 is a diagram showing a waveform of an evoked potential pulse acquired by the digital oscilloscope 42 based on an electrical signal from the electrode 14 attached to the twelfth intercostal nerve.

  Here, a waveform T12 of an evoked potential detected through the electrode 14 attached to the twelfth intercostal nerve by a stimulation pulse applied by the electrode 14 attached to the eleventh intercostal nerve, attached to the first lumbar nerve FIG. 2 shows a waveform L1 of an evoked potential detected through an electrode and a waveform L2 of an evoked potential detected through an electrode attached to the second lumbar nerve. The vicinity can be monitored to be normal with no spinal cord ischemia. When spinal cord ischemia occurs, the pulse waveform is flat.

  FIG. 8 shows the spinal cord evoked potential (Tic-ESCP) recorded between T12 and L2 with and without muscle relaxant, and the Tic-ESCP waveform is shown under either condition. Also consists of a small positive (P1) wave followed by a large negative (N1) wave. Each wave and incubation period are defined as shown in FIG. 9, and the upward rebound in the Tic-ESCP waveform is defined as negative in the present invention. Waveforms were recorded more clearly from the proximal intercostal nerve than from the distal intercostal nerve. When the muscle relaxant was used, the small P1 wave was unclear because the N1 wave was large. Since the baseline of Tic-ESCP is stable and the waveform is almost free of stimulus artifacts, the amplitude of Tic-ESCP is measured as the amplitude of the N1 wave. The latency of Tic-ESCP is measured as the latency of P1 and the latency of N1.

  From the above, the following can be understood.

  As an advantage of spinal cord evoked potential (Tic-ESCP) monitoring with intercostal nerve stimulation, first, the Tic-ESCP waveform is simple and reflects activation over a short segment of the spinal cord and is therefore less susceptible to external noise. Second, it does not require pre-operative preparation such as electrode placement outside the dura mater and is not only available in an emergency, but also used in patients undergoing anticoagulation or antiplatelet treatment Is possible. Third, muscle relaxants can be used and the nerve potential can be evaluated without muscle interference. Although the electrodes are small, the waveform is simple and clear, so the analysis of the waveform is easy. Fourth, because of direct stimulation to the nerve, less stimulation is needed.

  In FIG. 14, reference numeral 2 denotes an evoked potential electrode device attached to each of the upper and lower intercostal nerves exposed by the patient. The device 2 includes an electrode 14 that is fixed in contact with the intercostal nerve and captures an electrical signal based on a spinal evoked potential generated by the intercostal nerve stimulation.

  The electrode 14 is connected to one end of the connection cable 34. An insertion plug 35 is attached to the other end of the connection cable 34 and can be detachably connected to a monitor main body 70 having an oscilloscope 42 as indicated by an arrow.

  That is, on the upper surface of the case 70a of the monitor body 70, push buttons 80A and 80B of an operation switch 80, which will be described later, a display screen (areas 50a and 50b) of the display 50, an alarm buzzer 89a, an alarm lamp 89b, and the like are mounted. ing.

  As shown in FIG. 15, the monitor main body 70 accommodates electronic parts and the like below the signal amplifier 81 that operates in response to the push button operation of the stimulation unit 83 and the operation switch 80. The signal amplifier 81 amplifies the electrical signal captured by the electrode 14. The amplified signal is converted into a digital signal by the A / D converter 82 and input to the arithmetic processing unit 48. The arithmetic processing unit 48 performs arithmetic processing on the input signal to generate signal waveform data of the spinal cord evoked potential, supplies the signal waveform data to the display device 50, and outputs it to the comparator 85.

  In addition, when the arithmetic processing unit 48 receives a command from the operation switch 80, the arithmetic processing unit 48 outputs a content corresponding to the command to the display 50. In a normal case, the display 50 displays the signal waveform of the spinal cord evoked potential based on the signal waveform data of the spinal cord evoked potential from the arithmetic processing unit 48 in the area 50a of the display screen in an oscillographic manner.

  The AND gate 86 is turned ON by the ON command signal given from the operation switch 80 in the measurement preparation stage, and the signal waveform data of the spinal cord evoked potential in the pre-stage or the pre-stage of the patient obtained by the arithmetic processing unit 48. Is stored in the storage unit 49 as standard data. The storage unit 49 stores and saves the standard data.

  The comparator 85 compares the signal waveform data of the spinal cord evoked potential supplied from the arithmetic processing unit 48 with the standard data stored in advance in the storage unit 49, and outputs the difference to the determination unit 88. To do. The determination unit 88 determines the presence or absence of abnormality depending on whether or not the difference between the two data exceeds a certain allowable range. If it is determined that there is an abnormality, the abnormality information is output to the alarm buzzer 89a and the alarm lamp 89b and given to the display 50.

  When the abnormality information is received from the determination unit 88, the alarm buzzer 89a emits an alarm sound, for example, continuously or intermittently. The alarm lamp 89b emits an alarm by blinking a red lamp, for example. Further, the display 50 displays the content of the abnormality as a message in the area 50b on the display screen. Note that the alarm buzzer 89a, the warning lamp 89b, and the message display function unit of the display 50 include an acoustic alarm notification means using sound, an optical alarm notification means using light, and information using character information or image information. An alarm notification device including transmission type alarm notification means is configured.

  Next, the operation when the intraoperative evoked potential diagnosis support system of the present embodiment configured as described above is used in thoracoabdominal aortic surgery, thoracic descending aortic aneurysm surgery, and spinal cord injury surgery will be described.

  First, the operation when the signal waveform data of the spinal cord evoked potential measured before the operation of the patient prior to use is stored and stored in advance in the storage unit 49 as standard data for comparison will be described.

  It monitors spinal cord ischemia during surgery.

  The evoked potential electrode device 2 is connected to each of the exposed intercostal nerves, which are located above and below the aorta to be blocked, at an early stage before or during the operation when the patient is in a healthy state. Wear to make contact.

  In this state, the preparation mode push button 80A in the operation switch 80 is turned ON. The AND gate 86 is turned on to enter the preparation mode. In this state, the stimulation unit 40 generates a stimulation pulse, and this stimulation pulse is applied from the evoked potential electrode device 2 to the upper intercostal nerve 6. That is, the electric signal based on the spinal cord evoked potential taken in by the electrode 14 is amplified by the signal amplifier 81, converted into a digital signal by the A-D converter 82, and input to the arithmetic processing unit 48. The input digital signal is arithmetically processed by the arithmetic processing unit 48 to become signal waveform data of the spinal cord evoked potential. The signal waveform data of the spinal cord evoked potential is supplied as standard data to the storage unit 49 through the AND gate 86 which is already ON, and is stored and saved.

  Next, the operation during the operation will be described.

  In a state where the standard data is stored in the storage unit 49, the measurement mode push button 80B in the operation switch 80 is turned on. Then, the AND gate 86 is turned off and the measurement mode is set. In this state, when the stimulation pulse is generated by the stimulation unit 40, the signal waveform data of the spinal cord evoked potential generated every moment by the arithmetic processing unit 48 is supplied to the display 50 on one side and is displayed in the area 50a of the display screen. It is displayed as a signal waveform of spinal cord evoked potential. On the other hand, the signal waveform data of the spinal cord evoked potential is given to one input terminal of the comparator 85. Standard data is given from the storage unit 49 to the other input terminal of the comparator 85. Therefore, the comparator 85 sequentially compares the signal waveform data of the spinal cord evoked potential generated by the arithmetic processing unit 48 with the standard data stored in the storage unit 49 and detects the difference. The detected difference is sent to the determiner 88. In the determiner 88, the presence or absence of an abnormality is determined based on whether or not the difference between the two data exceeds the allowable range.

  As a result of the determination by the determination unit 88, when it is determined that there is an abnormality, an abnormality signal is issued from the determination unit 88, and this is given to the alarm buzzer 89a, the alarm lamp 89b, and the display unit 50. For this reason, an alarm sound is emitted from the alarm buzzer 89a, and the red alarm lamp 89b blinks to inform the patient of an abnormality. In addition, in the area 50b of the display screen of the display 50, the content of the abnormality is displayed as a message.

When the spinal cord is exposed to ischemia in this way, that is, when the measured signal waveform data of the spinal evoked potential deviates significantly from the standard data for comparison, the doctor and the nurse are automatically informed. An alarm is issued. For this reason, even a person who has little expertise regarding the waveform diagram can accurately grasp the spinal cord ischemia at that time.
(Intraoperative evoked potential diagnosis support system according to another embodiment)
Next, an intraoperative evoked potential diagnosis support system according to another embodiment will be described with reference to FIGS. 16 and 17.

  16 and 17, reference numeral 82 denotes an analog-to-digital converter. The analog-to-digital converter 82 converts the spinal cord evoked potential level detected by the evoked potential electrode device 2 into a digital signal and outputs it. 88 is a determination device, which is composed of, for example, a CPU having RAM, ROM, etc., from the spinal cord evoked potential level measured by the evoked potential electrode device 2, performs high level detection before operation and low level detection during operation, The alarm level set as the threshold value is compared with the spinal cord evoked potential level that is sequentially detected, and an alarm signal is output based on the result, and the entire apparatus is controlled.

  In order to automatically determine the spinal cord ischemic state, the determination can be made by storing a spinal cord ischemic state determination program in the ROM in advance. Alternatively, manual determination by setting operation of the operation unit 80 described below can also be performed.

  The RAM temporarily stores high level data of the detected spinal evoked potential level before the operation, data of the spinal evoked potential level during the operation, alarm level in the case of manual determination, required data, and the like. The alarm signal is output from the determination unit 88 when the detected spinal cord evoked potential level is lower than the alarm level, that is, when a spinal cord ischemia occurs.

  Reference numeral 80 denotes an operation unit constituted by, for example, a keyboard or an operation panel having push buttons, selection of automatic determination or manual determination, setting of spinal cord evoked potential level and high level measured by the evoked potential electrode device 2, and alarm. Set levels, release alarms, and set various required data. Reference numeral 50 denotes a display unit, which is composed of, for example, a CRT or a liquid crystal display device and displays a trend of the spinal cord evoked potential level, an alarm level, required data, and the like.

  89b is an alarm device, which is composed of, for example, a light emitting element such as a light emitting diode (LED) and its drive unit, and generates an alarm by lighting or blinking according to an alarm signal output from the determiner 88. Note that the alarm device is not limited to the one that performs an alarm by light, but may be an alarm device 89a that performs an alarm by sound shown in the figure. The alarm device 89a may be configured by an acoustic element such as a buzzer or a small speaker and a driving unit thereof, and may generate an alarm by a buzzer sound or voice. Further, the alarm device 90 can be configured to emit an alarm by light and sound at the same time by combining an LED and either a buzzer or a speaker. In this way, the alarm is reliably transmitted to the doctor and nurse.

  Reference numeral 49 denotes a recording device which records changes over time such as a trend waveform of the spinal cord evoked potential level output from the determiner 88 and an alarm level for later analysis and analysis.

  Next, the spinal cord ischemia state determination process will be described with reference to the flowchart of FIG.

  The evoked potential electrode device 2 is attached to the upper intercostal nerve so that the electrode 14 is electrically connected to the upper intercostal nerve, and the evoked potential electrode device 2 is connected to the lower intercostal nerve. The spinal cord evoked potential is taken in via the evoked potential electrode device 2 and the analog-digital converter 82 so as to be electrically connected to the intercostal nerve (step S1). The spinal cord evoked potential level data captured by the determiner 88 is sent to the display device 50, and the waveform of the spinal cord evoked potential level is displayed on the screen (step S2). As shown in FIGS. 8 and 9, for example, the value of the detected spinal cord evoked potential level suddenly changes from the minus side to the plus side, and the spinal cord ischemia state changes greatly.

  The determination unit 88 detects and stores the preoperative spinal evoked potential level from the captured spinal evoked potential level (step S3), and further detects and stores the intraoperative spinal evoked potential level (step S4).

  Next, the determiner 88 sets an alarm level in a range exceeding a predetermined range with respect to the stored spinal cord evoked potential level (step S5), and continues measuring the spinal cord evoked potential level (step S6). This alarm level is automatically set based on setting parameters such as a scheduled operation time, a patient's blood pressure value (before surgery), a patient's condition, and the like.

  The determination unit 88 monitors the spinal cord evoked potential levels sequentially input to detect whether the spinal cord ischemia state is lower than the alarm level (step S8). If it occurs, an alarm signal is sent to the alarm device 90, and an alarm is generated from the alarm device 90, for example, by flashing light (step S9).

  When it is determined in step S8 that the spinal cord evoked potential level is equal to or higher than the alarm level, the process returns to step S6 to measure the spinal cord evoked potential level, and the display of the trend waveform of the spinal cord evoked potential level in step S7 is continued.

  After the alarm is generated in step S9, the determination unit 88 determines again whether or not the spinal cord evoked potential level is lower than the alarm level (step S10). If the level is higher than the alarm level, the operation unit 80 is operated to cancel the alarm. (Step S11), the alarm of the alarm device 90 is stopped.

  If it is determined in step S10 that the spinal cord evoked potential level is still lower than the alarm level, that is, if spinal cord ischemia has occurred, the process returns to step S9 to continue the alarm.

  After terminating the alarm in step S11, the measurement of the spinal cord evoked potential level is started again (step S12), the spinal cord evoked potential level trend is displayed on the screen of the display device 50, or recording is performed by the recording device 7. (Step S13).

  Finally, it is determined whether or not to continue the measurement (step S14). If the measurement is not continued, the measurement is terminated. If the measurement is continued, the process returns to step S8, and the above-described processing from step S8 is repeated.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range from the description of specific preferred embodiments of the present invention based on the description of the present invention and common general technical knowledge. It is understood that the patent applications cited herein are to be incorporated by reference in their entirety as if the contents themselves were specifically described herein.

It is a perspective view of the evoked potential electrode device of one example of the present invention. FIG. 2 is a plan view of the evoked potential electrode device shown in FIG. 1. It is a sectional side view of the evoked potential electrode apparatus shown in FIG. FIG. 2 is a front view of the evoked potential electrode device shown in FIG. 1. FIG. 2 is a rear view of the evoked potential electrode device shown in FIG. 1. It is the schematic explaining the use condition of the evoked potential electrode apparatus of one Example of this invention. It is explanatory drawing of the intraoperative evoked potential diagnosis support system of one Example of this invention. It is the wave form diagram obtained using the intraoperative evoked potential diagnostic support system of one Example of this invention. It is a figure which defines the waveform of Tic-ESCP. It is the schematic of the evoked potential electrode apparatus of the other Example of this invention. FIG. 6 is a perspective view of an evoked potential electrode device according to still another embodiment of the present invention. It is action | operation explanatory drawing of the evoked potential electrode apparatus shown in FIG. It is a schematic sectional drawing of the evoked potential electrode apparatus of the further another Example of this invention. It is a schematic perspective view of the intraoperative evoked potential diagnosis support system of one Example of this invention. It is a block diagram which shows the structure of the intraoperative evoked potential diagnosis support system of one Example of this invention. It is a block diagram which shows the structure of the intraoperative evoked potential diagnosis support system of the other Example of this invention. It is a flowchart of the intraoperative evoked potential diagnosis support system of the other Example of this invention.

Explanation of symbols

2 evoked potential electrode device 12 case 14 electrode 15 hook portion 16 fixing means 18 opening portion 27 spring 28 fixing claw

Claims (15)

An intraoperative evoked potential diagnosis support system that supports intraoperative diagnosis based on spinal cord evoked potentials,
A first electrode electrically connected to the superior intercostal nerve located above the aorta that blocks during surgery;
A second electrode electrically connected to the lower intercostal nerve located below the aorta that blocks during surgery;
A stimulation applying unit that applies a stimulation signal to one of the electrodes connected to the corresponding intercostal nerve so that the intercostal nerve is stimulated;
A potential detection unit that detects the spinal cord evoked potential generated by the intercostal nerve stimulation via the other of the two electrodes connected to the corresponding intercostal nerve;
A spinal cord ischemia detection unit for detecting spinal cord ischemia based on the spinal cord evoked potential;
An intraoperative evoked potential diagnosis support system comprising: an alarm generation unit that receives a detection output of the spinal cord ischemia detection unit and generates an alarm when the spinal cord ischemia occurs. Each of the first and second electrodes is moved by an electrode holding member between an attachment position where the corresponding intercostal nerve can be attached to the electrode and a fixed position where the corresponding intercostal nerve is fixed by the electrode. Is held possible,
The potential detector includes a signal amplifier that amplifies the electrical signal captured by the electrode,
The spinal cord ischemia detection unit
An arithmetic processing unit for processing a signal amplified by the signal amplifier to obtain signal waveform data of a spinal cord evoked potential;
A storage unit that stores and saves signal waveform data of spinal evoked potentials before operation as standard data;
A comparator that compares standard data stored in the storage unit with signal waveform data of spinal evoked potential obtained by calculation processing in the calculation processor at the time of measurement;
As a result of comparison by the comparator, it has a determiner that determines the presence or absence of abnormality depending on whether or not the difference between the two data exceeds the allowable range,
The alarm generator is
Having an alarm notification device for issuing a warning when the determination device determines that there is an abnormality,
The intraoperative evoked potential diagnosis support system according to claim 1. As the standard data stored in the storage unit, the signal waveform data of the average spinal cord evoked potential before the operation, which is calculated by the arithmetic processing unit, is stored in advance in the storage unit as a measurement preparation operation. The intraoperative evoked potential diagnosis support system according to claim 2. 3. The alarm notification device is at least one of an acoustic alarm notification unit using sound, an optical alarm notification unit using light, and an information transmission type alarm notification unit using character information or image information. The intraoperative evoked potential diagnosis support system as described. An evoked potential electrode device with electrodes attached to each of the upper and lower exposed intercostal nerves of the aorta that block during surgery;
An evoked potential detection device for detecting a spinal cord evoked potential from the electrode;
Detect and store the spinal cord evoked potential before surgery and detect and memorize the spinal cord evoked potential during surgery, and any level from the change from the stored spinal cord evoked potential before surgery to the spinal cord evoked potential during surgery A determination unit for determining a spinal cord ischemia state by comparing the threshold value to the spinal evoked potential that varies over time and the threshold value,
An alarm alarm device for generating an alarm based on an instruction of the determination device;
Intraoperative evoked potential diagnosis support system. The evoked potential electrode device has a pair of electrodes and a holding portion that holds the pair of electrodes, and a tip portion of the electrode protrudes outward from an end portion of the holding portion,
The electrode and the holding portion are relatively movable;
A hook portion that can be engaged with the intercostal nerve is provided at the tip of the electrode, and the electrode or the holding portion is moved in a state where the intercostal nerve is engaged with the hook portion. The intraoperative evoked potential diagnosis support system according to claim 5, wherein the intercostal nerve can be sandwiched between the evoked potentials. The holding portion is a case, and the pair of electrodes are disposed in the case so as to protrude and immerse, and an elastic body is provided between the electrode and the case so as to immerse the pair of electrodes into the case. The intraoperative evoked potential diagnosis support system according to claim 6, wherein the intercostal nerve can be sandwiched between the hook portion of the electrode and the distal end portion of the case. The intraoperative evoked potential diagnosis support system according to claim 7, wherein an electrical connection means to the electrode is provided in the case. The intraoperative evoked potential diagnosis support system according to claim 8, wherein the electrical connecting means includes a stereo jack and an electrode cable that connects the stereo jack and the electrode. "" The intraoperative evoked potential diagnosis support system according to claim 6, wherein the holding portion is provided with a fixed nail capable of being pierced into a tissue. The holding portion is a cylindrical body that accommodates the electrode, and a pair of electrodes are arranged in the cylindrical body so as to be movable in the axial direction of the cylindrical body,
The support part which supports this electrode is fitted to this cylinder, and the elastic body which urges | bips so that an electrode may be immersed in a cylinder is arrange | positioned between this cylinder and this support part. The intraoperative evoked potential diagnosis support system described in 1. The holding portion is a tube that wraps the electrode, the tube is configured to be movable in the axial direction of the electrode, and a support portion that supports the electrode is movably fitted to the tube, and the support portion and the tube The intraoperative evoked potential diagnosis support system according to claim 6, wherein a spring for urging the tube in the direction of the hook portion of the electrode is disposed therebetween. The intraoperative evoked potential diagnosis support system according to claim 6, wherein each of the electrodes is surrounded by the tube, and the pair of tubes are connected by a connecting member. The intraoperative evoked potential diagnosis support system according to claim 6, wherein an interval between the pair of electrodes is 2 to 3 mm. The spinal cord evoked potential is detected from the intercostal nerve, and the preoperative spinal cord evoked potential is detected and stored, and the intraoperative spinal cord evoked potential is detected and stored. A threshold is set to an arbitrary level from the amount of change leading to the evoked potential, and the spinal cord evoked potential that changes over time is compared with the threshold to determine the spinal cord ischemia during the operation, and an alarm is based on the determination result A method for measuring spinal cord evoked potentials.

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