JPH03146028A - Measuring instrument for motor nerve conduction speed distribution - Google Patents

Abstract

PURPOSE:To obtain an exact measurement result by executing several times an operation for simulating two points being on the peripheral side and the central side of a nerve bundle, respectively through a prescribed time, and generating data for coordinating the respective magnitude and time intervals in a detected induced potential each time. CONSTITUTION:A first point being on the peripheral side and a second point being in the central side of a nerve bundle to be tested are stimulated, respectively. First stimulation stimulates a first point, and after a time T1 from this time point, an operation for stimulating a second point is executed plural times. Second stimulation stimulates a second point, and after a time T2 from this time point, a first point is stimulated, and also, after a time T3, the operation for stimulating a second point is executed plural times again. Moreover, an induced potential of a governing muscle of the nerve bundle to be tested is detected. In waveforms of the detected induced potential, the respective sizes of the waveforms are calculated, and data for coordinating the respective sizes and time T1, T3 is generated.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement of a motor nerve conduction velocity distribution measuring device.

(Prior art) There are various methods for measuring the conduction velocity distribution of nerve fibers in a motor nerve bundle, among which the collision method (Colisio method) is used.
n Method). There are several collision methods, and practical methods include the Hopf method and the In(lram) method.

First, the Ho-knob method will be explained with reference to FIG.

In the Ho/F method, one point on the peripheral side (hereinafter referred to as the distal point) and one point on the central side (hereinafter referred to as the proximal point) of the test nerve bundle are stimulated with super-stimulation. As shown in Figure 2, the order of applying this stimulus is to apply stimulus St (indicated by ma) to the distal point, wait a certain time T1, and then apply stimulus S2 (indicated by ma) to the proximal point. give.

Stimulus S1. When S2 is applied to the test nerve bundle, an impulse is generated in each nerve fiber. In Fig. 2, the anterograde impulse caused by the stimulus SL is shown as 1, the retrograde impulse is shown as the beak, and the antegrade impulse caused by the sting fis2 is shown as the tail.

When time T1 is short, the retrograde impulse caused by sting ′, tXLS1 and the antegrade impulse caused by sting ff1s2 collide in both fibers F, which have a high conduction velocity, and fibers S, which have a low conduction velocity, and stimulate the dominant muscle M. Only the evoked action potential wave (hereinafter referred to as potential wave) Ml due to S1 is generated (Fig. 2A).

When time T1 becomes longer, fiber F becomes thorny! Since the retrograde impulse due to Sl passes through the proximal point and passes through the refractory period RFP (Refractory Period) of this proximal point, the antegrade impulse due to sting:/a, S2 reaches muscle M, causing the sting 'aS1 In addition to the potential wave M1 caused by
A potential wave M2 is generated due to 1s2 (FIG. 2B).

When the time T1 becomes longer, the fibers S also have thorns 21S2.
Since the anterograde impulse due to this reaches the muscle M, the potential wave M2 based on the stimulus S2 becomes larger (Fig. 2C).

In the above example, there are two nerve fibers, but in reality, one nerve bundle is composed of many nerve fibers, and if the time T1 is gradually lengthened from zero, the potential wave M2 will change over a certain time Ti. It appears from min, gradually increases in size, and becomes constant from a certain time T1 max.

The maximum conduction velocity of the test nerve bundle can be determined from this time T1 min, and the minimum conduction velocity of the test nerve bundle can be determined from the time "1max".Then, from the relationship between time T1 and the potential wave M2, the test nerve bundle's maximum conduction velocity can be determined from the time T1 min. Conduction velocity distribution can be determined.

Next, the Ingram method will be explained with reference to FIG.

In the Ingram method, two points, a distal point and a proximal point, of the nerve bundle to be tested are stimulated. First, a stimulus SL (indicated by ) is applied to the proximal point,
Next, after a time T4, a stimulus S2 (indicated by ma) is applied to the distal point.
is given, and after time T5, a sting fis3 (indicated by ma) is given again to the proximal point. The time interval T5 between the stimulation S2 and the stimulation S3 is such that only these two stimulations ff1s2 and S3 are applied to the test nerve bundle.In the absence of the stimulation S1, the impulses generated by both stimulations reach all the nerve bundles. The time interval is preset such that a collision occurs on the female.

In the figure, the anterograde impulse due to the stimulus fis1 is indicated by 1, the anterograde impulse due to the stimulus S2 is indicated by 1, the retrograde impulse is indicated by 1, and the antegrade impulse due to the stimulus ff1s3 is indicated by ).

When time T4 is short, the anterograde impulse caused by stimulus S1 and the retrograde impulse caused by stimulus 5as2 are fiber F and fiber S.
In either case, a collision occurs and disappears, and a potential wave M2 based on the stimulus S2 and a potential wave M3 based on the stimulus S3 are generated in the muscle M (FIG. 4A).

When time T4 becomes longer, fiber F becomes thorny! Since the anterograde impulse by SL passes through the distal part and the stimulus S2 is applied to this distal part after the refractory period RFP of this distal part has passed, the order of the retrograde impulse of the stimulus S2 and the stimulus S3 is Dominant impulses cause collisions on fiber F. For this reason, muscle M
In addition to the potential wave M2 caused by the stimulus S2, the potential wave M1 caused by the stimulus SL appears, and the potential wave M3 is applied only through the fiber S! S3 results in a potential wave M3 (FIG. 4B). That is, the potential wave M3 becomes smaller as the time T4 becomes longer.

When time T4 becomes even longer, the same thing as above occurs on fiber S, and the muscle M gets pierced! The potential wave M3 due to S3 is no longer generated (FIG. 4C).

In this example as well, it is assumed that there are two nerve fibers, but in reality, the nerve bundle (■) is composed of many nerve fibers, and if time T4 is gradually lengthened from zero, the potential wave M3 will change over a certain time T. . 1. It remains constant up to this time, and as it becomes longer than this time, it gradually decreases and disappears at a certain time T4IIIax. time"
The maximum conduction velocity of this test nerve bundle can be determined from 4 min, and the minimum conduction velocity of this test nerve bundle can be determined from time T4 max. The conduction velocity distribution of the test nerve bundle can then be determined from the relationship between time T4 and potential wave M3.

(Problem M to be solved by the invention) In the Hopf method, the test muscle M is pierced as shown in Figure 2.
It is excited twice by the impulse (g) caused by f1s1 and the impulse (hoof) caused by sting ff1s2.

Doubly, when two stimulation impulses are applied to a muscle in succession, two potential waves are generated in the muscle, but the waveform of the potential wave caused by the second stimulation is due to the influence of the first stimulation.
A phenomenon occurs in which the potential wave becomes different from the potential wave caused only by the second stimulus. This is a phenomenon called the double stimulation effect, and the second potential wave changes depending on the time interval between the two stimulations. If the distance between the two stimulation points is sufficiently long, the two potential waves will also be generated temporally separated by light, so the double stimulation effect will not be a problem. However, in areas where the Hopf method is used, such as the upper limbs, the distance between the two stimulation points is approximately 15an to 20cm;
Heavy stimulation effects are a problem. This effect causes the following problems.

In the Hopf method, when the impulse caused by the stimulus S1 and the impulse caused by the stimulus S2 no longer collide, the magnitude of the waveform of the potential wave M2 becomes constant as the magnitude of the potential wave M1, as shown by the dashed line in Fig. 5. However, in reality, it does not become the same and continues to gradually increase even if collisions no longer occur, as shown by the solid line in FIG. For this reason, the above-mentioned T, which determines the lk small conduction velocity, cannot be clearly determined.

　maX Furthermore, the Hopf method has the following drawbacks.

In the Hopf method, when the time T1 is short, the two potential waves M1 and M2 generated in the muscle M overlap with each other. Therefore, in order to actually specify the waveform of potential wave M2, the subtraction method (Su
btraction Method) is used. That is, the stimulus SL is applied to the distal point independently, and the waveform of the potential wave M1 is memorized. Then, the potential wave M2' is obtained by subtracting the previously stored M1 from a wave formed by superimposing the potential waves M1 and M2 obtained in actual measurement.

This method is based on the premise that when the potential waves caused by each stimulus overlap, they become a summed wave. However, it is questionable whether it really adds up. Furthermore, the fact that the potential waves caused by the two stimuli overlap means that while the muscle M is responding to the first stimulus, the second stimulus is applied. Interval T1 between the first stimulus and the second stimulus
changes, so the second stimulus cannot always be applied to the muscle M when the response to the first stimulus is the same. The state of muscle M will react differently depending on the state at that time when the next stimulus is given, so the potential wave is simply the sum of the potential wave due to the first stimulus and the potential wave due to the second stimulus. There will be no waves.

The following problems are common to the Hopf method and the Ingram method.

First, each method measures the magnitude of the potential wave. However, it is not possible to confirm whether the change in the magnitude of this potential wave is purely due to the presence or absence of impulse collision.

For example, if the electrodes for stimulating the subject are not properly attached, or if there is poor contact in the electrical connections of various parts, this will greatly affect the potential waves being measured. Conventionally, even if such a situation occurred, there was no way to know about it.

Next, it was explained that the Hopf method includes the double stimulation effect, but this effect is also included in the Ingram method. In the Ingram method, the time interval between potential waves M2 and M3 is constant, but the time interval between potential waves M1 and M2 varies. Since this interval is short, the potential wave M1 and the potential wave M2 have a composite form, which changes with time T4 and influences the potential wave M3. According to Hopf method, time T ・, in1+n+
According to the n-gram method, it is not possible to accurately determine the time T.
+ax, but the potential waves detected by either method contain errors due to the above-mentioned double stimulation effect, making it impossible to obtain accurate results.

By the way, in both the Hopf method and the Ingram method, the size of the waveform of the potential wave due to the stimulation of the proximal point, for example, the area, is calculated, and this area and the time T1. A graph showing the relationship with T4 has been created. Then, referring to this graph, the Hopf method calculates the time T when the area of the waveform becomes zero when changing the time T1 from a large value to a small value, while the man-Ingram method changes the time T4 to a small value. Time T when the area of the waveform becomes zero when changing from a value to a large value
I'm looking for. In any case, it was difficult to judge whether or not the area became zero in the above graph even if maX was used.

Furthermore, both the Hopf method and the Ingram method include the problem of refractory period. Generally, when a certain nerve fiber is stimulated, an impulse runs through that nerve fiber, but when that impulse passes, for example, a certain point, that point becomes unable to receive impulses from distant stimulation for a while.

This period is the refractory period. Therefore, the time T1 in the Hopf method and the Ingram method. T4 includes conduction time and refractory period. To obtain the conduction velocity from time TI and T4, the refractory period must be determined correctly. However, since the refractory period varies depending on the conduction velocity, the time T1. The conduction velocity cannot be determined by uniformly subtracting a certain refractory period from T4. Conventionally, there are various methods of uniformly subtracting, but these methods do not yield correct results. There is also a method of double stimulating the stimulation point (l) and determining the refractory period from the muscle potential wave caused by this stimulation, but since the stimulation point (■) is double stimulated with the same intensity, It will be different. Furthermore, the method proposed by Leifer and adopted by Ingram is used to calculate the average conduction time from the cross-correlation function of the two potential waves caused by single stimulation of the proximal and distal points, and calculate the average conduction time. Conduction time and ho...
Is T1 indicating the 50% point of the gradual increase curve of the lf method or 50% of the potential wave gradual decrease curve of the Ingram method? ! There is a method of estimating the average refractory period from the difference from the point T5. It is assumed here that when all nerve fibers with conduction velocities faster than the average conduction time are excited, they form a potential wave of 50% the magnitude, but this assumption has not been proven.

The present invention has been made to eliminate such conventional drawbacks, and its purpose is to provide a motor nerve velocity distribution measuring device that can obtain accurate measurement results.

[Structure of the Invention] (Means for Solving the Problems) The first invention comprises a stimulation means for stimulating a first point on the peripheral side and a second point on the central side of a touched nerve bundle, respectively. A control means for controlling the timing at which the stimulation applying means stimulates the first point and the second point, respectively; a potential detection means for detecting an evoked potential of the dominant muscle of the test nerve bundle; and the potential detection means a data creation means for creating motor nerve conduction velocity distribution measurement data based on the evoked potential detected by the data creation means; a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; A motor nerve conduction velocity distribution measuring device comprising display means for displaying the velocity distribution created by the velocity distribution creation means, wherein the control means is means for performing the following first control and second control, and the control means is means for performing the following first control and second control, The generating means is configured to generate a waveform of the evoked potential detected by the potential detecting means, a waveform caused by stimulation at the second point in the second control, and a waveform generated by the stimulation at the second point in the second control.
Calculate the magnitude of each waveform due to the re-stimulation of the point, and calculate the magnitude of each waveform and the time T1. This is a means to discipline the data associated with T3.

First control: The stimulation applying means stimulates the first point and stimulates the second point after a time T1 from this point in time, and the operation is performed a plurality of times at different times T1.

Second control: an operation in which the stimulation applying means stimulates the second point, stimulates the first point after a time T2 from this point, and stimulates the second point again after a time T3 from this point. is performed a plurality of times at different times T3, and the time T2 is such that when the point (2) and the second point are each stimulated once, the impulses from both stimulations are applied to the test nerve bundle. The interval between the two stimulation points is set such that a collision occurs in any nerve fiber, and the time T3 is set to match the value taken by the time T1.

The second invention is the first invention except for the control means and the data creation means.
This is the same as the structure of the invention. Here, the control means is a means for performing the following first control and second control, and the data creation means is a means for performing the following first control and second control, and the data creation means is a means for performing the second control in the first control, out of the waveform of the evoked potential detected by the potential detection means. Waveform due to stimulation,
This means calculates the magnitude of each waveform caused by stimulation at the second point in the second control, and generates data that correlates each magnitude with time T1.

First control: The same as the first control in the first invention.

Second control: Control is performed such that the stimulation applying means stimulates the second point between each of the plurality of operations in the first control.

The third invention is the first invention except for the control means and the data creation means.
and the same as the second invention. Here, the control means is a means for controlling the first control and second control described below, and the data creation means is a means for controlling the second point in the first control out of the waveform of the evoked potential detected by the potential detection means. The magnitudes of the waveforms caused by the stimulation again at the second point and the waveforms caused by the stimulation of the second point in the second control are calculated, and the respective magnitudes and time T4 are calculated.
It is a means to discipline data that is associated with.

First control: The stimulation applying means stimulates the second point, stimulates the first point at time T4f & from this point, and stimulates the second point again after time T5 from this point. The control is performed a plurality of times at different times T4, and the time T5 is such that when the first point and the second point are each stimulated once, the impulses from both stimulations reach which part of the test nerve bundle. The interval between the two stimulation points is set so that a collision occurs even in the nerve fibers of .

Second control: Control is performed such that the stimulation applying means stimulates the second point between each of the plurality of operations in the first control.

The fourth invention is the first invention excluding the control means and the data creation means.
This is the same as the third invention. Here, the control means is means for performing the following first, second, and third controls, and the data creation means is a means for performing the following first, second, and third controls, and the data creation means is a means for performing the second control in the first control, out of the waveform of the evoked potential detected by the potential detection means. The waveform caused by the stimulation of
Calculate the magnitudes of the waveforms caused by re-stimulation of the second point in the second control and the waveforms caused by stimulation of the second point in the third control, and calculate the respective magnitudes and time T.
1 or time T3.

First control: Same as the first control in the first invention.

Second control: Same as the second control in the first invention.

Third control: Same as the second control in the second invention.

A fifth invention has a configuration common to the first to fourth inventions, and a display control means for controlling the display means;
and input means for inputting a signal to the display control means,
The data creation means calculates the magnitude of each waveform from the evoked potential detected by the potential detection means, and creates data in which each magnitude and each waveform are associated with time data based on the stimulation timing. and the display control means causes the display means to display the data created by the data creation means, and selects one of the waveforms and the corresponding size data according to a signal given from the input means. However, it is a means for displaying these on the display means in a manner different from other waveforms and other size data.

A sixth invention has a configuration common to the first to fifth inventions, and the control means is means for performing the following first and second controls, and the data creation means is the second invention. In addition to calculating and finding the magnitude of the evoked potential waveform due to the stimulation at the second point in the control of
The time Ld from the time when the point is stimulated until the evoked potential due to this stimulation first appears, and the time Ll from the time when the second point is stimulated until the time when the evoked potential due to this stimulus first appears) In the second control, the time T at which the evoked potential due to the stimulation of the second point starts to appear is -1 min, and the maximum velocity Vmax in the test nerve bundle is determined. Formula Vm to calculate the maximum conduction velocity Vmax from the time Ld, Lp and the distance MDST between the first point and the second point
The relational expression between ax=DST/(Lp−Ld) and the time T1 in the second control and the motor nerve conduction velocity corresponding to that T1 V=(DST+RFP・xV
＞/T1, the time Lp, man max Ld, T ・, distance MDST, speed Vmax
This is a means to calculate and obtain the speed V recorded in the manual.

First control: The stimulation applying means controls the first point and the second point.
Stimulate each point once at predetermined time intervals.

Second control: Same as the first control in the first invention.

(Operation) In the configuration of the first invention, the first control performed by the control means is the same as the control of the Hop method described above, so the explanation is omitted here.The second control performed by the control means is shown in FIG. First, a stimulus S is applied to the proximal point (second point).
After a time T2 from this point, a stimulus S2 (indicated by M) is given to the first point distal to the first point, and after a time T3 from this point, a stimulus 53 is given to the second point again. (V
) is performed a plurality of times at different times T3. Stimuli SL, S2. The marks indicating the impulses by S3 are the same as those in the Ingram method described above. The impulses of the stimulus Sl and the impulse 'aS2 always cause a collision in both the fibers F and S, regardless of the time T3. Therefore, the potential detection means detects the potential waves M2 and M3 of the stimulus S2 at the distal point and the stimulus S3 at the proximal point. These potential waves M2, M
3, whose magnitude is always constant regardless of time T3,
The interval at which the two potential waves appear coincides with time T3. Since this time T3 is further set to match the time T1 in the first control, the interval between the appearance of the potential waves M1 and M2 shown in FIG. 2 used in the explanation of the Hop method and that shown in FIG. The intervals at which potential waves M2 and M3 appear coincide. That is, by the second control, a state is created in advance on the muscle M in which no collision occurs on any nerve fibers using the Hop method.

Although two nerve fibers are shown in Figures 2 and 3, there are actually many nerve fibers in one nerve bundle, and in the first control (Hopf method) and second control, The times T1 and T3 can be changed so that the potential wave changes gradually.

Figure 6 shows the relationship between the magnitude of the potential wave M2 obtained by the first control (indicated by a circle) and the time T1, and the magnitude of the potential wave M3 obtained by the second control (indicated by a cross). ) and time T3 (equal to T1). To explain this diagram, in the first control, when time T1 is small, potential wave M2 does not appear and its magnitude is zero;
When 1 reaches a certain value, a potential wave M2 appears. Then, when the time T1 becomes even longer, the potential wave M2 suddenly increases, and then gradually increases. On the other hand, in the second control, the potential wave M3 hardly changes regardless of the time T3 (T1). For example, time T1=T3=Tx
When , the potential wave M2 in the first control appears a time Tx after the appearance of the potential wave M1 as shown in FIG. 7(a), and the potential wave M3 in the second control also appears as shown in FIG. 7(b). The potential wave M2 appears at a time T2t'lt after it appears. The potential wave M2 in the first control and the potential wave M3 in the second control are the potential waves to be detected, and both of these are potential waves of the same magnitude (Ml in the first control).

In the second control, M2 > occurs after time T8. Therefore, the states of the muscles when the potential wave M2 in the first control and the potential wave M3 in the second control are generated are always the same in terms of the double stimulation effect described above. As the time Tx gradually increases, the potential wave M2 shown in FIG. 7(a) also gradually increases, and this wave becomes the same as the potential wave M3 shown in FIG. 7(b).

The time Tx at this time is the interval T maX between the two stimulation points when no collision of impulses caused by the two stimulations occurs in the first control, that is, the Hop method. That is, although the waveform size indicated by the O mark and the waveform size indicated by the × mark in FIG. 6 both include a double stimulation effect, the effects at each time Tx are of the same degree, When the difference dx between the two is taken, each effect is canceled out, and the difference dx becomes a value that is not due to the double stimulation effect. When this difference is zero, that is, when no collision occurs,
Both waveforms match. The first matching Tx is the time T1max described above. Therefore, this value is a value that is not affected by the double stimulation effect. The minimum conduction velocity can be determined from this time T.

maX In this case, even if the above-mentioned subtraction method is used, the difference between values containing the same error is taken, so the errors are canceled out.

In the configuration of the second invention, the first control performed by the control means is the same as the control for implementing the Hop method described above, and the second control performed by the control means is, for example, the first control in the first control. 1 before the point is stimulated.
It stimulates the body twice.

The data creation means calculates the magnitude of the potential wave M2 caused by the first control, and calculates the magnitude of the potential wave M2 caused by the stimulation of the second point by the second control, and calculates the respective calculation results and the time T.
Create data that associates 1 with 1. According to this calculation result, the potential wave M in the first control is as shown in FIG.
2 (indicated by a circle) and the time T1, and the magnitude of the potential wave M2 generated by the second control near the time of measurement of the potential wave M2 in the first control is shown by the Δ mark. The relationship between the time T1 and the time T1 can be seen.

Therefore, if an abnormality occurs while measuring the potential wave M2 under the first control, it can be known from the fact that the potential wave M2 under the second control takes a particularly unusual value.

In the configuration of the third invention, the difference from the second invention is that the Ingram method is used for □ instead of the Hopf method.

In the configuration of the fourth invention, among the controls performed by the control means, the first and second controls have been explained in the first invention, and the third control has been explained in the second invention, so their explanation will be omitted. do. The data creation means creates data as shown in FIG. With this data, the measured value by the Hopf method can be corrected.

In the configuration of the fifth invention, the display control means causes the display means to display a plurality of waveforms and a plurality of size data, and
One waveform and its corresponding size data are selected in accordance with the signal applied to the input means, and these are displayed in a manner different from the others.

In the configuration of the sixth invention, the speed distribution creating means
To find the speed V from 1, V = (DST + RFP ・ xv ＞/'r1m
The reason why in maX was used is as follows.

First, it is generally known that the refractory period is inversely proportional to the conduction velocity. If the refractory period of the nerve line area with conduction velocity ■ is RFPV, then VxRFP = V xRFP, H, = v
1Ilax onst Therefore, RFP = V /VXRFPIIli,・
(1) v max On the other hand, V=DST/('r1-RFPv)...(2)
Therefore, by substituting equation (1) into equation (2), we get
V=(V XRFP・+DST>/
71 maX m l n .

Furthermore, since VII18x=MCV V=　(MCVXRFP　・　+DST＞/711n It can be written as

(Example) An embodiment including the first to sixth inventions described above will be described.

FIG. 1 shows an overall configuration diagram of this embodiment. In the figure, 1 is a pair of electrodes that detect evoked action potentials generated in the muscles of the living body, and 2 and 3 are a pair of electrodes that apply voltage to and stimulate the L nerve bundle of the living body, respectively. An amplifier 4 is connected to the electrode 1, and an A/D converter 5 is connected to the output side of the amplifier 4. The A/D converter 5 converts the analog signal provided from the amplifier 4 into a digital signal. Electrode 2.3 is connected to stimulator 6. The stimulation device 6 is a device that generates a predetermined potential difference between the electrodes 2 or 3 in accordance with the applied signal. 7 is a personal computer. The personal computer 7 includes a CPU, a bus 9 connected to the CPU 8, and a ROM l0. RAM11. I10 boat 12, CRT
Controller 13, keyboard controller 14, printer controller 15, FD controller 16, and CRT 17 connected to each of these controllers 13 to 16.
, keyboard 18, copy machine 19, floppy disk (
FD) It is admonished from the device 20. The output side of the A/D converter 5 is connected to the I10 port 12, and the input side of the stimulator 6 is connected to the I10 port 12. A program is stored in the ROM10, and the CPU exchanges data with the RAM II, the I10 port 12, and the controllers 13 to 16, and controls each part based on this program.

Next, the operation of the device of this embodiment will be explained.

First, the operator attaches electrode 2 to the subject's wrist, electrode 3 to the subject's cubital fossa, and electrode 1 to the subject's skin at a portion corresponding to the abductor pollicis brevis muscle.

Here, the wrist is the distal point and the elbow fossa is the proximal point.

Then, the operator operates the keyboard 18 of the personal computer 7 to cause the CPU to start operations as shown in FIG.

When starting, the cpus will read the ISI which will be described later.
Step 200), perform measurements based on control A (step 201), then perform measurements based on control B (step 202), and then perform measurements based on control C. (step 203), then l5Ix=ISI
, makes the following judgment (step 204), and here YES.
If it is, it is the end, and if it is No, the ISI at that time is
A predetermined time Δt is added to the value of (step 205), and the process returns to step 201. In this example, I S I 1 =3.
5ms, I S I n = 5.7ms, △t = 0,
It is 05m5. FIG. 12 shows the timing of signals generated by each control and the potential waves that appear in response to the signals.

The details of the measurement based on the control A (step 201) will be explained with reference to FIG. 11.

In step 301, the CPU determines whether it is time to import data. Here, the data is evoked potential data given to the I10 boat 12 from the electrode 1 via the amplifier 4 and A/D converter 5. This period is set to appear every 0.1m5ec. cpus is Y in step 301
If it is determined to be ES, the process proceeds to step 306, where data is fetched and stored in the RAM 11, and the process returns to step 301. If the CPU 8 determines No in step 301, the process proceeds to step 302 and determines whether it is time to send a signal. Here, the signal is the signal (x-1>) shown in FIG. If the CPU 8 determines YES in step 302, it proceeds to step 307, sends out the above signal, and returns to step 301.The stimulation device 6 uses this signal to generate a potential difference in the electrode 3 at the proximal point. If the CPU 8 determines No in step 302, the process proceeds to step 303 and determines whether a predetermined time has elapsed.In other words, the CPU 5 determines whether sufficient time has elapsed to detect the potential wave. cpus is step 3.
If NO is determined in step 03, the process returns to step 301 and YES
If so, the process advances to step 304. In step 304, the CPU 8 calculates the area of the potential waveform based on the data stored in the RAM 11. That is, at this time, the waveform data (X-ia) as shown in FIG. 12(b) is stored in RAMll.
is stored, so calculate the area of this waveform. Then, in step 305, the CPU 8 sends this calculation result to l5I.
x and store it in RAMII and also store it on CRT19.
displayed on the screen. Here, waveform data (x-1a) is also displayed.

The details of the measurement based on control B (step 202) are explained in the thirteenth section.
This will be explained with reference to the figures. This control B is the same as the control explained using FIG. That is, the proximal point is stimulated first, the distal point is stimulated after time T2, and the proximal point is stimulated again after time T3. Here, time T2 is a fixed time that is set slightly shorter than the time it takes for an impulse traveling on a nerve fiber with the fastest conduction velocity to depart from a proximal point and reach a distal point, and is set in advance. It's what's needed.

To determine this T2, a conventional MCV measurement method is used. In this embodiment, it is set to 4.0 ms. The stimulation time interval is generally ISI (InterStimulum).
(us Interval), henceforth T3 will be indicated by ISI. I S I 1 in the first control
“It is set to 3.5m5ec.

FIG. 13 will be explained. First, the CPU determines whether it is time to import data (401). Here, data is evoked potential data given to I10 boat 12 from electrode 1 via amplifier 4 and A/D converter 5, as in the case of control rnA. At this time, as in the case of control A, O, 1m5
It is set so that it appears every ec. If the CPU 8 determines YES in step 401, the process proceeds to step 402, reads the data, stores it in the RAM 11, and returns to step 401. If the CPU 5 determines NO in step 401, the process proceeds to step 403, and determines whether it is time to send the first signal.

Here, the first signal is the signal (X-
2>, and is a signal given to the stimulation device 6 via the ■/○ port 12 after a certain period of time TA has elapsed since the start of the process according to this flowchart. CPt
If J8 determines YES in step 4t)3, it sends out the first signal in step 409 and returns to step 401. The stimulation device 6 uses this signal to generate a potential difference in the electrode 3 at the proximal point, thereby stimulating the proximal point. If the cpus determines NO in step 403, it proceeds to step 404 and determines whether it is time to send the second signal. Here, the second signal is the second signal of the signal (x-2) shown in FIG.
This is a signal given to the stimulator 6 via the I10 port 12 after 4 m5 (here, 4 m5) has elapsed. CPU8 is step 4
If YES in step 04, the process proceeds to step 410, where the second signal is sent and the process returns to step 401. Stimulator 6
generates a potential difference in the electrode 2 at the distal point by means of the second signal, thereby stimulating the distal point. cpus step 404
If the answer is NO, the process proceeds to step 405, where it is determined whether it is time to send the third signal. Here, the third signal is the third signal of the signal (x-2) shown in FIG. 12(a),
After the time ISI has elapsed since the second signal was sent, I
10 is a signal given to the stimulation device 6 via the boat 12. If cpus determines YES in step 405, it proceeds to step 411, sends out the third signal, and performs step 4.
Return to 01. The stimulation device 6 generates a potential difference again at the electrode 3 at the proximal point using the third signal to stimulate the proximal point. If cpus determines No in step 405, it proceeds to step 40B and determines whether a predetermined period of time has elapsed. That is, CPtJ8 determines whether sufficient time has elapsed to detect the potential wave. If the CPU determines NO in step 406, the process returns to step 401, and if it determines YES, the process proceeds to step 407. In step 407, the CPU 8
The area of the potential waveform is calculated based on the data stored in AMII. In other words, at this time, the RAM 11 has the information shown in FIG.
) is stored, so the area of the second waveform (the shaded part) is calculated.Then, the CPU 8 executes step 408.
fi This calculation result is associated with ■SIx and stored in RAM11.
and display it on the screen of the CRT 19. Here, the second waveform of the waveform data (x-2a) is also displayed.

The details of the measurement based on control #C (step 203) are described in the 14th section.
This will be explained with reference to the figures.

This control C is the Hop method control explained in FIG.

First, stimulate the distal point, and after time T1, stimulate the proximal point. Here, 1 hour T1 is the time S in control B mentioned above.
It is the same as Ix and changes in units of 0.05m5ec, in the first measurement.

I S I 1 = 3.5 m5ec.

FIG. 14 will be explained. First, the CPU determines whether it is time to import data (501). Here, data is I1 from electrode 1 via amplifier 4 and A/D converter 5 as in control A.
This is the evoked potential data given to the 0 boat 12.

This period is also set to appear every 0.1 fflSeC, similar to the first control. CPU8 is step 50
If YES is determined in step 1, the process proceeds to step 502, where the data is fetched and stored in the RAM 11, and the process proceeds to step 501.
Return to If the cpus determines No in step 501, it proceeds to step 503 and determines whether it is time to send the first signal. Here, the first signal is the signal (
x-3>, and after a certain period of time TA has elapsed from the start of processing according to this flowchart, I10
This is a signal given to the stimulation device 6 via the boat 12. C
If the PU8 determines YES in step 503, it proceeds to step 50B, sends out the first signal, and proceeds to step 50i.
Return to The stimulators use this signal to generate a potential difference in the electrode 2 at the distal point, thereby stimulating the distal point. CPU8
is N at step 503.

If it is determined that this is the case, the process proceeds to step 504, and it is determined whether it is time to send the second signal. Here, the second signal is shown in Fig. 12(a).
The signal shown in (x-3> is the second signal of
This is a signal given to the stimulator 6 via the I10 boat 12 after a time period SXx has elapsed since the signal was sent. CPU
8, if YES is determined in step 504, step 50
The process proceeds to step 9, where the second signal is sent, and the process returns to step 501. The stimulation device 6 stimulates the proximal point by generating a potential difference in the electrode 3 at the proximal point using the second signal. cpus
If NO is determined in step 504, the process proceeds to step 505, where it is determined whether a predetermined time has elapsed. That is, CPtJ8
determines whether sufficient time has elapsed to detect the potential wave. The CPU 8 returns N in step 505.

If it is determined to be YES, the process returns to step 501, and if it is determined to be YES, the process proceeds to step 506. In step 506, the CPU 8 calculates the area of the potential waveform based on the data stored in RAMII. That is, at this time, since waveform data (x-33) as shown in FIG. 12(b) is stored in the RAM 11, the area of the second waveform (the shaded part) is calculated. .

Then, cpus transfers the calculation result of step 507 to IS
I, and store it in the RAM 11 in association with the CRT 1.
Display on screen 9. Here, the second waveform of the waveform data (x-38) is also displayed.

When the processing based on the flowchart of FIG. 10 is performed in this way, l5Ix gradually increases as shown in FIG. 12. ISI, the potential wave M by the first control
When A and its area data, the potential wave M8 due to the second control and its area data, and the potential wave MC due to the third control and its area data are displayed, the result is as shown in Figure 159Figure 15 (A) ( B) (C) are the potential waves MA,
They correspond to MB and MC, and are shown vertically aligned with different ISIs. FIG. 15(D) shows the areas of the potential waves MA, MB, and MC, where the horizontal axis is ISI and the vertical axis is area. In addition to the functions shown in the aforementioned flowchart, the CPU of this embodiment has the functions shown in Fig. 15 (I
)), it has means for expressing the difference in area between potential wave MB and potential wave MC by its length.

Furthermore, cpus in this example sets the upper and lower limits of the horizontal axis coordinates for the waveforms shown in Figures 15 (A) to (C), extracts the characteristic parts of these waveforms, and calculates the area of these waveforms. It has means for calculating and means for interpolating the data thus obtained. The results of the processing performed by these means are shown in FIGS. 16 and 17. The CPU 8 then performs the processing shown in the flowchart of FIG.

FIG. 19 will be explained. First, CPLI8 steps 601
It is determined whether the first instruction key provided on the keyboard 18 has been pressed. cpus is YE in step 601
If it is determined to be S, the process proceeds to step 602, as shown in FIG. 17(C).
1 waveform (predetermined) of the potential wave IVIC shown in FIG. Display these in red. Here, other waveforms and area data are displayed in the same color other than red. Next, the CPU 8 proceeds to step 603 and determines whether the second instruction key provided on the keyboard 18 has been pressed. If the CPU 8 determines YES in step 603, it proceeds to step 606, selects the waveform with the larger ISI among the waveforms adjacent to the waveform currently displayed in red, and displays that waveform and its corresponding area data in red. At the same time, the waveform and area data that have been displayed in red are changed to the same color as other waveform and area data, and the process proceeds to step 607. If the cpus determines No in step 603, it proceeds to step 604 and determines whether the third instruction key provided on the keyboard 18 has been pressed. CPU
8, if YES is determined in step 604, step 60
Proceed to step 5, select the waveform with the smaller ISI adjacent to the waveform currently displayed in red, display that waveform and its corresponding area data in red, and display the area data that was previously displayed in red. The waveform and area data are colored in the same color as other waveform and area data, and the process proceeds to step 607. cpus
is also executed in step 6 when it is determined No in step 604.
Proceed to 07. CPU 8 uses keyboard 1 in step 807.
It is determined whether the fourth instruction key provided at 8 has been pressed. If the cpus determines YES in step 607, it proceeds to step 60B, where it stores the ISI of the waveform and area shown in red in RAM II, and then proceeds to step 60B.

Return to 603. As described later, this ISI
This is used as min data. Therefore, before pressing the fourth instruction key, the operator operates the second instruction key and the third instruction key to select the waveform shown in red,
For example, the selection is made in order from the larger ISI to the smaller one, and the fourth instruction key is pressed when the first linear waveform is selected. According to this operation, I S I m is more accurate than using only the graph (D) showing area data.
in can be determined. In this way I S
I min is stored in RAM II. If the CPU 8 determines NO in step 607, the process proceeds to step 609.
It is determined whether the fifth instruction key provided on the keyboard 18 has been pressed. The CPU 8 returns N in step 607.

If it is determined, the process returns to step 603 and 1. If YES, the process advances to step 610. cpus step 610
At that time, the waveform and area ISI shown in red are stored in RAM II. This ISI is ISI II
This is used as Iax data. Therefore, the operator must press the second instruction key and the third instruction key before pressing the fifth instruction key.
Move the area data shown in red by operating the instruction key, check the point where MB and MC first match, and then press the fifth instruction key. In this way I S I
max is stored in RAIVllll. When the CPU finishes processing in step 610, the process proceeds to step 611, and changes the waveform and area data currently displayed in red to the same color as other waveforms and area data.

According to this process, I S I min and I S I max can be accurately obtained with simple key operations.

Next, the CPU 8 performs the processing shown in the flowchart of FIG.

First, in step 701, the CPU 8 inputs the data shown in FIG. 17(D) and lSlm1n obtained in the previous process.

Based on ISI, ISI min to m
MA at each ISI up to ax ISI max,
M.B.

MCxMA/MB is calculated from the area value of MC.

This value is the area value of MC corrected MC (real)
It is.

Here, the reason for setting VIC[real) = MCxMA /MB will be described below.

MC = MA
It is prevented from becoming the same size as A.

Here (double stimulus effect) = MB /MA (collision effect)
It is expressed as =MC(real)/MA. Therefore, MC=lVIA XMB /MA xMC(real)
/MA Therefore, Mc(real) = MCxMA /
It is expressed in MB.

Next, in step 702, the CPU 8 controls the MC in each ISI.
(real) is stored in RAM II, and the corrected data is displayed on the CRT 17 as shown in FIG.

Next, the CPU 8 performs the processing shown in FIG.

First, in step 801, it is determined whether it is time to import data.

This period is set to appear every o, 1m5ec. If the CPU 8 determines YES in step 801, the process proceeds to step 804, and the process proceeds from electrode 1 to amplifier 4.
, takes in the evoked potential data applied to the I10 port 12 via the A/D converter 5, stores it in the RAM 11, and returns to step 801.

If it is determined No in step 801, step 80
Proceed to step 2, where it is determined whether it is time to send out the first signal. This timing is determined based on whether a predetermined period of time has elapsed since this process started. If the CPU 8 determines YES in step 802, it proceeds to step 803.
After outputting the first signal to the stimulator 6 through the 10 port 12, the process returns to step 801. This first signal causes the stimulator 6 to apply a potential difference to the electrode 2 at the distal point to stimulate the distal point. The CPU 8 returns N at step 802.

If it is determined that
Determine whether it is time to send the signal. During this period, the first
This is the time when a predetermined period of time has passed since the signal was sent. If the cpus determines YES in step 805, it proceeds to step 80B, where the stimulator 6 receives the second
After outputting the signal, the process returns to step 801. This second signal causes the stimulator 6 to apply a potential difference to the voltage at the proximal point 3. If the cpus determines No in step 805, it proceeds to step 807, and determines whether a predetermined period of time has elapsed since the second signal was sent. cpus is step 80
If it is judged as No in step 7, the process returns to step 801 and Y.
If it is determined that it is ES, the process advances to step 808.

In step 808, the CPU 5 calculates the potential wave latency Lp due to stimulation at the proximal point and the potential wave latency Ld due to stimulation at the distal point based on the data stored in RAMII. At this time, RAMII records the potential waves caused by the stimulation of the proximal and distal points, so the IJ of the nerve fiber with the maximum conduction velocity starts from the time when the second signal is sent.
It can be determined as the time from when the potential wave starts to appear, and similarly, Ld can be determined as the time from when the first signal is sent to when the potential wave starts to appear.

Next, in step 809, cpus calculates the minimum refractory period RFPmin. This is LJ), Ld obtained in the previous step 80B, and ISI − obtained in the previous process.
The formula RFP −=ISImi, −(Lpman
man - Ld).

Next, cpus determines the maximum conduction velocity Vm8x, or MCV, in step 810. This is step 80
The Lp and Ld obtained in B and the distance DST between the distal point and the proximal point measured in advance and stored in RAMII are expressed by the formula MC.
It is obtained by substituting V=DST/(Lp-Ld).

Next, in step 811, the cpus
Find which relational expression. This is the above DST, RFP,
, MCV is obtained by substituting the formula V=(DST+1n RFPIIli, XMCV>/ISI).

Next, in step 812, the CPU 8
The relational expression obtained in 1 and the data shown in Fig. 18 (RAM1
A histogram of conduction velocity is created every 1 m/sec based on
Store in I.

When determining the conduction velocity V from the ISI, the above method has the advantage of not only being able to accurately obtain the conduction velocity, but also being able to cope with the following situations.

In general, in the case of a normal person, I S I m, o is (Lp
-Ld). However, in a pathological state, r s
I m1ll f! shorter than E(LD-t,d). In other words, the refractory period may take a negative value. This should not happen in principle, but it does happen. The reason for this is that in pathological conditions, the response of nerve bundles deteriorates,
The point is that they use stronger stimuli than normal people to increase this response level. This is because when strong stimulation is applied to the proximal and distal points, the range in which the stimulation reaches the nerve expands, as shown in Figure 23, and the distance used for MCV measurement (D) IcV
However, there is a difference between the distance Dcoll and the distance Dcoll where the excitement actually causes a collision. That is, Dcoll<D
), a negative refractory period occurs. In such a case, the value of this negative refractory period can be calculated using the above method, that is, the formula V
= (DST+RFPITl,,XMCV)/A question arises as to whether it can be used as is in ISI, but there is no problem in using it in this formula. The reason is explained below.

RFPob the observed RFPmin Let the true RFPIIlio be RFPreal.

The speed ■ at a certain ISI is calculated as V = (D) fcV +RFPobxMCV) /I
It is obtained as SI...(1). MCV is D) iCV is also D
The same is true for coll, so the true V at DCOI+ is V= (Dcoll+RFPrealxMCV)/IS
I...(2) It is obtained as follows.

Here, RFPObS = I S I,i, −(L
p - Ld) = DCO1l/MCV + RFPreal-DHCV /MCV = (Dcoll-D)iCV + RFPrealxMCV)/MCV... (3) When formula (3) is substituted into formula (1), V = (D)IcV +Dcoll-DMCV +RF
PrealxMCV)/l5I = (Dcoll+RFPrealxMCV)/ISI
This equation is equation (2). In other words, the calculated V matches the true V.

FIGS. 24 to 28 are diagrams showing the results of each process when other subjects were measured using the apparatus of this embodiment.

Fig. 24 is shown in Fig. 15, Fig. 25 is shown in Fig. 16, and Fig. 26 is shown in Fig. 15.
The figures correspond to FIG. 17, FIG. 27 corresponds to FIG. 18, and FIG. 28 corresponds to FIG. 22, respectively.

In the above embodiment, the electrode 2.3 and the stimulation device 6 constitute the stimulation device, the electrode 1, the amplifier 4 and the A/D converter 5 constitute the potential detection means, and the CRT 7 constitutes the display means. It consists of The control means in the first invention is
Steps 503, 504, 505 shown in FIG.
, 508, 509 (first control) and steps 403, 404, 405, 408 shown in FIG.

409, 410, 411 (corresponds to second control).

The data creation means in the first invention includes steps 501, 502, 506, 507 shown in FIG.
Steps 401, 402, 407, 4 shown in Figure 3
It corresponds to 08.

The control means in the second invention includes steps 503, 504, 505, 508, 509 shown in FIG.
(First control) and step 302 shown in FIG.
307, 303 (second control).
The data creation means in the invention includes steps 501, 502, 506, 507 shown in FIG. 14 and steps 301, 306, 304, 305 shown in FIG.
is equivalent to

The control means in the fourth invention includes steps 503, 504, 505, 508, 509 shown in FIG.
(First control) and step 403 shown in FIG.
404, 405.

406, 409, 410, 411 (second control) and steps 302, 307, 3 shown in FIG.
03 (third control). The data creation means in the fourth invention is step 501 shown in FIG.
, 502 , 506 .

507 and steps 401, 402, shown in FIG.
407.

408 and steps 301, 306, shown in FIG.
304.

It corresponds to 305.

The data creation means in the fifth invention corresponds to steps 501, 502, 506, and 507 shown in FIG. The display means in the fifth invention includes the keyboard 18 and corresponds to steps 601 to 611 shown in FIG. 19.

The control means in the sixth invention corresponds to steps 802, 803, 805, 806, and 807 shown in FIG. 21, and the data creation means corresponds to step 80 shown in FIG.
1°804, corresponding to BO8-812.

Next, another embodiment will be described. This example is an improvement on the measurement using the Ingram method described above. The configuration of this embodiment is approximately the same as that shown in FIG.
10 stores a program shown in the flowchart of FIG. FIG. 30 shows the timing of signals that the CPU 8 outputs to the stimulation device 6 and the potential waves that appear in response to these signals.

The operation of this embodiment will be explained.

First, in step 900, the CPU 8 executes the ISI, which will be described later.
is set to 15Ix=ISI, and then in step 901 it is determined whether or not it is the data import time, and if it is, the process advances to step 902 to import the data.

That is, the CPU 8 samples the evoked potential appearing on the I10 port 12 from the electrode 1 via the amplifier 4 and A/D converter 5 at predetermined intervals, and stores the data in the RAM 11. CPU8 is step 90
If NO is determined in step 1, the process proceeds to step 903 and it is determined whether it is time to send out the first signal. Here, the first signal is the signal (x-1> shown in FIG. 30(a)), which is transmitted to the stimulator 6 via the I10 port 12 after a predetermined time TA after starting the process according to this flowchart. If cpus is determined as YES in step 903, the process proceeds to step 910, transmits the first signal, and returns to step 901.The stimulation device 6 uses this signal to apply a potential difference to the electrode 3 at the proximal point. If the cpus determines NO in step 903, it proceeds to step 904 and determines whether it is time to send the second signal.Here, the second signal is the signal shown in FIG. The signal (x
-2), which is a signal given to the stimulation device 6 via the I10 boat 12 for a certain period of time TBf& after sending out the first signal. If the CPU 8 determines YES in step 904, it proceeds to step 911, sends out the second signal, and returns to step 901. The stimulation device 6 stimulates the proximal point by generating a potential difference in the electrode 3 at the proximal point using the second signal. Here, the interval T between the first and second signals
8 are separated to such an extent that the potential waves generated by the respective signals are not influenced by each other.

If the cpus determines No in step 904, it proceeds to step 905 and determines whether to send the third signal.

Here, the third signal is the signal (X-
3), and the time l5I after sending the second signal
This is a signal given to the stimulator 6 via the I10 port 12 after x has elapsed. If the cpus determines YES at the step knob 905, the process proceeds to step 912, sends out the third signal, and returns to step 901.

The stimulation device 6 stimulates the distal point by generating a potential difference in the electrode 3 at the distal point using the third signal. Here, the interval ISI between the second signal and the third signal is set to increase Δ every time as described later. PH1 is step 90
If NO is determined in step 5, the process proceeds to step 906, and it is determined whether it is time to send the fourth signal. Here, the fourth signal is the 30th signal.
This is the signal (x-4) shown in Figure (a), and a certain period of time T has passed since the third signal was sent. I10 port 12 after elapsed
This is a signal given to the stimulation device 6 via the stimulator 6. If cpus determines YES in step 906, it proceeds to step 913, sends out the fourth signal, and returns to step 901. The stimulation device 6 stimulates the proximal point by generating a potential difference in the electrode 3 at the proximal point using the fourth signal. Here, the interval T between the third signal and the fourth signal.

is constant and its value is set slightly shorter than the time required for an impulse to travel between the distal and proximal points of the fiber with maximum conduction velocity. CPU8 goes to step 906
If the answer is No, the process proceeds to step 907, where it is determined whether a predetermined period of time has elapsed. That is, the CPU 8 determines whether sufficient time has elapsed to detect the potential wave. If the CPU 8 determines NO in step 907, the process returns to step 901, and if it determines YES, the process proceeds to step 908. cpu
In step 908, S calculates the area of the potential waveform based on the data stored in the RAM 11. That is, at this time R
Since waveform data as shown in FIG. 30(b) is stored in AM11, the waveform (x-18) for the first signal and the waveform (x-48) for the fourth signal (x-48) are
Calculate the area of each area (both shown with diagonal lines). Then, in step 909, cpus converts these calculation results into l5I.
x and stored in the RAM 11 and CRT 19
displayed on the screen.

The CPU 8 then proceeds to step 914, where the current IS
Determine whether I = ISIo. ISI is a preset value. If cpus determines YES in step 914, it ends, and if it determines NO, it ends in step 9.
Proceed to step 15. In step 915, cpus updates the current CPU 5I.
Add x=Δt and return to step 901.

When the process shown in FIG. 29 is performed, l5Ix gradually increases as shown in FIG. 30, and the potential wave generated by the fourth signal gradually decreases. When this process is completed, data as shown in Fig. 31 will be displayed and R
It is stored in AM11. In the figure, the Δ mark is the area of the potential wave M[) according to the first signal, and the O mark is the area of the potential wave ME according to the fourth signal.

According to this embodiment, by monitoring changes in MD when measuring using the Ingram method, it is possible to determine whether or not the measurement is being performed normally.

In this example, steps 903-90 of FIG.
7. 910 to 915 correspond to the control means of the third invention,
Steps 900 to 902 and 908 to 909 in FIG. 29 correspond to the data creation means of the third invention.

[Effects of the Invention] According to the first invention, it is possible to accurately determine the maximum time interval between two stimulation points at which no collision occurs in the Hopff method. Therefore, the accurate minimum conduction velocity can also be obtained by the Hopf method.

According to the second invention, abnormalities in the measurement state can be easily discovered in the Hopf method.

According to the third invention, abnormalities in measurement conditions can be easily discovered in the Ingram method.

According to the fourth invention, the magnitude of the potential waveform that is not affected by the double stimulation effect can be accurately determined for each stimulation interval using the Hopf method.

According to the fifth invention, in both the Hopf method and the Ingram method, when a plurality of sets of potential waveforms obtained from a muscle and their corresponding waveform areas are displayed, l among them can be easily identified.

According to the sixth invention, it is possible to accurately correct the refractory period in the Hopf method.

As described above, according to the first to fifth inventions, it is possible to accurately measure the motor nerve conduction velocity distribution.

[Brief explanation of the drawing]

Figure 1 shows the constituent countries of the device including the first to sixth inventions, and Figures 2 and 4 illustrate the Hopf method and Ingram method, respectively, which are the conventional motor nerve velocity distribution measurement principles. 3 is a diagram for explaining the measurement principle of the first and fourth invention devices, FIG. 5 is a diagram for explaining the problems to be solved with the conventional device, and FIGS. 6 and 7 are The figures for explaining the first invention in detail, FIGS. 8 and 9, are the second invention and the fourth invention.
Figures 10 to 2 are diagrams for explaining the effects of each of the inventions.
FIG. 8 is an explanatory diagram of the operation of one embodiment, and FIGS. 29 to 31 are explanatory diagrams of the operation of other embodiments. 1.2.3... Electrode 4... Amplifier 5... A/D converter 6... Stimulator 7... Personal computer 9... Bus 10... ROM 11... RAM 12...I10 boat 17...CRT 18...keyboard

Claims (6)

[Claims] (1) Stimulation applying means that stimulates a first point on the peripheral side and a second point on the central side of the nerve bundle to be tested, and this stimulation applying means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. In the motor nerve conduction velocity distribution measuring device, the control means causes the stimulation applying means to stimulate the first point and to stimulate the second point after a time T_1 from this point, if the time T_1 is different. a first control in which the stimulation applying means stimulates the second point, stimulates the first point after a time T_2 from this point, and then repeats the stimulation again after a time T_3 from this point; The control is to perform the action of stimulating the second point a plurality of times at different times T_3, and the time T_2 is set when the first point and the second point are each stimulated once. The time interval T_3 is set to be equal to the value taken by the time T_1, and the time T_3 is set to match the value taken by the time T_1. Of the waveforms of the evoked potentials detected by the potential detecting means, the data generating means is configured to perform a waveform of the stimulation at the second point in the first control and a waveform of the second point in the second control.
A motor nerve conduction velocity distribution measuring device characterized in that the magnitude of each waveform due to re-stimulation of the point is calculated, and data is created in which each magnitude is associated with the times T_1 and T_3. (2) Stimulation applying means that stimulates a first point on the peripheral side and a second point on the central side of the nerve bundle to be tested, and this stimulation applying means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. In the motor nerve conduction velocity distribution measuring device, the control means changes the time T_1 so that the stimulation applying means stimulates the first point and stimulates the second point after a time T_1 from this point. and a second control in which the stimulation applying means is controlled to stimulate the second point between each of the plurality of operations in the first control. The data creation means is configured to generate a waveform of the evoked potential detected by the potential detection means by stimulation at the second point in the first control, and a waveform of the waveform caused by stimulation at the second point in the second control.
A motor nerve conduction velocity distribution measuring device characterized in that the magnitude of each waveform due to stimulation at a point is calculated, and data is created in which each magnitude is associated with the time T_1. (3) Stimulation applying means for stimulating a first point on the peripheral side and a second point on the central side of the nerve bundle to be tested, and this stimulation applying means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. In the motor nerve conduction velocity distribution measuring device, the control means is configured such that the stimulation applying means stimulates the second point, stimulates the first point after a time T_4 from this point, and further stimulates the first point for a time T_5 from this point. The control is such that the operation of stimulating the second point again later is performed multiple times at different times T_4, and the time T_5 is such that the first point and the second point are each stimulated once. a first control in which the impulses from both stimulations collide with each other in any of the nerve fibers of the test nerve bundle; A second control is performed to stimulate the second point between each movement, and the data creation means is configured to control the first point out of the waveform of the evoked potential detected by the potential detection means. Data in which the magnitudes of the waveforms resulting from the re-stimulation of the second point in the control and the waveforms resulting from the stimulation of the second point in the second control are calculated, and each magnitude is associated with the time T_4. A motor nerve conduction velocity distribution measuring device characterized by creating a motor nerve conduction velocity distribution. (4) Stimulation applying means that stimulates a first point on the peripheral side and a second point on the central side of the test nerve bundle, and this stimulation applying means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. In the motor nerve conduction velocity distribution measuring device, the control means causes the stimulation applying means to stimulate the first point and to stimulate the second point after a time T_1 from this point, if the time T_1 is different. a first control in which the stimulation applying means stimulates the second point, stimulates the first point after a time T_2 from this point, and then repeats the stimulation again after a time T_3 from this point; The control is to perform the action of stimulating the second point a plurality of times at different times T_3, and the time T_2 is set when the first point and the second point are each stimulated once. The time interval T_3 is set to be equal to the value taken by the time T_1, and the time T_3 is set to match the value taken by the time T_1. and a third control in which the stimulation applying means is controlled to stimulate the second point between each of the plurality of operations in the first control or the second control, The data creation means includes a waveform of the evoked potential detected by the potential detection means, a waveform caused by stimulation at the second point in the first control, and a waveform at the second point in the second control.
Calculate the respective sizes of the waveform due to the stimulation of the point again and the waveform due to the stimulation of the second point in the third control,
A motor nerve conduction velocity distribution measuring device characterized in that data is created in which each magnitude is associated with the time T_1 or the time T_3. (5) Stimulation applying means that stimulates a first point on the peripheral side and a second point on the central side of the nerve bundle to be tested, and this stimulation applying means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. A motor nerve conduction velocity distribution measuring device, comprising a display control means for controlling the display means, and an input means for inputting a signal to the display control means, wherein the data creation means is configured to detect the induced voltage detected by the potential detection means. The size of each waveform is calculated from the potential, and data is created in which each size and each waveform are associated with time data based on the stimulation timing, and the display control means is generated by the data creation means. displaying data on the display means, and selecting one of the waveforms according to a signal provided from the input means.
A motor nerve conduction velocity distribution measuring device characterized in that the motor nerve conduction velocity distribution measuring device selects the data and the size data corresponding thereto, and displays these on the display means in a manner different from other waveforms and other size data. (6) Stimulating means for stimulating a first point on the peripheral side and a second point on the central side of the nerve bundle to be tested, and this stimulating means stimulates the first point and the second point, respectively. a control means for controlling the timing of each stimulation, a potential detection means for detecting the evoked potential of the muscle governing the test nerve bundle, and data for measuring motor nerve conduction velocity distribution based on the evoked potential detected by the potential detection means. a velocity distribution creation means for creating a motor nerve conduction velocity distribution based on the data created by the data creation means; and a display means for displaying the velocity distribution created by the velocity distribution creation means. In the motor nerve conduction velocity distribution measuring device, the control means is configured to perform first control such that the stimulation applying means stimulates the first point and the second point at a predetermined time interval. , performing a second control in which the stimulation applying means stimulates the first point and stimulates the second point after a time T_1 from this point a plurality of times at different times T_1; The data creation means determines the magnitude of an evoked potential waveform caused by stimulation of the second point in the second control based on the evoked potential detected by the potential detection means, and
The time Ld from the time when the first point in the first control is stimulated to the time when the evoked potential caused by this stimulation first appears, and the time Ld from the time when the second point is stimulated to the time when the evoked potential caused by this stimulation appears. Time L until first appearance
p, and the time T_1 when an evoked potential due to stimulation of the second point starts to appear in the second control.
, T_1_m_i_n is calculated, and the formula RFP_m_i_n=T_ represents the refractory period RFP_m_i_n of the nerve fiber with the maximum conduction velocity V_m_a_x in the test nerve bundle.
1_m_i_n-(Lp-Ld) and the times Ld, L
Formula V_m_a_x that indicates the maximum conduction velocity V_m_a_x from p and the distance DST between the first point and the second point
=DST/(Lp-Ld) and the relational expression V=(DST+RFP_m_i_n×V
_m_a_x)/T_1 and the times Lp, Ld, T_
1_m_i_n, distance DST, and velocity V_m_a_x to calculate and obtain the motor nerve conduction velocity V.