JPH066119B2 - Motor nerve conduction velocity distribution measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) 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 the motor nerve bundle. Among them, the collision method (Collison Metho
There is d). There are several collision methods, and the Hopf method and the Ingram method are practical methods.

First, the Hoff method will be described with reference to FIG.

In the Hoff 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 nerve bundle to be tested are stimulated by superstimulation. As shown in FIG. 2, the order of giving this stimulus is as follows. First, the stimulus S1 (shown by ▼) is given to the distal point, then a certain time T ₁ is set, and then the stimulus S2 (to the proximal point is given. Given). When the stimuli S1 and S2 are applied to the test nerve bundle, impulses are generated in each nerve fiber. In FIG. 2, the antegrade impulse by the stimulus S1 is shown by the retrograde impulse, and the antegrade impulse by the stimulus S2 is shown. It shows with.

When the time T ₁ is short, the retrograde impulse due to the stimulus S1 and the anterograde impulse due to the stimulus S2 cause collision in both the fiber F having a high conduction velocity and the fiber S having a low conduction velocity, and the stimulus S1 is applied to the dominant muscle M. A evoked action potential wave (hereinafter, referred to as a potential wave) M1 is generated (FIG. 2A).

When the time T ₁ becomes longer, in the fiber F, the retrograde impulse due to the stimulus S1 passes through the proximal point and passes the refractory period RFP (Refractory Period) of the proximal point.
The antegrade impulse due to reaches the muscle M, and in addition to the potential wave M1 due to the stimulus S1, the potential wave M2 due to the stimulus S2 occurs (FIG. 2B).

When the time T ₁ is further increased, the antegrade impulse due to the stimulus S2 reaches the muscle M even in the fiber S, so that the potential wave M2 based on the stimulus S2 becomes large (FIG. 2C).

In the above example, the number of nerve fibers is two, but in reality, one nerve bundle is composed of many nerve fibers, and if the time T ₁ is gradually lengthened from zero, the potential wave M2 is at a certain time. Appearing from T _1min , gradually increasing, and at a certain time T _1max
To be constant. From this time T _1min, the maximum conduction velocity of the subject nerve bundle can be obtained, and from the time T _1max , the minimum conduction velocity of the subject nerve bundle can be obtained. And time T
The conduction velocity distribution of the nerve bundle to be tested can be obtained from the relationship between ₁ and the potential wave M2.

Next, the ingram method will be described with reference to FIG. The ingram method also stimulates two points, the distal point and the proximal point, of the test nerve bundle. First, given a proximal point to the stimulus S1 (▽ indicated by), then stimulation S2 (indicated by ▼) distally point at a time T _4, stimulated proximal point again after ₅ time T S3 ( Given). The time interval T ₅ between the stimulus S2 and the stimulus S3 is such that, when only these two stimuli S2 and S3 are given to the test nerve bundle (when the stimulus S1 is absent), the impulses generated by both stimuli are all. The time interval is set in advance so that the collision occurs on the nerve fiber. In the figure, the anterograde impulse by the stimulus S1 is shown by the anterograde impulse and the retrograde impulse by the stimulus S2, and the anterograde impulse by the stimulus S3 is shown. It shows with.

When the time T ₄ is short, the antegrade impulse due to the stimulus S1 and the retrograde impulse due to the stimulus S2 collide and disappear in both the fiber F and the fiber S, and the stimulus S is applied to the muscle M.
A potential wave M2 based on 2, the potential wave _{M 3} based on stimulation S3
Occurs (FIG. 4A).

Passes through the antegrade impulses distal portion by fibers F in stimulated S1 when the time T ₄ is long, and since stimulation S2 is given to the distal portion after passing the refractory period RFP of the distal portion, stimulation The retrograde impulse of S2 and the antegrade impulse of stimulus S3 cause a collision on the 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 S1 appears, and the potential wave M3 becomes the fiber S.
The electric potential wave M3 is generated by the stimulus S3 applied via the electric field (Fig. 4B). That potential wave M3 is reduced by time T ₄ is prolonged.

Moreover also happen that similar to the above at time T ₄ the longer the fiber S, the potential wave M3 stimulation S3 changes not occur in the muscle M (Fig. 4 C).

Although the nerve fibers are two in this example, actually is one nerve bundle is composed from a number of nerve fibers, a certain time is potential wave M3 if gradually increasing the time T ₄ from zero until T _4min is constant, it becomes longer than the time T _4min gradually decreases and disappears at a certain time _T 4max. It is possible to obtain the maximum conduction rate of the subject nerve bundle from time T _4min, it is possible to obtain the minimum conduction velocity of the subject nerve bundle from time _T 4max. And time T ₄
The conduction velocity distribution of the nerve bundle to be tested can be obtained from the relationship between and the electric potential wave M3.

(Problems to be Solved by the Invention) In the Hoff method, the test muscle M has an impulse () caused by the stimulus S1 and an impulse caused by the stimulus S2 as shown in FIG. Get excited twice by. Generally, when two impulses are continuously applied to a muscle, two electric potential waves are generated in the muscle, but the waveform of the electric potential wave generated by the second stimulation is simply the second stimulation due to the influence of the first stimulation. The phenomenon that it becomes different from the electric potential wave due to only occurs. 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 are also generated sufficiently apart in time, and the double stimulation effect does not pose a problem. However, where the Hoff method is used,
For example, in the upper limb, the distance between two stimulation points is about 15 cm to 20 cm, and this double stimulation effect poses a problem. This effect causes the following problems.

In the Hoff method, when the impulse S1 and the impulse S2 cease to collide with each other, the potential wave M2 has the same magnitude (constant) as that of the potential wave M1 as shown by the alternate long and short dash line in FIG. It should be, but it does not actually become the same, and even if there is no collision as shown by the solid line in FIG. Therefore, it is not possible to clearly determine the T _1max that determines the minimum conduction velocity.

Furthermore, the Hoff method has the following drawbacks.

In the Hoff method, when the time T ₁ is short, the two electric potential waves M1 and M2 generated in the muscle M overlap each other. Therefore, in order to actually specify the waveform of the potential wave M2, the subtraction method (Subtracti
on Method) is used. That is, the stimulus S1 is independently applied to the distal point and the waveform of the potential wave M1 is stored.
Then, the potential wave M2 is obtained by subtracting the previously stored M1 from the wave formed by superposing the potential waves M1 and M2 obtained by actual measurement. This method is based on the premise that when the potential waves due to the respective stimuli overlap, the added wave results. But I wonder if it really adds up. Further, the fact that the potential waves of the two stimuli overlap means that the second stimulus is applied while the muscle M is undergoing the reaction of the first stimulus. Since the interval T ₁ between the first stimulus and the second stimulus changes, the second stimulus is not always applied when the response by the first stimulus in the muscle M is always the same. When the next stimulus is given, the state of the muscle M reacts differently according to the state at that time. Therefore, the potential wave of the first stimulus and the potential wave of the second stimulus are simply added to the potential wave. It won't be a wave.

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

First, the magnitude of the potential wave is measured by any method. However, it is not possible to confirm whether the change in the magnitude of the electric potential wave is purely due to the presence or absence of impulse collision.

For example, when the attachment of electrodes for giving a stimulus to a subject is not appropriate, or when the electrical connection of each part is poorly contacted, the potential wave during measurement is greatly affected. Even if such a situation occurs, there has been no method of knowing it in the past.

Next, it was explained that the Hoff method includes a dual stimulus effect, but this effect is also included in the Ingram method. In the Ingram method, the time interval between the potential waves M2 and M3 is constant, but the time interval between the potential waves M1 and M2 changes. And this problem is less since the potential wave M1 and the potential wave M2 becomes a form complexed, this is to influence the potential wave M3 changes with time T _4. The Hoff method can accurately _{calculate the} time T _1min , and the Ingram method can accurately _{calculate the} time T _4max. However, the potential waves detected by either method include the error due to the above double stimulation effect. However, accurate results cannot be obtained.

By the way, in both the Hoff method and the ingram method, the magnitude of the waveform of the electric potential wave due to the stimulation of the proximal point, for example, the area is calculated and a graph showing the relationship between this area and the times T ₁ and T ₄ is created. And determine the time T _1min at which the area of the waveform becomes zero when the Hoff method was changed from a large value of time T ₁ to a smaller value with reference to this graph,
On the other hand, in the Ingram method, when the time T ₄ is changed from a small value to a large value, the time T _4max when the area of the waveform becomes zero is obtained. In any case, it was difficult to judge whether the area became zero in the above graph.

Further, both the Hoff method and the Ingram method include the problem of the refractory period. In general, when a nerve fiber is stimulated, an impulse runs on the nerve fiber, but when the impulse passes, for example, a certain point, the point causes a state in which the impulse due to another stimulation is not accepted for a while. This period is the refractory period. Therefore, the times T ₁ and T ₄ in the Hoff method and the ingram method include the conduction time and the refractory period. In order to obtain the conduction velocity from the times T ₁ and T ₄ , the refractory period must be obtained correctly. However, the refractory period depends on the conduction velocity, so that the time T ₁ , T ₄
Therefore, if a certain refractory period is uniformly drawn, the conduction velocity is not required. Although there are various methods for uniformly drawing the values, the correct result cannot be obtained. Again 1
There is a method to double-stimulate the stimulation point of and to obtain the refractory period from the electric potential wave of the muscle by this stimulation. However, since the single stimulation point is double-stimulated with the same intensity, the refractory period in the Hoff method is It will be different. Furthermore, the method adopted by Ingram and proposed by Leifer, that is, the average conduction time is calculated from the cross-correlation of two potential waves by single stimulation at the proximal point and the distal point, and this average There is a method of estimating the average refractory period from the difference between the conduction time and T ₁ showing the 50% point of the Hoff method's gradual increase curve, or T ₅ showing the 50% point of the Ingram's potential wave gradual decrease curve. Here it is hypothesized that all nerve fibers with a conduction velocity faster than the mean conduction time will form a 50% magnitude potential wave when they are excited, but this assumption has not been proved.

The present invention has been made in order to eliminate such a conventional drawback, and an object thereof is to provide a motor nerve velocity distribution measuring device capable of obtaining an accurate measurement result.

[Structure of the Invention] (Means for Solving the Problems) The first invention is a stimulus applying means for stimulating a first point on the peripheral side and a second point on the central side of a test nerve bundle, respectively. The control means controls the timing at which the stimulus applying means respectively stimulates the first point and the second point, the potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and the potential detecting means Data creating means for creating motor nerve conduction velocity distribution measurement data based on the detected evoked potential, velocity distribution creating means for producing motor nerve conduction velocity distribution based on the data created by this data creating means, and this velocity In the motor nerve conduction velocity distribution measuring device, which comprises a display unit for displaying the velocity distribution created by the distribution creating unit, the control unit is a unit for performing the following first control and second control. Among the waveforms of the evoked potentials detected by the potential detecting means, the generating means includes the waveform by the stimulation of the second point in the first control, and the second waveform in the second control.
This is a means for calculating the size of each waveform by the second stimulation of the point of ( ₃₎ and creating data in which the respective sizes are associated with the times T ₁ , T ₃ .

First control: The stimulation applying means stimulates the first point, and after a time T ₁ from this point of time, an operation of stimulating the second point is performed a plurality of times at different times T ₁ .

Second control: The stimulus applying means stimulates the second point, stimulates the first point after time T ₂ from this time point, and again stimulates the second point after time T ₃ from this time point. The operation of performing the operation is performed a plurality of times at different times T ₃ , wherein the time T ₂ is an impulse due to both stimulations when the first point and the second point are stimulated once each. The intervals between both stimulation points are set so that collision occurs in any nerve fiber of the test nerve bundle, and the time T ₃ is set to match the value taken by the time T ₁ .

The second invention is the first invention except the control means and the data creating means.
It is the same as the configuration of the invention. Here, the control means is a means for performing the following first control and second control, and the data generating means is for the second point in the first control of the waveform of the evoked potential detected by the potential detecting means. This is means for calculating the size of each waveform by the stimulus and the waveform by the stimulus at the second point in the second control, and creating data in which each size is associated with time T ₁ .

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

Second control: The stimulating means controls the second point to be stimulated during each of the plurality of operations in the first control.

A third invention is the first invention except the control means and the data creating means.
And the same as the second invention. Here, the control means is a means for performing the first control and the second control described below, and the data creating means re-creates the second point in the first control in the waveform of the evoked potential detected by the potential detecting means. Of the waveform by the stimulation and the waveform by the stimulation of the second point in the second control, and calculate the magnitude and time T of each waveform.
_This is a means for creating data in which ₄ and ₄ are associated with each other.

First control: The stimulating means stimulates the second point, stimulates the first point after time T ₄ from this time point, and stimulates the second point again after time T ₅ after this time point. a operating a control to perform a plurality of times by varying the said time T _4, the test impulse with both stimulation when the time T ₅ is the first point and the second point is stimulated once each The interval between both stimulation points is set so that collision occurs in any nerve fiber of the nerve bundle.

Second control: The stimulus applying means controls to stimulate the second point between each of the plurality of operations in the first control.

A fourth invention is the first invention except the control means and the data creating means.
To 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 the second point in the first control in the waveform of the evoked potential detected by the potential detection means. Of the waveform by the second stimulation in the second control, the waveform by the stimulation of the second point in the third control, and the respective magnitudes are calculated. This is means for creating data in which time T ₁ or time T ₃ is associated.

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

Second control: The same as the second control in the first invention.

Third control: The same as the second control in the second invention.

A fifth invention has a configuration common to the above-mentioned first to fourth inventions, and a display control means for controlling the display means,
An input means for inputting a signal to the display control means,
The data creating means is a means for calculating the size of each waveform from the evoked potential detected by the potential detecting means, and creating data in which each size and each waveform are associated with time data based on the stimulation time. The display control means causes the display means to display the data created by the data creation means, and selects any one of the waveforms and the corresponding size data in accordance with a signal given from the input means. However, it is a means for displaying these on the display means in a mode different from other waveforms and other size data.

A sixth invention has a configuration common to the above first to fifth inventions, the control means is means for performing the following first and second controls, and the data creating means is the second control means. The magnitude of the evoked potential waveform due to the stimulus at the second point in the control of the
The time Ld from the time when the point is stimulated to the first appearance of the evoked potential due to this stimulus, and the time Lp from the time when the second point is stimulated to the time when the evoked potential due to this stimulation first appears. Then, in the second control, T _1min , which is the time T ₁ when the evoked potential due to the stimulation of the second point starts to appear, is obtained and has the maximum transmission speed V _max in the nerve bundle to be _tested. nerve fibers refractory period RFP _min the expressions RFP _min = T _1min - and (Lp-Ld), the time Ld, the distance between the second point and the first point and Lp D
Formula for _{obtaining the} maximum conduction velocity V _max from ST V _max = DS
T / a (Lp-Ld), the in the second control time _{T 1} and the relation _{V = (DST + RFP min ×} V max) / T 1 between the motor nerve conduction velocity V corresponding to the _{T 1,} the It is a means for calculating and obtaining the speed V from the times Lp, Ld, T _1min , the distance DST, and the speed V _max .

First control: the stimulus applying means has the first point and the second point.
Each point is stimulated once for each predetermined time interval.

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

(Operation) In the configuration of the first aspect of the invention, the first control performed by the control means is the same as the control of the Hoff method described above, and therefore the description thereof is omitted here. The second control performed by the control means will be described with reference to FIG. First, the stimulus S at the proximal point (second point)
1 (indicated by ▽) is given, and after a time T ₂ from this time point, a stimulus S2 ( ) Is given, and after a further time T ₃ from this point of time, the operation of giving the stimulus S3 (shown by) again to the second point is performed a plurality of times at different times T ₃ . Stimulus S1, S
The marks indicating the impulses due to S2 and S3 are the same as in the ingram method described above. Impulse stimulus S1 and stimulation S2 are fibers F, causing always collisions regardless of the time T ₃ in any of the S. Therefore, the potential detecting means is the stimulation S at the distal point.
2 and the potential waves M2 and M3 of the stimulus S3 at the proximal point are detected. This potential wave M2, M3 is always constant irrespective of T ₃ its magnitude time intervals two potential wave that appears is consistent with the time T _3. Since this time T ₃ is set so as to coincide with the time T ₁ in the first control, the interval between the appearance of the potential waves M1 and M2 shown in FIG. The intervals at which the potential waves M2 and M3 appear in the figure match. That is, the second control creates a state on the muscle M in which collision does not occur on all nerve fibers by the Hoff method in advance.

Although two nerve fibers are shown in FIGS. 2 and 3, there are actually many nerve fibers in one nerve bundle. In the first control (Hoff method) and the second control, Times T ₁ and T ₃ can be changed so that the potential wave gradually changes.
FIG. 6 shows the relationship between the magnitude of the electric potential wave M2 obtained by the first control (indicated by a circle) and the time T _1, and the magnitude of the electric potential wave M3 obtained by the second control (the mark of ×). And the time T ₃ (equal to T ₁ ). To explain this Figure, the magnitude does not appear potential wave M2 when the first time in the control T1 is small is zero, the time T ₁
When a certain value is reached, the potential wave M2 appears. And the potential wave M2 When the time T ₁ is further increased rapidly increases, then becomes gradually larger. On the other hand, in the second control, the potential wave M3 hardly changes regardless of the time T ₃ (T ₁ ). Here, for example, when the time T ₁ = T ₃ = T _X , the potential wave M2 in the first control appears after the time T _X from the appearance of the potential wave M1 as shown in FIG.
The potential wave M3 in the control of 1 appears after the time T ₂ from the appearance of the potential wave M2 as shown in FIG. 7 (b). Potential wave M2 in the first control and potential wave M3 in the second control
Is a potential wave to be detected, and these are all generated after a time T _X due to generation of a potential wave of the same magnitude (M1 in the first control, M2 in the second control).
Therefore, the states of the respective muscles when the potential wave M2 in the first control and the potential wave M3 in the second control are always the same in terms of the above-mentioned dual stimulation effect. Then, when the time T _X gradually increases, FIG.
The potential wave M2 shown in (a) also gradually increases, and this wave is shown in FIG.
It becomes the same as the potential wave M3 shown in (b). Time at this time T _X
Is the interval T _1max between the two stimulation points when impulse collisions due to the two stimulations no longer occur in the first control, that is, the Hoff method. That is, the magnitudes of the waveforms indicated by the circles and the magnitudes of the waveforms indicated by the x marks shown in FIG. 6 both include the dual stimulus effect, but the effect at each time T _X is similar. the difference d taking _X effect of each is offset the difference d _X therebetween is a value that does not depend on the double stimulating effect. When this difference is zero, that is, when the collision does not occur, the two waveforms coincide with each other. The first matching T _X is the time T _1max described above. Therefore, this value is a value that is not affected by the double stimulation. This time T
_The minimum conduction velocity can be known from _1max . in this case,
Even when the subtraction method described above is used, the difference between the values including the same error is taken, and the error is canceled.

In the configuration of the second invention, the first control performed by the control means is the same as the control for implementing the Hoff method described above, and the second control performed by the control means is, for example, the first control in the first control. The second point 1 before the point is stimulated
It stimulates the times. Data generating means calculates the magnitude of the potential wave M2 by the first control, and calculates the magnitude of the potential wave M2 stimulation of the second point by the second control, the respective calculation results and time T ₁ Create data that associates and. According to this calculation result, as shown in FIG. 8, the relationship between the magnitude of the potential wave M2 (indicated by a circle) and the time T ₁ in the first control is known, and the potential wave M2 in the first control is obtained. The relationship between the magnitude of the potential wave M2 generated by the second control (indicated by Δ) and the time T ₁ can be understood in the vicinity of the time of measurement of. Therefore, if an abnormality occurs during measurement of the potential wave M2 by the first control, it can be known that the potential wave M2 in the second control has a particularly changed value.

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

In the configuration of the fourth invention, the first and second controls among the respective controls performed by the control means have been described in the first invention, and the third control has been described in the second invention, so description thereof will be omitted. To do. The data creating means creates data as shown in FIG. This data makes it possible to correct the measured values by the Hoff method.

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 magnitude data, and
One waveform and size data corresponding to the one waveform are selected according to the signal given to the input means, and these are displayed in a mode different from the others.

In the configuration of the sixth aspect of the invention, the velocity distribution creating means sets the time T
_The reason why V = (DST + RFP _min × V _max ) / T ₁ is used to obtain the velocity V from ₁ is as follows.

First, it is generally known that the refractory period is inversely proportional to the conduction velocity. Let RFP _V be the refractory period of nerve fibers with conduction velocity V. V × RFP _V = V _max × RFP _min = Const Therefore RFP _V = V _max / V × RFP _min (1) On the other hand, V = DST / (T _{Since 1−} RFP _V ) ... (2), when the equation (1) is substituted into the equation (2) and arranged, V = (V _max × RFP _min + DST) / T ₁ .

Since V _max = MCV, it can be written as V = (MCV × RFP _min + DST) / T ₁ .

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

FIG. 1 shows the overall configuration of this embodiment. In the figure, 1 is a pair of electrodes for detecting an evoked action potential generated in a muscle of a living body, and 2 and 3 are a pair of electrodes for applying a voltage to one nerve bundle of the living body for stimulation. 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 an analog signal given from the amplifier 4 into a digital signal. The electrodes 2, 3 are connected to the stimulator 6. The stimulator 6 is a device that generates a predetermined potential difference in the electrode 2 or the electrode 3 in accordance with a given signal. 7 is a personal computer. The personal computer 7 includes a CPU 8, a bus 9 connected to the CPU 8, a ROM 10, a RAM 11, an I / O port 12, a CRT controller 13, a keyboard controller 14, a printer controller 15, and an FD controller 16 connected to the bus 9. And a CRT 17 connected to these controllers 13 to 16, a keyboard 18, a copying machine
19, a floppy disk (FD) device 20. The output side of the A / D converter 5 is connected to the I / O port 12, and the input side of the stimulator 6 is connected to the I / O port 12. The program is stored in ROM10, and CP
Based on this program, U8 sends and receives data to and from the RAM 11, I / O port 12, and controllers 13 to 16 and controls each unit.

Next, the operation of the apparatus of this embodiment will be described.

First, the operator attaches the electrode 2 to the subject's wrist, the electrode 3 to the subject's elbow fossa, and the electrode 1 to the skin of the portion corresponding to the subject's 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 make the CPU 8
10 Start the operation as shown in Fig. 10.

At the start, the CPU 8 sets ISI _X described later to ISI _X = ISI ₁ (step 200), performs measurement based on control A (step 201), and then performs measurement based on control B (step 202), then performs a measurement based on the control C (step 203), _then, ISI X = ISI _n performs Kano (step 204), where it becomes a YES the end, when the NO value of ISI _X at that time Is added to Δ for a fixed time (step 205) and the process returns to step 201.
In this example, ISI ₁ = 3.5 ms, ISI _n = 5.7 ms, Δt =
It is 0.05 ms. FIG. 12 shows the timing of the signal generated by each control and the potential wave that appears in response to the signal.

The details of the measurement (step 201) based on the above control A are described in the eleventh section.
It will be described with reference to the drawings.

The CPU 8 determines in step 301 whether it is time to take in the data. Here, the data is evoked potential data given from the electrode 1 to the I / O port 12 via the amplifier 4 and the A / D converter 5. This time is set to appear every 0.1 msec. If the CPU 8 determines YES in step 301, the CPU 8 proceeds to step 306 to fetch the data and R
Store in AM11 and return to step 301. If the CPU 8 determines NO in step 301, the CPU 8 proceeds to step 302 and determines whether it is a signal sending time. Here, the signal is the signal (x-1) shown in FIG. 12 (a), and after a predetermined time TA has elapsed from the start of the processing according to this flowchart, the I / O
This is a signal given to the stimulator 6 via the port 12. CP
If U8 determines YES in step 302, the process advances to step 307 to send the above signal and return to step 301. The stimulator 6 generates a potential difference in the electrode 3 at the proximal point by this signal and stimulates the proximal point. CPU8 is step 302
If NO is determined in step 303, the process proceeds to step 303, and it is determined whether a predetermined time has elapsed. That is, the CPU 8 determines whether or not enough time has passed to detect the potential wave. If the CPU 8 determines NO in step 303, the process returns to step 301, and YE
If S is determined, the process proceeds 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 RAM 11
Since the waveform data (x-1a) as shown in FIG. 6B is stored, the area of this waveform is calculated. And CPU8
In step 305, this calculation result is stored in the RAM 11 in association with ISI _X and displayed on the screen of the CRT 19.
Here, the waveform data (x-1a) is also displayed.

Details of the control B-based measurement (step 202) will be described with reference to FIG. This control B is the same as the control described with reference to FIG. That is, first the proximal point is stimulated, the distal point is stimulated after time T ₂ , and the proximal point is stimulated again after time T ₃ . Here, the time T ₂ is a constant time that is set to be slightly shorter than the time taken for the impulse traveling on the nerve fiber having the fastest conduction velocity to start from the proximal point and reach the distal point, It is required in advance. This T ₂ is obtained by the MCV measurement method that has been conventionally used. In this embodiment, it is set to 4.0 ms. The stimulation time interval is generally ISI (Iter Stimulus Interval)
Therefore, T ₃ will be referred to as ISI hereinafter. In the first control, ISI ₁ = 3.5 msec is set.

FIG. 13 will be explained. First, the CPU 8 determines whether it is time to take in data (401). Here, the data is the same as in the case of control A, from the electrode 1 via the amplifier 4 and the A / D converter 5 to I
This is evoked potential data given to the / O port 12.
Similar to the case of the control A, this time is also set to appear every 0.1 msec. CPU8 is YES at step 401.
If so, the process proceeds to step 402, the data is fetched, stored in the RAM 11, and the process returns to step 401. CPU8
If NO is determined in step 401, the process proceeds to step 403,
It is determined whether it is the first signal transmission time. Here, the first signal is the first signal of the signal shown in Figure 12 (a) (x-2) , I / O port after a predetermined time T _A has passed since the start of the process by the flowchart Stimulator 6 through 12
Is a signal to give to. CPU8 is YES in step 403.
If so, the first signal is transmitted in step 409 and the process returns to step 401. The stimulator 6 generates a potential difference in the electrode 3 at the proximal point by this signal and stimulates the proximal point. If the CPU 8 determines NO in step 403, it proceeds to step 404 and determines whether it is the second signal transmission time. Here, the second signal is the second signal of the signal (x-2) shown in FIG. 12 (a).
The second signal is a signal given to the stimulator 6 via the I / O port 12 after a lapse of a fixed time T ₂ (here, 4 ms) from the transmission of the first signal. If the CPU 8 determines YES in step 404, the process proceeds to step 410, the second signal is transmitted, and the process returns to step 401. The stimulator 6 generates a potential difference in the electrode 2 at the distal point by the second signal,
Stimulates its distal point. CPU8 is NO in step 404
If it is determined, the process proceeds to step 405, and it is determined whether it is the third signal transmission timing. Here, the third signal is the third signal of the signal (x-2) shown in FIG. 12 (a), and the I / O port after the time ISI _{X has} elapsed since the second signal was transmitted. 12
Is a signal given to the stimulator 6 via the. If the CPU 8 determines YES in step 405, the CPU 8 proceeds to step 411, transmits the third signal, and returns to step 401. Stimulator 6
Causes the electrode 3 at the proximal point to generate a potential difference again by the third signal to stimulate the proximal point. CPU8 is step 40
If NO is determined in 5, the process proceeds to step 406 and it is determined whether a predetermined time has elapsed. That is, the CPU 8 determines whether or not enough time has passed to detect the potential wave. If the CPU 8 determines NO in step 406, the process returns to step 401, and YE
If it is judged as S, the operation proceeds to step 407. CPU8 is step 4
At 07, the area of the potential waveform is calculated based on the data stored in the RAM 11. That is, at this time, the RAM 11 shown in FIG.
Since the waveform data (x-2a) as shown in (b) is stored, the area of the second waveform (hatched portion) is calculated. Then, the CPU 8 proceeds to step 408
Then, this calculation result is stored in the RAM 11 in association with the ISI _X and is also displayed on the CRT.
Display on screen 19. Here, the second waveform of the waveform data (x-2a) is also displayed.

Details of the measurement (step 203) based on the control C will be described with reference to FIG.

This control C is the control of the Hoff method described in FIG.
First, the distal point is stimulated, and after time T ₁ , the proximal point is stimulated. Here, the time T ₁ is the time I in the control B described above.
It is the same as SI _X and changes in 0.05 msec units.
In the first measurement, ISI ₁ = 3.5 msec.

FIG. 14 will be explained. First, the CPU 8 determines whether it is time to take in data (501). Here, the data is the evoked potential data given to the I / O port 12 from the electrode 1 through the amplifier 4 and the A / D converter 5 as in the control A. This time is also set so that it appears every 0.1 msec as in the first control. If the CPU 8 determines YES in step 501, the CPU 8 proceeds to step 502 to load the data into the RAM 1
Store in 1 and return to step 501. CPU8 is step 50
If NO is determined in 1, the process proceeds to step 503, and it is determined whether it is the first signal transmission time. Here, the first signal is shown in Fig. 12 (a).
In a 1st signal of the signal (x-3) showing a signal supplied after a predetermined time T _A has passed since the start of the process by this flow chart to stimulator 6 through the I / O port 12. If the CPU 8 determines YES in step 503, it proceeds to step 508 and sends the first signal to step 5
Return to 01. The stimulator 6 uses this signal to cause the electrode 2 at the distal point to
A potential difference is generated between the two to stimulate its distal point. CPU
If step 8 determines NO in step 503, step 8 proceeds to step 504 to determine whether it is the second signal transmission timing. Here, the second signal is the second signal of the signal (x-3) shown in FIG. 12 (a) and is the I / O port 12 after a lapse of time ISI _X from the transmission of the first signal. Is a signal given to the stimulator 6 via the. If the CPU 8 determines YES in step 504, the CPU 8 proceeds to step 509 and sends the second signal to step 5
Return to 01. The stimulator 6 generates a potential difference in the electrode 3 at the proximal point by the second signal to stimulate the proximal point. CP
If U8 determines NO in step 504, the process advances to step 505 to determine whether a predetermined time has elapsed. That is, the CPU 8
Determine if enough time has passed to detect the potential wave. If the CPU 8 determines NO in step 505, the process returns to step 501, and if YES, proceeds to step 506. C
In step 506, the PU 8 calculates the area of the potential waveform based on the data stored in the RAM 11. That is, at this time R
AM11 has waveform data (x-3) as shown in FIG. 12 (b).
Since a) is stored, the area of the second waveform (hatched portion) is calculated. And CPU
In step 507, 8 stores this calculation result in RAM 11 in association with ISI _X and displays it on the screen of CRT 19. Here, the second waveform of the waveform data (x-3a) is also displayed.

When the processing based on the flowchart of FIG. 10 is performed in this manner, ISI _X gradually increases as shown in FIG. When the potential wave MA and its area data under the first control, the potential wave MB and its area data under the second control, and the potential wave MC and its area data under the third control are displayed corresponding to ISI _X , It becomes like the figure. Fig. 15
(A), (B), and (C) correspond to the potential waves MA, MB, and MC, respectively, and are shown in the state of being aligned in the vertical direction with different ISI _X. FIG. 15 (D) shows the potential waves MA, MB, M.
In the figure showing the area of C, the horizontal axis is ISI and the vertical axis is area. In addition to the functions shown in the above-mentioned flow chart, the CPU 8 of this embodiment has the potential wave MB as shown by the vertical line in FIG.
And means for expressing the difference in area of the potential wave MC by its length. Further, the CPU 8 of this example sets the upper and lower limits of the abscissa coordinates for the waveforms shown in FIGS. 15 (A) to (C), extracts characteristic portions of these waveforms, and determines the areas of these waveforms. It has means for calculating and further means for interpolating the data thus obtained. The processing results performed by these means are shown in FIGS. 16 and 17. And the CPU 8 is the 19th
The process shown in the flowchart of the figure is performed.

FIG. 19 will be explained. First, in step 601, the CPU 8 determines whether the first instruction key provided on the keyboard 18 has been pressed. The CPU 8 proceeds to step 602 where YES is determined in step 601, and the potential wave MC 1 shown in FIG.
Waveform (predetermined) and its corresponding 17th
The area data (circle) shown in FIG. 3D is selected, and the CRT controller 13 is controlled to display them in red on the screen of the CRT 17. 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. CPU8 is step 60
If YES is determined in 3, the process proceeds to step 606, the waveform adjacent to the waveform currently displayed in red and having a larger ISI is selected, and the waveform and the corresponding area data are displayed in red. The waveform and area data displayed in red up to the same color as the other waveforms and area data are made the same and the process proceeds to step 607. When the CPU 8 determines NO in step 603, it proceeds to step 604 and determines whether the third instruction key provided on the keyboard 18 is pressed. CPU8
If YES is determined in step 604, the process proceeds to step 605, and the IS waveform is adjacent to the waveform currently displayed in red.
Select the waveform with the smaller I, display the waveform and the area data corresponding to it in red, and make the waveform and area data that were previously displayed in red the same color as other waveforms and area data. Proceed to 607. The CPU 8 also proceeds to step 607 when determining NO in step 604. C
In step 607, the PU 8 determines whether the fourth instruction key provided on the keyboard 18 has been pressed. If the CPU 8 determines YES in step 607, the CPU 8 proceeds to step 608, at which time the ISI of the waveform and area shown in red is RA.
After storing in M11, the process returns to step 603. This ISI is used as ISI _min data as described later. For this reason, the operator operates the second instruction key and the third instruction key before pressing the fourth instruction key to select the waveforms shown in red, for example, from the larger ISI to the smaller one. , When the first linear waveform is selected, the fourth instruction key is pressed. According to this operation, ISI _min can be determined more accurately than only by the graph (D) showing the area data. In this way ISI _min becomes R
It is stored in AM11. If the CPU 8 determines NO in step 607, the CPU 8 proceeds to step 609 and determines whether the fifth instruction key provided on the keyboard 18 has been pressed. CP
If U8 determines NO in step 607, it returns to step 603, and if it determines YES, it advances to step 610. CPU8
Stores in step 610 the ISI of the waveform and area then shown in red in RAM 11. This ISI is IS
It is used as I _max data. Therefore, the operator has to press the second instruction key and the third instruction key before pressing the fifth instruction key.
Is operated to move the area data shown in red, and it is confirmed that MB and MC first match, and then the fifth instruction key is pressed. In this way, ISI _max is stored in the RAM 11. Upon completion of the processing of step 610, the CPU 8 proceeds to step 611 and makes the waveform and area data currently displayed in red the same color as the other waveform and area data.

According to this process, ISI _min and ISI _max can be accurately obtained by a simple key operation.

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

First, the CPU 8 determines MA, MB, MC in each ISI from ISI _mim to ISI _max based on the data shown in FIG. _17D in step 701 and the ISI _min and ISI _max obtained in the previous processing. Calculate MC × MA / MB from the area value of. This value is MC
MC (real) obtained by correcting the area value of.

Here, the reason for setting MC (real) = MC × MA / MB will be described below.

MC = MA × (double stimulus effect) × (collision effect) In other words, MC originally appears in the same size as MA, but the double stimulus effect and impulse collision make it the same size as MA. It is hindered.

Here, (double stimulus effect) = MB / MA (collision effect) = MC (real) / MA. Therefore, MC = MA × MB / MA × MC (real) / MA Therefore, MC (real) = MC × MA / MB.

Next, the CPU 8 proceeds to step 702 in which MC (re
(al) is stored in the RAM 11 and the data corrected as shown in FIG. 18 is displayed on the CRT 17.

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

First, in step 801, it is determined whether it is time to take in data. This time is set to appear every 0.1 msec.
When the CPU 8 determines YES in step 801, the process proceeds to step 804 and the electrode 1 to the amplifier 4 and the A / D converter 5 are connected.
The evoked potential data given to the I / O port 12 is fetched via the, stored in the RAM 11, and the process returns to the step 801. If it is determined NO in step 801, step 8
In 02, it is determined whether it is time to send the first signal. This time is determined by whether or not a predetermined time has elapsed since the start of this process. When the CPU 8 determines YES in step 802, the CPU 8 proceeds to step 803, outputs the first signal to the stimulator 6 via the I / O port 12, and then returns to step 801. The first signal causes the stimulator 6 to apply a potential difference to the electrode 2 at the distal point to stimulate the distal point. When the CPU 8 determines NO in step 802, the CPU 8 proceeds to step 805 and determines here whether it is time to send the second signal. This time is a time when a predetermined time has elapsed from the time when the first signal was transmitted. CP
If the U8 determines YES in step 805, the U8 proceeds to step 806, where it outputs the second signal to the stimulator 6 and then returns to step 801. This second signal causes the stimulator 6 to apply a potential difference to the electrode 3 at the proximal point. When the CPU 8 determines NO in step 805, the CPU 8 proceeds to step 807 and determines whether a predetermined time has passed since the second signal was sent. If the CPU 8 determines NO in step 807, the process returns to step 801. If it determines YES, the process proceeds to step 808.

In step 808, the CPU 8 obtains the potential wave latency Lp due to the stimulation of the proximal point and the potential wave latency Ld due to the stimulation of the distal point based on the data stored in the RAM 11. R
At this time, in AM11, the electric potential wave by the stimulation of the proximal point and the distal point is recorded. Therefore, the Lp of the nerve fiber having the maximum conduction velocity has the electric potential wave from the time point when the second signal is transmitted. It can be calculated as the time until the start of appearance, and similarly, Ld can be calculated as the time from the time when the first signal is sent to the time when the potential wave starts to appear.

Next, in step 809, the CPU 8 determines the minimum refractory period R.
Find FP _min . This is L obtained in the previous step 808
p, Ld and ISI _min obtained in the previous processing are expressed by the formula RFP
_min = ISI _min- (Lp-Ld).

Next, the CPU 8 determines in step 810 the maximum conduction velocity V
_max, that is, MCV is calculated. This is the formula MCV = DST obtained by using Lp and Ld obtained in step 808 and the distance DST between the distal point and the proximal point measured in advance and stored in the RAM 11.
It is obtained by substituting it into / (Lp-Ld).

Next, the CPU 8 obtains a relational expression between each ISI and V in step 811. This is the above DST, RFP _min ,
MCV is expressed by the formula V = (DST + RFP _min × MCV) /
It is obtained by substituting it into ISI.

Next, in step 812, the CPU 8 creates a conduction velocity histogram every 1 m / sec based on the relational expression obtained in step 811 and the data (stored in the RAM 11) shown in FIG. As shown in FIG. 22, it is displayed on the screen of the CRT 17 and stored in the RAM 11.

When obtaining the conduction velocity V from ISI, the above method has an advantage that not only the conduction velocity can be accurately obtained, but also the following situations can be dealt with.

Generally, in the case of a normal person, ISI _min is longer than (Lp-Ld). However, ISI _min (Lp
-Ld) shorter. That is, the refractory period may take a negative value. This should not happen in principle, but it does happen. The cause is that the reaction of nerve bundles deteriorates in a pathological state, and a stronger stimulus than that of a normal person is used to increase the reaction level. This is because, when a strong stimulus is applied to the proximal and distal points, the range over which the nerve is stimulated expands as shown in FIG. 23, and the distance DMCV used for MCV measurement and the distance Dcol of the part where the excitement actually causes a collision. Because there will be a difference. That is, Dcoll <DMC
Because of V, there is a negative refractory period. In such a case, the value of this negative refractory period is calculated by the above method, that is, the formula V = (D
There is a problem of whether it can be used as it is for ST + RFP _min × MCV) / ISI, but there is no problem even if it is used in this formula. The reason will be described below.

Let the observed RFP _min be RFP ob and the true RFP _{min be} RFP real.

The velocity V at a certain ISI is calculated as V = (DMCV + RFPob * MCV) / ISI (1). Since MCV is the same in both DMCV and Dcoll, the true V in Dcoll is calculated as V = (Dcoll + RFPreal × MCV) / ISI (2).

Here, RFPobs = ISI _min - When (Lp-Ld) = Dcoll / MCV + RFPreal-DMCV / MCV = (Dcoll-DMCV + RFPreal × MCV) / MCV ... (3) (3) Substituting equation in the equation (1), V = (DMCV + Dcoll-DMCV + RFPreal × MCV) /
ISI = (Dcoll + RFPreal × MCV) / ISI This formula is formula (2). That is, the calculated V is the true V
It agrees with.

24 to 28 are diagrams showing the results of each process when another subject was measured using the device of this example.

FIG. 24 corresponds to FIG. 15, FIG. 25 corresponds to FIG. 16, FIG. 26 corresponds to FIG. 17, FIG. 27 corresponds to FIG. 18, and FIG. 28 corresponds to FIG.

In the above embodiments, the electrodes 2, 3 and the stimulating device 6 constitute a stimulating device, the electrode 1, the amplifier 4 and the A / D converter 5 constitute a potential detecting means, and the CRT 7 constitutes a displaying means. There is. And the control means in the first invention is
Step 503,504,505,508,509 (first control) shown in FIG. 14 and step 403,404,405,406,409,410, shown in FIG.
This corresponds to 411 (second control). The data creating means in the first invention is composed of steps 501, 502, 50 shown in FIG.
6, 507 and steps 401, 402, 407, 408 shown in FIG.

The control means in the second invention is the step shown in FIG.
It corresponds to 503, 504, 505, 508, 509 (first control) and steps 302, 307, 303 (second control) shown in FIG. The data creating means in the second invention comprises steps 501, 502, 506, 507 shown in FIG. 14 and steps 301, 306, 3 shown in FIG.
It is equivalent to 04,305.

The control means in the fourth invention is the step shown in FIG.
This corresponds to 503, 504, 505, 508, 509 (first control), steps 403, 404, 405, 406, 409, 410, 411 (second control) also shown in FIG. 13 and steps 302, 307, 303 (third control) shown in FIG. 11. The data creating means in the fourth invention is the 14th
Steps 501, 502, 506, 507 shown in the figure and steps 401, 402, 407, 408 shown in FIG. 13 and steps 301, 306, 3 shown in FIG.
It is equivalent to 04,305.

The data creating means in the fifth invention corresponds to steps 501, 502, 506, 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.

The control means in the sixth invention is the step shown in FIG.
Equivalent to 802, 803, 805, 806, 807, the data creation means is the 21st
This corresponds to steps 801, 804, 808 to 812 shown in the figure.

Next, another embodiment will be described. This example is an improvement of the above-described Ingram measurement. The structure of this embodiment is substantially the same as that shown in FIG.
10 stores the program shown in the flowchart of FIG. FIG. 30 shows timings of signals output from the stimulator 6 by the CPU 8 and potential waves appearing in response to these signals.

The operation of this embodiment will be described.

The CPU 8 first sets ISI _X, which will be described later, at step 900 to ISI _X = ISI ₁ , and then at step 900.
At 901, it is judged whether or not the present time is the data acquisition time, and if it is the time, the process proceeds to step 902 to acquire the data. That is,
The CPU 8 samples the evoked potential appearing at the I / O port 12 from the electrode 1 through the amplifier 4 and the A / D converter 5 at a predetermined interval and stores the data in the RAM.
Store in 11. If the CPU 8 determines NO in step 901, it proceeds to step 903 and determines whether it is time to send the first signal. Here, the first signal is a signal shown in Figure 30 (a) (x-1) , I / O port after a predetermined time T _A from the start of the process by the flowchart
This is a signal given to the stimulator 6 via 12. If the CPU 8 determines YES in step 903, it proceeds to step 910,
The first signal is transmitted and the process returns to step 901. Stimulator 6
Generates a potential difference on the electrode 3 at the proximal point by this signal and stimulates the proximal point. If the CPU 8 determines NO in step 903, it proceeds to step 904 and determines whether it is the second signal transmission time. Here, the second signal is a signal shown in Figure 30 (a) (x-2) , stimulator via the I / O port 12 after a predetermined time T _B after sending said first signal It is a signal to be given to 6. CPU8 is YE in step 904.
If S is determined, the process proceeds to step 911, the second signal is transmitted, and the process returns to step 901. The stimulator 6 generates a potential difference in the electrode 3 at the proximal point by the second signal to stimulate the proximal point. Wherein intervals of the first and second th signal T _B the potential waves generated by the respective signal is separated to a degree which is not affected with each other. If the CPU 8 determines NO in step 904, the CPU 8 proceeds to step 905 and determines whether the third signal is transmitted. Here, the third signal is a signal shown in Figure 30 (a) (x-3) , stimulator via the I / O port 12 after a time ISI _X elapsed since sending the second signal It is a signal to be given to 6. CPU8 is YE in step 905.
If S is determined, the process proceeds to step 912, the third signal is sent, and the process returns to step 901. The stimulator 6 generates a potential difference in the electrode 3 at the distal point by the third signal and stimulates the distal point. Here, the interval ISI _X between the second signal and the third signal is set so as to increase by Δt as described later. If the PU 8 determines NO in step 905, it proceeds to step 906 and determines whether it is the fourth signal transmission time. Here, the fourth signal is the signal (x-4) shown in FIG. 30 (a), which is stimulated via the I / O port 12 after a certain time T _{C has} elapsed since the third signal was transmitted. This is a signal given to the device 6. If the CPU 8 determines YES in step 906, the CPU 8 proceeds to step 913, transmits the fourth signal, and then executes step 9
Proceeding to step 13, the fourth signal is transmitted and the process returns to step 901. The stimulator 6 generates a potential difference in the electrode 3 at the proximal point by the fourth signal to stimulate the proximal point. The third here
The interval T _C between the first signal and the fourth signal is constant, and its value is set to be slightly shorter than the time required for the impulse to travel between the distal point and the proximal point of the fiber having the maximum conduction velocity. There is. If the CPU 8 determines NO in step 906, the CPU 8 proceeds to step 907 and determines whether a predetermined time has elapsed. That is, the CPU 8 determines whether or not enough time has passed to detect the potential wave. If the CPU 8 determines NO in step 907, it returns to step 901, and if it determines YES, it advances to step 908. In step 908, the CPU 8 calculates the area of the potential waveform based on the data stored in the RAM 11. That is, at this time, since the waveform data as shown in FIG. 30 (b) is stored in the RAM 11, the waveform for the first signal (x-1a) and the waveform for the fourth signal (x-4a) among them are stored. Calculate each area (shaded).
Then, the CPU 8 sends these calculation results to I in step 909.
It is stored in the RAM 11 in association with the SI _X and the CRT 19
Displayed on the screen. Next, the CPU 8 proceeds to step 914, where it is judged whether or not ISI _X = ISI _n at present. IS
I _n is a preset value. CPU8 step
If YES is determined in 914, the process is ended, and if NO is determined, the process proceeds to step 915. The CPU 8 adds the current ISI _X = Δt in step 915 and returns to step 901.

When the processing shown in FIG. 29 is performed, as shown in FIG.
SI _X gradually increases, and the potential wave generated by the fourth signal gradually decreases. When this process ends, the data shown in FIG. 31 is displayed and the RAM 11
Stored in. In the figure, the symbol Δ indicates the potential wave M corresponding to the first signal.
The area of D, the mark ◯ is the area of the potential wave ME corresponding to the fourth signal. According to this embodiment, it is possible to determine whether or not the measurement is normally performed by monitoring the change in MD when the measurement is performed using the ingram method.

In this embodiment, steps 903 to 907 and 910 to FIG.
915 corresponds to the control means of the third invention, and steps 900 to 902 and 908 to 909 of FIG. 29 correspond to the data creating means of the third invention.

[Effect of the Invention] According to the first invention, the maximum time between two stimulation points at which collision does not occur in the Hopf method can be accurately obtained. Therefore, the Hopf method also gives an accurate minimum conduction velocity.

According to the second invention, it is possible to easily find an abnormality in the measurement state in the Hopf method.

According to the third invention, it is possible to easily find the abnormality of the measurement state in the ingram method.

According to the fourth aspect, the magnitude of the potential waveform that is not affected by the dual stimulus effect in the Hopf method can be accurately obtained for each stimulation interval.

According to the fifth invention, in both the Hopf method and the ingram method, when a plurality of sets of potential waveforms obtained from muscles and corresponding waveform areas are displayed, 1 of them can be easily specified.

According to the sixth aspect, the refractory period can be accurately corrected in the Hopf method.

As described above, according to the first to fifth inventions, the motor nerve conduction velocity distribution can be accurately measured.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus including the first to sixth inventions, and FIGS. 2 and 4 are diagrams for explaining the conventional Hopf's method and the Ingram method, which are the measurement principles of the motor nerve velocity distribution, respectively. FIG. 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 by the conventional device, and FIGS. 6 and 7 are FIG. 8, FIG. 8 and FIG. 9 for explaining the operation of the first invention are drawings for explaining the operation of the second invention and the fourth invention respectively, and FIGS.
FIG. 14 is an operation explanatory view of one embodiment, and FIGS. 29 to 31 are operation explanatory views 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 ... I / O port 17 ... CRT 18 ... Keyboard

Claims (6)

[Claims] 1. A stimulus applying means for stimulating a first point on the peripheral side and a second point on the central side of a test nerve bundle, respectively, and the stimulus applying means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and for measuring the nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means In the motor nerve conduction velocity distribution measuring device comprising: the control means, the stimulus applying means stimulates the first point, and the operation of stimulating the second point after a time T ₁ from this time is the time. T The varied and first control for causing a plurality of times, the stimulus applying means to stimulate the points of the second, stimulating the first point from the point after a time T _2,
This time is a control in which the operation of stimulating the second point is performed again a plurality of times after the time T ₃ from this point of time, with the time T ₃ being different, and the time T ₂ is the first point and the second point. Is set to the interval between both stimulation points at which an impulse caused by both stimulations when each point is stimulated once occurs a collision in any nerve fiber of the test nerve bundle, and the time T ₃ is the time T ₁ The second control is set so as to match the value taken by the data generating means, and the data creating means selects one of the second points in the first control of the waveform of the evoked potential detected by the potential detecting means. Waveform by stimulus and the second in the second control
2. A motor nerve conduction velocity distribution measuring device, characterized in that the size of each waveform by the second stimulation of the point is calculated, and the data in which the respective sizes are associated with the times T ₁ and T ₃ are created. 2. A 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, respectively, and the stimulating means means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and for measuring the nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means In the motor nerve conduction velocity distribution measuring device comprising: the control means, the stimulus applying means stimulates the first point, and the operation of stimulating the second point after a time T ₁ from this time is the time. T The varied and first control for causing a plurality of times, the second control for controlling such stimulation applying means to stimulate the second point in each interval of said plurality of operation in the first control The data creating means includes a waveform of the evoked potential detected by the potential detecting means due to the stimulation at the second point in the first control, and the second waveform in the second control.
2. A motor nerve conduction velocity distribution measuring apparatus, characterized in that the size of each waveform due to the stimulation of the point is calculated, and data in which each size is associated with the time T ₁ is created. 3. A stimulus 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, respectively, and the stimulus applying means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and for measuring the nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means In the motor nerve conduction velocity distribution measuring device comprising: the control means, the stimulation applying means stimulates the second point, and the first point is stimulated at time T ₄ from this time point, and from this time point. Further The operation to stimulate the second point again after between T ₅ at different said time T ₄ a control to perform a plurality of times, the time T ₅ is the second point and the point of the first is the A first control in which an impulse due to both stimuli when stimulated once is set to an interval between both stimulus points at which a collision occurs in any nerve fiber of the nerve bundle to be tested; And a second control for controlling so as to stimulate the second point between each of the plurality of operations in the control of, the data creating unit is configured to detect the waveform of the evoked potential detected by the potential detecting unit. Of these, the magnitudes of the waveform of the second point in the first control due to the second stimulation and the magnitude of the waveform of the second point in the second control due to the stimulation are calculated, and the magnitude and the time T ₄ are calculated. Create data that is associated with Motor nerve conduction velocity distribution measuring apparatus according to claim and. 4. A stimulus 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, respectively, and the stimulus applying means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and for measuring the nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means In the motor nerve conduction velocity distribution measuring apparatus comprising: the control means, the stimulation applying means stimulates the first point, and the operation of stimulating the second point after a time T ₁ from this time point is the time point. T The varied and first control for causing a plurality of times, the stimulus applying means to stimulate the points of the second, stimulating the first point from the point after a time T _2,
This time is a control in which the operation of stimulating the second point is performed again a plurality of times after the time T ₃ from this point of time, with the time T ₃ being different, and the time T ₂ is the first point and the second point. Is set to the interval between both stimulation points at which an impulse caused by both stimulations when each point is stimulated once occurs a collision in any nerve fiber of the test nerve bundle, and the time T ₃ is the time T ₁ And a second control that is set so as to match the value taken by the stimulating means and the stimulus imparting means sets the second point between each of the plurality of operations in the first control or the second control. Performing a third control for controlling so as to stimulate, wherein the data creating means includes a waveform of the evoked potential detected by the potential detecting means, a waveform by stimulation at the second point in the first control, The second in the control of two
Of the waveform of the second point stimulated in the third control, and the size of each waveform of the second point stimulated in the third control,
An apparatus for measuring velocity distribution of motor nerve conduction, characterized by creating data in which each size is associated with the time T ₁ or the time T ₃ . 5. A 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, respectively, and the stimulating means means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the nerve bundle to be tested, and for measuring motor nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means A motor nerve conduction velocity distribution measuring apparatus comprising: a display control unit for controlling the display unit; and an input unit for inputting a signal to the display control unit, wherein the data creating unit is the potential The magnitude of each waveform is calculated from the evoked potential detected by the output means, and data is created by associating each magnitude and each waveform with time data based on the time of stimulation, and the display control means is The data created by the data creating means is displayed on the display means, and any one of the waveforms and the magnitude data corresponding thereto are selected in accordance with the signal given from the input means, and these are selected as other waveforms. A motor nerve conduction velocity distribution measuring device characterized in that it is displayed on the display means in a mode different from other size data. 6. A 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, respectively, and the stimulating means means for stimulating the first point and the second point. Control means for controlling the timing of stimulating each point, potential detecting means for detecting the evoked potential of the dominant muscle of the test nerve bundle, and for measuring the nerve conduction velocity distribution based on the evoked potential detected by this potential detecting means Data creating means for creating data, velocity distribution creating means for creating a motor nerve conduction velocity distribution based on the data created by the data creating means, and display means for displaying the velocity distribution created by the velocity distribution creating means In the motor nerve conduction velocity distribution measuring device, the control means controls the stimulus applying means to stimulate the first point and the second point at predetermined time intervals. Control and A second control in which the stimulating means stimulates the first point, and the operation of stimulating the second point after a time T ₁ from this time point is performed a plurality of times at different times T _1. The data creating means obtains the size of the evoked potential waveform by the stimulation of the second point in the second control, based on the evoked potential detected by the potential detecting means,
The time Ld from the time when the first point in the first control is stimulated to the time when the evoked potential due to this stimulation first appears and the evoked potential due to this stimulus from the time when the second point is stimulated Time L until the first appearance
p is calculated, T _1min which is the time T ₁ when the evoked potential due to the stimulation of the second point starts to appear in the second control, and the maximum conduction velocity V _max in the nerve bundle to be _tested is calculated. RFP showing the refractory period RFP _min of nerve fibers with
_min = _T1min- (Lp-Ld) and the times Ld and Lp
And V _max = DST / (Lp-L) that indicates the maximum conduction velocity V _max from the distance DST between the first point and the second point.
d) and the time T ₁ and its T in the second control
Relational expression with motor nerve conduction velocity V corresponding to ₁ V = (DS
T + RFP _min × V _max ) / T ₁ and the time Lp, L
A motor nerve conduction velocity distribution measuring device characterized in that the motor nerve conduction velocity V is calculated and calculated from d, T _1min , distance DST and velocity V _max .