Sensory disturbance evaluation system

Abstract

To easily identify the degree and cause of a sensory disturbance.SOLUTION: A sensory disturbance evaluation system according to the present invention comprises: a measuring device 20 that measures a current perception threshold at a predetermined site of a measurement subject by stimulating a nerve that manages the predetermined site of the measurement subject; and a display device 69 that displays a plurality of blood vessel domination regions respectively managed by a plurality of major blood vessels of the human body and the predetermined site of the measurement subject at which the current perception threshold is measured in an overlapping manner, and that displays the current perception threshold at the predetermined site of the measurement subject measured by the measuring device 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sensory disorder evaluation system.

Background Art

[0002] Sensory disorder is a common symptom of peripheral neuropathy associated with diabetes and severe lower limb ischemia. Sensory disorder is progressive and irreversible, and it is considered to be caused by the neuropathy due to continuous hyperglycemia in diabetes and also by vascular stenosis. Since the subjective symptoms in the initial stage of sensory disorder are not clear, it is difficult to detect sensory disorder early and perform appropriate treatment. As a result, the sensory disorder progresses to cause a lower limb ulcer, leading to a situation where the lower limb with the ulcer has to be amputated.

[0003] Therefore, as a device for measuring sensory disorder to detect sensory disorder, there is a pain measurement device for objectively measuring the pain felt by the subject (see Patent Document 1). The pain measurement device measures the current value of the stimulus current that gives a sensation equivalent to the pain sensation felt by the subject due to illness or the like when electricity is supplied to the electrode attached to the subject as the pain-corresponding current value. It has been found that the higher the pain-corresponding current value measured by the pain measurement device, the more advanced the sensory disorder.

[0004] In recent years, it has also been found in recent research that when blood flow is improved by performing revascularization on the microvessels of the lower limb affected by sensory disorder, the sensory disorder is also improved (see Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, after performing revascularization, although sensory disturbance is once improved, sensory disturbance may progress again. In this case, the sensory disturbance may be caused by stenosis of microvessels as described above, but on the other hand, it may also be caused by other neurological disorders. In such a case, it is difficult to determine whether the sensory disturbance is due to recurrence of stenosis of the microvessels in the lower extremities or due to other neurological disorders. Therefore, a system for easily identifying the cause of sensory disturbance using a measuring device is desired.

[0008] The present invention has been made in view of such problems, and an object thereof is to provide a sensory disturbance evaluation system capable of easily identifying the degree of sensory disturbance and the cause of sensory disturbance.

Means for Solving the Problems

[0009] A sensory disturbance evaluation system according to one aspect of the present invention includes a measurement unit that measures the current perception threshold at a predetermined site of a subject by stimulating the nerve that innervates the predetermined site of the subject, a plurality of vascular dominance regions each dominated by a plurality of major blood vessels of the human body, and a control unit that overlays and displays the plurality of vascular dominance regions and the predetermined site of the subject at which the current perception threshold is measured, and displays the current perception threshold at the predetermined site of the subject measured by the measurement unit on a display unit.

Effects of the Invention

[0010] According to the sensory disorder evaluation system of the present invention, the degree of sensory disorder and the cause of sensory disorder can be easily specified.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0012] [One Embodiment] FIG. 1 is a diagram showing an example of the configuration of the sensory disorder evaluation system 10 according to the present embodiment. As shown in FIG. 1, the sensory disorder evaluation system 10 is composed of a measuring device 20, a PC (personal computer) 60, and a printer 80. The measuring device 20 is connected to each of the PC 60 and the printer 80 by predetermined cables 81 and 82. Also, the PC 60 is connected to the printer 80 by a predetermined cable 83. By connecting the measuring device 20 and the PC 60 with the cable 81, the PC 60 can transmit a signal indicating an operation command to the measuring device 20. Also, the measuring device 20 can transmit a signal (measurement signal) indicating the result of measurement to the PC 60. Further, by connecting each of the measuring device 20 and the PC 60 to the printer 80 as an output unit by the cables 82 and 83, the data processed by the measuring device 20 or the PC 60 can be printed by the printer 80.

[0013] (Definition of Current Perception Threshold) The measuring device 20 is a device that measures the current perception threshold (CPT: Current Perception Threshold) by supplying current to the electrode unit 22 worn by the subject on the target site. The measuring device 20 corresponds to the measuring unit described in the claims. Here, the current perception threshold refers to the current value of the stimulus current when the current value of the stimulus current supplied to the subject is gradually increased from 0 and the subject first feels the electrical stimulus. The higher the current perception threshold, the duller the sensation of the target site of the subject, and the lower the current perception threshold, the sharper the sensation of the target site of the subject.

[0014] <Internal Configuration of Measuring Device 20> As shown in FIG. 2, the measuring device 20 includes a main body 21, an electrode unit 22, and a hand switch 23. The electrode unit 22 is attached to the lower limb (e.g., toes) of the person to be measured, and current is supplied from the main body 21. The electrode unit 22 is provided at one end of a cable 24. A male connection terminal 25 is provided on the other end side of the cable, and is inserted into a female connection terminal (not shown) provided on the main body 21. The hand switch 23 is a switch operated by the person to be measured. The hand switches 23 are each provided at one end of a cable 26. A male connection terminal 27 is provided on the other end of the cable 26 provided with the hand switch 23 at one end, and is inserted into a female connection terminal (not shown) provided on the main body 21.

[0015] As shown in FIG. 2, the main body 21 includes an MPU (Micro Processing Unit) 31, a boost transformer 32, a voltage control circuit 33, an output control circuit 34, a protection circuit 35, a current detection circuit 36, an external RAM 37, a nonvolatile memory 38, an image display unit 39, a display driver 40, an address decoder 41, an I / F (interface) circuit 42, and an operation unit 43.

[0016] The MPU 31 internally includes a ROM (Read Only Memory), a RAM (Random Access Memory), a timer, and an output interface (not shown). A measurement program is stored in the internal ROM of the MPU 31. When an operation command is transmitted from the PC 60 to the MPU 31 via the I / F circuit 42, the MPU 31 processes the operation command from the PC 60 according to the control program stored in the internal ROM while using the temporary storage function of the external RAM 37, and executes a predetermined algorithm. Also, by executing the predetermined algorithm, the MPU 31 supplies drive signals to the boost transformer 32, the voltage control circuit 33, and the output control circuit 34, respectively.

[0017] The boost transformer 32 boosts the voltage from a DC power supply (not shown) according to the drive signal from the MPU 31. More specifically, the boost transformer 32 drives a transistor with a square-wave drive signal from the MPU 31 using a timer to boost the voltage from the DC power supply. For example, the boost transformer 32 boosts a 12V voltage applied by the DC power supply to 100V - 120V. The voltage control circuit 33 adjusts the DC voltage output from the boost transformer 32 according to the drive signal from the MPU 31. Also, the voltage control circuit 33 outputs a detection signal for detecting the voltage value in the voltage control circuit 33 towards the MPU 31. The MPU 31 controls so that a voltage equal to or higher than a specified value is not output from the output control circuit 34 based on the detection signal input to the MPU 31 from the voltage control circuit 33.

[0018] The output control circuit 34 is a PWM control circuit for controlling the rectified voltage output from the voltage control circuit 33 by PWM (Pulse Width Modulation). This output control circuit 34 outputs a pulsed voltage in the range of, for example, 5V - 100V according to the drive signal from the MPU 31. The protection circuit 35 is a limiter circuit that prevents a current equal to or higher than a predetermined value from being supplied from the output control circuit 34 to the electrode worn by the person to be measured. The protection circuit 35 outputs a detection signal for detecting the current limit value towards the MPU 31.

[0019] The current detection circuit 36 is a circuit for detecting the effective value of the current applied to the person to be measured from the protection circuit 35 via the electrode. The current detection circuit 36 of this embodiment is composed of, for example, a resistor and an operational amplifier. The current detection circuit 36 outputs a detection signal for detecting the current value of the current supplied to the electrode towards the MPU 31. In this embodiment, the waveform of the current supplied from the output control circuit 34 to the electrode is a pulse waveform with a 5Hz period.

[0020] For example, in a current perception threshold test, generally, sine waves with periods of 2000 Hz, 250 Hz, and 5 Hz are used. Among these sine waveforms, the sine waveform with a period of 2000 Hz selectively stimulates Aβ nerve fibers, which are myelinated nerves with a diameter of 5 to 15 μm. Also, the sine waveform with a period of 250 Hz selectively stimulates Aδ nerve fibers, which are myelinated nerves with a diameter of 1 to 5 μm. And the sine waveform with a period of 5 Hz selectively stimulates C fibers, which are unmyelinated nerves with a diameter of 0.4 to 1.5 μm. For example, in the case of sensory impairment caused by diabetes, it is known that the sensation is lost due to the invasion of unmyelinated nerves. In the present embodiment, a current composed of a pulse waveform including a component with a period of 5 Hz that stimulates this C fiber is applied to the electrode, or the current perception threshold is measured by stimulating with a pulse waveform including components of sine waveforms of 2000 Hz and 250 Hz.

[0021] As described above, the external RAM 37 is a memory for the MPU 31 to execute a predetermined algorithm. If the capacity of the internal RAM of the MPU 31 is sufficient, the external RAM 37 does not need to be provided. The non-volatile memory 38 is a memory that stores predetermined setting values such as the rising speed of the voltage output from the output control circuit 34 (that is, the increase degree of the stimulation current supplied to the electrode), the limit value of the voltage supplied to the current detection circuit 36, or measurement data of pain for a predetermined number of times in the past.

[0022] The image display unit 39 is a display device such as a liquid crystal display device that displays the voltage value in the voltage control circuit 33 and the current value of the stimulation current supplied to the electrode. Image data output from the MPU 31 and processed by the display driver 40 is displayed on the image display unit 39.

[0023] The address decoder 41 is a logic circuit for exchanging signals between the external RAM 37, the display driver 40, and the MPU 31. Also, the I / F circuit 42 is a circuit for exchanging signals between the MPU 31 and the PC 60 and for supplying signals from the MPU 31 to the printer 80.

[0024] The operation unit 43, although not shown in the figure, includes, for example, setting buttons that are operated when setting the measurement device 20, measurement buttons that are operated when measuring with the measurement device 20, and buttons for scrolling the display content displayed on the image display unit 39. Here, the operation unit 43 and the image display unit 39 constitute the operation panel P of the measurement device 20.

[0025] The electrode unit 22 has two electrodes 22a and 22b. These two electrodes 22a and 22b are, for example, sized to be attachable to the big toe of the person to be measured and are bipolar electrodes. A current is applied to these two electrodes 22a and 22b. The hand switch 23 is for the person to be measured to start or stop the application of current to the electrode unit 22.

[0026] <Internal Configuration of PC60> As shown in FIG. 3, the PC60 has, for example, a CPU (Central Processing Unit) 61, a ROM 62, and a RAM 63. The CPU 61, ROM 62, and RAM 63 are connected via a bus 64. Connected to the bus 64 are an I / O (Input / Output) port 65, a communication port 66, and a storage device 67. Connected to the I / O port 65 are an input device 68, a display device 69, and an audio device 70. Also, connected to the communication port are the measurement device 20 and a printer 80. Here, the display device 69 corresponds to the display unit and output unit described in the claims.

[0027] The input device 68 inputs various data and commands to the PC60. The input device 68 is, for example, a keyboard or a mouse. The display device 69 displays various data. The display device 69 is, for example, an LCD (Liquid Crystal Display) panel or an EL (Electrpnic Luminescent) panel. The audio device 70 is a device that outputs sound, such as a speaker. The audio device 70 outputs sounds such as those during the measurement of the above-described current perception threshold and warning sounds.

[0028] The storage device 67 is, for example, a hard disk drive. The storage device 67 stores a measurement application program 71 and an operating program (not shown) that forms the operating environment of the measurement application program 71. In addition to various data used when the measurement application program 71 is executed, the storage device 67 also stores data (measurement data) obtained when the measurement application program 71 is executed.

[0029] The measurement application program 71 is a program that is executed, for example, when measuring the current perception threshold.

[0030] Although the above-described measurement application program 71 is assumed to be stored in a storage device 67 such as a hard disk drive, it may be stored in a storage medium such as an optical disk, a magnetic disk, or a USB memory and executed by being read by a disk drive (not shown).

[0031] The CPU 61 functions as a control unit 75 and an evaluation unit 76 by executing the measurement application program 71 stored in the storage device 67. When the measurement application program 71 is executed, the control unit 75 outputs a display command for displaying a display screen based on the measurement application program 71 to the display device 69. In addition, the control unit 75 transmits a measurement start command to the measurement device 20. Further, when the control unit 75 receives a measurement signal from the measurement device 20, it outputs a display command for performing a display based on the measurement signal to the display device 69. Further, the control unit 75 outputs a reproduction command to the audio device 70 as necessary.

[0032] The evaluation unit 76 evaluates the sensory impairment of the subject based on the measurement signal (measurement data) from the measurement device 20. Examples of the evaluation of sensory impairment include evaluation of the progress of sensory impairment, comparative evaluation with a healthy lower limb, and further identification of the cause of sensory impairment.

[0033] <Current Perception Threshold Measurement Process> Next, the process flow during the measurement of the current perception threshold will be described with reference to FIG. 4. First, the measurer selects, via the input device 68, a part of the subject's body where the current perception threshold is to be measured (hereinafter referred to as the measurement part), and attaches the electrodes 22a and 22b to the part of the subject's body corresponding to the selected measurement part (step S101).

[0034] Next, the control unit 75 of the PC 60 sends a measurement start command to the measurement device 20, and the measurement device 20 starts measuring the current perception threshold (step S102).

[0035] For example, when the subject operates the hand switch 23, the control unit 75 sends a measurement start command to the measurement device 20, and the measurement device 20 supplies a current with a pulse waveform having a period of, for example, 5 Hz to the electrode unit 22. The current with a pulse waveform having a period of 5 Hz gradually increases from 0. When the current applied to the electrode unit 22 increases and the subject first feels an electrical stimulus, if the hand switch 23 is operated again, the application of the current to the electrode unit 22 is stopped by the measurement device 20. The measurement device 20 sets the current value when the hand switch 23 is operated again as the current perception threshold. Then, the measurement device 20 transmits the current perception threshold as a measurement signal to the PC 60, and the received current perception threshold is stored in the storage device 67. The measurement of the current perception threshold is repeated until the PC 60 receives the measurement signal three times.

[0036] When the PC 60 receives the measurement signal three times (step S103: Yes), the control unit 75 sends a measurement end command to the measurement device 20, and the measurement device 20 ends the measurement.

[0037] Thereafter, the evaluation unit 76 calculates the average value of the current perception thresholds measured three times (step S104).

[0038] The control unit 75 displays the measured current perception threshold and the average value of the current perception threshold on the display device 69 (step S105). Further, when a print command is input to the control unit 75 by the input device as necessary, the control unit 75 outputs the image data displayed on the display device 69 and the print command to the printer 80. Thereby, the screen displayed on the display device 69 is printed.

[0039] <Display Example> Next, the display screen displayed on the display device 69 of the PC 60 will be described. FIG. 5 shows an example of the screen 90 of the display device 69 when measuring the current perception threshold.

[0040] As shown in FIG. 5, on the screen (hereinafter, measurement screen) 90 for measuring the current perception threshold, for example, it is possible to register a patient who is the subject to be measured, select a patient, print the measurement result, and graphically display the examination result of the subject to be measured. In addition to this, the settings of the measuring device 20 can be performed. In the measurement screen 90 shown in FIG. 5, a plurality of regions 91, 92, 93, 94 are provided.

[0041] Among the plurality of regions 91, 92, 93, 94, the region 91 is, for example, a region for selecting a measurement site. The region 91 includes, for example, a region 91a for selecting a measurement site from the names of the measurement sites and a region 91b for displaying the measurement site as an illustration.

[0042] The region 91a is a region for selecting a measurement site from the names of the measurement sites. For example, when the user inputs an operation of the "▽" mark, a plurality of measurable sites are displayed. In the present embodiment, for example, in addition to the "inner part of the forearm (left)", not shown, any one of "inner part of the forearm (right)", "Achilles tendon part (left)", "Achilles tendon part (right)", "big toe (left)" and "big toe (right)" can be selected.

[0043] The region 91b is a region for displaying the selected measurement site as an illustration. In the center, an illustration of the human body is displayed, and illustrations of measurable sites are displayed around it.

[0044] FIG. 6 is a diagram for explaining the illustration displayed in region 91b. In region 91b, for the illustration A1 of the human body and the six illustrations A2, A3, A4, A5, A6, A7 indicating the measurement sites, for example, dermatomes and angiosomes are superimposed and displayed on the human body. Note that illustration A2 is an illustration showing the right hand, and illustration A3 is an illustration showing the left hand. Also, illustration A4 is an illustration showing the dorsal part of the right foot, and illustration A5 is an illustration showing the sole of the right foot. Also, illustration A6 is an illustration showing the dorsal part of the left foot, and illustration A7 is an illustration showing the sole of the left foot. As shown in FIG. 6, the selected measurement sites are displayed, for example, in illustrations A1 and A7, by a circular frame M1, for example.

[0045] The dermatomes will be described. In the human body, the spinal cord is composed of a plurality of spinal cord segments such as the cervical spinal cord, thoracic spinal cord, lumbar spinal cord, sacral spinal cord, and coccygeal spinal cord. And from each spinal cord segment of the spinal cord, one pair or a plurality of pairs of spinal nerves extend to the corresponding parts of the human body. The cervical spinal cord has, for example, 8 spinal cord segments, and for example, 8 pairs of cervical nerves control the skin sensation in the region from the neck to the hand of the human body. Also, the thoracic spinal cord has, for example, 12 spinal cord segments, and 12 pairs of thoracic nerves control the skin sensation in the regions of the chest, the middle of the back, and a part of the arm of the human body. Also, the lumbar spinal cord has, for example, 5 spinal cord segments, and 5 pairs of lumbar nerves control the skin sensation in the region from the waist to a part of the leg (the anterior region of the human body in the leg). Furthermore, the sacral spinal cord has, for example, 5 spinal cord segments, and 5 pairs of sacral nerves control the skin sensation in the region from the buttocks to a part of the leg (the region from the buttocks to the heel side of the leg) of the human body. Note that the regions of the human body skin dominated by the above-described spinal nerves are called dermatomes (also called nerve-dominated regions).

[0046] An explanation will be given about angiosomes. The human body has a plurality of major blood vessels, and a plurality of microvessels branch off from these plurality of major blood vessels. The anatomical blood supply regions in these plurality of major blood vessels are called angiosomes (also referred to as blood supply regions). For example, in the lower leg, there are a total of six angiosomes, namely, one anterior tibial artery supply region, two peroneal artery supply regions, and three posterior tibial artery supply regions. By means of these angiosomes, it is possible to recognize which major blood vessels dominate each region of the human body.

[0047] Figure 7 is a diagram for explaining the display method of dermatomes and angiosomes. The illustration A7 in Figures 7A to 7C represents the sole of the left foot. Figure 7A shows the angiosomes of the sole of the left foot. In this example, the angiosomes are classified and displayed in regions F1, F2, F3, and F4. Also, Figure 7B shows the dermatomes of the sole of the left foot. In this example, the dermatomes are classified and displayed in regions G1, G2, and G3. Note that Figure 7C shows the angiosomes shown in Figure 7A and the dermatomes shown in Figure 7B superimposed. In this way, at least one of the angiosomes or dermatomes can be displayed, or the angiosomes and dermatomes can be displayed superimposed.

[0048] The display method of angiosomes and dermatomes was explained using the illustration A7 of the sole of the left foot. Although the case where they are superimposed and displayed was explained, they can also be displayed as shown in Figure 7 in the illustrations A1 of the whole body, illustration A2 showing the right hand, illustration A3 showing the left hand, illustration A4 showing the dorsal side of the right foot, illustration A5 showing the sole of the right foot, and illustration A6 showing the dorsal side of the left foot.

[0049] Returning to FIG. 5, in region 92, the three measured values of the selected measurement site M1 current perception threshold and its average value are displayed. Region 93 is an area where the three measurement results by the measuring device are displayed in a graph. Further, region 94 displays the previous measurement result and the current measurement result for each measurement site. Here, the measurement data indicating the past measurement results of the subject is associated with the basic data of the subject and stored, for example, in the storage device 67. Note that the measurement data may be stored in a data server (not shown) together with the basic data of the subject. The measurement data is updated each time the measurement is performed by the measuring device 20.

[0050] From the above, the measurer and the subject can recognize the current perception threshold of the selected measurement site M1. Also, the dermatome and ankiosam that dominate the measurement site M1, that is, the nerve and blood vessel, can be recognized. Further, since the previous measurement result and the current measurement result can be recognized, it is possible to recognize whether the sensory disorder is progressing or the sensory disorder is improving.

[0051] <Sensory disorder evaluation process> The evaluation unit 76 of the PC 60 can evaluate the sensory disorder based on the measurement results obtained by the current perception threshold measurement process. The evaluation performed by the evaluation unit 76 is, for example, a comparative evaluation with a healthy lower limb and identification of the cause of the sensory disorder. The control unit 75 displays the result evaluated by the evaluation unit 76 on the display device 69.

[0052] (Comparative evaluation with a healthy lower limb) As a comparative evaluation with a healthy lower limb, the evaluation unit 76 evaluates, for example, the degree of sensory impairment in the lower limb with sensory impairment by comparing it with the measurement results of a healthy lower limb. Here, as a healthy lower limb, for example, if one of the two lower limbs of the subject is healthy, the one lower limb can be regarded as a healthy lower limb. In addition to this, it is also possible to regard a lower limb without sensory impairment in the same generation as the subject as a healthy lower limb. When a lower limb without sensory impairment in the same generation as the subject is regarded as a healthy lower limb, the average value, median value, etc. of the measurement results of a plurality of healthy lower limbs can be used.

[0053] (Identification of the cause of sensory impairment) As described above, the measurer or the subject can recognize the dermatome and angiosome that dominate the measurement site, that is, the types of nerve innervation areas and vascular supply areas corresponding to the measurement site. However, just by that, it is difficult to determine whether the sensory impairment is due to a disease in the nerve innervation area or a disease in the vascular supply area.

[0054] In particular, in recent research, it has been found that when blood flow is improved by performing revascularization on the microvessels of the lower limb with sensory impairment, the sensory impairment is also improved, as shown in FIG. 8.

[0055] FIG. 8A shows the changes in the current perception threshold (CPT) before performing revascularization (treatment) on the lower limb, immediately after performing the revascularization (treatment), and 3 months after performing the revascularization (treatment), for example. FIG. 8B shows the change in the skin perfusion pressure (SPP) on the dorsum of the foot of the treated lower limb, and FIG. 8C shows the change in the skin perfusion pressure (SPP) on the sole of the foot of the treated lower limb. Here, the skin perfusion pressure (SPP) means the perfusion pressure at the skin level and is an index of microcirculation at the skin level, indicating at what pressure the microcirculation is perfusing. Revascularization may hereinafter be referred to as treatment.

[0056] An increase in the current perception threshold compared to past measurement results indicates that the sensory impairment is worsening, while a decrease indicates that the sensory impairment is improving. On the other hand, an increase in skin perfusion pressure (SPP) compared to past data indicates that blood flow is improving, and a decrease indicates that blood flow is worsening.

[0057] As shown in FIG. 8A, the current perception threshold before treatment is 42.5 μA, while the current perception threshold immediately after treatment is 37.6 μA, and the current perception threshold three months after treatment tends to decrease to 25.7 μA. Also, as shown in FIGS. 8B and 8C, the skin perfusion pressure (SPP) on the dorsal and plantar surfaces of the lower limb where treatment was performed is increased after treatment and three months after treatment, respectively, compared to before treatment. In this case, it can be said that the sensory impairment is also improving along with the improvement of blood flow in the lower limb.

[0058] However, sensory impairment may progress again after revascularization. In such a case, it is difficult to determine whether the sensory impairment is due to recurrence of stenosis of the microvessels in the lower limb or other neurological disorders.

[0059] Therefore, the evaluation unit 76 identifies the cause of the sensory impairment using, for example, inspection data of the microvessels in the lower limb and the measurement signal of the current perception threshold in the measuring device 20.

[0060] First, inspection data of the microvessels in the lower limb is stored in advance in the storage device 67 or a data server (not shown). Then, the evaluation unit 76 compares the current perception threshold obtained by the measurement in the measuring device 20 with past measurement results to determine whether the sensory impairment is worsening or improving. Also, the evaluation unit 76 compares the inspection data of the microvessels in the lower limb with past inspection data to determine whether the blood flow is worsening or improving.

[0061] Next, the evaluation unit 76 identifies the cause of the sensory disorder. When it is determined that the sensory disorder is deteriorating and, at the same time, it is determined that the blood flow in the lower limbs is improving (no stenosis or the like (including recurrence) occurs in the microvessels), the evaluation unit 76 identifies that the cause of the sensory disorder is not a disease in the vascular innervation area but a disease in the nerve innervation area.

[0062] Also, when the evaluation unit 76 determines that the blood flow and the sensory disorder are deteriorating, the evaluation unit 76 identifies that the cause of the sensory disorder is a disease in the vascular innervation area.

[0063] (Specific examples of identifying the cause of the sensory disorder) Figure 9A shows the changes in the current perception threshold (CPT) of the measured subjects A, B, and C. Figure 9B shows the changes in the skin perfusion pressure (SPP) on the dorsal side of the feet of the lower limbs of the measured subjects A, B, and C, and Figure 9C shows the changes in the skin perfusion pressure (SPP) on the plantar side of the feet of the lower limbs of the measured subjects A, B, and C. The data in Figure 9 are stored in the storage device 67.

[0064] In the case of the measured subject A, as shown in Figure 9A, the current perception threshold three months after the treatment has increased compared to the current perception threshold after the treatment. Therefore, the evaluation unit 76 determines that the sensory disorder is deteriorating. In the case of the measured subject A, as shown in Figures 9B and 9C, the skin perfusion pressure (SPP) three months after the treatment has decreased compared to the skin perfusion pressure (SPP) on the dorsal side and the plantar side of the feet after the treatment. Therefore, the evaluation unit 76 determines that the blood flow is deteriorating. Based on the above, since the evaluation unit 76 determines that the blood flow and the sensory disorder are deteriorating, in the case of the measured subject A, the evaluation unit 76 identifies that the cause of the sensory disorder is a disease in the vascular innervation area.

[0065] In the case of the measured subjects B and C, as shown in Figure 9A, the current perception threshold three months after the treatment has decreased compared to the current perception threshold after the treatment. Therefore, the evaluation unit 76 determines that the sensory disorder is improving. In the cases of the subject B and the subject C, as shown in FIGS. 9B and 9C, the skin perfusion pressure (SPP) three months after the treatment is higher than that on the dorsal surface or the plantar surface of the foot after the treatment. Therefore, the evaluation unit 76 determines that the blood flow has improved. From the above, since the evaluation unit 76 has determined that the blood flow and the sensory disorder have improved, in the cases of the subject B and the subject C, it is evaluated that the sensory disorder has improved along with the improvement of the blood flow.

[0066] Although illustration is omitted, when the current perception threshold three months after the treatment is higher than that after the treatment, the evaluation unit 76 determines that the sensory disorder has deteriorated. Also, when the skin perfusion pressure (SPP) three months after the treatment is higher than that on the dorsal surface or the plantar surface of the foot after the treatment, the evaluation unit 76 determines that the blood flow has improved. In this case, the evaluation unit 76 specifies that the cause of the sensory disorder is a disease in the nerve innervation area.

[0067] [Other Embodiments] In the above description, the description has been centered on measuring the current perception threshold of the lower limbs of the subject, but the measuring device 20 may measure the current perception threshold of other parts of the subject. For example, the measuring device 20 can measure the current perception threshold of the tongue, and the evaluation unit 76 can evaluate the sensory disorder related to taste.

[0068] In the above description, the current perception threshold is defined as the current value of the stimulus current when the subject first feels the electrical stimulus when the current value of the stimulus current supplied to the subject is gradually increased from 0, but it may be the current value when the subject first feels pain. In this case, the measuring device 20 can be applied as a pain measuring device.

[0069] [Supplementary Explanation of the Embodiment] Thus, in the sensory disorder evaluation system according to this embodiment, by evaluating the sensory disorder of the subject, it is possible to evaluate the degree of progression of the sensory disorder, compare it with a healthy lower limb, and identify the cause of the sensory disorder.

[0070] In the sensory disorder evaluation system according to this embodiment, the current perception threshold at the measurement site of the subject is measured, and based on the measured current perception threshold, the degree (progression degree) of the sensory disorder is evaluated and the cause of the sensory disorder is identified. However, it is also possible to simply display the current perception threshold measured at the measurement site of the subject on the display device 69 together with the angiosome and dermatome corresponding to the measurement site. In this case, the doctor who gave the measurement instruction can confirm the current perception threshold measured at the measurement site of the subject displayed on the display device 69 and the angiosome and dermatome corresponding to the measurement site, and thereby evaluate the degree of the sensory disorder of the subject or identify the cause of the sensory disorder.

[0071] In this embodiment, the sensory disorder evaluation system 10 including the measurement device 20, the PC (Personal Computer) 60, and the printer 80 is described as an example, but the configuration of the printer 80 is not necessarily required.

[0072] Also, in this embodiment, the sensory disorder evaluation system 10 including the measurement device 20, the PC (Personal Computer) 60, and the printer 80 is used, but it may be a sensory disorder evaluation device integrating the measurement device 20 and the PC (Personal Computer) 60.

[0073] [Summary of the Invention]

[0074] (1) The sensory disorder evaluation system is a measurement device 20 that measures the current perception threshold at a predetermined site of the subject by stimulating the nerve that innervates the predetermined site of the subject, and A plurality of angiosomes (regions F1 to F4 in FIG. 7) each dominated by a plurality of major blood vessels of the human body are superimposed and displayed with the predetermined site (frame M1 in FIG. 6) of the subject for measuring the current perception threshold, and a PC60 that displays the current perception threshold (measurement screen 92 in FIG. 5) at the predetermined site of the subject measured by the measuring device 20 on the display device 69, It is characterized by having.

[0075] With this configuration, the user can recognize the blood vessels that dominate the area where the sensory disorder has occurred, along with the progression of the sensory disorder, based on the current perception threshold measured by the measuring device 20.

[0076] (2) Further, the control unit 75 can superimpose and display a plurality of blood vessel-dominated regions and a plurality of nerve-dominated regions each dominated by a plurality of nerves of the human body (FIG. 7C).

[0077] With this configuration, it becomes possible to recognize the blood vessels and nerves that dominate the area where the sensory disorder has occurred, along with the progression of the sensory disorder, based on the current perception threshold measured by the measuring device 20.

[0078] (3) Further, the measuring device 20 can have a size that can be measured for the big toe of the subject and can have an electrode unit 22 that is a bipolar electrode.

[0079] With this configuration, it becomes possible to easily measure the current perception threshold at the big toe of the human body.

[0080] (4) Further, it can have an evaluation unit 76 that evaluates the sensory disorder that has developed at the predetermined site of the subject using at least one of the current perception threshold at the predetermined site of the subject, the blood vessel-dominated region corresponding to the predetermined site of the subject, or the nerve-dominated region corresponding to the predetermined site of the subject.

[0081] By configuring in this way, it is possible not only to evaluate the progression degree of sensory disorder at a predetermined site, but also to identify whether the cause of the sensory disorder is due to the blood vessel that supplies the predetermined site or due to the nerve that supplies the predetermined site.

[0082] (5) Further, the predetermined site is the lower limb of the subject, and the evaluation unit 76 can evaluate the sensory disorder in the affected limb of the subject by comparing the current perception threshold of the lower limb where the sensory disorder occurs in the subject with the current perception threshold of the healthy limb of the subject.

[0083] According to this, the degree of sensory disorder of the lower limb where the sensory disorder occurs in the subject can be easily grasped.

[0084] (6) Further, the predetermined site is the lower limb of the subject, and the evaluation unit 76 can evaluate the sensory disorder in the affected limb of the subject by comparing the current perception threshold of the lower limb where the sensory disorder occurs in the subject with the current perception threshold of the lower limb of a healthy person different from the subject.

[0085] According to this, the degree of sensory disorder of the subject with respect to a healthy person can be easily grasped.

Explanation of Reference Numerals

[0086] 10…Sensory Disorder Evaluation System 20…Measuring Device 60…PC 69…Display Device 76…Evaluation Unit 80…Printer

Claims

1. A measurement unit that measures the current perception threshold at a predetermined site of the subject by stimulating a nerve that innervates the predetermined site of the subject; A control unit that superimposes and displays a plurality of vascular regions each dominated by a plurality of major blood vessels of the human body and the predetermined site of the subject at which the current perception threshold is measured, and displays the current perception threshold at the predetermined site of the subject measured by the measurement unit on a display unit; A sensory disorder evaluation system, characterized by comprising the above.

2. The sensory disorder evaluation system according to claim 1, wherein the control unit can superimpose and display the plurality of vascular regions and a plurality of nerve regions each dominated by a plurality of nerves of the human body.

3. The sensory disorder evaluation system according to claim 1, wherein the measurement unit has a measurable size of the big toe of the subject and an electrode unit that is a bipolar electrode.

4. The sensory disorder evaluation system according to claim 1, further comprising an evaluation unit that evaluates a sensory disorder developed at the predetermined site of the subject using at least one of the current perception threshold at the predetermined site of the subject, the vascular region corresponding to the predetermined site of the subject, or the nerve region corresponding to the predetermined site of the subject.

5. The predetermined site is the lower limb of the subject, The sensory disorder evaluation system according to claim 4, wherein the evaluation unit evaluates a sensory disorder in the affected limb of the subject by comparing the current perception threshold of the lower limb in which the sensory disorder occurs in the subject with the current perception threshold of the healthy limb of the subject.

6. The predetermined site is the lower limb of the subject, The sensory disorder evaluation system according to claim 4, wherein the evaluation unit evaluates a sensory disorder in the affected limb of the subject by comparing the current perception threshold of the lower limb in which the sensory disorder occurs in the subject with the current perception threshold of the lower limb of a healthy person different from the subject.

7. The sensory disorder evaluation system according to claim 4, further comprising an output unit capable of outputting an evaluation result by the evaluation unit.

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