JP3808492B1 - Pain measuring device - Google Patents

Abstract

To provide a pain measuring apparatus capable of measuring the degree of pain felt by a person to be measured over a wide range by electrical stimulation without pain.
A pain measuring device (1) includes an electrode (3) attached to a person to be measured (2) and a stimulation current generating means for generating a stimulation current to be supplied to the electrode (3). Based on the applied stimulation current, the pain felt by the person under measurement 2 is measured. In this pain measuring device 1, when the current value of the stimulation current is gradually increased from 0, the stimulation current stimulates the Aβ fiber before the Aδ fiber and does not stimulate the C fiber.
[Selection] Figure 1

Description

The present invention also relates to pain measurement equipment for the human body in order to objectively measure the pain that the subject is feeling.

  Conventionally, the present applicant has proposed a pain measuring device for objectively measuring the pain felt by the measurement subject (see, for example, Patent Document 1). The pain measuring device disclosed in Patent Document 1 quantitatively evaluates the degree of pain felt by a measurement subject based on a stimulation current applied to the measurement subject from an electrode attached to the measurement subject. It can be configured. That is, the pain measuring apparatus disclosed in Patent Document 1 measures the magnitude of electrical stimulation (current value of stimulation current) that is felt with the same intensity as the pain felt by the person being measured. It is the composition which can evaluate the degree of the pain which is feeling quantitatively. In this pain measuring apparatus, a stimulation current having a rectangular pulse waveform is used as the stimulation current applied to the subject.

Japanese Patent No. 3699258

  If a new pain occurs in the measurement subject due to the stimulation current applied to measure the pain, the measurement of the pain becomes painful for the measurement subject. Therefore, different types of electrical stimulation without pain are given to the measurement subject, and the pain is measured from the magnitude of the different types of electrical stimulation (electrical stimulation without pain) that feels as strong as the pain the measurement subject feels. There is a need in the market for pain measuring devices that can be quantitatively evaluated.

  Here, in the pain measuring device disclosed in Patent Document 1, when the current value of the stimulation current applied to the measurement subject is small, no new pain is generated in the measurement subject due to the stimulation current. Therefore, in this pain measuring device, when the pain felt by the subject is small, the pain is quantitatively evaluated without feeling new pain due to the stimulation current (that is, by a different kind of electrical stimulation without pain). it can. However, in the pain measuring device disclosed in Patent Document 1, when the stimulation current exceeds a predetermined value, new pain is generated in the measurement subject due to the stimulation current. Moreover, it became clear by research of this inventor that the lower limit of the stimulation current which generates this painful electrical stimulation is a relatively low value. Therefore, in the pain measuring device disclosed in Patent Document 1, even if the pain felt by the person being measured is not so great, if painful electrical stimulation is not applied, the pain is quantitatively evaluated. I can't. As a result, it is difficult to measure the degree of pain felt by the subject in a wide range without causing the subject to feel pain.

An object of the present invention, by electrical stimulation without pain is to provide a pain measurement equipment capable of measuring the degree of pain the subject feels a wide range.

  In order to solve the above problems, the present inventor has made various studies. In particular, the inventor of the present application paid attention to the characteristics of the stimulation current applied to the person to be measured, and conducted various studies on the characteristics of the stimulation current. As a result, when the stimulation current has a predetermined characteristic, it has been found that the degree of pain felt by the measurement subject can be measured over a wide range by electrical stimulation without pain. .

The present invention is based on such new knowledge, and includes an electrode attached to the measurement subject and a stimulation current generation unit that generates a stimulation current supplied to the electrode, and is provided from the electrode to the measurement subject. based on the stimulation current that, in the pain measurement device for a human body to measure the pain the subject feels the stimulation current, when increasing gradually the current value of the stimulation current from 0, before the Aδ fibers In addition to stimulating the Aβ fiber and not stimulating the C fiber, a protection circuit serving as a limiter circuit that prevents a current exceeding a predetermined value from being supplied to the electrode as a stimulation current, and a minimum sensed current value for the Aβ fiber An image display means for displaying, and the stimulation current is a total value in the range of 50 Hz to 500 Hz of the peak value of the power spectrum indicating the intensity of stimulation for each frequency component, and the power spectrum. By setting the ratio of the peak value to the total value in the range of 50 Hz to 3000 Hz to be in the range of 1: 3 to 1:12, the minimum sensed current value for the Aβ fiber is the Aδ fiber due to the stimulation current consisting of a conventional rectangular wave. It is assumed that the current value is larger than the minimum sensed current value for A, and the ratio between the minimum sensed current value for the measured subject's Aβ fiber and the measured pain-corresponding current value is displayed on the image display means. characterized in that way the.

  In the pain measurement device of the present invention, the stimulation current does not stimulate the C fibers involved in persistent dull pain transmission. Therefore, in this pain measuring apparatus, the measurement subject does not feel the persistent dull pain caused by the stimulation of the C fibers due to the stimulation current. Further, in the present invention, when the current value of the stimulation current is gradually increased from 0, Aβ fibers that are not involved in pain transmission are earlier than the Aδ fibers that are involved in instantaneous sharp pain transmission. stimulate. Therefore, it becomes possible to measure the degree of pain felt by the person to be measured over a wide range by electrical stimulation without pain.

  In the present specification, “does not stimulate C fibers” includes not only stimulating C fibers but also cases where the stimulation on C fibers is negligibly small compared to stimulation on Aδ fibers and Aβ fibers. included.

In the present invention, the stimulation current is such that the current value serving as the pain threshold value for the Aδ fiber is a larger current value than the current value serving as the pain threshold value for the Aδ fiber due to the stimulation current composed of the conventional rectangular wave. it is not preferable to be.

Moreover, based on said new knowledge, this invention is equipped with the electrode with which a to-be-measured person is mounted | worn, and the stimulation current production | generation means which produces | generates the stimulation current supplied to an electrode, and is given to a to-be-measured person from an electrode. based on the stimulation current, the pain measurement device for a human body to measure the pain the subject feels the stimulation current, the frequency component of 5Hz are free first, the stimulation of each frequency component of the stimulation current the sum value in the range from 50Hz to peak value of the power spectrum of 500Hz indicating the strength, the ratio of the sum value in the range of 3000Hz from 50Hz peak value of the power spectrum 1: the range of 3 to 1:12 Thus, when the current value of the stimulation current is gradually increased from 0, the Aβ fiber is stimulated before the Aδ fiber and the C fiber is not stimulated. A protection circuit serving as a limiter circuit that prevents the power supply from being supplied and an image display means for displaying the minimum sensed current value for the Aβ fiber, and the power spectrum has a peak value for each integer multiple of 50 Hz. The peak value is approximately equal between 50 Hz and 500 Hz, and is maximum between 50 Hz and 2000 Hz, and the image display means measures the minimum sensed current value for the Aβ fiber of the measurement subject. The ratio to the current value corresponding to pain is displayed .

In the pain measuring apparatus of the present invention, the stimulation current does not include a frequency component of 5 Hz that stimulates the C fibers. Therefore, in this pain measuring device, the measurement subject does not feel the persistent dull pain caused by the stimulation of C fibers. Further, in the present invention, the sum of the peak values of the power spectrum related to the stimulation of the Aδ fiber in the range of 50 Hz to 500 Hz and the peak value of the power spectrum related to the stimulation of the Aβ fiber are in the range of 50 Hz to 3000 Hz. The ratio to the total value at 1 is in the range of 1: 3 to 1:12. Therefore, it becomes possible to measure the degree of pain felt by the person to be measured over a wide range by electrical stimulation without pain. In addition, it is possible to measure pain by using different types of electrical stimulation that are not accompanied by pain and that are closer to the pain felt by the measurement subject. In the present invention, the peak value of the power spectrum is substantially equal between 50 Hz and 500 Hz and maximum between 50 Hz and 2000 Hz, which facilitates generation of the stimulation current waveform. In the present invention, the power spectrum may be approximately equal and maximum at around 250 Hz and around 2000 Hz.

  In this specification, “the frequency component of 5 Hz is not included” means that the stimulation current does not include any frequency component of 5 Hz, and the frequency component of 5 Hz is a frequency component of 250 Hz or 2000 Hz. This is the case when it is included at a negligible ratio. That is, in this specification, even when the frequency component of 5 Hz is included in the stimulation current at a ratio of 1/1000 or less with respect to the frequency component of 250 Hz or 2000 Hz, “the frequency component of 5 Hz is not included”. It corresponds to.

In the present invention, the image display means displays the ratio between the minimum sensed current value for the Aβ fiber and the pain-corresponding current value in the bar graph indicating the pain-corresponding current value, and displays the minimum sensed current value for the Aβ fiber as a bar graph. Is preferred. If comprised in this way, it will become easy to grasp | ascertain the to-be-measured person's pain index.

  In the present invention, the stimulation current preferably has only a frequency component in the range of 50 Hz to 3000 Hz. A frequency component of 50 Hz or less and a frequency component of 3000 Hz or more are not involved in stimulation of Aδ fibers and Aβ fibers. Therefore, when the stimulation current has only a frequency component in the range of 50 Hz to 3000 Hz, the Aδ fiber and the Aβ fiber can be efficiently stimulated with a small stimulation current.

As described above, in such pain measurement equipment to the present invention, by electrical stimulation without pain, it is possible to measure the degree of pain the subject feels a wide range.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(Schematic configuration of pain measuring device)
FIG. 1 is a perspective view showing a configuration of a pain measuring apparatus 1 according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the main body 4 and peripheral devices of the pain measuring apparatus 1 shown in FIG. FIG. 3 is a diagram showing an example of a screen display of the personal computer 6 shown in FIG.

  The pain measuring apparatus 1 according to the present embodiment is an apparatus for objectively measuring the pain felt by the person 2 to be measured due to illness or injury. That is, the pain measuring apparatus 1 of this embodiment is an apparatus for quantitatively evaluating the pain felt by the person under measurement 2. As shown in FIG. 1, the pain measuring device 1 measures an pain, an electrode 3 mounted on the inner side of the upper arm 2 a of the person to be measured 2, a main body 4 that supplies a predetermined stimulation current to the electrode 3, and pain. The operation button 5 operated by the person 2 to be measured, the personal computer (PC) 6 for outputting a predetermined operation signal to the main body 4 and displaying the measurement result of pain, and the measurement result of pain. And a printer 7 for printing on printing paper or the like. The electrode 3, the operation button 5, the PC 6 and the printer 7 are connected to the main body 4 by a predetermined cable.

  In this embodiment, the electrode 3 is attached to the inner side of the upper arm 2a of the person to be measured 2. However, the attachment position of the electrode 3 may be a place where the amount of muscle and sweat glands are small and the attachment is easy. For example, it may be other than the inner side of the upper arm 2a. For example, the mounting position of the electrode 3 may be a heel. Thus, intermittent or continuous contraction of the muscle can be prevented by mounting the electrode 3 at a location where the amount of muscle is small.

  As shown in FIG. 2, the main body 4 includes an MPU (Micro Processing Unit) 9, a step-up transformer 10, a voltage control circuit 11, an output control circuit 12, a protection circuit 13, a current detection circuit 14, an external circuit, A RAM 15, a nonvolatile memory 16, an image display unit 17, a display unit driver 18, an address decoder 19, and an I / F (interface) circuit 20 are provided.

  The MPU 9 includes a ROM, a RAM, a timer, and an output interface (not shown). The ROM inside the MPU 9 stores in advance a program for performing processing for calculating the degree of pain felt by the person under measurement 2 from the current value of the stimulation current supplied to the electrode 3. When an operation signal is input from the PC 6 to the MPU 9 via the I / F circuit 20, the MPU 9 operates from the PC 6 according to the program stored in the internal ROM while using the temporary storage function of the external RAM 15. The signal is processed and a predetermined algorithm is executed. Further, by executing a predetermined algorithm, the MPU 9 supplies drive signals to the step-up transformer 10, the voltage control circuit 11, and the output control circuit 12, respectively.

  The step-up transformer 10 steps up a voltage from a DC power supply (not shown) in accordance with a drive signal from the MPU 9. More specifically, the step-up transformer 10 drives a transistor with a square-wave drive signal from the MPU 9 using a timer to step up the voltage from the DC power supply. For example, the step-up transformer 10 boosts a voltage of 12V applied by a DC power source to 100V to 120V. The voltage control circuit 11 adjusts the DC voltage output output from the step-up transformer 10 according to the drive signal from the MPU 9. Further, as shown in FIG. 2, a detection signal for detecting a voltage value in the voltage control circuit 11 is output from the voltage control circuit 11 and input to the MPU 9. Based on the detection signal input to the MPU 9, the output control circuit 12 is controlled so as not to output a voltage exceeding a specified value.

  The output control circuit 12 is a PWM control circuit for controlling the rectified voltage output from the voltage control circuit 11 by PWM (Pulse Width Modulation). The output control circuit 12 outputs a pulse voltage in the range of 5V to 100V, for example, according to the drive signal from the MPU 9. The protection circuit 13 is a limiter circuit that prevents a current greater than a predetermined value from being supplied from the output control circuit 12 to the electrode 3 attached to the measurement subject 2. As shown in FIG. 2, a detection signal for detecting a current limit value is output from the protection circuit 13 and input to the MPU 9.

  The current detection circuit 14 is a circuit for detecting the effective value of the current applied from the protection circuit 13 to the subject 2 through the electrode 3. The current detection circuit 14 of this embodiment is configured by, for example, a resistor or an operational amplifier. As shown in FIG. 2, a detection signal for detecting the current value of the stimulation current supplied to the electrode 3 (that is, the stimulation current applied to the person 2 to be measured) is output from the current detection circuit 14 to the MPU 9. Entered. In this embodiment, the waveform of the stimulation current supplied from the output control circuit 12 to the electrode 3 (that is, the stimulation current applied to the person 2 to be measured) is a pulse waveform with a period of 50 Hz.

  Thus, in this embodiment, the stimulation current supplied to the electrode 3 by the MPU 9, DC power supply (not shown), step-up transformer 10, voltage control circuit 11, output control circuit 12, protection circuit 13 and current detection circuit 14 is supplied. Stimulating current generating means for generating is configured.

  As described above, the external RAM 15 is a memory for the MPU 9 to execute a predetermined algorithm. The external RAM 15 need not be provided if the internal RAM capacity of the MPU 9 is sufficient. The non-volatile memory 16 has predetermined values such as a rate of increase of the voltage output from the output control circuit 12 (that is, the degree of increase in the stimulation current supplied to the electrode 3) and a limit value of the voltage supplied to the current detection circuit 14. Is a memory in which the set value is stored.

  The image display means 17 is a display device such as a liquid crystal display device that displays the voltage value in the voltage control circuit 11 and the current value of the stimulation current supplied to the electrode 3 on the outside of the main body 4 (see FIG. 1). The image display means 17 displays the image data output from the MPU 9 and processed by the display means driver 18.

  The address decoder 19 is a logic circuit for exchanging signals between the external RAM 15 and the display means driver 18 and the MPU 9. The I / F circuit 20 is a circuit for exchanging signals between the MPU 9 and the PC 6 and for supplying signals from the MPU 9 to the printer 7.

  The operation button 5 includes a stop switch for the person to be measured 2 to stop supplying the stimulation current to the electrode 3, a start switch for starting the supply of the stimulation current, and the like. Further, as shown in FIG. 1, the PC 6 includes a display unit 6 a for displaying pain measurement results in the pain measurement device 1. The display unit 6a is, for example, a liquid crystal display device. Further, for example, the measurement result of the pain measuring apparatus 1 is displayed on the display unit 6a as shown in FIG. The display contents of the display unit 6a shown in FIG. 3 will be described later.

(Characteristics of stimulation current)
FIG. 4 is a graph showing the peak value of the power spectrum that represents the intensity of stimulation for each frequency component of the stimulation current applied from the electrode 3 shown in FIG. FIG. 5 is a graph for explaining an actual change in the power spectrum representing the intensity of stimulation for each frequency component of the stimulation current applied from the electrode 3 shown in FIG.

  The inventor of the present application has been studying for a long time what kind of stimulation current can be used to measure the degree of pain felt by the person 2 to be measured in a wide range by electrical stimulation without pain. As a result of the research, it has been found that the stimulation current that can measure the degree of pain felt by the measurement subject 2 over a wide range by electrical stimulation without pain has a predetermined characteristic. And in the pain measuring apparatus 1 of this form, it decided to generate the stimulation electric current which has this peculiar property. Hereinafter, a stimulation current capable of measuring the degree of pain felt by the person 2 to be measured over a wide range by electrical stimulation without pain (that is, a stimulus applied from the electrode 3 to the person 2 to be measured in this embodiment). Current characteristics will be described.

  Represents the intensity of stimulation for each frequency component of the stimulation current (that is, the stimulation current of the present embodiment) that can measure the degree of pain felt by the person under measurement 2 in a wide range by the electrical stimulation without pain. The power spectrum (specifically, the power spectrum representing the intensity of stimulation for each frequency component of the pulse wave of the stimulation current) has a peak value for each integer multiple of 50 Hz, and at other frequencies, A special pattern without a peak value is shown. That is, as schematically shown in FIG. 5, the power spectrum of the stimulation current in this embodiment has a peak value every 50 Hz, such as 50 Hz, 100 Hz, 150 Hz, etc., and at other frequencies, the peak Has no value. Note that the power spectrum of the stimulation current increases and decreases as shown in FIG. 5 depending on each frequency.

  In FIG. 4, only the peak value of the power spectrum of the stimulation current of this embodiment is shown by dots (see graphs G1 and G2). For reference, FIG. 4 shows a peak of the power spectrum of a stimulation current (hereinafter referred to as a conventional stimulation current) composed of a rectangular pulse wave that has been used in the pain measurement apparatus by the applicant of the present application. Only the values are shown (see graphs G3 and G4). Here, a pulse wave having a period of 50 Hz is used as the pulse wave of the conventional stimulation current. As a result of the inventor's research, accidentally, the power spectrum of the conventional stimulation current has a peak value at every frequency that is an integral multiple of 50 Hz, similarly to the power spectrum of the stimulation current of this embodiment, and other frequencies. Then, it turned out that the special pattern which does not have a peak value is shown. In FIG. 4, in order to distinguish from the peak value of the power spectrum of the stimulation current of this embodiment, a state in which the peak values of the power spectrum of the conventional stimulation current are connected by a solid line is illustrated. In FIG. 4, the horizontal axis represents frequency (unit: Hz), and the vertical axis represents stimulation intensity (unit: dB (decibel)). FIG. 4 is a graph of the logarithm of which the horizontal axis is a logarithmic scale.

  Here, the current values of the stimulation current of this embodiment having the peak value of the power spectrum shown in FIG. 4 and the conventional stimulation current are equal. Further, each peak value of the power spectrum shown in FIG. 4 (that is, the intensity of stimulation for each frequency component) increases and decreases in proportion to the increase and decrease of the current value of each stimulation current.

  FIG. 4 shows two graphs, a graph G1 and a graph G2, as graphs showing the transition of the peak value of the power spectrum of the stimulation current of this embodiment. The difference between the graph G1 and the graph G2 is caused by variations in stimulation current during measurement. Similarly, FIG. 4 shows two graphs, a graph G3 and a graph G4, as graphs showing the transition of the peak value of the power spectrum of the conventional stimulation current, and the difference between the graph G3 and the graph G4 is also shown. This is caused by variations in stimulation current during measurement.

  As can be seen from FIG. 4, the graphs G1 and G2 and the graphs G3 and G4 have greatly different patterns of change. As can be seen from the graphs G1 and G2, the peak value of the power spectrum of the stimulation current of this embodiment is substantially equal in the range of 50 Hz to 500 Hz. In particular, in the graph G1, the peak value of the power spectrum of the stimulation current of this embodiment is substantially equal in the range of 50 Hz to 1050 Hz. Further, the peak value of the power spectrum of the stimulation current of this embodiment is the maximum in the range of 50 Hz to 2000 Hz. More specifically, in the graph G1, the peak value of the power spectrum near 1050 Hz is maximum, and in the graph G2, the peak value of the power spectrum near 150 Hz is maximum. On the other hand, as can be seen from the graphs G3 and G4, the peak value of the power spectrum of the conventional stimulation current decreases at a frequency of 100 Hz or more. In particular, it rapidly decreases at a frequency of 500 Hz or higher.

  Here, when a simple sinusoidal stimulation current (stimulation current having only a certain frequency component) is applied to the measurement subject 2, as shown in FIG. 4, instantaneous sharp pain, pressure, and temperature It is a stimulation current having a frequency component of 250 Hz that efficiently stimulates Aδ fibers involved in transmission, which is involved in transmission of contact and pressure, and efficiently stimulates Aβ fibers that are not involved in pain transmission. It is conventionally known that the stimulation current has a frequency component of 2000 Hz. When a simple sinusoidal stimulation current is applied to the person 2 to be measured, the stimulation current having a frequency component of 5 Hz efficiently stimulates the C fibers involved in the transmission of continuous dull pain. It has been known for some time.

  The stimulation current of this embodiment and the conventional stimulation current include a frequency component of 250 Hz that efficiently stimulates Aδ fibers and a frequency component of 2000 Hz that efficiently stimulates Aβ fibers. Further, the stimulation current of this embodiment and the conventional stimulation current do not contain any frequency component of 5 Hz that stimulates C fibers efficiently, or are negligible compared with frequency components of 250 Hz and 2000 Hz. The frequency component of 5 Hz (for example, less than 1/1000 of the frequency component of 250 Hz or 2000 Hz) is included.

  In addition, it is an integrated value from 50 Hz to 500 Hz of the power spectrum of the stimulation current that is involved in the stimulation of the Aδ fiber, and in order to participate in stimulation of the Aβ fiber, the power spectrum of the stimulation current is from 50 Hz to 3000 Hz. It is considered to be an integral value up to the range.

(Pain measurement method)
FIG. 6 is a graph for explaining the concept of the pain measuring method in the pain measuring apparatus 1 shown in FIG. FIG. 7 is a flowchart showing a pain measurement procedure in the pain measurement apparatus 1 shown in FIG.

  Hereinafter, a method for measuring pain in the pain measuring apparatus 1 will be described.

  In this embodiment, in order to measure the pain felt by the person under measurement 2 (that is, to quantitatively evaluate pain), the current values of two stimulation currents having different sizes are measured. As shown in FIG. 6, one is a stimulus when the person to be measured 2 first feels an electrical stimulus when the current value of the stimulus current applied to the person to be measured 2 is gradually increased from 0. The current value of the current (that is, the sensing threshold; hereinafter, this current value is referred to as the “minimum sensed current value”), and the other is that when the current value of the stimulation current is further increased, This is a current value of a stimulation current that gives a sense similar to that of a pain felt due to a disease or the like (hereinafter, this current value is referred to as a “pain corresponding current value”).

The minimum sensed current value is a reference value for quantitatively evaluating pain. That is, a value obtained by dividing the pain-corresponding current value by the minimum sensed current value is defined as a pain index, and the pain felt by the measurement subject 2 is quantitatively evaluated based on the pain index. Even if the cause of pain is the same, the way people feel pain varies from person to person.As a result, assessing pain using the pain index allows quantitative pain assessment that suppresses the effects of individual differences in how pain is felt. It becomes possible. Note that the pain felt by the person to be measured 2 may be evaluated based on the pain level defined by the following equation.
(Pain degree) = (Pain-corresponding current value−Minimum sensed current value) / Minimum sensed current value

  The pain measurement procedure in the pain measurement apparatus 1 is, for example, as shown in the flowchart of FIG. That is, when measuring the pain felt by the person 2 to be measured, first, the electrode 3 is attached to the person 2 to be measured (step S1). Thereafter, the current value of the stimulation current applied to the person to be measured 2 is gradually increased from 0. Then, when the person under test 2 first feels electrical stimulation, he presses the stop switch of the operation button 5 held by the hand. The stimulation current is stopped by pressing the stop switch, and the current value at that time is stored in the MPU 9 as the minimum sensed current value (step S2). At this time, the MPU 9 may store only the value without stopping the stimulation current.

  After that, when the current value of the stimulation current is further increased and a different kind of electrical stimulation (electric stimulation without pain) that feels the same intensity as the pain sensation felt by the person under measurement 2 is felt The person 2 presses the stop switch of the operation button 5 held by the hand. The stimulation current is stopped by pressing the stop switch, and the current value at that time is stored in the MPU 9 as a pain-corresponding current value (step S3). When the measurement of the minimum sensed current value and the pain-corresponding current value is completed, the pain index is calculated, and the minimum sensed current value, the pain-corresponding current value, and the pain index are displayed on the display unit 6a of the PC 6 (step S4). The pain measurement result is printed on the printing paper by the printer 7, or the measurement result data is stored in the PC 6 (step S5), and the pain measurement is completed.

  The minimum sensed current value, the pain-corresponding current value, and the pain index are displayed on the display unit 6a, for example, as shown in FIG. That is, the minimum sensed current value, the pain-corresponding current value, and the pain index are displayed in the measurement data display area α1 and the measurement result display area α2 on the display unit 6a.

  In the display example shown in FIG. 3, in the measurement data display area α1, three measured values of the minimum sensed current value and an average value thereof are displayed under the display of “Minimum”. In the measurement data display area α1, three measurement values of pain corresponding current values (only one measurement is performed in the display example of FIG. 3) and an average value thereof are displayed under the display of “Pain”. Yes. Further, in the measurement data display area α1, a pain index is displayed on the right side of the display of “Pain Ratio”. The pain index displayed in the measurement data display area α1 is a value obtained by dividing the average value of the pain-corresponding current by the average value of the minimum sensed current. Further, on the right side of the display of the pain corresponding current value, the average value of the minimum sense current and the average value of the pain corresponding current are displayed as a stacked vertical bar graph. In FIG. 3, the black portion is the average value of the minimum sense current, and the white portion is the average value of the pain-corresponding current.

  In the display example shown in FIG. 3, the measurement result display area α2 displays the measurement results of pain of five persons to be measured 2 or the measurement results of five pains for one person to be measured 2. Has been. Specifically, in the measurement result display area α2, the average value of the minimum sensed current value of each measurer 2 is displayed under the display of “Min Ave”, and under the display of “Pain Ave”, The average value of the pain corresponding current value of the measurer 2 is displayed. Also, the pain index of each measurer 2 is displayed under the display of “Pain Ratio”, and the average value of the minimum sensed current and the average value of the pain-corresponding current of each measurer 2 are stacked horizontally on the left end. It is displayed as a bar graph. In FIG. 3, the black portion is the average value of the minimum sense current, and the white portion is the average value of the pain-corresponding current.

  In the display unit 6a, various information such as the gender and age of the person to be measured 2 is displayed in the person-to-be-measured data display area α3, and the measurement data display area α1 and the measurement result display area α2 are displayed in the graph type display area α4. The graph type displayed in the graph is displayed, and the scale of the graph displayed in the measurement data display region α1 and the measurement result display region α2 is displayed in the graph scale display region α5.

(Pain caused by stimulation current to the subject)
FIG. 8 is a graph showing the measurement results of the pain generation current value and the minimum sensed current value, which are the current values of the stimulation current at which the person to be measured 2 feels pain, and (A) shows the stimulation according to the embodiment of the present invention. The measurement result when an electric current is provided to the person to be measured 2 is shown, and (B) shows the measurement result when the stimulation current consisting of a conventional rectangular wave is given to the person to be measured 2.

  When the stimulation current of this embodiment was applied to the eight measurement subjects 2, the minimum sensed current value was 3.36 ± 0.76 mA as shown in FIG. 8 (A). Further, the current value of the stimulation current was increased to about 33 mA, which is the upper limit value of the pain measuring apparatus 1, but the person under measurement 2 did not feel pain due to the stimulation current. The person under measurement 2 did not feel pain due to the stimulation current, but felt a different kind of stimulus (ie, a stimulus not accompanied by pain) that felt as strong as the pain, and the magnitude of this stimulus. From this, quantitative evaluation of pain was possible.

  On the other hand, when the stimulation current consisting of the conventional rectangular wave is applied to the eight persons 2 to be measured, the minimum sensed current value is 0.79 ± 0 as shown in FIG. .24 mA. Further, when the stimulation current was increased, the subject 2 felt pain due to the stimulation current. The pain generation current value, which is the current value of the stimulation current at which the subject 2 feels pain, was 6.66 ± 3.03 mA.

(Main effects of this form)
In the pain measuring apparatus 1 of this embodiment, a stimulation current in which the peak value of the power spectrum changes as indicated by the graphs G1 and G2 in FIG. Therefore, as described with reference to FIG. 8A, the measurement subject 2 can measure the pain felt by the measurement subject 2 without feeling new pain due to the stimulation current.

  The effect of this embodiment will be described in more detail with reference to FIG. FIG. 9 is a schematic graph for explaining the intensity of stimulation given to the Aδ fiber and the Aβ fiber by the stimulation current according to the embodiment of the present invention and the stimulation current composed of a conventional rectangular wave, respectively.

  As described above, it is the integral value from 50 Hz to 500 Hz of the power spectrum that is involved in the stimulation of the Aδ fiber, and the integral value from 50 Hz to 3000 Hz of the power spectrum is involved in the stimulation of the Aβ fiber. It is considered to be. Therefore, here, the integrated value of the power spectrum from 50 Hz to 500 Hz is defined as the total value of the stimulation intensity involved in the stimulation of the Aδ fiber. In addition, an integrated value from 50 Hz to 3000 Hz of the peak value of the power spectrum is defined as the total value of the stimulation intensity related to the stimulation to the Aβ fiber.

  Further, it is the total value of the stimulation strengths of the Aδ fibers, and is the minimum value that the measured person 2 feels stimulation (hereinafter, this value is referred to as “Aδ fiber sensing threshold” and is also expressed in this way in FIG. 9). Is the sum of the stimulation strengths of the Aβ fibers, and is the minimum value at which the measured person 2 feels the stimulation (hereinafter, this value is referred to as “Aβ fiber sensing threshold” and is also expressed in this way in FIG. 9) It is known to be about one third of that. Further, it is the total value of the stimulation intensity of the Aδ fibers, and is the minimum value at which the measured person 2 feels pain (hereinafter, this value is referred to as “Aδ fiber pain threshold” and is also expressed in this way in FIG. 9). Is known to be about 5 times the sensing threshold for Aδ fibers. From the above, in FIG. 9, the vertical axis represents the total value of the stimulation intensity, and the ratio of the Aδ fiber sensing threshold, the Aβ fiber sensing threshold, and the Aδ fiber pain threshold is displayed as the vertical axis values. In the vertical axis of FIG. 9, since the magnitude of the Aδ fiber sensing threshold is “1”, the magnitude of the sensing threshold of the Aβ fiber is “3”, and the pain threshold of the Aδ fiber is “5”. Since Aβ fibers are not involved in pain transmission, it is theoretically considered that there is no pain threshold for Aβ fibers.

  From the graph G1 or G2 in FIG. 4 showing the characteristics of the stimulation current of this embodiment, the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is calculated. The ratio of the sum total value and the sum of the stimulation strengths of the Aβ fibers was about 1: 6. On the other hand, when the ratio between the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is calculated from the graph G3 or G4 of FIG. The ratio of the total strength value to the total stimulation strength value of Aβ fibers was about 1: 2. The ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is the sum of the peak values of the power spectrum related to the stimulation of the Aδ fibers in the range of 50 Hz to 500 Hz. , The ratio of the peak value of the power spectrum associated with the stimulation to the Aβ fiber to the sum value in the range of 50 Hz to 3000 Hz.

  From the ratio of the sum of the stimulation strengths of the Aδ fibers to the sum of the stimulation strengths of the Aβ fibers, and the measurement results of the pain (measurement results shown in FIG. 8) given to the measurement subject 2 by the stimulation current described above. When the stimulation current of this embodiment is used, even if the stimulation current is increased, the ratio of the total stimulation intensity of the Aδ fibers to the total stimulation intensity of the Aβ fibers is always 1: 6. Therefore, it is considered that Aβ fibers first sense electrical stimulation (that is, Aβ fibers are involved in the measurement of the minimum sensed current value). On the other hand, when the conventional stimulation current is used, even if the stimulation current is increased, the ratio between the total stimulation intensity of the Aδ fibers and the total stimulation intensity of the Aβ fibers is always 1: 2. Therefore, it is considered that Aδ fibers first sense electrical stimulation (that is, Aδ fibers are involved in the measurement of the minimum sensed current value).

  That is, when the stimulation current of the present embodiment is used, when the current value of the stimulation current is gradually increased from 0, the Aβ fiber is increased before the total value of the stimulation intensity of the Aδ fiber reaches the detection threshold of the Aδ fiber. The sum of the stimulation intensities reaches the Aβ fiber sensing threshold. In other words, the stimulation current of this embodiment stimulates Aβ fibers before Aδ fibers. Further, in the stimulation current of this embodiment, since the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is about 1: 6, as shown in FIG. When the total stimulation intensity reaches the sensing threshold of Aβ fibers (ie, the total stimulation intensity of Aβ fibers is at the position of point B), the total stimulation intensity of Aδ fibers is “0.5. ”And the detection threshold of the Aδ fiber has not been reached (that is, the position of the point A is reached).

  On the other hand, in the case of using the conventional stimulation current, when the current value of the stimulation current is gradually increased from 0, the total value of the stimulation intensity of the Aβ fiber reaches the sensing threshold of the Aβ fiber before the Aδ fiber is detected. The sum of the stimulation intensities reaches the Aδ fiber sensing threshold. Further, in the conventional stimulation current, since the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is about 1: 2, as shown in FIG. When the total strength value reaches the Aδ fiber sensing threshold (that is, the total stimulation strength value of the Aδ fibers is at the position C), the total stimulation strength value of the Aβ fibers is “2”. , The detection threshold for Aβ fibrils has not been reached (ie, the position of point D is reached).

  In FIG. 9, point A and point B are connected by a solid line, and point C and point D are connected by a two-dot chain line. However, this is a straight line for convenience of viewing the graph. Straight lines have no particular meaning.

  Here, a case where the current value of the stimulation current is further increased will be considered. When the stimulation current is increased, the total value of the stimulation intensity increases. When the sum of the stimulation strengths of the Aδ fibers reaches the pain threshold value of the Aδ fibers, the person to be measured 2 feels new pain due to the stimulation current. Therefore, it is harsh for the person to be measured 2 to give a stimulation current having a current value higher than this, and after the person to be measured 2 starts to feel new pain due to the stimulation current, the measurement of pain is not continued. Can not. That is, the pain can be measured by the pain measuring apparatus 1 from when the person under measurement 2 starts to feel electrical stimulation until the person to feel pain due to the electrical stimulation. In other words, until the total value of the stimulation intensity of the Aδ fibers reaches the point E (until the total value of the stimulation intensity reaches “5”), the measurement of the pain of the measurement subject 2 by the stimulation current without pain. It will be possible.

  When the stimulation current of this form is used, the minimum sensed current value is the value of the stimulation current when the Aβ fiber first senses an electrical stimulus, that is, when the total value of the stimulation intensity of the Aβ fiber reaches point B. Value. At this time, the total value of the stimulation strength of the Aδ fiber is 0.5 as described above, and is located at the position of the A point. Therefore, the total value of the stimulation strength of the Aδ fiber is in the range from the A point to the E point. In this case, it is possible to measure pain by a stimulation current without pain. That is, pain can be measured if the sum of the stimulation strengths of the Aδ fibers is in the range of 0.5 to 5, and the stimulation current having a current value 10 times the minimum sensed current value is used as the stimulation current without pain. It becomes possible to apply an electric current to the person 2 to be measured. In addition, the range of the total value of the stimulation intensity of the Aβ fibers corresponding to this pain measurable range is 3 to 30.

  On the other hand, when the conventional stimulation current is used, the minimum sensed current value is when the Aδ fiber first senses an electrical stimulus, that is, when the sum of the stimulation strengths of the Aδ fiber reaches point C. Is the value of the stimulation current. Therefore, if the sum of the stimulation intensities of the Aδ fibers is in the range from the C point to the E point, it is possible to measure pain by a stimulation current without pain. That is, pain can be measured only when the sum of the stimulation strengths of the Aδ fibers is in the range of 1 to 5, and a stimulation current having a current value five times the minimum sensed current value as a stimulation current without pain. Only current can be applied to the person 2 to be measured. It should be noted that the range of the sum value of the stimulation strengths of the Aβ fibers corresponding to this measurable range of pain is 2 to 10.

  As described above, when the conventional stimulation current is used, only the stimulation current having a current value five times the minimum sensed current value can be applied to the measurement subject 2, whereas the stimulation current of this embodiment is used. In this case, a stimulation current having a current value 10 times the minimum sensed current value can be applied to the measurement subject 2 without causing pain. That is, when the stimulation current of this embodiment is used, the range in which the pain of the person to be measured 2 can be measured by the stimulation current without pain is twice that when the stimulation current is used with the conventional stimulation current. It becomes possible to measure the degree of pain felt by 2 over a wide range. In addition, when the stimulation current of this embodiment is used, the degree of pain can be measured over a wide range by the stimulation current without pain. Therefore, as described with reference to FIG. Even if the current value is increased to about 33 mA, which is the upper limit value of the pain measuring apparatus 1, the measurement subject 2 does not feel pain due to the stimulation current. In other words, before the sum of the stimulation strengths of the Aδ fibers reaches the pain threshold of the Aδ fibers, the pain of the measurement subject 2 can be reduced by different types of stimulations (ie, stimulations that do not involve pain) that are as strong as the pains. The quantitative evaluation can be completed, and the measurement subject 2 does not feel new pain due to the stimulation current.

  As described above, when the stimulation current of this embodiment is used, the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers (that is, the power spectrum associated with the stimulation of the Aδ fibers). The ratio of the sum of the peak values of 50 Hz to 500 Hz and the sum of the peak values of the power spectrum associated with stimulation of Aβ fibers in the range of 50 Hz to 3000 Hz is about 1: 6. When the current value of the stimulation current is gradually increased from 0, the stimulation current stimulates the Aβ fibers before the Aδ fibers. Therefore, it becomes possible to measure the degree of pain felt by the person under measurement 2 over a wide range by electrical stimulation without pain.

  The stimulation current of this embodiment includes a frequency component of 250 Hz that efficiently stimulates Aδ fibers and a frequency component of 2000 Hz that efficiently stimulates Aβ fibers. Therefore, it is possible to measure pain by using different types of electrical stimulation that are closer to the pain felt by the person to be measured 2. That is, if a stimulus current not containing a frequency component of 250 Hz that efficiently stimulates Aδ fibers involved in pain transmission is given to the person to be measured 2, a wider range of different types of electrical stimulation without pain can be measured. It is also possible to give it to the person 2. However, if the frequency component of 250 Hz that efficiently stimulates Aδ fibers involved in pain transmission is not included at all, the stimulation of completely different sensation from pain is compared with the actual pain felt by the subject 2. This makes it difficult to properly evaluate pain. On the other hand, when the 250 Hz frequency component and the 2000 Hz frequency component are included in the stimulation current as in this embodiment, the pain is caused by different types of electrical stimulation that is closer to the pain felt by the person to be measured 2. Can be measured.

  In the pain measuring apparatus 1 of the present embodiment, the stimulation current does not include a frequency component of 5 Hz that stimulates C fibers involved in the transmission of continuous dull pain. Therefore, in this pain measuring device, the measurement subject does not feel the persistent dull pain caused by the stimulation of C fibers.

  Further, in the stimulation current of this embodiment, the peak value of the power spectrum is substantially equal at least between 50 Hz and 500 Hz, and is maximum between 50 Hz and 2000 Hz. This facilitates generation of the stimulation current waveform.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

  In the stimulation current of the above-described embodiment, the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers is about 1: 6. However, as can be seen from FIG. 9, if the ratio of the sum of the stimulation strengths of the Aδ fibers to the sum of the stimulation strengths of the Aβ fibers is 1: 3 or more, that is, the sum of the stimulation strengths of the Aβ fibers. If the value obtained by dividing the value by the sum of the stimulation strengths of the Aδ fibers is 3 or more, when the current value of the stimulation current is gradually increased from 0, the Aβ fibers can be stimulated before the Aδ fibers. Thus, it becomes possible to measure pain over a wide range compared to the conventional case.

  Further, when the ratio of the sum of the stimulation strengths of the Aδ fibers to the sum of the stimulation strengths of the Aβ fibers is larger than 1:12, that is, the sum of the stimulation strengths of the Aβ fibers is expressed as the stimulation strength of the Aδ fibers. When the value divided by the sum of the values becomes larger than 12, stimulation to the Aβ fibers not involved in pain transmission becomes relatively strong, and different types of electrical stimulation that are closer to the pain felt by the measured person 2 Makes it difficult to measure pain. Therefore, in order to measure pain by different types of electrical stimulation with a sense closer to pain, the ratio of the sum of the stimulation strengths of the Aδ fibers and the sum of the stimulation strengths of the Aβ fibers should be 1:12 or less. Is preferred.

  Thus, by setting the ratio of the sum of the stimulation strengths of the Aδ fibers to the sum of the stimulation strengths of the Aβ fibers in the range of 1: 3 to 1:12, the electrical stimulation without pain causes the target to be covered. The degree of pain felt by the measurer 2 can be measured over a wide range. In addition, it is possible to measure pain by using different types of electrical stimulation that are not accompanied by pain and that are closer to the pain felt by the person under measurement 2.

Further, the transition of the peak value of the power spectrum of the stimulation current having the above-described effect is not limited to the graph G1 and the graph G2 shown in FIG. When the current value of the stimulation current is gradually increased from 0, the Aβ fiber is stimulated before the Aδ fiber, or the ratio of the sum of the stimulation strength of the Aδ fiber and the sum of the stimulation strength of the Aβ fiber There 1: if to satisfy the condition that is in the range of from 3 to 1:12, the peak value of the power spectrum of the stimulation current is a graph showing the graph G 5 and FIG. 10 (B) shown in FIG. 10 (a) it may be changes as the G 6.

  That is, as shown in FIG. 10A, the peak value of the power spectrum may change so that the maximum value of the curve connecting the peak values of the power spectrum appears in the vicinity of 250 Hz and 2000 Hz. In this case, as indicated by the solid line in FIG. 10A, the peak value of the power spectrum is such that the maximum values in the vicinity of 250 Hz and 2000 Hz are equal and the maximum value is the maximum value of the peak value of the power spectrum. May be changed, or, as indicated by a broken line in FIG. 10A, a maximum value in the vicinity of 250 Hz may be the maximum value of the peak value of the power spectrum. Further, as indicated by a two-dot chain line in FIG. 10A, a maximum value in the vicinity of 2000 Hz may be the maximum value of the peak value of the power spectrum.

  Further, as shown by the solid line in FIG. 10B, the peak value of the power spectrum may gradually increase from near 250 Hz to near 2000 Hz and thereafter gradually decrease. As indicated by the broken line in (B), the peak value of the power spectrum may change so as to gradually decrease as the frequency increases from around 250 Hz.

  In addition, as shown to FIG. 10 (A) and (B), it is preferable that a stimulation current has only a frequency component of the range of 50 Hz to 3000 Hz. A frequency component of 50 Hz or less and a frequency component of 3000 Hz or more are not involved in stimulation of Aδ fibers and Aβ fibers. Therefore, when the stimulation current has only a frequency component in the range of 50 Hz to 3000 Hz, the Aδ fiber and the Aβ fiber can be efficiently stimulated with a small stimulation current.

  Furthermore, in the above-described form, the stimulation current includes a frequency component of 250 Hz and a frequency component of 2000 Hz. In addition to this, for example, the Aδ fiber may be stimulated by including a frequency component in the vicinity of 250 Hz, although the frequency component of 250 Hz is not included in the stimulation current. Similarly, the Aβ fiber may be stimulated by including a frequency component in the vicinity of 2000 Hz although the frequency component of 2000 Hz is not included in the stimulation current.

It is a perspective view which shows the structure of the pain measuring apparatus concerning Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the main-body part of the pain measuring device shown in FIG. 1, and its peripheral device. It is a figure which shows an example of the screen display of the personal computer shown in FIG. It is a graph which shows the peak value of the power spectrum showing the intensity | strength of the stimulus for every frequency component of the stimulation current provided to a to-be-measured person from the electrode shown in FIG. It is a graph for demonstrating the actual change of the power spectrum showing the intensity | strength of the stimulus for every frequency component of the stimulation current provided to a to-be-measured person from the electrode shown in FIG. It is a graph for demonstrating the idea of the measuring method of the pain in the pain measuring apparatus shown in FIG. It is a flowchart which shows the measurement procedure of the pain in the pain measuring apparatus shown in FIG. It is a graph which shows the measurement result of the pain generation | occurrence | production current value which is the electric current value of the stimulation current which a measurement person feels pain, and the minimum sensing current value, (A) is a measurement object's stimulation current concerning embodiment of this invention. (B) shows the measurement result when a stimulation current consisting of a conventional rectangular wave is applied to the measurement subject. It is a typical graph for demonstrating the intensity | strength of the stimulation which the stimulation current concerning embodiment of this invention and the stimulation current which consists of the conventional rectangular wave give to A (delta) fiber and A (beta) fiber, respectively. It is a graph which shows the peak value of the power spectrum of the stimulation current concerning other forms of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pain measuring apparatus 2 Person to be measured 3 Electrode 9 MPU9 (a part of stimulation current generation means)
10 Step-up transformer (part of stimulation current generation means)
11 Voltage control circuit (part of stimulation current generation means)
12 Output control circuit (part of stimulation current generation means)
13 Protection circuit (part of stimulation current generation means)
14 Current detection circuit (part of stimulation current generating means)

Claims (4)

An electrode attached to the measurement subject; and a stimulation current generating means for generating a stimulation current supplied to the electrode, and based on the stimulation current applied from the electrode to the measurement subject. In the pain measuring device for the human body that measures the pain felt by the person,
Said stimulation current, when increasing gradually the current value of the stimulation current from 0 to thereby stimulate Aβ fibrils earlier than Aδ fibers, and shall not stimulate C fibers,
A protection circuit serving as a limiter circuit for preventing a current of a predetermined value or more from being supplied to the electrode as the stimulation current, and an image display means for displaying a minimum sensed current value for the Aβ fiber,
The stimulation current includes a total value in the range of 50 Hz to 500 Hz of the peak value of the power spectrum indicating the intensity of stimulation for each frequency component, and a total value in the range of 50 Hz to 3000 Hz of the peak value of the power spectrum. When the ratio of A is in the range of 1: 3 to 1:12, the minimum sensed current value for the Aβ fiber is larger than the minimum sensed current value for the Aδ fiber due to the stimulation current made of a conventional rectangular wave. The image display means displays the ratio of the minimum perceived current value for the Aβ fiber of the measured person and the measured pain-corresponding current value. Pain measurement device. The stimulation current has a larger current value as a pain threshold value for the Aδ fiber than a current value as a pain threshold value for the Aδ fiber due to a stimulation current made of a conventional rectangular wave. The pain measuring apparatus according to claim 1. An electrode attached to the measurement subject; and a stimulation current generating means for generating a stimulation current supplied to the electrode, and based on the stimulation current applied from the electrode to the measurement subject In the pain measuring device for the human body that measures the pain felt by the person,
The stimulation current, the frequency component of 5Hz are free First, the total value in the range from 50Hz to peak value of the power spectrum of 500Hz indicating the strength of the stimulation of each frequency component of the stimulation current, the power spectrum When the ratio of the peak value to the total value in the range of 50 Hz to 3000 Hz is in the range of 1: 3 to 1:12, the current value of the stimulation current is gradually increased from 0 before the Aδ fiber. Stimulate Aβ fibers and not C fibers,
A protection circuit serving as a limiter circuit for preventing a current of a predetermined value or more from being supplied to the electrode as the stimulation current, and an image display means for displaying a minimum sensed current value for the Aβ fiber,
The power spectrum has a peak value for each frequency that is an integral multiple of 50 Hz, and the peak value is substantially equal between 50 Hz and 500 Hz, and is maximum between 50 Hz and 2000 Hz. A pain measuring apparatus, characterized in that the means displays a ratio between a minimum sensed current value of the subject to be measured for the Aβ fiber and a measured pain corresponding current value . The image display means displays the ratio between the minimum sensed current value for the Aβ fiber and the pain-corresponding current value in a bar graph indicating the pain-corresponding current value, and the minimum sensed current value for the Aβ fiber as a bar graph. The pain measuring device according to claim 1, 2 or 3, wherein the device is configured as described above.

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