WO2007013326A1

WO2007013326A1 - Living body state judgment device and stimulus intensity judgment device

Info

Publication number: WO2007013326A1
Application number: PCT/JP2006/314173
Authority: WO
Inventors: Tadashi Uchiumi; Atsushi Yamanaka
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2005-07-26
Filing date: 2006-07-18
Publication date: 2007-02-01

Abstract

Heat rate data and blood pressure data on a liming body are measured. By performing correlation analysis between the heart rate data and the blood pressure data, an index value indicating the stability of the autonomic nerve of the living body is calculated. When judging the state of the living body from the calculated index value, the living body state of an examinee to which an external stimulus is applied is judged according to the index value obtained from the heart rate data and the blood pressure data measured when an external stimulus is applied to the examinee and the index value obtained from the heart rate data and the blood pressure data measured when an external stimulus is not applied to the examinee. By using the physiological index indicating the stability of the autonomic nerve according to the aforementioned method, it is possible to objectively and accurately judge/evaluate a living body state and an external stimulus applied to the living body.

Description

Specification

Biological state determination device and stimulus intensity determination device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a determination device for measuring and determining the influence of a living body due to an external force stimulus, and a determination device for evaluating and determining the strength of an external stimulus that can affect the living body. .

Background art

[0002] External stimuli such as images The method for evaluating the influence of a living body is based on a subjective evaluation method that obtains a test subject's response using a questionnaire and a physiological index based on physiological data measured from the subject. There is an objective evaluation method that calculates and evaluates biological effects from the changes.

[0003] As a conventional example of the subjective evaluation method, there is SSQ (Simula tor Sickness Questionnaire) frequently used to evaluate sickness. This consists of 16 questions, and the evaluation value is calculated according to the formula determined from the answers of the subjects.

[0004] As a conventional example of the objective evaluation method, there is a method using a physiological index called p max that measures subject force heart rate and blood pressure and calculates correlation analysis power. This method is described below. The basic idea is that the heart rate of the heart is feedback controlled by the blood pressure detected by the living body using the vascular sensory system. As a result of this control, the blood pressure and the heart rate have a correlation called a Meyer wave with a period of about 10 seconds. It is based on the hypothesis that there will be fluctuations. The measurement procedure is as follows. (1) Using an electrocardiograph and a sphygmomanometer, measure heart rate and blood pressure for a certain period of time. (2) Time-series data power obtained in (1) above The frequency band of the above Meyer wave is extracted by filtering. (3) Calculate the cross-correlation function between the heart rate data and blood pressure data processed in (2) above, and calculate the maximum value of the cross-correlation function. This value is a physiological index called pmax.

[0005] Conventionally, since the blood pressure and the feedback of the heart rate function normally without being disturbed in a resting state, the correlation between the heart rate data in the Mayer wave band and the blood pressure data is high, and p max is a high value. And feedback when the autonomic nervous system that controls the heartbeat receives external stimuli Was disturbed and p max was thought to decrease.

Disclosure of the invention

Problems to be solved by the invention

[0006] As described above, it is expected that an objective evaluation result can be obtained by paying attention to the value of the physiological index p max. In practice, however, the p max value alone is not necessarily an objective indicator, and the interpretation of the indicator needs to be changed depending on the external stimuli perceived by the subject and the subject's own sensitivity. The fact that there are also has become a force.

[0007] For example, FIG. 10 plots the relationship between p max at rest and p max when subjected to some external stimulus in each experiment conducted on six subjects. However, when p max is compared between resting and external stimuli, there are cases where the values are higher when external stimuli are received. The external stimulus in this experiment is a live-action image that was intentionally taken with a large amount of movement, and some subjects complain of a very strong discomfort. When actually viewing this video, a high evaluation value was obtained by the above-mentioned subjective evaluation (SSQ), that is, for subjects who felt subjective intoxication, etc., compared to the time average value of p max at rest. In addition, the time average value of p max when viewing the above video showed a higher value (see the four points on the upper right in the figure). On the other hand, for subjects whose SSQ rating is relatively low, i.e., subjects who do not feel much sickness subjectively, the time average value of p max at rest is originally low, and the above video is viewed. The time-average value of p max at that time was even lower (see the two points on the lower side of the figure). Thus, the physiological index max) has different effects depending on the subject, and therefore a comprehensive evaluation method considering this point is necessary to obtain a more accurate evaluation result.

[0008] Although it is possible to evaluate the degree of influence of external stimuli such as images by the above subjective evaluation, the subjective evaluation depends on the individual characteristics of the evaluator (ease of video sickness, etc.). Therefore, in order to obtain an objective evaluation result, an evaluation method that does not rely only on subjective evaluation is necessary.

[0009] The present invention has been made in view of the above points, and provides a determination apparatus capable of performing a more accurate determination regarding a biological state using a physiological index indicating the stability of an autonomic nerve. It is for the purpose. Similarly, the indicator is used to affect the living body. The purpose is to provide an evaluation device that can objectively evaluate the degree of influence of possible external stimuli.

Means for solving the problem

[0010] In order to solve the above-described problem, the living body state determination apparatus of the present invention measures the heart rate data and blood pressure data of a living body, and performs correlation analysis between the heart rate data and the blood pressure data, thereby A biological state determination device that calculates an index value indicating the stability of an autonomic nerve and determines a state of an autonomic nerve of the living body based on the index value, for determining the state of the autonomic nerve! A first index value, which is the index value obtained from heart rate data and blood pressure data measured under conditions in which the person to be judged receives an external stimulus, and the person to be judged receives the external stimulus. Based on the second index value, which is the index value obtained from the heart rate data and blood pressure data measured under certain conditions, the subject's judgment when receiving an external stimulus is received. It is characterized by determining the state of the autonomic nerve.

[0011] As another form different from the above, the biological state determination apparatus of the present invention measures a pulse wave of a living body, estimates heart rate data and blood pressure data from the pulse wave, and estimates An index value indicating the stability of the autonomic nerve of the living body is calculated by performing a correlation analysis between the heart rate data and the blood pressure data, and the state of the autonomic nerve of the living body is determined based on the index value based on the pulse wave A biological state determination device for determining the state of the autonomic nerve, and a first index value based on the pulse wave measured under a condition in which the determination target is receiving an external stimulus; The person to be judged when receiving the external stimulus based on the second index value based on the pulse wave measured under the condition! It is characterized by judging the state of autonomic neurology.

[0012] In addition, the stimulation intensity determination device of the present invention measures the heart rate data and blood pressure data of the living body, and performs correlation analysis between the heart rate data and the blood pressure data, thereby stabilizing the autonomic nerve of the living body. An stimulation intensity determination device that calculates an index value indicating a degree, holds the index values for a plurality of persons, and determines the intensity of an external stimulus applied to a living body based on the plurality of index values In the determination of the intensity of the external stimulus, the first index value obtained from the heart rate data and blood pressure data measured under the condition that the subject is given the external stimulus, and the subject Measured under the conditions given the external stimulus! The intensity of the external stimulus applied to the living body is determined based on a distribution characteristic for a plurality of persons regarding the second index value obtained from the heart rate data and the blood pressure data. is there.

[0013] As another form different from the above, the stimulation intensity determination device of the present invention measures a pulse wave of a living body, estimates heart rate data and blood pressure data from the pulse wave, and estimates By calculating a correlation analysis between the heart rate data and the blood pressure data, an index value indicating the stability of the autonomic nerve of the living body is calculated, and an index value based on the pulse wave for a plurality of persons is maintained, and a plurality of index values are stored. A stimulation intensity determination device for determining the intensity of an external stimulus applied to a living body based on an index value based on the pulse wave, and for determining the intensity of the external stimulus! The first index value based on the pulse wave measured under the condition given the external stimulus, and the subject is given the external stimulus! / Based on the distribution characteristics of multiple people with respect to the second index value based on the pulse wave, It is characterized in determining the strength of the applied external stimuli.

The invention's effect

[0014] According to the present invention, when determining that a living body is affected by an external stimulus, it is possible to make a highly accurate determination in consideration of individual differences for each person to be determined. Further, when determining the strength of the external stimulus itself, it is possible to obtain a determination result without depending on the subjectivity, while making a determination according to the degree of the effect that the living body actually receives.

Brief Description of Drawings

FIG. 1 is a block diagram showing a configuration example of a biological state determination apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a structural example of a pulse wave sensor.

FIG. 3 is a diagram showing a substantial amount of heart rate and blood pressure appearing in a pulse wave waveform.

FIG. 4 is a graph showing the relationship between measured heart rate equivalent and blood pressure equivalent and their cross-correlation coefficients.

FIG. 5 is a diagram showing an example of characteristics relating to physiological indices at rest and stimulation of a living body.

FIG. 6 is a block diagram showing a configuration example of a biological state determination apparatus according to Embodiment 2 of the present invention.

FIG. 7 is a diagram illustrating an example of a configuration of a characteristic table serving as a reference when determining a biological state. FIG. 8 is a block diagram illustrating a configuration example of a stimulation intensity determination device according to Embodiment 3 of the present invention.

FIG. 9 is a diagram showing an example of distribution characteristics of physiological index values according to stimulus intensity.

FIG. 10 is a diagram showing a general relationship between physiological indices at rest and stimulation of a living body. Explanation of symbols

[0016] 10 Pulse wave sensor

11 Light emitter

12 Receiver

100, 200 Biological condition determination device

300 Stimulus intensity judgment device

101 Pulse wave measurement unit

102 Heart rate estimator

103 Blood pressure estimator

104 Correlation analyzer

105 Indicator storage

201, 301 Characteristic storage

106, 202 Status judgment part

302 Strength judgment part

107-1-3 output selector

203— 1-3 output selector

303— 1-3 output selector

BEST MODE FOR CARRYING OUT THE INVENTION

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

Example 1

[0018] FIG. 1 is a diagram illustrating an internal configuration example of a biological state determination device according to Embodiment 1 of the present invention. As shown in FIG. 1, a living body state determination apparatus 100 according to the present embodiment includes a pulse wave measuring unit 101 that measures a pulse wave of a living body, a heart rate estimating unit 102 that estimates a heart rate of the measured pulse wave force, Similarly, the blood pressure estimator 103 for estimating the pulse wave force blood pressure, the estimated heart rate and A correlation analysis unit 104 that analyzes the correlation of blood pressure and calculates a physiological index value max) indicating the stability of the autonomic nerve, an index storage unit 105 that stores the physiological index value, and the stored Based on the physiological index value and the physiological index value obtained from the newly measured pulse wave, the state determination unit 106 that determines the state of the living body under the newly measured condition, and the output destination of the physiological index value Output switching units 107-1 and 107-2 for switching.

[0019] When the biological state determination apparatus 100 according to the present embodiment is used to determine the biological state, the pulse wave in the resting state of the person to be determined is measured in advance and the physiological index value is calculated. The resting state means a condition that does not give a special external stimulus, and is a condition that becomes a reference when determining a biological state under a condition that a separate external stimulus is given. The calculated physiological index value of the resting state is stored in the index storage unit 105 as a reference value for each individual person to be judged. The processing up to this point needs to be performed for each person to be judged as preparation for determining the biological state. After that, the pulse wave is measured again under the condition that the person to be judged is receiving an external stimulus, and a new physiological index value is calculated. Finally, based on the calculated two physiological index values, the living state of the person to be determined can be determined.

[0020] Hereinafter, the operation of the biological state determination apparatus 100 will be described in detail.

The pulse wave measurement unit 101 is configured to include a pulse wave sensor that is attached to a fingertip or the like and detects a change in blood flow, that is, a pulse wave. The pulse wave sensor is generally configured using an optical sensor.

FIG. 2 is a diagram illustrating an example of a pulse wave sensor. As shown in FIG. 2, the pulse wave sensor 10 includes a light emitting unit 11 and a light receiving unit 12, and the light emitting unit 11 and the light receiving unit 12 are arranged so that the fingertips are sandwiched between them when in use. When measuring the pulse wave, the light irradiated from the light-emitting unit 11 is received by the light-receiving unit 12 through the fingertip blood vessel. At this time, the change in light transmittance is measured. It is detected as a change in blood volume at the fingertip, that is, a pulse wave. The detected pulse wave data is output to the heart rate estimation unit 102 and the blood pressure estimation unit 103 according to a time series. Although not shown in the figure, the arrangement of the light emitting unit and the light receiving unit is different, and the reflected light reflected by the blood vessel or the like is received by the light receiving unit to change the reflected light. There is also an example of a pulse wave sensor configured to detect changes in [0023] Heart rate estimation section 102 obtains a pulse wave frequency from the rising interval of the pulse wave data, and outputs this as an amount corresponding to the heart rate. The blood pressure estimation unit 103 obtains an intra-pulse integral value from the waveform of the pulse wave data, and outputs this as an amount corresponding to blood pressure. Figures 3 (a) and 3 (b) show the relationship between the pulse wave data and the pulse wave frequency, and the relationship between the pulse wave data and the integral value within the beat, respectively.

[0024] The correlation analysis unit 104 performs correlation analysis on the heart rate equivalent and blood pressure equivalent obtained in this manner, and calculates a physiological index value. Regarding the calculation method of the physiological index value, as with the conventional method already described as the background art, the time-series data power of the obtained heart rate equivalent and blood pressure equivalent is extracted and the frequency band of the Meyer wave is extracted. The cross-correlation function is calculated, and the maximum value max) of the cross-correlation function is calculated. Figure 4 shows the relationship between the time-series data of the heart rate equivalent and blood pressure equivalent and the cross-correlation function related to it. Fig. 4 (a) shows an example in which the cycles of the Mayer wave components in relation to heart rate and blood pressure (pulse wave integral value) are synchronized with each other, that is, in a state where the correlation is high. The maximum value of / 0 max is a large value close to 1. On the other hand, as shown in Fig. 4 (b), p max is a small value close to 0 when the two are out of sync. The p max calculated as described above, that is, the physiological index value, is output to the index storage unit 105 or the state determination unit 106 via the output switching unit 107-1, in response to an instruction from the control unit (not shown) in FIG. The

[0025] The index storage unit 105 stores the physiological index value and personal identification information corresponding to the physiological index value. The personal identification information is obtained by designation by the user of the apparatus according to the present embodiment via an input unit (not shown), and may be a personal name or arbitrary name, or a serial number or arbitrary symbol according to some standard. Etc. The physiological index value stored in the index storage unit 105 is output to the state determination unit 106 via the output switching unit 107-2 according to an instruction from the control unit. Here, the output switching units 107-1 and 107-2 operate so as to be connected to a or b in the figure in response to an instruction from the control unit. That is, go to a in the figure when measuring the pulse wave at rest of the person to be judged, and then when measuring the pulse wave in a condition where the person is receiving an external stimulus, Each is connected to b. [0026] After that, the state determination unit 106 determines the biological state of the person to be determined from the physiological index value obtained from the correlation analysis unit 104 and the physiological index value obtained from the index storage unit 105 (about the determination method). The determination result is output to a display device or storage device (not shown). At this time, the control unit is input via the input unit so that the physiological index value obtained from the correlation analysis unit 104 and the physiological index value obtained from the index storage unit 105 are data corresponding to the same person. The current identification information of the person to be judged is compared with the individual identification information corresponding to each physiological index value stored in the index storage unit 105, and the physiological index value output from the index storage unit 105 is selected and controlled. .

[0027] Here, a determination method of the biological state in the state determination unit 106 will be described. In order to determine the biological state, the physiological index value p maxl in the resting state measured and calculated in advance for the person to be determined and the physiological / measured physiological state measured and calculated in the state of receiving some external stimulus such as a video stimulus. An index value / o ma _X 2 is required. Between the two, there is a relational expression that is a criterion for determining whether or not it is affected by an external stimulus. By applying both index values to the relational expression, the person to be judged can be It is possible to determine whether or not the camera has been adversely affected by motion sickness due to visual stimulation.

[0028] The relational expression serving as a judgment criterion represents the characteristics shown in FIG. 5 regarding p maxl and p maxS. As shown in Fig. 5, when comparing the physiological index value p max2 at the time of external stimulation with the physiological index value p maxl at rest, the tendency that max2 is higher than the value of p maxl Group G1 has a characteristic that depends on the value of p maxl, and group G2, which tends to show a value lower than the value of max2 force S p maxl. This characteristic can be expressed as a function depending on the value of P maxl (the solid line in the figure is a straight line indicating the function representing the above characteristic).

[0029] According to the above characteristics, based on the p maxl and max2 values of a person to be judged, whether the person to be judged has been adversely affected by an external stimulus such as the above image stimulus such as video sickness. This can be determined as follows.

[0030] (1) Persons to whom p maxl belongs to the G1 group:

(1 -a) When maxK p max2: It was adversely affected.

[0031] (1 -b) p max ^: p max S: No adverse effect was observed. [0032] (2) Persons to whom p maxl belongs to the G2 group:

(2-a) When p maxl <= max 2: No adverse effect.

[0033] (2-b) When p maxl> p max 2: A bad scene was received.

[0034] As described above, the determination result as described above may be output to a display device or a storage device, or the value of / o maxl and p maxS itself, or the value of p maxl The value and the data of the difference value between p max2 and p maxl may be recorded as measurement data for each individual to be judged.

In the living body state determination apparatus according to the present embodiment, the physiological index value is calculated after estimating the heart rate and the blood pressure from the measured pulse wave, but the conventional technology is used instead of the pulse wave. As described above, the heart rate and blood pressure may be directly measured, and the physiological index value may be calculated similarly.

Example 2

Next, a biological state determination apparatus according to Embodiment 2 of the present invention will be described. FIG. 6 is a diagram illustrating an internal configuration example of the biological state determination device according to the present embodiment. As shown in FIG. 6, the living body state determination apparatus 200 according to the present embodiment includes a pulse wave measurement unit 101 that measures a pulse wave of a living body, and a heart rate estimation unit 102 that estimates a measured pulse wave force heart rate. Similarly, a blood pressure estimation unit 103 that estimates pulse wave force blood pressure, a correlation analysis unit 104 that analyzes the correlation between the estimated heart rate and blood pressure, and calculates a physiological index value indicating the stability of the autonomic nerve, From the index storage unit 105 for storing the physiological index value, the characteristic storage unit 201 for storing the characteristic table related to the physiological index value, the stored physiological index value, and the newly measured pulse wave Based on the obtained physiological index value and the above characteristic table, the state determination unit 202 that determines the state of the living body under the newly measured condition and the output switching unit 203-1, 203- that switches the output destination of the physiological index value Have 2, 203-3!

[0037] When the biological state is determined using the biological state determination device according to the present embodiment, the determination subject measures a pulse wave in a resting state in advance and calculates a physiological index value. The calculated physiological index value in the resting state is stored in the index storage unit 105 as a reference value for each individual person to be judged. After that, the pulse wave is measured again under the condition that the person to be judged receives an external stimulus, and a new physiological index value is calculated. Finally, the two calculated physiological index values and Based on the contents of the characteristic table recorded in the characteristic storage unit 201, the biological state of the person to be determined is determined.

[0038] Hereinafter, the operation of the biological state determination apparatus 200 will be described in detail. The pulse wave measuring unit 101, the heart rate estimating unit 102, the blood pressure estimating unit 103, the correlation analyzing unit 104, and the index storing unit 105 function in the same manner as described in the first embodiment. Detailed description is omitted.

In the biological state determination device according to the present embodiment, as with the device according to the first embodiment, a physiological index value is calculated in the correlation analysis unit 104 based on data obtained from a pulse wave, and the calculated physiological index value is used. Then, it is output to the index storage unit 105 or the state determination unit 202 via the output switching unit 203-1 in accordance with an instruction of a control unit force (not shown). On the other hand, the physiological index value is also stored in the characteristic storage unit 201. The physiological index value stored in the characteristic storage unit 201 constitutes a characteristic table by collecting a plurality of data (a configuration example of the characteristic table will be described later). The state of the physiological index value stored in the index storage unit 105 and the contents of the characteristic table stored in the characteristic storage unit 201 are determined through the output switching units 203-2 and 203-3 according to instructions from the control unit. The data is output to the unit 202. The output switching units 203-1, 203-2, and 203-3 operate so as to be connected to a or b in the figure in response to an instruction from the control unit. In other words, go to a in the figure when measuring the pulse wave of the person being judged to be resting, and b in the figure when measuring the pulse wave under conditions where the person being judged is receiving an external stimulus. Are connected to each other.

[0040] Thereafter, in the state determination unit 202, from the physiological index value obtained from the correlation analysis unit 104, the physiological index value obtained from the index storage unit 105, and the contents of the characteristic table stored in the characteristic storage unit 201 Then, the biological state of the person to be determined is determined (the determination method will be described later), and the determination result is output to a display device or storage device (not shown).

Here, the configuration of the characteristic table stored in the characteristic storage unit 201 and the biological state determination method in the state determination unit 202 will be described. In the biological state determination device according to the present embodiment, in order to determine the biological state, the physiological index value p maxl in the resting state measured and calculated in advance for the person to be determined and some external stimulus such as a video stimulus were received. Measured in state 'Calculated physiological index value p max2 and resting state physiological index value p Use the characteristic table for maxl. The characteristic table is configured to include elements as shown in FIG. 7 for each of a plurality of physiological index values, and the external stimulation force is applied to the living body by the difference in physiological index values between the resting state and the state receiving external stimulation. It is configured so that the degree of impact can be judged.

[0042] The state determination unit 202 refers to a table corresponding to the physiological index value pmaxl in the resting state, and uses the difference value between pmax2 and pmaxl of the determination target as an index to determine the subject from the current external stimulus. An evaluation value indicating the degree of influence received by the judge is taken out. The evaluation value may be recorded as a numerical value directly indicating the degree of influence of the external stimulus, or may be recorded as a level value indicating the level of strength or the like.

It should be noted that the biological state determination apparatus according to the present embodiment estimates the heart rate and blood pressure from the measured pulse wave, respectively, in the same manner as the biological state determination apparatus described in the first embodiment. Although the index value is calculated, it may be replaced with a configuration in which the physiological index value is calculated by directly measuring the heart rate and blood pressure instead of the pulse wave as in the prior art.

Example 3

[0044] Next, a stimulus intensity determination apparatus according to Embodiment 3 of the present invention will be described.

FIG. 8 shows an internal configuration example of the stimulation intensity determination device according to the present embodiment. As shown in FIG. 8, the stimulation intensity determination device 300 according to the present embodiment includes a pulse wave measurement unit 101 that measures a pulse wave of a living body, a heart rate estimation unit 102 that estimates a measured pulse wave force heart rate, Similarly, a blood pressure estimation unit 103 that estimates the pulse wave force blood pressure, a correlation analysis unit 104 that analyzes the correlation between the estimated heart rate and blood pressure and calculates a physiological index value indicating the stability of the autonomic nerve, From the index storage unit 105 for storing the physiological index value, the characteristic storage unit 301 for storing the characteristic table related to the physiological index value, the stored physiological index value, and the newly measured pulse wave Based on the obtained physiological index value and the characteristic table, an intensity determination unit 302 that determines the intensity of the external stimulus given under the newly measured condition, and an output switching unit 303 that switches an output destination of the physiological index value — 1, 303-2, 303— 3.

The stimulation intensity determination device 300 according to the present embodiment is substantially the same as the biological state determination device shown in the second embodiment in configuration. However, the difference is that the determination target is not the biological state but the intensity of the external stimulus. [0047] When an external stimulus is determined using the stimulation intensity determination apparatus according to the present embodiment, a pulse wave in a resting state of the measurement subject is measured in advance in order to obtain a physiological index value as a reference for determination. The physiological index value is calculated in advance. The calculated physiological index value is stored in the index storage unit 105 as the reference value of the individual to be measured, as in the above embodiment. On the other hand, the characteristic storage unit 301 stores a characteristic table corresponding to physiological index values in a resting state. Thereafter, the pulse wave of the measurement subject is measured again under the condition that the measurement subject receives the external stimulus to be judged, and a new physiological index value is calculated. Finally, the stimulus intensity of the external stimulus is determined based on the two calculated physical index values and the contents of the characteristic table.

[0048] In the stimulation intensity determination device according to the present embodiment, as in the biological state determination device described in Embodiment 2, the correlation analysis unit 104 calculates the physiological index value based on the data from which the pulse wave force can also be obtained. The physiological index value thus output is output to the index storage unit 105 or the strength determination unit 302 via the output switching unit 3031 according to an instruction from a control unit (not shown). On the other hand, the physiological index value is also stored in the characteristic storage unit 301. The physiological index values stored in the characteristic storage unit 301 constitute a characteristic table by collecting a plurality of data (an example of the characteristic table configuration will be described later). The physiological index value stored in the index storage unit 105 and the contents of the characteristic table stored in the characteristic storage unit 301 are sent to the strength determination unit 302 via the output switching units 303-2 and 303-3 according to instructions from the control unit. Is output.

[0049] The output switching units 303-1, 303-2, and 303-3 operate so as to be connected to a or b in the figure in response to an instruction from the control unit. That is, go to a in the figure when measuring the patient's resting pulse wave, and then go to the figure when measuring the pulse wave under conditions where the measured person is receiving an external stimulus. Are connected to each other.

[0050] After that, the intensity determination unit 302 uses the physiological index value obtained from the correlation analysis unit 104, the physiological index value obtained from the index storage unit 105, and the contents of the characteristic table stored in the characteristic storage unit 301. Then, the intensity of the external stimulus is determined (the determination method will be described later), and the determination result is output to a display device or storage device (not shown).

Here, the configuration of the characteristic table stored in the characteristic storage unit 301 and the method for determining the stimulus intensity in the intensity determination unit 302 will be described. When determining the stimulus intensity, Physiological index value pm axl in the resting state calculated in advance for the measurement subject and measured in a state of receiving some external stimulus such as video stimulus * Calculated physiological index value p max2 and physiological The characteristic table for the index value p maxl is used. The characteristic table includes elements as shown in FIG. 7 with respect to at least one physiological index value, and the stimulus of external stimulation is determined by the difference in physiological index value between the resting state and the state receiving external stimulation. It is comprised so that intensity | strength can be determined. The intensity determination unit 302 refers to the table corresponding to the physiological index value p maxl in the resting state of the measurement subject, and uses the difference value between p max2 and p maxl of the measurement target as an index and relates to the external stimulus to be determined An evaluation value indicating the stimulus intensity is taken out. The evaluation value may be recorded as a numerical value directly indicating the intensity of the external stimulus, or may be recorded as a level value indicating the intensity level or the like. As a structure of the characteristic table, a table may be prepared for all values that can be expressed with respect to the physiological index value (p maxl) at rest. In order to reduce this, prepare a table corresponding to pm axl in a predetermined range for each p maxl value range, and refer to one table in common with p maxl in the corresponding range. Also good. In that case, a table to be referred to may be selected based on the average value in p maxl within a predetermined range.

By the way, the characteristics that serve as the determination criteria in the above-described determination are strictly different for each property of the external stimulus, and indicate characteristics according to the degree of influence on the living body. Figure 9 shows the difference in characteristics depending on the stimulus intensity of external stimulation. Plotted in Fig. 9 is the same subject, i.e., the same p maxl value, due to the difference in the force stimulus intensity, which is the data for 6 external subjects for two types of external stimuli with different stimulus intensity. However, the max2 value is different, and the distribution characteristics of the data for multiple people tend to differ for each stimulus intensity (see the two approximate lines in the figure). Therefore, by evaluating based on the calculation results of physiological index values for a plurality of measurement subjects, it is possible to determine the stimulus intensity with higher accuracy than the determination by a single measurement subject. Specifically, for an external stimulus, when trying to determine the intensity of the stimulus based on the physiological index values of the two subjects A and B, based on the physiological index value of the subject A, The evaluation result is expressed as `` 2 (ϋν,) '' in the example of Fig. 7. On the other hand, if the evaluation result is `` 4 (slightly strong) '' based on the physiological index value of measured person B, the average of both is taken and `` 3 (slightly weak) '' is the final result. What is necessary is just to output as a judgment result.

[0053] In addition, a method of determining the stimulation intensity according to the distribution characteristics of data for a plurality of people is also conceivable. For example, as shown in FIG. 9, when it is preliminarily divided that there are two types of distribution characteristics for external stimuli with different stimulation intensities, the pulse wave data force for multiple persons actually obtained can be obtained. By evaluating whether the distribution of the index value is close to the deviation between the two types of distribution characteristics, the stimulus intensity corresponding to the closer distribution characteristic can be selected as the determination result. According to this method, when the stimulation intensity is determined, the characteristic storage unit 301 stores the approximate expression representing the distribution characteristic of the physiological index value, the evaluation value of the stimulation intensity corresponding thereto, Is included. As another method, an approximate straight line representing the distribution characteristic of the stimulus intensity as shown in Fig. 9 or the parameter of the approximate curve itself can be considered as the stimulus intensity. For example, in the two types of distribution characteristics shown in Fig. 9, the slope of the approximate line representing the distribution characteristics of the one with stronger stimulus intensity is larger. It may be treated as a value indicating strength.

[0054] In order to accurately determine the stimulus intensity by a plurality of persons to be measured as described above, a characteristic table having a sufficient scale is required. In order to construct such a characteristic table, all the physiological index values and other parameters obtained each time the external stimulus is determined are stored in the characteristic storage unit 301 in the stimulation intensity determination apparatus according to the present embodiment. It is possible to record and refill and expand the characteristic table. In this way, the characteristic table is enriched, and the accuracy of the stimulus intensity determination is further improved according to V.

It should be noted that, in the stimulation intensity determination device according to the present embodiment, the measured pulse wave force also estimated the heart rate and the blood pressure, respectively, similarly to the biological state determination devices shown in the first and second embodiments. The physiological index value is calculated as described above. However, instead of the pulse wave, a configuration in which the heart rate and blood pressure are directly measured and the physiological index value is calculated as in the conventional technique may be replaced.

Industrial applicability The present invention can be used as a biological state determination device and a stimulus intensity determination device.

Claims

The scope of the claims

[1] The heart rate data and blood pressure data of the living body are measured, and an index value indicating the stability of the autonomic nerve of the living body is calculated by performing correlation analysis between the heart rate data and the blood pressure data. A biological state determination device that determines a state of an autonomic nerve of a living body based on a value,

In determining the state of the autonomic nerve, the first index which is the index value obtained from the heart rate data and the blood pressure data measured under the condition that the determination subject receives an external stimulus. Based on the value and the second index value that is the index value obtained from the heart rate data and blood pressure data measured under conditions where the person to be judged has received the external stimulus, A biological state determination device, characterized by determining a state of an autonomic nerve of the person to be determined when receiving an external stimulus.

[2] By measuring a pulse wave of a living body, estimating heart rate data and blood pressure data from the pulse wave, and performing correlation analysis between the estimated heart rate data and the blood pressure data, the living body's autonomic nerve A biological state determination device that calculates an index value indicating a degree of stability of the body and determines a state of an autonomic nerve of the living body based on the index value based on the pulse wave,

In determining the state of the autonomic nerve, the person to be judged receives an external stimulus, the first index value based on the pulse wave measured under the condition, and the person to be judged is the external person. Based on the second index value based on the pulse wave measured under the condition after receiving the stimulus, the state of the subject's autonomic nerve when receiving external stimulation is determined. A biological state determination device characterized by:

[3] By measuring the heart rate data and blood pressure data of the living body and performing correlation analysis between the heart rate data and the blood pressure data, an index value indicating the stability of the autonomic nerve of the living body is calculated. A stimulation intensity determination device that holds the index value for a person and determines the intensity of an external stimulus applied to a living body based on a plurality of the index values,

For the determination of the intensity of the external stimulus, the first index value obtained from the heart rate data and blood pressure data measured under the condition where the measurement subject is given the external stimulus, Based on the distribution characteristics of multiple persons regarding the second index value obtained from the heart rate data and the blood pressure data measured under the condition when the measurement person is given the external stimulus, A stimulation intensity determination apparatus characterized by determining the intensity of the external stimulation to be applied. By measuring the pulse wave of the living body, estimating heart rate data and blood pressure data from the pulse wave, and performing correlation analysis between the estimated heart rate data and the blood pressure data, the stability of the autonomic nerve of the living body In addition, the index value based on the pulse wave for a plurality of persons is stored, and the intensity of the external stimulus applied to the living body is determined based on the index value based on the plurality of pulse waves. A stimulation intensity determination device,

For the determination of the intensity of the external stimulus, the first index value based on the pulse wave measured under the condition where the measurement subject is given the external stimulation, and the measurement subject is the external stimulus. The intensity of the external stimulus given to the living body is determined based on the distribution characteristics for multiple people with respect to the second index value based on the pulse wave measured under conditions where no physical stimulus is given A stimulation intensity determination device characterized by: