JP2007098002A - Biological information detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological information detecting device where influence of noise is reduced and which is portable. <P>SOLUTION: The biological information detecting device is provided with: a cuff for pressurization; a cuff pressure detection means for detecting cuff pressure which the cuff applies; a cuff pressure varying means for varying the cuff pressure which the cuff applies; a pulse wave detection means which detects the pulse wave of the external ear; and a blood pressure judgment means which calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection means and judges blood pressure from the calculated pulse wave amplitude. The cuff pressure varying means gradually reduces the cuff pressure increased once. The blood pressure judgment means judges systolic pressure or diastolic pressure on the basis of a time when the pulse wave amplitude becomes a value established in advance when the cuff pressure varying means reduces or increases the cuff pressure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a biological information detection apparatus that detects biological information that is not easily affected by noise and has excellent portability.

  With the aging of society, dealing with adult lifestyle-related diseases has become a major social issue. It is recognized that long-term blood pressure data collection is very important, especially for diseases related to high blood pressure. From such a viewpoint, various biological information detection devices including blood pressure have been developed.

  As a patent that describes a conventional device for detecting biological information with the outer ear, there is a patient monitor device that can be always worn (see, for example, Patent Documents 1 and 2). A device that is inserted into the external auditory canal or other parts of the external ear and is always worn. Infrared light that radiates the pulse, pulse wave, electrocardiogram, body temperature, pulse wave blood oxygen saturation, blood pressure, etc. into the living body, visible It can be calculated from the amount of light received.

  However, in the case of the above-described apparatus, since a specific method of how to measure the blood pressure value from the detected pulse wave is not clearly described, the feasibility is unknown. On the other hand, regarding blood pressure measurement, a blood pressure measurement device using a pulsation waveform of a blood vessel (see, for example, Non-Patent Document 1) is a blood pressure measurement device using another method such as a cuff vibration method or a volume compensation method (eg, non-patent). There is a research result that blood pressure can be measured with higher accuracy compared to Reference 2.).

The names of the auricles are based on Non-Patent Documents 3 and 4.
JP-A-9-128203 JP-A-11-128174 Osamu Tochikubo, Yoshiki Kawashima, Eiji Miyajima, Masao Ishii: A new photo-oscillometric method of the remedy the delta-theorem. Journal of Hypertension 1997, Vol. 15, no. 2, pp. 148-151, FIG. 1, FIG. 3 Kenichi Yamakoshi, Tatsuo Togawa: “Biological Sensors and Measuring Devices”, MM Society of Japan / ME Textbook Series A-1, pages 39-52 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 126, Medical School, issued October 1, 1996 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 127, Medical School, issued October 1, 1996

  In the above-described conventional biological information in the outer ear part, in particular, a device for measuring blood pressure, since a specific method of how to measure the blood pressure value from the detected pulse wave is not clearly described, the feasibility is It is unknown. Further, in the case of a portable biological information detection device, particularly a configuration in which biological information is detected by a light emitting element and a light receiving element, how to remove noise due to body movement is a very important issue.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a portable biological information detection apparatus that can reduce the influence of noise and can be carried.

  In order to achieve this object, the biological information detection apparatus according to the present invention calculates a peak and a valley of a pulse wave from the detected pulse wave, and compares the calculated pulse wave amplitude to determine systolic blood pressure or dilation. It is characterized by determining the period blood pressure.

  Since the systolic blood pressure or the diastolic blood pressure is determined by comparing the pulse wave amplitude, noise included in both of the compared pulse wave amplitudes can be canceled. Furthermore, steep noise can be eliminated from the fluctuation range of the pulse wave amplitude. Therefore, in the biological information detection apparatus that measures the blood pressure value, the influence of noise can be reduced when determining systolic blood pressure or diastolic blood pressure. In addition, since the biological information can be determined by comparing the pulse wave amplitude, the circuit configuration can be simplified. Therefore, the size can be reduced. Therefore, it is possible to provide a portable biological information detection device that can reduce the influence of noise and is portable.

  Specifically, the biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, and a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff. And a pulse wave detecting means for detecting a pulse wave of the outer ear, and a blood pressure determining means for calculating a pulse wave amplitude from the pulse wave detected by the pulse wave detecting means and determining a blood pressure from the calculated pulse wave amplitude. The biological information detection apparatus, wherein the cuff pressure varying unit gradually decreases the cuff pressure once increased, and the blood pressure determining unit is configured to reduce the cuff pressure varying unit when the cuff pressure is decreased by the cuff pressure varying unit. Begins to decrease the cuff pressure, and the systole is based on the time when the ratio of the pulse wave amplitude to the pulse wave amplitude at the time when the pulse wave amplitude becomes constant for the first time becomes equal to or higher than a predetermined ratio. It is characterized by determining blood pressure.

  While the cuff pressure is being reduced by the cuff pressure variable means, it is determined when the ratio of the pulse wave amplitude to the pulse wave amplitude at the time when the pulse wave amplitude first becomes constant exceeds the preset fixed ratio. Therefore, it is possible to remove noise at the initial stage of decompression in the detection of the expression of the pulse wave amplitude. Therefore, in the biological information detection apparatus that measures the blood pressure value while reducing the cuff pressure, the influence of noise can be reduced when determining the arterial artery or the systolic blood pressure of the artery.

  The biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff, and an outer ear. Biological information detection comprising: a pulse wave detection unit that detects a pulse wave of the first pulse; and a blood pressure determination unit that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit and determines a blood pressure from the calculated pulse wave amplitude The cuff pressure varying means gradually decreases the cuff pressure once increased, and the blood pressure determining means is a time point when the pulse wave amplitude starts to decrease when the cuff pressure is decreased by the cuff pressure varying means. The diastolic blood pressure is determined based on the above.

  Since the pulse wave amplitude is contrasted and the point in time when the pulse wave amplitude starts to decrease is determined as the maximum pulse wave amplitude, the influence of background noise can be eliminated. At this time, since the pulse wave amplitude is compared to determine the point in time when the pulse wave amplitude becomes maximum, it is possible to accurately determine minute fluctuations in the pulse wave amplitude. Therefore, in the biological information detection apparatus that measures the blood pressure value while reducing the cuff pressure, the influence of noise can be reduced when determining the diastolic blood pressure of the arteriole.

  The biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff, and an outer ear. Biological information detection comprising: a pulse wave detection unit that detects a pulse wave of the first pulse; and a blood pressure determination unit that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit and determines a blood pressure from the calculated pulse wave amplitude The cuff pressure varying means gradually decreases the cuff pressure once increased, and the blood pressure determining means is a time point when the pulse wave amplitude starts to decrease when the cuff pressure is decreased by the cuff pressure varying means. Is determined to be at the maximum pulse wave amplitude, and after the maximum pulse wave amplitude, the ratio of the pulse wave amplitude to the pulse wave amplitude at the maximum pulse wave amplitude becomes equal to or less than a predetermined constant rate. It is characterized by determining diastolic blood pressure based on

  Since the time point at which the pulse wave amplitude starts decreasing is determined by comparing the pulse wave amplitude, the influence of background noise can be eliminated when determining the time point at which the pulse wave amplitude becomes maximum. At this time, since the pulse wave amplitude is compared to determine the point in time when the pulse wave amplitude becomes maximum, it is possible to accurately determine minute fluctuations in the pulse wave amplitude. Furthermore, since the diastolic blood pressure is determined based on the point in time when the ratio of the pulse wave amplitude to the pulse wave amplitude at the maximum pulse wave amplitude falls below a preset fixed ratio, the influence of background noise is eliminated. can do. Therefore, in the biological information detection apparatus that measures the blood pressure value while reducing the cuff pressure, the influence of noise can be reduced when determining the diastolic blood pressure of the artery.

  The biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff, and an outer ear. Biological information detection comprising: a pulse wave detection unit that detects a pulse wave of the first pulse; and a blood pressure determination unit that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit and determines a blood pressure from the calculated pulse wave amplitude The cuff pressure varying means gradually increases the cuff pressure, and the blood pressure determining means determines when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure varying means. After the maximum pulse wave amplitude is determined, the contraction is based on the point in time when the ratio of the pulse wave amplitude to the pulse wave amplitude at the maximum pulse wave amplitude is equal to or less than a preset fixed ratio. It is characterized by determining the period blood pressure.

  Since the time point at which the pulse wave amplitude starts decreasing is determined by comparing the pulse wave amplitude, the influence of background noise can be eliminated when determining the time point at which the pulse wave amplitude becomes maximum. At this time, since the pulse wave amplitude is compared to determine the point in time when the pulse wave amplitude becomes maximum, it is possible to accurately determine minute fluctuations in the pulse wave amplitude. Furthermore, since the systolic blood pressure is determined based on the point in time when the pulse wave amplitude has decreased by a certain percentage with respect to the maximum pulse wave amplitude, the influence of background noise can be eliminated. Therefore, in the biological information detection apparatus that measures the blood pressure value while increasing the cuff pressure, it is possible to reduce the influence of noise when determining the arterial artery or the systolic blood pressure of the artery.

  The biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff, and an outer ear. Biological information detection comprising: a pulse wave detection unit that detects a pulse wave of the first pulse; and a blood pressure determination unit that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit and determines a blood pressure from the calculated pulse wave amplitude The cuff pressure varying means gradually increases the cuff pressure, and the blood pressure determining means is expanded on the basis of the time when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure varying means. It is characterized by determining the period blood pressure.

  Since the time point at which the pulse wave amplitude starts decreasing is determined by comparing the pulse wave amplitude, the influence of background noise can be eliminated when determining the time point at which the pulse wave amplitude becomes maximum. At this time, since the pulse wave amplitude is compared to determine the point in time when the pulse wave amplitude becomes maximum, it is possible to accurately determine minute fluctuations in the pulse wave amplitude. Therefore, in the biological information detecting apparatus that measures the blood pressure value while increasing the cuff pressure, the influence of noise can be reduced when determining the diastolic blood pressure of the arteriole.

  The biological information detecting apparatus according to the present invention includes a cuff to be compressed, a cuff pressure detecting unit for detecting the cuff pressure to be compressed by the cuff, a cuff pressure varying unit for changing the cuff pressure to be compressed by the cuff, and an outer ear. Biological information detection comprising: a pulse wave detection unit that detects a pulse wave of the first pulse; and a blood pressure determination unit that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit and determines a blood pressure from the calculated pulse wave amplitude The cuff pressure varying means gradually increases the cuff pressure, and the blood pressure determining means determines when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure varying means. Based on the time when the ratio of the pulse wave amplitude to the pulse wave amplitude at the time of the maximum pulse wave amplitude is equal to or less than a preset fixed ratio before the maximum pulse wave amplitude is determined. Diastolic blood pressure is determined.

  Since the time point at which the pulse wave amplitude starts decreasing is determined by comparing the pulse wave amplitude, the influence of background noise can be eliminated when determining the time point at which the pulse wave amplitude becomes maximum. At this time, since the pulse wave amplitude is compared to determine the point in time when the pulse wave amplitude becomes maximum, it is possible to accurately determine minute fluctuations in the pulse wave amplitude. In addition, since the diastolic blood pressure is determined based on the time when the pulse wave amplitude ratio is less than or equal to a preset fixed ratio with respect to the pulse wave amplitude at the maximum pulse wave amplitude, the influence of background noise is eliminated. can do. Therefore, in the biological information detection apparatus that measures the blood pressure value while increasing the cuff pressure, the influence of noise can be reduced when determining the diastolic blood pressure of the artery.

  It is preferable that the blood pressure determination unit calculates a cuff pressure corresponding to a time point when a pulse wave amplitude moved by the number of pulse wave amplitudes set in advance from the time point determined as systolic blood pressure is detected as a systolic blood pressure value. .

  According to the present invention, the systolic blood pressure value can be calculated based on the time point determined as the systolic blood pressure.

  Preferably, the blood pressure determination means calculates a cuff pressure corresponding to a point in time when a pulse wave amplitude shifted by the number of pulse wave amplitudes set in advance is detected as a diastolic blood pressure as a diastolic blood pressure value. .

  According to the present invention, the diastolic blood pressure value can be calculated based on the time point determined as the diastolic blood pressure.

  When the time from when the pulse wave detecting means starts to detect a pulse wave reaches a certain time, the blood pressure determining means resets the constant ratio to a preset ratio smaller than the constant ratio, and the cuff pressure The variable means preferably varies the cuff pressure applied by the cuff.

  When the set value of a certain ratio is too large, it is possible to reset the certain ratio and lower the determination threshold. Therefore, the blood pressure can be reliably determined.

  When the time from when the pulse wave detection means starts detecting the pulse wave reaches a certain time, the blood pressure determination means resets the constant ratio to a preset ratio larger than the constant ratio, and the cuff pressure The variable means preferably varies the cuff pressure applied by the cuff.

  When the set value of the fixed ratio is too small, the fixed ratio can be reset and the determination threshold can be lowered. Therefore, the blood pressure can be reliably determined.

  Preferably, the blood pressure determination unit calculates, for each second predetermined range, an average value of the pulse wave amplitude in the first predetermined range from the pulse wave detected by the pulse wave detection unit.

  Since the blood pressure determination means determines using the moving average value, it is possible to remove a steep fluctuation of the pulse wave amplitude. Therefore, the influence of steep noise caused by body movement can be reduced.

  The blood pressure determination means calculates a ratio of pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection means, determines whether or not the ratio of the pulse wave amplitudes is outside a certain range; When the ratio of the pulse wave amplitudes is outside a certain range, it is preferable to replace the previously detected pulse wave amplitude of the two pulse wave amplitudes with the latest pulse wave amplitude.

  Based on the past pulse wave amplitude, noise can be determined from a steep fluctuation of the pulse wave amplitude. Furthermore, since the pulse wave amplitude detected before of the pulse wave amplitudes of the two pulse waves is replaced with the latest pulse wave amplitude, the pulse wave amplitude including noise is subject to determination of systolic blood pressure or diastolic blood pressure. Can be outside.

  The blood pressure determination means calculates a ratio of pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection means, determines whether or not the ratio of the pulse wave amplitudes is outside a certain range; The cuff pressure varying means preferably varies the cuff pressure that the cuff presses when the blood pressure determining means determines that the ratio of the pulse wave amplitudes is outside a certain range.

  Based on the past pulse wave amplitude, noise can be determined from a steep fluctuation of the pulse wave amplitude. Furthermore, since the cuff pressure varying means varies the cuff pressure, the blood pressure value can be remeasured.

  The blood pressure determination unit calculates a time interval between pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection unit, determines whether or not the time interval is outside a certain range, and the time interval Is outside the fixed range, it is preferable that the pulse wave amplitude detected by the pulse wave detecting means is excluded from the determination target.

  According to the present invention, the pulse wave detected at a time interval longer than the pulse interval can be determined as noise, and the pulse wave amplitude determined as noise can be excluded from the determination of systolic blood pressure or diastolic blood pressure.

  It is preferable that the blood pressure determination means further calculates the pulse rate from the pulse wave detected by the pulse wave detection means.

  Since the pulse rate is further calculated in addition to the blood pressure value, more accurate biological information can be detected.

  ADVANTAGE OF THE INVENTION According to this invention, the influence of noise can be reduced and the portable biological information detection apparatus can be provided.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.

  FIG. 1 is a schematic diagram illustrating an example of a biological information detection apparatus according to the present embodiment. 1 includes a cuff 11 to be compressed, a cuff pressure detecting means 12 for detecting the cuff pressure to be compressed, a cuff pressure varying means 13 for changing the cuff pressure to be compressed, and an outer ear. A pulse wave detection unit 14 that detects a pulse wave 101 and a blood pressure determination unit 15 that calculates a pulse wave amplitude from the pulse wave detected by the pulse wave detection unit 14 and determines a blood pressure from the calculated pulse wave amplitude. .

  The cuff 11 is pressed. For example, two opposing cuffs are sandwiched and pressed. For example, there is an air cuff that expands or contracts by air pressure. Further, it may be compressed by expanding or contracting with an actuator.

  The cuff pressure detecting means 12 detects the cuff pressure that the cuff 11 presses. For example, a barometer that detects the air pressure in the cuff 11. Further, mechanical energy applied to the surface of the cuff 11 may be converted into electric energy, and examples thereof include a piezoelectric method, an electrostatic induction method, and an electromagnetic induction method. As long as the piezoelectric method is used, for example, a bimorph, monomorph, unimorph, laminated type, Mooney type, multi-Mooney type, cymbal type or the like that uses the displacement of a single ceramic may be used.

  The cuff pressure varying means 13 varies the cuff pressure that the cuff 11 compresses. For example, an air pump that supplies air sucked from the outside into the cuff 11 to increase the pressure in the cuff 11 and exhausts the air in the cuff 11 to the outside to decrease the pressure in the cuff 11 can be used. . As the air pump, for example, one that increases the pressure of the cuff 11 to a predetermined pressure at a stretch and gradually decreases the pressure can be used. Moreover, you may use what gradually increases the pressure of the cuff 11 to a predetermined pressure. The increase or decrease in cuff pressure is preferably at a constant rate. The predetermined pressure is a pressure at which arterioles or arterial blood flow stops, and is, for example, a pressure about 30 mmHg higher than the maximum blood pressure value of the subject. Furthermore, the air pump preferably starts increasing the pressure of the cuff 11 every predetermined time. The predetermined time is a preset time and may be a predetermined time. The predetermined time is preferably variable depending on the subject. Moreover, you may start the increase in the pressure of the cuff 11 according to the signal input from the outside.

  Further, the cuff pressure varying means 13 preferably varies the cuff pressure that the cuff 11 presses when the time from when the pulse wave detecting means 14 starts detecting the pulse wave reaches a certain time. The certain time is a time during which it can be determined that the systolic blood pressure or the diastolic blood pressure cannot be determined. For example, it may be a time sufficient to determine systolic blood pressure or diastolic blood pressure after starting to detect a pulse wave.

  Further, the blood pressure determination means 15 calculates the ratio of the pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection means 14, and determines whether or not the ratio of the pulse wave amplitudes is outside a certain range. It is preferable. “Pulse wave amplitude ratio out of a certain range” means that the pulse wave amplitude ratio exceeds a certain range. For example, it may be determined that a range exceeding a certain range of pulse wave amplitude ratios has been reached. If it is determined whether or not the ratio of the pulse wave amplitudes is outside a certain range, it is possible to determine the noise from the steep pulse wave amplitude fluctuation based on the past pulse wave amplitudes. Furthermore, when the blood pressure determination means 15 determines that the ratio of the pulse wave amplitude is outside a certain range, the cuff pressure varying means 13 preferably varies the cuff pressure that the cuff 11 presses. At this time, the cuff pressure compressed by the cuff 11 can be varied, and the blood pressure value can be measured again. Therefore, the blood pressure value can be remeasured when receiving a large noise due to the body movement of the subject.

  The pulse wave detection means 14 detects a pulse wave. The pulse wave detection means 14 preferably detects the pulse wave of the outer ear 101. Furthermore, it is preferable to detect the pulse wave of the tragus 111. For example, a photoelectric sensor that detects light emitted from a light emitting element with a light receiving element. As the light emitting element, for example, an edge emitting laser, a surface emitting laser, or an LED can be used. The characteristics such as the wavelength, amplitude, and phase of the emitted light are not limited. For example, light scattered by blood vessels included in the outer ear 101 may be used. Alternatively, the light may be scattered by a fluid such as hemoglobin that flows inside the blood vessel of the outer ear 101. As the light receiving element, for example, a photodiode such as a silicon photodiode, a photoelectric conducting element such as CdS, a photoelectric tube, a position sensor, a CCD, a MOS, or the like can be used. The characteristics such as the wavelength, amplitude, and phase of the received light are not limited. Further, the light emitting element and the light receiving element may be Doppler radars. Since the detection of the pulse wave using light is less influenced by external vibrations, the pulse wave can be stably detected from arterioles such as peripheral blood vessels where the pulse wave is weak. Therefore, the pulse wave can be stably detected by using the photoelectric sensor. The pulse wave detection means 14 is not limited to the above, and may be, for example, one that detects Korotkoff sounds of an artery, or one that detects pressure or vibration due to pulsation.

  The blood pressure determination unit 15 calculates the pulse wave amplitude from the pulse wave detected by the pulse wave detection unit 14, and determines the time point of systolic blood pressure or diastolic blood pressure based on the calculated pulse wave amplitude. Furthermore, it is preferable to calculate the systolic blood pressure value or the diastolic blood pressure value from the cuff pressure corresponding to the determined systolic blood pressure or diastolic blood pressure.

  The blood pressure determination unit 15 calculates the pulse wave amplitude from the pulse wave detected by the pulse wave detection unit 14. FIG. 2 is a schematic diagram illustrating an example of pulse wave signal output. The horizontal axis represents time, and the vertical axis represents pulse wave signal output. The pulse wave signal output shown in FIG. 2 is an example of the signal output of the pulse wave detected by the pulse wave detecting means 14 shown in FIG. 1, and valleys 25 and peaks 26 are shown. The pulse wave amplitude calculated by the blood pressure determination unit 15 can be, for example, a pulse wave signal output from the valley 25a to the mountain 26a or a pulse wave signal output from the mountain 26a to the valley 25b.

  Here, an example of determination of peaks and valleys will be described with reference to FIG. FIG. 3 is a schematic diagram illustrating a first example of a peak of the pulse wave signal output. FIG. 3A illustrates a case where “mountain” is determined, and FIG. 3B illustrates a case where it is not determined “mountain”. The horizontal axis represents time, and the vertical axis represents pulse wave signal output. The pulse wave signal outputs 32a to 32g shown in FIG. 3A are examples of pulse wave signal outputs detected by the pulse wave detecting means 14 shown in FIG. The output gradually increases from the pulse wave signal output 32a, peaks at the pulse wave signal output 32d, and decreases to the pulse wave signal output 32g. At this time, the blood pressure determination means 15 determines “mountain” when the difference 36 between the output values of the pulse wave signal output 32d and the pulse wave signal output 32g is larger than a predetermined value. The predetermined value is a predetermined threshold value. The same applies to the determination of “valley” as well as the determination of “mountain”. On the other hand, in the pulse wave signal outputs 33a to 33g shown in FIG. 3B, the pulse wave signal output 33d has a peak, decreases to the pulse wave signal output 33f, and pulse waves from the pulse wave signal output 33f. It increases over the signal output 33g. At this time, the blood pressure determination unit 15 does not determine “mountain” because the difference 37 between the output values of the pulse wave signal output 33d and the pulse wave signal output 33f is smaller than a predetermined value. The same applies to the determination of “valley” as well as the determination of “mountain”. Thus, it is preferable that the blood pressure determination unit 15 determines a peak or a valley when the pulse wave amplitude is greater than or equal to a predetermined amplitude. By providing a predetermined value, that is, a threshold value determined in advance, it is possible to smooth the pulse wave signal output and reduce the influence of noise.

  Furthermore, it is preferable that the blood pressure determination unit 15 shown in FIG. 1 calculates an average value of the pulse wave amplitude in the first predetermined range from the pulse wave detected by the pulse wave detection unit 14 and outputs the average value as the pulse wave amplitude. The first predetermined range is, for example, the number of pulse wave amplitudes. In this case, for example, the blood pressure determination unit 15 calculates an average value 27 of four pulse wave amplitudes from the valley 25c to the valley 25e shown in FIG. The number of pulse wave amplitudes in the first predetermined range is not limited. For example, it may be 3 or less, or 5 or more. The first predetermined range is, for example, a time width. In this case, for example, the blood pressure determination unit 15 calculates the average value of the pulse wave amplitude calculated during the time width from the valley 25c to the valley 25e shown in FIG. The time width of the first predetermined range is not limited. Since the blood pressure determination means 15 determines using the average value, it is possible to remove the steep fluctuation of the pulse wave amplitude. Therefore, the influence of steep noise caused by body movement can be reduced.

  Furthermore, it is preferable that the blood pressure determination means 15 shown in FIG. 1 calculates the average value of the pulse wave amplitude for each second predetermined range. The second predetermined range is, for example, the number of pulse wave amplitudes. For example, every time the pulse wave amplitude in the first predetermined range is newly calculated. For example, when the average value 27 of the four pulse wave amplitudes from the valley 25c to the valley 25e shown in FIG. 2 is calculated, the four pulse wave amplitudes from the valley 25c to the valley 25e are calculated and then the valley 25e to the valley 25g are calculated. The average value 28 of the four pulse wave amplitudes up to is calculated. The number of pulse wave amplitudes in the second predetermined range is not limited. For example, there may be one, or two or more. The second predetermined range is, for example, a time width. In this case, it can be set for each average period of the pulse wave. The time width of the second predetermined range is not limited. Thus, if the blood pressure determination unit 15 shown in FIG. 1 calculates the moving average value of the pulse wave amplitude as the pulse wave amplitude, the blood pressure determination unit 15 can remove the steep fluctuation of the pulse wave amplitude. Therefore, the influence of steep noise due to body movement can be reduced.

  FIG. 4 is a schematic diagram illustrating a second example of a peak of the pulse wave signal output. FIG. 4A illustrates a case where “mountain” is determined, and FIG. 4B illustrates a case where it is not determined “mountain”. The horizontal axis represents time, and the vertical axis represents pulse wave signal output. Pulse wave signal outputs 34a to 34g shown in FIG. 4A are examples of pulse wave signal outputs when the moving average value of the pulse wave signal output 32 shown in FIG. 3 is calculated. The pulse wave signal output 34 is smoothed from the pulse wave signal output 32 shown in FIG. At this time, the blood pressure determination means 15 determines “mountain” because the difference 38 between the output values of the pulse wave signal output 34d and the pulse wave signal output 34g is larger than a predetermined value. The predetermined value is a predetermined threshold value. Pulse wave signal outputs 35a to 35g shown in FIG. 4B are examples of pulse wave signal outputs when the moving average value of the pulse wave signal output 33 shown in FIG. 3 is calculated. At this time, the blood pressure determination means 15 does not determine “mountain” because the difference 39 between the output values of the pulse wave signal output 35d and the pulse wave signal output 35f is smaller than a predetermined value. The same applies to the determination of “valley” as well as the determination of “mountain”. Thus, it is preferable that the blood pressure determination means 15 calculates the moving average value of the pulse wave signal output, and determines that it is a peak or a valley when the pulse wave amplitude of the moving average value is greater than or equal to a predetermined amplitude. . By providing a predetermined value, that is, a threshold value determined in advance, the pulse wave signal output can be smoothed and the influence of fluctuations in pulse wave amplitude due to noise can be reduced.

  The blood pressure determination unit 15 determines blood pressure from the calculated pulse wave amplitude. As the blood pressure determination means 15, first blood pressure determination means for determining blood pressure based on the pulse wave amplitude when the cuff pressure is decreased can be used. The blood pressure determination means 15 can use second blood pressure determination means for determining blood pressure based on the pulse wave amplitude when the cuff pressure is decreased.

  The first blood pressure determination means 15 will be described with reference to FIGS. 5A and 5B are graphs showing a first example of blood pressure value measurement of the biological information detection device, where FIG. 5A shows a change over time in pressure, and FIG. 5B shows a change over time in pulse wave signal output. A cuff pressure 61 shown in FIG. 5A is a cuff pressure detected by the cuff pressure detecting means 12 shown in FIG. The pulsation internal pressure 62 is a pulsation internal pressure at each time point. A pulse wave signal output 63 shown in FIG. 5B is a pulse wave signal output of the pulse wave detected by the pulse wave detecting means 14 shown in FIG.

  The cuff pressure varying means 13 temporarily increases the cuff pressure 61 up to the pressure P0, and then gradually decreases the cuff pressure 61. The pressure P0 is a pressure set in advance and is a pressure at which the blood flow of the artery that detects the pulse wave stops. The cuff pressure varying means 13 gradually decreases the cuff pressure 61 from the pressure P0 to a pressure lower than the pressure P3 in the order of the time T0, the time T1, the time T2, and the time T4.

  When the cuff pressure is decreased by the cuff pressure varying means 13, the first blood pressure determining means 15 starts to decrease the cuff pressure 61 and the pulse wave amplitude at the time point T0 when the pulse wave amplitude becomes constant for the first time. The systolic blood pressure is determined with reference to a time point T1 at which the ratio of the pulse wave amplitude to the wave amplitude 40 is equal to or higher than a predetermined constant ratio. The time point T0 is a time point when the cuff pressure varying means 13 starts to decrease the cuff pressure 61 and the pulse wave amplitude becomes constant for the first time. “Constant” means constant within the range of noise. When the cuff pressure 61 is initially reduced, noise equivalent to the generated pulse wave amplitude may occur. The time T0 is the time when the noise becomes substantially constant or lowest. The pulse wave amplitude 40 is a pulse wave amplitude at a time T0 when the pulse wave amplitude first becomes constant after the cuff pressure 61 starts to be reduced. The pulse wave amplitude 41 is a pulse wave amplitude at a time point T1 at which the ratio of the pulse wave amplitude (pulse wave amplitude 41 / pulse wave amplitude 40) becomes equal to or higher than a predetermined constant ratio. The preset constant ratio is a preset threshold, and can be, for example, an increase amount of the pulse wave amplitude that can determine that the pulse wave amplitude has appeared. By determining such a time point T1, the cuff pressure 61 at the time point T1 can be detected, and the systolic blood pressure value P1 can be calculated. Therefore, the blood pressure value can be measured.

  In this way, the first blood pressure determination means 15 has a pulse wave amplitude with respect to the pulse wave amplitude at the time T0 when the pulse wave amplitude first becomes constant while the cuff pressure 61 of the cuff pressure varying means 13 is decreasing. Since the time point T1 at which the ratio becomes equal to or greater than a predetermined constant ratio is determined, noise at the initial stage of decompression can be removed in the detection of the expression of the pulse wave amplitude. Since the influence of noise at the initial stage of decompression can be eliminated, it is possible to accurately determine the onset time of the pulse wave amplitude. Therefore, in the biological information detecting device 91 that measures the blood pressure value while reducing the cuff pressure 61, the influence of noise is reduced when determining the time point T1 at which the arterial artery or the systolic blood pressure value P1 of the artery can be calculated. Can be made.

  Further, the first blood pressure determination means 15 uses the cuff pressure 61 corresponding to the time point when the pulse wave amplitude moved by the preset number of pulse wave amplitudes is detected from the time point T1 determined as the systolic blood pressure. It is preferable to calculate as a value. The number of pulse wave amplitudes is, for example, the number of pulses of pulse wave signal output. It may be the number of peaks of pulse wave signal output or the number of valleys of pulse wave signal output. The number of pulse wave amplitudes set in advance is not limited. For example, the number may be two, three, or four or more. The time point T1 when the pulse wave amplitude is detected is, for example, the time point of the valley when the pulse wave amplitude is “mountain-valley” or the time point of the mountain when the pulse wave amplitude is “valley-mountain”. Further, it may be intermediate between the time point of the mountain and the time point of the valley. In this way, if the cuff pressure 61 corresponding to the time point moved by the number of pulse wave amplitudes set in advance from the time point T1 is calculated as the systolic blood pressure value P1, the pulse wave amplitude in which the pulse wave amplitude is reliably expressed is calculated. It is possible to calculate the systolic blood pressure value P1. Therefore, in the biological information detection apparatus 91 that measures the blood pressure value while decreasing the cuff pressure 61, the influence of noise can be reduced when the arterial artery or artery systolic blood pressure value P1 is calculated.

  The first blood pressure determination means 15 preferably determines the diastolic blood pressure with reference to a time point T2 at which the pulse wave amplitude starts to decrease when the cuff pressure 61 of the cuff pressure varying means 13 decreases. The time point at which the pulse wave amplitude starts to decrease may be determined by comparing two pulse wave amplitudes, or may be determined by comparing three or more pulse wave amplitudes. Moreover, you may determine whether it started decreasing using the threshold value demonstrated in above-mentioned FIG. By determining the time point T2, the cuff pressure 61 at the time point T2 can be detected, and the diastolic blood pressure value P2 can be calculated. Therefore, the blood pressure value can be measured.

  Thus, since the time T2 at which the pulse wave amplitude starts to decrease is determined by comparing the pulse wave amplitude, the influence of the background noise can be eliminated when determining the time T2 when the pulse wave amplitude becomes maximum. . Therefore, in the biological information detecting device 91 that measures the blood pressure value while decreasing the cuff pressure 61, the influence of noise is reduced when determining the time point T2 at which the arterial diastolic blood pressure value P2 can be calculated. Can do. Furthermore, since the time T2 when the pulse wave amplitude becomes maximum is determined by comparing the pulse wave amplitude, it is possible to accurately determine the minute fluctuation of the pulse wave amplitude. Therefore, since the value of the maximum pulse wave amplitude 42 with high accuracy can be used, the time point T2 at which the arterial diastolic blood pressure value P2 can be calculated can be accurately determined.

  Further, the first blood pressure determination means 15 uses the cuff pressure 61 corresponding to the time point when the pulse wave amplitude moved by the number of preset pulse wave amplitudes is detected from the time point T2 determined as the diastolic blood pressure. It is preferable to calculate the value P2. The number of pulse wave amplitudes and the time point when the pulse wave amplitude is detected can be the same as the calculation of the systolic blood pressure value described above. In this way, if the cuff pressure 61 corresponding to the time point moved by the number of pulse wave amplitudes set in advance from the time point T2 is calculated as the diastolic blood pressure value P2, when calculating the diastolic blood pressure value P2 of the arteriole, The influence of noise can be reduced.

  The determination of diastolic blood pressure is not limited to the above. For example, the first blood pressure determination unit 15 determines that the time T2 at which the pulse wave amplitude starts to decrease when the cuff pressure 61 of the cuff pressure varying unit 13 decreases is the maximum amplitude, and after the maximum pulse wave amplitude T2, The diastolic blood pressure may be determined with reference to a time point T4 at which the ratio of the pulse wave amplitude is equal to or less than a predetermined constant ratio with respect to the pulse wave amplitude 42 at the maximum pulse wave amplitude T2. The pulse wave amplitude 43 is a pulse wave amplitude at a time point T4 when the ratio of the pulse wave amplitude (pulse wave amplitude 43 / pulse wave amplitude 40) becomes equal to or less than a predetermined ratio set in advance. The predetermined ratio set in advance is a threshold set in advance. For example, the amount of reduction can be determined so that it can be determined that the pulse wave amplitude has sufficiently decreased. The threshold value is not limited and is preferably set to a value according to the subject. By determining the time point T4, the cuff pressure 61 at the time point T4 can be detected, and the diastolic blood pressure value P3 can be calculated. Therefore, the blood pressure value can be measured.

  As described above, the first blood pressure determination unit 15 uses the time when the ratio of the pulse wave amplitude to the pulse wave amplitude 42 at the maximum pulse wave amplitude T2 is equal to or less than a predetermined ratio as a reference. Since the blood pressure is determined, the influence of background noise can be eliminated. Therefore, in the biological information detecting apparatus 91 that measures the blood pressure value while decreasing the cuff pressure 61, the influence of noise can be reduced when determining the time point T4 at which the arterial diastolic blood pressure value P3 can be calculated. it can. Furthermore, since the time T2 when the pulse wave amplitude becomes maximum is determined by comparing the pulse wave amplitude, it is possible to accurately determine the minute fluctuation of the pulse wave amplitude. Therefore, since the value of the maximum pulse wave amplitude 42 with high accuracy can be used, the time point T4 at which the arterial diastolic blood pressure value P3 can be calculated can be accurately determined. Also in this case, the cuff pressure 61 corresponding to the time point when the pulse wave amplitude shifted by the preset number of pulse wave amplitudes is detected from the time point T4 determined as the diastolic blood pressure is calculated as the diastolic blood pressure value P3. It is preferable. If the cuff pressure 61 corresponding to a time point shifted by the number of pulse wave amplitudes set in advance from the time point T4 is calculated as the diastolic blood pressure value P3, the influence of noise is reduced when calculating the diastolic blood pressure value of the artery. be able to.

  The second blood pressure determination means 15 will be described with reference to FIGS. 6A and 6B are graphs showing a second example of blood pressure value measurement of the biological information detection device, where FIG. 6A shows a change over time in pressure, and FIG. 6B shows a change over time in pulse wave signal output. A cuff pressure 65 shown in FIG. 6A is a cuff pressure detected by the cuff pressure detecting means 12 shown in FIG. The pulsation internal pressure 66 is a pulsation internal pressure at each time point. A pulse wave signal output 67 shown in FIG. 6B is a pulse wave signal output of the pulse wave detected by the pulse wave detecting means 14 shown in FIG.

  The cuff pressure varying means 13 shown in FIG. 1 gradually increases the cuff pressure 65 from a pressure lower than the pressure P3 to a pressure higher than the pressure P0 in the order of time T5, time T6, time T7, and time T8.

  The second blood pressure determination means 15 determines the diastolic blood pressure with reference to a time point T7 at which the pulse wave amplitude starts to decrease when the cuff pressure 65 of the cuff pressure varying means 13 is increased. The time point T7 is a time point at which the pulse wave amplitude starts to decrease, and is a time point at which the maximum pulse wave amplitude 52 that maximizes the pulse wave amplitude is calculated. By determining the time point T7, the cuff pressure 65 at the time point T7 can be detected, and the diastolic blood pressure value P2 can be calculated. Therefore, the blood pressure value can be measured.

  Thus, since the second blood pressure determination means 15 compares the pulse wave amplitude and determines the time T7 at which the pulse wave amplitude starts to decrease, the background blood pressure is determined at the time T7 when the pulse wave amplitude becomes maximum. The influence of noise can be eliminated. Therefore, in the biological information detecting apparatus 91 that measures the blood pressure value while increasing the cuff pressure 65, the influence of noise is reduced when determining the time point T7 at which the arterial diastolic blood pressure value P2 can be calculated. Can do. Furthermore, since the time T7 when the pulse wave amplitude becomes maximum is determined by comparing the pulse wave amplitude, a minute fluctuation in the pulse wave amplitude can be accurately determined. Therefore, the time point T7 at which the arterial diastolic blood pressure value P2 can be calculated can be accurately determined.

  Further, the second blood pressure determination means 15 shown in FIG. 1 has a cuff pressure 65 corresponding to the time point when the pulse wave amplitude that has been moved by the number of pulse wave amplitudes set in advance is detected from the time point T7 determined as the diastolic blood pressure. Is preferably calculated as the diastolic blood pressure value P2. The number of pulse wave amplitudes and the point in time when the pulse wave amplitudes are detected can be the same as the calculation of the systolic blood pressure value described above with reference to FIG. If the cuff pressure 65 corresponding to the time point that has moved by the number of pulse wave amplitudes set in advance from the time point T7 is calculated as the diastolic blood pressure value P2, the influence of noise is calculated when calculating the diastolic blood pressure value P2 of the arteriole. Can be reduced.

  The determination of diastolic blood pressure is not limited to the above. For example, the second blood pressure determination unit 15 determines that the time T7 at which the pulse wave amplitude starts to decrease when the cuff pressure 65 of the cuff pressure varying unit 13 increases is the maximum pulse wave amplitude, and the maximum pulse wave amplitude T7 Before, the diastolic blood pressure may be determined on the basis of the time T6 when the ratio of the pulse wave amplitude to the pulse wave amplitude 52 at the maximum pulse wave amplitude T7 is equal to or less than a predetermined constant ratio. The pulse wave amplitude 51 is a pulse wave amplitude at a time point T6 at which the pulse wave amplitude is smaller than the maximum pulse wave amplitude 52 by a certain percentage. The predetermined ratio set in advance is a threshold set in advance. By determining the time point T6, the cuff pressure 65 at the time point T6 can be detected, and the diastolic blood pressure value P3 can be calculated. Therefore, the blood pressure value can be measured.

  Thus, since the second blood pressure determination means 15 compares the pulse wave amplitude and determines the time T7 at which the pulse wave amplitude starts to decrease, the background blood pressure is determined at the time T7 when the pulse wave amplitude becomes maximum. The influence of noise can be eliminated. Furthermore, since the diastolic blood pressure is determined based on the time T6 when the ratio of the pulse wave amplitude to the pulse wave amplitude 52 of the maximum pulse wave amplitude T7 is equal to or less than a predetermined constant, the background noise The influence can be eliminated. Therefore, in the biological information detecting device 91 that measures the blood pressure value while increasing the cuff pressure 65, the influence of noise can be reduced when determining the time point T6 at which the arterial diastolic blood pressure value P3 can be calculated. it can. Furthermore, since the time T7 when the pulse wave amplitude becomes maximum is determined by comparing the pulse wave amplitude, a minute fluctuation in the pulse wave amplitude can be accurately determined. Therefore, since the value of the maximum pulse wave amplitude 52 with high accuracy can be used, the time point T6 at which the arterial diastolic blood pressure value P3 can be calculated can be accurately determined.

  In this case, the second blood pressure determination unit 15 further sets the cuff pressure 65 corresponding to the time point when the pulse wave amplitude moved by the number of pulse wave amplitudes set in advance is detected from the time point T6 determined as the diastolic blood pressure. It is preferable to calculate as the diastolic blood pressure value P3. If the cuff pressure 65 corresponding to a time point that is moved by the number of pulse wave amplitudes set in advance from the time point T6 is calculated as the diastolic blood pressure value P3, the influence of noise is reduced when calculating the diastolic blood pressure value of the artery. be able to.

  For example, when the cuff pressure 65 of the cuff pressure varying unit 13 increases, the second blood pressure determination unit 15 determines that the time T7 at which the pulse wave amplitude starts to decrease is the maximum pulse wave amplitude, and the maximum pulse wave amplitude T7 Later, it is preferable to determine the systolic blood pressure with reference to a time T8 when the ratio of the pulse wave amplitude to the pulse wave amplitude 52 at the maximum pulse wave amplitude T7 becomes equal to or less than a predetermined constant ratio. The time point T7 at which the pulse wave amplitude starts to decrease can be determined in the same manner as the determination at the time point T2 at which the pulse wave amplitude starts to decrease described above with reference to FIG. The pulse wave amplitude 53 is a pulse wave amplitude at a time point T8 when the ratio of the pulse wave amplitude (pulse wave amplitude 53 / pulse wave amplitude 52) becomes equal to or less than a predetermined ratio set in advance. By determining the time point T8, the cuff pressure 65 at the time point T8 can be detected, and the arteriole or arterial systolic blood pressure value P1 can be calculated. Therefore, the blood pressure value can be measured.

  As described above, the second blood pressure determination unit 15 determines the systolic blood pressure on the basis of the time point when the pulse wave amplitude is reduced by a certain percentage with respect to the maximum pulse wave amplitude 52, so that the influence of the background noise can be eliminated. it can. Therefore, in the biological information detecting apparatus 91 that measures the blood pressure value while increasing the cuff pressure 65, the influence of noise is reduced when determining the time point T8 at which the arterial artery or arterial systolic blood pressure value P1 can be calculated. Can be made. Furthermore, since the time T7 when the pulse wave amplitude becomes maximum is determined by comparing the pulse wave amplitude, a minute fluctuation in the pulse wave amplitude can be accurately determined. Therefore, since the value of the maximum pulse wave amplitude 52 with high accuracy can be used, it is possible to accurately determine the time point T8 at which the arteriole or arterial systolic blood pressure value P1 can be calculated.

  Further, the second blood pressure determination means 15 shown in FIG. 1 has a cuff pressure 65 corresponding to the time point when the pulse wave amplitude that has been moved by the number of pulse wave amplitudes set in advance is detected from the time point T8 determined as the systolic blood pressure. Is preferably calculated as the systolic blood pressure value P1. The number of pulse wave amplitudes and the preset number of pulse wave amplitudes can be the same as those described with reference to FIG. The time point T8 determined as the systolic blood pressure is, for example, the time point of the valley when the pulse wave amplitude is “mountain-valley” or the time point of the mountain when the pulse wave amplitude is “valley-mountain”. Further, it may be intermediate between the time point of the mountain and the time point of the valley. As described above, if the cuff pressure 65 corresponding to the time point that is moved by the number of pulse wave amplitudes set in advance from the time point T8 is calculated as the systolic blood pressure value P1, the arterial artery or artery systolic blood pressure value is calculated. , Noise effects can be reduced.

  Furthermore, the blood pressure determination means 15 resets the predetermined ratio to a preset ratio smaller than the predetermined ratio when the time after the pulse wave detection means 14 starts detecting the pulse wave reaches a predetermined time. Is preferred. The certain time is a time during which it can be determined that the determination is impossible. For example, it may be a time sufficient to determine systolic blood pressure or diastolic blood pressure after starting to detect a pulse wave. The constant ratio is, for example, the ratio of the pulse wave amplitude at the time point T1 described with reference to FIG. 5 (pulse wave amplitude 41 / pulse wave amplitude 40). When the set value of a certain ratio is too large, it is possible to reset the certain ratio and lower the determination threshold. Therefore, it can be determined with an appropriate threshold value for each measurement.

  The blood pressure determination means 15 preferably resets the constant ratio to a preset ratio larger than the constant ratio when the time since the pulse wave detection means 14 starts detecting the pulse wave reaches a predetermined time. . The certain time is a time during which it can be determined that the determination is impossible. For example, it may be a time sufficient to determine systolic blood pressure or diastolic blood pressure after starting to detect a pulse wave. The certain ratio is, for example, the ratio of the pulse wave amplitude at the time point T4 described with reference to FIG. 5 (pulse wave amplitude 43 / pulse wave amplitude 42). Further, the ratio is the pulse wave amplitude ratio (pulse wave amplitude 51 / pulse wave amplitude 52) at time T5 described with reference to FIG. Also, the ratio of the pulse wave amplitude at the time point T8 described with reference to FIG. 6 (pulse wave amplitude 53 / pulse wave amplitude 52). When the set value of a certain ratio is too large and determination is impossible, the certain ratio can be reset to a determinable range. Therefore, systolic blood pressure or diastolic blood pressure can be reliably determined.

  The blood pressure determination means 15 calculates the ratio of the pulse wave amplitudes of the two latest pulse waves detected by the pulse wave detection means 14, determines whether the ratio of the pulse wave amplitudes is outside a certain range, When the ratio of the pulse wave amplitudes is outside a certain range, it is preferable to replace the previously detected pulse wave amplitude of the two pulse wave amplitudes with the latest pulse wave amplitude. The latest ratio of the pulse wave amplitudes of the two pulse waves is, for example, the ratio of the two pulse wave amplitudes calculated continuously. “Outside of a certain range” is, for example, a pulse wave amplitude that cannot be detected continuously if only the pulse wave amplitude is detected. Based on the amplitude of the past pulse wave, it can be detected that a large noise is suddenly included in the pulse wave amplitude. In the measurement of blood pressure values in the outer ear, sudden large noise may occur due to body movement. At this time, if the pulse wave amplitude containing a large noise is removed, the influence of the large noise due to the body movement can be reduced. If the ratio of the pulse wave amplitudes is within a certain range, the pulse wave amplitude detected later among the pulse wave amplitudes of the two pulse waves may be set as the latest pulse wave amplitude. At this time, the cuff pressure compressed by the cuff 11 can be varied to determine the systolic blood pressure or the diastolic blood pressure again. In this way, the blood pressure determination unit 15 can determine noise from the ratio of the two pulse wave amplitudes. Furthermore, since the pulse wave amplitude detected before of the pulse wave amplitudes of the two pulse waves is replaced with the latest pulse wave amplitude, the pulse wave amplitude including noise is subject to determination of systolic blood pressure or diastolic blood pressure. Can be outside.

  The blood pressure determination unit 15 preferably calculates a time interval between the pulse wave amplitudes of the two latest pulse waves detected by the pulse wave detection unit 14 and determines whether or not the time interval is outside a certain range. The pulse wave amplitudes of the latest two pulse waves are, for example, “mountain” and “valley” of the latest detected pulse wave signal output. It is good also as two "mountains" of the pulse wave signal output detected the latest. The certain range is a time interval that cannot be a pulse wave. The certain range may be a time interval of the pulse wave amplitude when the pulse is the slowest. Since it is determined whether or not the time interval of the pulse wave amplitudes of the two latest pulse waves is outside a certain range, the pulse wave amplitude and noise can be determined.

  Furthermore, when the blood pressure determination unit 15 determines that the ratio of the pulse wave amplitudes is outside a certain range, it is preferable that the pulse wave amplitude detected by the pulse wave detection unit 14 so far is excluded from the determination target. Excluding the pulse wave amplitude from the determination refers to, for example, deleting the pulse wave amplitude determined by the blood pressure determination unit 15 from the memory storing the pulse wave amplitude. Since the pulse wave amplitude determined as noise is excluded from the determination of systolic blood pressure or diastolic blood pressure, the influence of noise can be reduced.

  The blood pressure determination unit 15 preferably further calculates the pulse rate from the pulse wave detected by the pulse wave detection unit 14. Since blood pressure is determined and the pulse rate is further calculated, more accurate biological information can be detected.

  As described above, the biological information detecting apparatus 91 according to the present embodiment calculates the peak and valley of the pulse wave from the detected pulse wave, and determines the systolic blood pressure and the diastolic blood pressure by comparing the pulse wave amplitude. Therefore, the influence of background noise or steep noise included in the pulse wave amplitude can be reduced. In addition, since the biological information can be determined by comparing the pulse wave amplitude, the circuit configuration can be simplified. Therefore, the size can be reduced. Therefore, it is possible to provide a portable biological information detection device that can reduce the influence of noise and is portable. Furthermore, if a pulse wave is detected from the outer ear, the burden at the time of wearing is light, and thus portability is excellent.

  Since the biological information detection apparatus according to the present invention can detect biological information from the outer ear, it can also be used for beauty and health applications.

It is a schematic diagram which shows an example of the biometric information detection apparatus which concerns on Embodiment 1. FIG. It is a schematic diagram which shows an example of a pulse wave signal output. It is a schematic diagram which shows the 1st example of the peak of a pulse wave signal output, (a) shows the case where it determines with a "mountain", (b) shows the case where it is not determined with a "mountain". It is a schematic diagram which shows the 2nd example of the peak of a pulse wave signal output, (a) shows the case where it determines with a "mountain", (b) shows the case where it is not determined with a "mountain". It is a graph which shows the 1st example of the blood-pressure value measurement of a biometric information detection apparatus, (a) shows the time change of a cuff pressure, (b) shows the time change of a pulse wave signal output. It is a graph which shows the 2nd example of the blood-pressure value measurement of a biometric information detection apparatus, (a) shows the time change of a cuff pressure, (b) shows the time change of a pulse wave signal output.

Explanation of symbols

11 Cuff 12 Cuff pressure detecting means 13 Cuff pressure varying means 14 Pulse wave detecting means 15 Blood pressure determining means 25 Valley 26 Mountain 27, 28 Moving average value 32, 33 Pulse wave signal output 36, 37 Difference in pulse wave signal output 34, 35 Moving average value 38, 39 Difference in moving average value 40 Pulse wave amplitude at the time when the pulse wave amplitude first becomes constant
41 Minimum amplitude during decompression 42 Maximum pulse wave amplitude 43 Amplitude in which the maximum pulse wave amplitude has been reduced by a certain percentage 51 Pulse wave amplitude in which the pulse wave amplitude is a certain percentage less than the maximum amplitude 52 Maximum pulse wave amplitude 53 Maximum pulse wave amplitude in a constant ratio Decreased amplitude 61, 65 Cuff pressure 62, 66 Pulsating internal pressure 63, 67 Pulse wave amplitude 91 Biological information detection device 101 Outer ear 111 Tragus 112 Ear ring T1 Time point when pulse wave amplitude appears T2 Time point of maximum pulse wave amplitude T4 Maximum amplitude When the constant rate decreases T5 When the pressure increases T6 When the amplitude is less than the maximum amplitude by a certain rate T7 When the maximum amplitude T8 When the maximum amplitude decreases by a certain rate P0 Pressure at which the blood flow stops
P1 systolic blood pressure P2 diastolic blood pressure in arteriole P3 diastolic blood pressure in artery

Claims (15)

With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually decreases the cuff pressure once increased,
When the cuff pressure is decreased by the cuff pressure variable means, the blood pressure determination means starts to decrease the cuff pressure, and the pulse wave amplitude at the time when the pulse wave amplitude becomes constant for the first time, A biological information detecting apparatus, wherein a systolic blood pressure is determined based on a time point when a ratio of a pulse wave amplitude becomes equal to or higher than a predetermined constant ratio. With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually decreases the cuff pressure once increased,
The biological information detecting apparatus, wherein the blood pressure determining means determines the diastolic blood pressure based on a time point when the pulse wave amplitude starts to decrease when the cuff pressure of the cuff pressure changing means is decreased. With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually decreases the cuff pressure once increased,
The blood pressure determination means determines the time when the pulse wave amplitude starts to decrease when the cuff pressure is decreased by the cuff pressure varying means as the maximum pulse wave amplitude, and after the maximum pulse wave amplitude, A biological information detection apparatus, wherein a diastolic blood pressure is determined based on a time point when a ratio of a pulse wave amplitude is equal to or less than a predetermined constant ratio with respect to a pulse wave amplitude of time. With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually increases the cuff pressure,
The blood pressure determining means determines the time when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure varying means as the maximum pulse wave amplitude, and after the maximum pulse wave amplitude, A biological information detecting apparatus, wherein a systolic blood pressure is determined based on a time point when a ratio of a pulse wave amplitude to a predetermined pulse wave amplitude is equal to or less than a predetermined pulse wave amplitude. With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually increases the cuff pressure,
The biological information detecting apparatus according to claim 1, wherein the blood pressure determining means determines the diastolic blood pressure on the basis of a time point when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure varying means. With a cuff to press,
Cuff pressure detecting means for detecting the cuff pressure that the cuff compresses;
Cuff pressure varying means for varying the cuff pressure to be compressed by the cuff;
Pulse wave detecting means for detecting the pulse wave of the outer ear;
A blood pressure determination unit that calculates a pulse wave amplitude from a pulse wave detected by the pulse wave detection unit, and determines a blood pressure from the calculated pulse wave amplitude;
The cuff pressure varying means gradually increases the cuff pressure,
The blood pressure determination means determines the time when the pulse wave amplitude starts to decrease when the cuff pressure is increased by the cuff pressure variable means as the maximum pulse wave amplitude, and before the maximum pulse wave amplitude, A biological information detection device that determines a diastolic blood pressure based on a time point when a ratio of a pulse wave amplitude is equal to or less than a predetermined constant ratio with respect to a pulse wave amplitude at the time of amplitude.   The blood pressure determination means calculates a cuff pressure corresponding to a point in time when a pulse wave amplitude moved by the number of pulse wave amplitudes set in advance from the time point determined as systolic blood pressure is detected as a systolic blood pressure value. The biological information detecting device according to claim 1 or 4.   The blood pressure determination means calculates a cuff pressure corresponding to a point in time when a pulse wave amplitude shifted by the number of pulse wave amplitudes set in advance is detected as a diastolic blood pressure as a diastolic blood pressure value. The biological information detection device according to claim 2, 3, 5, or 6.   When the time from when the pulse wave detection means starts detecting the pulse wave reaches a certain time, the blood pressure determination means resets the constant ratio to a preset ratio smaller than the constant ratio, and the cuff pressure The living body information detecting apparatus according to claim 1, wherein the variable means varies the cuff pressure applied by the cuff.   When the time from when the pulse wave detecting means starts to detect a pulse wave reaches a certain time, the blood pressure determining means resets the constant ratio to a preset ratio larger than the constant ratio, and the cuff pressure The living body information detecting apparatus according to claim 3, 4 or 6, wherein the variable means varies the cuff pressure applied by the cuff.   The blood pressure determination means calculates, from the pulse wave detected by the pulse wave detection means, an average value of the pulse wave amplitude in a first predetermined range as a pulse wave amplitude for each second predetermined range. The biological information detection apparatus according to any one of 1 to 10.   The blood pressure determination means calculates a ratio of pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection means, determines whether or not the ratio of the pulse wave amplitudes is outside a certain range; The pulse wave amplitude detected before of the pulse wave amplitudes of the two pulse waves is replaced with the latest pulse wave amplitude when the ratio of the pulse wave amplitudes is outside a certain range. 11. The biological information detection device according to any one of 11 above. The blood pressure determination means calculates a ratio of pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection means, determines whether or not the ratio of the pulse wave amplitudes is outside a certain range;
The cuff pressure varying means varies the cuff pressure compressed by the cuff when the blood pressure determining means determines that the ratio of the pulse wave amplitudes is outside a certain range. Any biological information detection apparatus of description.   The blood pressure determination unit calculates a time interval between pulse wave amplitudes of the latest two pulse waves detected by the pulse wave detection unit, determines whether or not the time interval is outside a certain range, and the time interval The biological information detection apparatus according to claim 1, wherein when the pulse wave is out of a predetermined range, the pulse wave amplitude detected by the pulse wave detection unit is excluded from the determination target. 15. The biological information detection apparatus according to claim 1, wherein the blood pressure determination unit further calculates a pulse rate from a pulse wave detected by the pulse wave detection unit.

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