JP2009172204A - Biological information acquisition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological information acquisition device capable of accurately acquiring biological information of a driver such as electrocardiographic information. <P>SOLUTION: This biological information acquisition device is provided with a first electrocardiographic sensor electrode 210 and a second electrocardiographic sensor electrode 220, a main airbag 270 which displaces the electrocardiographic sensor electrodes 210 and 220 by inflation and deflation, and a control processing section 100 where a measurement pressure value measured by a seat type back pressure distribution sensor 261 provided near the electrocardiographic sensor electrodes 210 and 220 are input, which controls the inflation/deflation of the main airbag 270 and which determines the state of the living body based on electric signals detected by the electrocardiographic sensor electrodes 210 and 220, wherein the control processing section 100 is characterized in inflating/deflating the main airbag 270 according to the measured pressure value measured by the seat type back pressure distribution sensor 261 and acquiring the electric signals detected by the electrocardiographic sensor electrodes 210 and 220. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biological information acquisition apparatus that is mounted on a seat portion of a vehicle or the like and senses a weak signal from the heart that is important in judging the health condition of a driver efficiently and non-invasively.

  In recent years, intelligent vehicles have been further promoted, and various techniques for monitoring the health of passengers centered on drivers have been proposed.

For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-329956), a monitoring unit that monitors a driving state of a driving object by a driver, a biological signal detection unit that detects a biological signal of the driver, and the biological signal detection described above. Calculating means for quantifying information contained in the biological signal detected by the means, and determining means for determining the driver's skill level from the driving information by the monitoring means and the change of the biological signal information from the start of driving by the calculating means A driver monitoring device is disclosed.
JP 2004-329956 A

  In the device described in Patent Document 1, there is a problem that the biological signal detecting means for detecting the biological signal of the driver does not disclose how the biological signal of the driver is specifically detected. In other words, in-vehicle biological signal sensors do not require the driver to wear the sensing equipment on the skin, and the driver is bothered while sitting on the seat while wearing it. In addition, a biological signal must be acquired.

  In sensing biological signals under such circumstances, there are technically high barriers that must be solved. However, Patent Document 1 does not disclose any such thing. In particular, an electrocardiographic sensor that acquires information related to the heart, which is important for judging the health condition of the driver, needs to sense a weak electrical signal from the heart while the driver of the clothing is sitting on the seat. Although there is technical difficulty, there is no description in Patent Document 1 regarding a technique related to efficient acquisition of a weak signal in such a vehicle-mounted biological signal sensor.

  To measure biological signals such as weak electrocardiographic signals in a biometric information acquisition device such as an in-vehicle electrocardiographic sensor that employs a method that does not attach electrodes directly to the skin, for example, a capacitive electrode is embedded in a sheet. There is a method of acquiring a weak signal from the heart with this capacitive electrode. However, when biometric information is acquired by such a mechanism, there is a problem that measurement is impossible when the driver's back is separated from the capacitive electrode. Even if the driver's back is touching the capacitive electrode, if the adhesion is low, static electricity or the like appears as noise, so that accurate biological information cannot be acquired.

  In other words, if the driver's back is away from the sheet in which the capacitive electrode is embedded or the adhesion to the sheet is low, an erroneous measurement value such as heart rate will be acquired. However, there was a problem that the driver's condition was judged erroneously.

  In order to solve the above problems, the invention according to claim 1 is mounted on a seat portion, detects an electrical signal related to a living body non-invasively, and determines the state of the living body based on the detected electrical signal. A biological information acquisition device, an electrode attached inside a seat, a main airbag that is provided inside the seat and displaces the electrode by expanding and contracting, a pressure sensor provided near the electrode, and the pressure A control process in which a measured pressure value applied to the seat measured by a sensor is input, the expansion and contraction of the main airbag is controlled, and a living state is determined based on an electrical signal detected by the electrode And the control processing unit inflates and contracts the main airbag according to the measured pressure value measured by the pressure sensor, and And obtaining an electrical signal issued.

  According to the biological information acquisition apparatus of the first aspect of the present invention, the control processing unit inflates and contracts the main airbag according to the measured pressure value measured by the pressure sensor, and then uses the electrode. Since the detected electrical signal is acquired, biological information such as electrocardiographic information relating to the driver can be reliably acquired, and the biological state of the driver can be accurately grasped.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration for acquiring an electrocardiogram signal in the biological information acquisition apparatus according to the embodiment of the present invention, and FIG. 2 is an electrocardiogram signal in the biological information acquisition apparatus according to the embodiment of the present invention. FIG. 3 is a diagram illustrating an electrical connection for acquisition, and FIG. 3 is a diagram illustrating a main part of a circuit configuration of the biological information acquisition apparatus according to the embodiment of the present invention.

  In addition, although the biometric information acquisition apparatus of this embodiment assumes mounting in vehicles, such as a motor vehicle, a hybrid vehicle, and an electric vehicle, it is also possible to mount in other moving means, such as a train, a ship, and an aircraft. It is.

  In the present embodiment, the target for acquiring biological information such as heart-related information (heart rate / electrocardiogram) is a vehicle driver, and the configuration of electrodes and the like for acquiring the biological information is provided in the driver's seat. However, the biometric information acquisition target person may be a passenger such as a passenger seat and a rear seat, and the configuration of the present invention can be applied to these passenger seats and the like as well. Is.

  In the present embodiment, non-invasive means a state in which the electrode is not in direct contact with the skin of the subject (driver). Obtaining a biological signal non-invasively means obtaining the biological signal in a state in which the configuration of the electrode or the like does not directly touch the skin of the subject (driver).

  In this embodiment, the portion of the electrode or the like arranged on the sheet is such that the electrode can acquire a necessary signal through the clothes of the driver and the skin of the sheet. In addition, when the configuration of the electrode or the like is arranged on the handle, the electrode can be placed through the skin of the handle cover even when the handle cover is arranged so as to cover the electrode without the driver's hand touching the electrode surface. An electrocardiogram signal can be acquired.

  In the present embodiment, the biometric information is described using an example of an electrocardiographic sensor that acquires information related to the heart of the driver (heart rate, electrocardiogram, etc.). However, the configuration of the present invention includes other biometric information. The present invention can also be applied to a biological information acquisition device that acquires the information. More specifically, it is also applicable to acquiring biological information such as breathing, body temperature, body weight, body fat, blood pressure, sweating, line of sight, myoelectricity, skin impedance of the passenger. Here, a weak electric signal from the heart, which is information acquired from the driver's heart, is referred to as an electrocardiographic signal.

  1 to 3, 10 is a driver's seat, 21 is a first-stage amplifier section for a first electrode, 25 is a coaxial cable for a first ECG sensor electrode, and 31 is a first-stage amplifier section for a second ECG sensor electrode. , 35 is a coaxial cable for the second ECG sensor electrode, 40 is a ground electrode, 45 is a ground cable, 50 is a second stage amplifier section, 51 is an amplifier, 52 is a high pass filter, 53 is a low pass filter, and 200 is an electrocardiogram. An information acquisition unit, 201 is an electrode unit, 210 is a first electrocardiographic sensor electrode, and 220 is a second electrocardiographic sensor electrode.

  As shown in FIGS. 1 and 2, the sheet 10 is a driver's seat, and in this embodiment, the driver is an object to be monitored by the biological information acquisition apparatus. Inside the sheet 10, electrocardiographic sensor electrodes 210 and 220 made of, for example, capacitive electrodes are provided so as not to be exposed to the sheet 10. Further, the ground electrode 40 is disposed in a portion (seat portion) of the seat 10 where the driver's buttocks hit, and the ground electrode 40 is connected to the second-stage amplifier unit 50 by a ground cable 45. The ground electrode 40 is used as a configuration for determining a reference potential for removing an offset signal generated in a signal from the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220).

  As shown in FIGS. 1 and 2, the driver's seat 10 is provided with first and second electrocardiographic sensor electrodes 210 and 220, and the driver gets on the vehicle, sits on the driver's seat 10 and holds the steering wheel. When driving the vehicle, a weak current is detected from the electrocardiographic sensor electrodes 210 and 220 on the driver's back. These weak currents are amplified and acquired by the control processing unit 100 of the biological information acquisition apparatus as information (heart rate, electrocardiogram, etc.) relating to the driver's heart. The electrocardiographic sensor electrodes 210 and 220 used for acquiring such information related to the heart (heart rate and electrocardiogram) are composed of, for example, capacitive electrodes. As such a capacitive electrode, for example, those described in JP-A-2005-511174 can be used.

  For the first electrocardiogram sensor electrode 210 and the second electrocardiogram sensor electrode 220 in the electrocardiogram information acquisition unit 200, for example, a capacitive electrocardiograph sensor electrode having an oxide film layer provided on the surface thereof is used. The sensor electrode 210 is disposed so as to be substantially on the left side of the driver's back, and the second electrocardiographic sensor electrode 220 is disposed so as to be approximately on the right side of the driver's back.

  A signal detected between the first electrocardiographic sensor electrode 210 and a predetermined reference potential is transmitted from the first electrocardiographic sensor electrode first-stage amplifier unit 21 and from the second electrocardiographic sensor electrode 220 to a predetermined reference potential. A signal detected between the first and second potentials is amplified by the first-stage amplifier unit 31 for the second electrocardiographic sensor electrode to a signal level of about 1 mV to several mV (for example, 2 mV). .

  The distance between the first electrocardiographic sensor electrode 210 and the input terminal of the first electrocardiographic sensor electrode first stage amplifier unit 21, the second electrocardiographic sensor electrode 220 and the second electrocardiographic sensor electrode first stage amplifier unit The distance between the first and second ECG sensor electrodes 210 and 220 is preferably as short as possible in order to avoid the influence of external noise. The first stage amplifier section is arranged. Therefore, as shown in FIG. 2, the first stage amplifier part 21 for the first ECG sensor electrode and the first stage amplifier part 31 for the second ECG sensor electrode are both provided in the seat 10 (particularly the backrest part). Form.

  A pair of the first ECG sensor electrode 210 and the first stage amplifier unit 21 for the first ECG sensor electrode, and a pair of the second ECG sensor electrode 220 and the first stage amplifier unit 31 for the second ECG sensor electrode are electrodes. The unit 201 is unitized, and the electrode unit 201 adopts a structure that can move as described later.

  The output signal from the first stage amplifier unit 21 for the first ECG sensor electrode and the output signal from the first stage amplifier unit 31 for the second ECG sensor electrode are both output to the second stage amplifier unit 50, respectively. The second-stage amplifier unit 50 performs the second-stage amplification.

  The signals from the first-stage amplifier unit 21 for the first ECG sensor electrode and the first-stage amplifier unit 31 for the second ECG sensor electrode are the coaxial cable 25 for the first ECG sensor electrode and the second ECG sensor electrode, respectively. The coaxial cable 35 is transmitted to the second-stage amplifier unit 50, and the second-stage amplifier unit 50 performs the second-stage amplification. The amplified signal amplified by the second stage amplifier unit 50 is processed by a signal processing circuit (not shown) or the like. A signal processed by the signal processing circuit or the like is input from the electrocardiogram information acquisition unit 200 to the control processing unit 100 and used as information for determining the appropriateness of the biological signal, determining the health condition of the driver, and the like.

  Next, an amplification circuit of the heart rate sensor in the electrocardiogram information acquisition unit 200 of the biosensor will be described. Since the circuit configuration of the first stage amplifier is common to that for the first ECG sensor electrode 210 and that for the second ECG sensor electrode 220, only one circuit configuration is shown in FIG. ing. In FIG. 3, AMP1 to AMP3 are amplifiers, and C1 and C3 are capacitors.

  The capacitor C1 is interposed between the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220) and AMP1, and the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220), AMP1 and Are AC coupled (AC coupled). As a result, the offset signal generated in the signal input to the first stage amplifier section is removed. The output from the AMP2 is input to the AMP3 and fed back to the input of the AMP1 through the capacitor C3, thereby forming a bootstrap circuit. By these AMP1 and AMP2, the detection signal from the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220) can be amplified to about 1 mV with stable and low noise. AMP3 has an amplification factor of about several times, and the output signal of the first stage amplifier from AMP3 has a level of about several mV (for example, 2 mV).

  The output signal from the first-stage amplifier unit 21 for the first ECG sensor electrode (first-stage amplifier unit 31 for the second ECG sensor electrode) is amplified to about several times by the first-stage amplifier unit, and then described above. In this way, it is guided to the second stage amplifier section by the coaxial cable and amplified by several tens of times by the second stage amplifier section. Due to such a two-stage amplifier configuration, the configuration of the biological information acquisition apparatus of the present embodiment is an optimal configuration for mounting in a vehicle or the like.

  The circuit configuration of the second-stage amplifier section is common to the signal for the first ECG sensor electrode 210 and the signal for the second ECG sensor electrode 220. Only the configuration is shown.

  In FIG. 3, 51 indicates an amplifier, 52 indicates a high-pass filter, and 53 indicates a low-pass filter. The second-stage amplifier unit 50 is provided with an amplifier 51 that amplifies the signal from the first-stage amplifier unit on the order of several tens of times, and a high-pass filter 52 and a low-pass filter 53.

  The high-pass filter 52 and the low-pass filter 53 are provided to suppress signals of frequencies other than the frequency of the electrocardiogram waveform as much as possible. With these filters, the second-stage amplifier unit 50 selectively selects only the frequency related to the electrocardiogram. You can get it. The amplified signal amplified by the second-stage amplifier unit 50 is processed by a signal processing circuit (not shown) or the like and used as information acquired by the electrocardiogram information acquisition unit 200.

  Next, a pressure sensor provided in the biological information acquisition apparatus according to the embodiment of the present invention will be described with reference to FIGS. The electrocardiographic sensor, which is the biometric information acquisition apparatus of the present invention, measures information relating to the heart (heart rate / electrocardiogram) while wearing clothes as a state determination means for a driver or the like while driving a vehicle. A capacitive electrode is embedded in 10 and a weak electrocardiographic signal from the heart is acquired by this capacitive electrode.

  However, when biometric information is acquired by such a mechanism, there is a problem that measurement is impossible when the driver's back is away from the sheet in which the capacitive electrode is embedded. Also, even if the driver's back is touching a sheet with capacitive electrodes embedded, if the adhesion is low, static electricity, etc. will be noise, and accurate biological information cannot be acquired. As a result, the measured value such as the heart rate becomes wrong, and the state of the driver is erroneously determined.

  Therefore, the biometric information acquisition apparatus of the present invention employs a configuration for bringing the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220) into close contact with the driver's back. Hereinafter, the configuration for this will be described more specifically.

  FIG. 4 is a diagram showing an outline of a sheet adjustment mechanism in the biological information acquiring apparatus according to the embodiment of the present invention, and FIG. 5 is a transparent view of the sheet of the biological information acquiring apparatus according to the embodiment of the present invention from the front. FIG. 6 is a diagram showing an outline of an electrode unit of the biological information acquiring apparatus according to the embodiment of the present invention, and FIG. 7 is an electrode unit movable portion of the biological information acquiring apparatus according to the embodiment of the present invention. FIG. 8 is a diagram showing an outline of the airbag unit of the biological information acquiring apparatus according to the embodiment of the present invention.

  4 to 8, 10 is a sheet, 201 is an electrode unit, 202 is an electrode unit frame portion, 203 is an electrode unit X axis, 204 is an electrode unit X axis drive source, 205 is an electrode unit Y axis, and 206 is an electrode unit. Y-axis drive source, 210 is a first electrocardiographic sensor electrode, 220 is a second electrocardiographic sensor electrode, 230 is an electrode unit movable part, 231 is a first electrode pressure sensor, 232 is a second electrode pressure sensor, and 233 is a third electrode Electrode pressure sensor, 235 is a fifth electrode pressure sensor, 240 is an airbag unit, 241 is a first airbag cell, 242 is a second airbag cell, 243 is a third airbag cell, 244 is a fourth airbag cell, 245 is the fifth airbag cell, 246 is the sixth airbag cell, 247 is the seventh airbag cell, and 251 is the first airbag cell control. 252 is a second airbag cell control valve, 253 is a third airbag cell control valve, 254 is a fourth airbag cell control valve, 255 is a fifth airbag cell control valve, and 256 is a sixth airbag cell control valve Reference numeral 257 denotes a seventh airbag cell control valve, 261 denotes a seat-type back pressure distribution sensor, 262 denotes a seat-type seating surface pressure distribution sensor, 270 denotes a main airbag, and 271 denotes a main airbag control valve.

  As shown in FIGS. 4 and 5, on the back portion of the sheet 10, a pair of the first ECG sensor electrode 210 and the first-stage amplifier unit 21 for the first ECG sensor electrode, the second ECG sensor electrode 220, and As described above, an electrode unit 201 in which a pair of first-stage amplifier units 31 for the second electrocardiographic sensor electrode is arranged is provided, and an electrocardiogram signal is acquired by an electrode mounted on the electrode unit 201. It is as follows.

  In addition, a seat-type back pressure distribution sensor 261 is provided on the back portion (back portion) of the seat 10, and the load distribution between the seat related to the seat back portion and the driver's body is determined by the driver sitting. It can be measured. Similarly, a seat-type seating surface pressure distribution sensor 262 is provided on the seating surface portion of the seat 10 so that the load distribution between the seat related to the seating surface portion and the driver's body can be measured. It has become. The pressure distribution measured by these pressure distribution sensors is input to the control processing unit 100 and used for determination in the processing flow of the biological information acquisition apparatus of the present invention.

  A main airbag 270 is embedded in the seat back portion. The main airbag 270 is connected to an air pump (not shown) via a main airbag control valve 271, and is adjusted by the main airbag control valve 271, and receives supply of air from the air pump. ing. The main airbag control valve 271 opens and closes the valve in response to a control signal from the control processing unit 100. As the main airbag control valve 271 is opened and closed, the main airbag 270 can be inflated and contracted.

  As shown in FIG. 6, the electrode unit 201 mainly includes an electrode unit frame portion 202 and an electrode unit movable portion 230 that is displaced relative to the electrode unit frame portion 202. A pair of first ECG sensor electrode 210 (second ECG sensor electrode 220) and first ECG sensor electrode first-stage amplifier section 21 (second ECG sensor electrode first-stage amplifier section 31) is provided in section 230. Is installed.

  The electrode unit movable part 230 receives the driving force from the electrode unit X-axis drive source 204 and the electrode unit Y-axis drive source 206, and two-dimensionally displaces on the electrode unit X-axis 203 and the electrode unit Y-axis 205. It is like that. Any known mechanism for the displacement of the electrode unit movable part 230 can be used. Control signals from the control processing unit 100 are input to the electrode unit X-axis drive source 204 and the electrode unit Y-axis drive source 206, respectively, so that the drive of the drive source is turned on and off and the electrode unit movable unit 230 is displaced. It has become.

  FIG. 7 shows the electrode unit movable portion 230 in more detail. Four electrode pressure sensors, a first electrode pressure sensor 231 to a fourth electrode pressure sensor 234, are arranged at four corners of the upper surface portion of the first electrocardiogram sensor electrode 210 (second electrocardiogram sensor electrode 220). The pressure in the vicinity of the electric sensor electrode can be measured. The pressure values measured by the first electrode pressure sensor 231 to the fourth electrode pressure sensor 234 are input to the control processing unit 100 and used as determination material for determination processing. An airbag unit 240 is provided on the back surface of the first-stage amplifier unit 21 for the first ECG sensor electrode (the first-stage amplifier unit 31 for the second ECG sensor electrode).

  FIG. 8 is a view showing the airbag unit 240 in more detail. The airbag unit 240 is configured as an aggregate of seven airbag cells, the first airbag cell 241 to the seventh airbag cell 247. In the present embodiment, the airbag unit 240 is configured by seven airbag cells, but the present invention is not limited to this.

  The first airbag cell 241 to the seventh airbag cell 247 are connected to an air pump (not shown) via a main airbag control valve 271 to control the first airbag cell control valve 251 to the seventh airbag cell. While being adjusted by the valve 257, the supply of air is received from the air pump. The first airbag cell control valve 251 to the seventh airbag cell control valve 257 are configured to open and close the valves in response to a control signal from the control processing unit 100. As the first airbag cell control valve 251 to the seventh airbag cell control valve 257 are opened and closed, each of the first airbag cell 241 to the seventh airbag cell 247 can be expanded and contracted independently. It has become.

  Next, the operation | movement as the whole biometric information acquisition apparatus of this invention is demonstrated. FIG. 9 is a diagram showing an outline of a block configuration of the biological information acquisition apparatus according to the embodiment of the present invention. As shown in FIG. 9, the biological information acquisition apparatus according to the present embodiment mainly includes a control processing unit 100, an electrocardiogram information acquisition unit 200, an electrode unit 201, a main inflator 270, a driver posture detection unit 450, and a determination result output. A unit 600 and a storage unit 900.

  In the biological information acquisition apparatus of this embodiment, the electrical signals acquired by the first electrocardiogram sensor electrode 210 and the second electrocardiogram sensor electrode 220 in the electrocardiogram information acquisition unit 200 are the pressures detected by the driver posture detection unit 450. Based on the distribution and the like, it is determined whether or not it is appropriate for grasping the driver's condition. The determination of the pressure value for this purpose is executed by the control processing unit 100. Further, the driver status and the like ascertained by the control processing unit 100 are output from the determination result output unit 600 and the like.

  In the block diagram of the biometric information acquisition apparatus of this embodiment shown in FIG. 4, the control processing unit 100 is an electronic control unit, and includes a CPU, a ROM that holds a program operating on the CPU, a RAM that is a work area of the CPU, and the like. It is a general-purpose information processing mechanism.

  The electrocardiogram information acquisition unit 200 includes first and second electrocardiographic sensor electrodes 210 and 220 and an amplification unit that amplifies a weak current collected from these electrodes, and sits in the driver's seat 10 to operate a steering wheel. The heart rate and electrocardiogram data (electrocardiogram signal), which are information related to the driver's heart, are acquired.

  The driver posture detection unit 450 detects the driver's mind based on the sensing results of the seat-type back pressure distribution sensor 261 provided on the driver back portion of the seat 10 and the seat-type seat pressure distribution sensor 262 provided on the seat surface portion. This is to detect whether or not the vehicle is in the correct position for acquiring the electric signal.

  The main airbag control valve 271 that has received the control signal from the control processing unit 100 performs expansion and contraction of the main airbag 270 by opening and closing to control the supply amount of air from the air pump.

  The pressure values measured by the first electrode pressure sensor 231 to the fourth electrode pressure sensor 234 of the electrode unit 201 are input to the control processing unit 100 and used for determination in the algorithm.

  The first airbag cell control valve 251 through the seventh airbag cell control valve 257 that have received the control signal from the control processing unit 100 are opened and closed to control the supply amount of air from the air pump. The 1 airbag cell 241 to the 7th airbag cell 247 are expanded and contracted.

  Further, upon receiving a control signal from the control processing unit 100, the electrode unit X-axis drive source 204 and the electrode unit Y-axis drive source 206 of the electrode unit 201 are driven to displace the electrode unit movable unit 230 in the XY two-dimensional direction. .

  The determination result output unit 600 constitutes an output interface in the biological information acquisition apparatus, and includes a display 610 that displays characters, graphics, and image information, and a speaker 620 that outputs sound. The determination result output unit 600 is not limited to the above configuration, and other man-machine interface mechanisms can be used.

  The storage unit 900 is composed of a relatively large-capacity storage device such as a hard disk, and stores programs executed by the control processing unit 100 and parameters used. In addition, such a storage unit 900 stores personal information files of individual drivers. This personal information file is a personal information file for each driver who uses the vehicle. The personal information is the basic information of biometric information that each driver can have (average heart rate (learning from past history), heart rate determination threshold, Medical history, doctor contact information). Such a personal information file can be used to determine whether or not the acquired electrocardiogram signal is appropriate.

  Next, a flow for obtaining biological information will be described. FIG. 10 is a diagram showing a flowchart of the biological signal acquisition process in the biological information acquisition apparatus according to the embodiment of the present invention. This flowchart can be positioned as a subroutine for various other processes executed by the control processing unit 100.

  In FIG. 10, when the electrocardiogram signal acquisition process is started in step S100, it is subsequently determined in step S101 whether or not the driver is seated based on the pressure distribution measured by the seat-type seating surface pressure distribution sensor 262. . When the result of determination in step S101 is YES, the process proceeds to step S102, and when it is NO, the process returns to step S101.

  In step S102, the body shape / attitude of the driver is detected based on the pressure distribution from the back surface of the driver measured by the seat-type back surface pressure distribution sensor 261.

  In step S103, the position of the driver's heart is estimated based on the measured pressure distribution on the back surface of the driver. It is also effective to store a database for each driver in the storage unit 900 in order to estimate the position of the heart of the driver.

  In step S104, the sheet 10 is deformed in accordance with the body shape and posture of the driver. At this time, the control processing unit 100 controls the main airbag control valve 271 to expand and contract the main airbag 270.

  In step S105, a sensor position correction subroutine is executed.

  In S106, it is determined whether or not the driver is seated based on the pressure distribution generated between the body of the driver and the skin portion of the seat measured by the seat-type seating surface pressure distribution sensor 262. When the result of the determination in step S106 is YES, the process proceeds to step S107, and when it is NO, the process returns to step S106.

  In step S107, the process ends.

  Step S200 and subsequent steps show a flowchart of the sensor position correction subroutine. When the sensor position correction subroutine is started in step S200, the process proceeds to step S201, and the pressure distribution is measured by the sheet-type back pressure distribution sensor 261. Next, in step S202, the sheet-type back pressure distribution sensor 261 determines whether or not the amount of change in pressure distribution is greater than a predetermined reference. This step is a step for checking whether any problem is caused by inflating the air bag.

  When the determination result in step S202 is YES, the process proceeds to step S102 of the main routine. When the determination result in step S202 is NO, the process proceeds to step S203.

  In step S203, the first electrode pressure sensor 231 to the fourth electrode pressure sensor 234 measure the pressure around the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220).

  In step S204, with reference to the pressure measured in step S203, the electrode unit movable unit 230 is displaced and moved by driving the electrode unit X-axis drive source 204 and the electrode unit Y-axis drive source 206, and the electrocardiogram signal. The first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220) is arranged at an appropriate position for acquisition.

  In step S205, it is determined whether or not the distribution of pressure values acquired by each of the first electrode pressure sensor 231 to the fourth electrode pressure sensor 234 is greater than or equal to a reference value. When the determination in step S205 is YES, the process proceeds to step S206, and when the determination in step S205 is NO, the process proceeds to step S104 of the main routine.

  In step S206, driving of the electrode unit X-axis drive source 204 and the electrode unit Y-axis drive source 206 is stopped, and the position of the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220) is fixed. This is to prevent the electrocardiographic sensor electrode from sliding with the main airbag 270 (no friction).

  In step S207, a process for acquiring an electrocardiogram signal is executed, and the process returns in step S208.

  According to the operation of the biometric information acquisition apparatus as described above, the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor) is placed on the driver's back by the expansion / contraction operation of the main airbag 270 according to the body shape / attitude of the driver. The electrode 220) can be brought into close contact with each other, and the first electrocardiographic sensor electrode 210 (locally) depending on the pressure distribution obtained by each of the first electrode pressure sensor 231 to the fourth electrode pressure sensor 234. The position of the second electrocardiographic sensor electrode 220) is controlled so as to acquire an electrocardiographic signal, so that biological information such as electrocardiographic information related to the driver can be reliably acquired, and the biological body of the driver It becomes possible to grasp the state accurately.

  The sheet adjustment mechanism of the biological information acquisition apparatus that operates based on the algorithm as described above will be schematically illustrated. FIG. 11 is a diagram showing the operation of the sheet adjustment mechanism in the biological information acquisition apparatus according to the embodiment of the present invention.

  FIG. 11A shows an ideal state in which the biological information acquisition apparatus acquires an electrocardiogram signal in a state where the driver's back is in close contact with the sheet 10. On the other hand, FIG. 11B shows a case where the driver's back is separated from the seat 10. In such a situation, the body type / posture measured by the seat-type back pressure distribution sensor 261 is an electrocardiogram signal. The control processing unit 100 inflates the main airbag 270 by controlling the main airbag control valve 271. FIG. 11C shows a state where the back of the driver is in close contact with the seat 10 due to the expansion of the main airbag 270. In the biological information acquisition apparatus of the present embodiment, the electrode unit movable unit 230 is further moved after the state shown in FIG. 11C, and the optimal position of the first electrocardiographic sensor electrode 210 (second electrocardiographic sensor electrode 220). Then, it is controlled to acquire an electrocardiogram signal. For this reason, an electrocardiographic signal relating to the driver can be reliably acquired, and the biological information of the driver is not erroneously determined.

It is a figure which shows the structure outline for the electrocardiogram signal acquisition in the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the electrical connection for the electrocardiogram signal acquisition in the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the principal part of the circuit structure of the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the sheet | seat adjustment mechanism outline in the biometric information acquisition apparatus which concerns on embodiment of this invention. It is the figure which looked at the sheet | seat of the biometric information acquisition apparatus which concerns on embodiment of this invention transparently from the front. It is a figure which shows the outline of the electrode unit of the biological information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the outline of the electrode unit movable part of the biological information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the outline of the airbag unit of the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the outline of a block structure of the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows the flowchart of the biometric signal acquisition process in the biometric information acquisition apparatus which concerns on embodiment of this invention. It is a figure which shows operation | movement of the sheet | seat adjustment mechanism in the biometric information acquisition apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Driver's seat, 21 ... First stage amplifier for first electrode, 25 ... Coaxial cable for first ECG sensor electrode, 31 ... First stage amplifier for second ECG sensor electrode , 35 ... Coaxial cable for second electrocardiographic sensor electrode, 40 ... Ground electrode, 45 ... Ground cable, 50 ... Second stage amplifier, 51 ... Amplifier, 52 ... High pass filter 53 53 Low pass filter 100 Control processing unit 200 Electrocardiogram information acquisition unit 201 Electrode unit 202 Electrode unit frame unit 203 Electrode Unit X-axis, 204 ... Electrode unit X-axis drive source, 205 ... Electrode unit Y-axis, 206 ... Electrode unit Y-axis drive source, 210 ... First electrocardiographic sensor electrode, 220 ... Second electrocardiographic sensor electrode, 23 ... Electrode unit movable part, 231 ... first electrode pressure sensor, 232 ... second electrode pressure sensor, 233 ... third electrode pressure sensor, 235 ... fifth electrode pressure sensor, 240 ..Airbag unit, 241 ... first airbag cell, 242 ... second airbag cell, 243 ... third airbag cell, 244 ... fourth airbag cell, 245 ... 5th airbag cell, 246 ... 6th airbag cell, 247 ... 7th airbag cell, 251 ... 1st airbag cell control valve, 252 ... 2nd airbag cell control valve, 253 ... Third airbag cell control valve, 254 ... Fourth airbag cell control valve, 255 ... Fifth airbag cell control valve, 256 ... Sixth airbag cell control valve 257 ... seventh air bag cell control valve, 261 ... seat type back surface pressure distribution sensor, 262 ... seat type seat surface pressure distribution sensor, 270 ... main airbag, 271 ... main Airbag control valve, 450 ... Driver posture detection unit, 600 ... Determination result output unit, 610 ... Display, 620 ... Speaker, 900 ... Storage unit

Claims (1)

A biological information acquisition device that is mounted on a seat part, detects an electrical signal related to a living body in a non-invasive manner, and determines the state of the living body based on the detected electrical signal,
An electrode mounted inside the seat;
A main airbag that is provided inside the seat and displaces the electrode by expanding and contracting; and
A pressure sensor provided in the vicinity of the electrode;
A measured pressure value applied to the seat measured by the pressure sensor is input, and the inflation and deflation of the main airbag is controlled, and the living state is determined based on the electrical signal detected by the electrode. A control processing unit,
The control processing unit acquires an electrical signal detected by the electrode after inflating and contracting the main airbag according to a measured pressure value measured by the pressure sensor. apparatus.

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