Heartbeat detecting apparatus

• US 8,082,026 B2
• Filed: 09/05/2007
• Issued: 12/20/2011
• Est. Priority Date: 09/28/2006
• Status: Expired due to Fees

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Ando, Mitsuhiro, Kogure, Shunsuke, Imamura, Ayako
• Primary Examiner(s): Evanisko, George
• Assistant Examiner(s): Fairchild, Mallika
• Application Number:
  US12/441,071
• Publication Number:
  US 20100056937A1
• Time in Patent Office: 1,567 Days
• Field of Search: 340/573, 340/575, 340/576, 600/508, 600/509, 600/527
• US Class Current: 600/509
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0255 Recording instruments specially adapted therefor
• CPC Class Codes: A61B 5/6887 mounted on external non-worn devices, e.g. non-medical devices
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60N 2/0022 for sensing anthropometric parameters, e.g. heart rate or body temperature
• CPC Class Codes: B60N 2/0026 for distinguishing between humans, animals or objects
• CPC Class Codes: B60N 2/003 characterised by the sensor mounting location in or on the seat
• CPC Class Codes: B60N 2/0035 characterised by the sensor data transmission, e.g. wired connections or wireless transmitters therefor; characterised by the sensor data processing, e.g. seat sensor signal amplification or electric circuits for providing seat sensor information
• CPC Class Codes: B60N 2230/30 Signal processing of sensor data
• CPC Class Codes: B60W 2540/22 Psychological state; Stress level or workload
• CPC Class Codes: B60W 2540/221 Physiology, e.g. weight, heartbeat, health or special needs

Abstract

A heart beat sensor (10) comprises signal processing means (15) for performing frequency analysis of the output signal of a piezoelectric sensor (1) installed in a seat (2) and judging means (16) judges on the basis of the results of the frequency analysis that if the amplitude of the signal component in a first preset frequency range included in the output signal is in a preset amplitude range, the signal component includes a human body seating waveform indicating a person is seated in the seat (2).

Claims

1. A heartbeat detecting apparatus comprising:

a plurality of piezoelectric sensors providing output signals;

a seat containing the plurality of piezoelectric sensors;

each output signal including a signal component;

a signal processing device that executes a frequency analysis separately on the respective output signals to provide a result; and

a determining device that

determines that the signal component of each of two or more of the output signals includes a waveform of a seated person indicating that a person is seated on the seat, based on the result of the frequency analysis, when the signal component exists within a first predetermined frequency range and within a predetermined amplitude range,

determines that the signal component of each of the two or more output signals is a potential heartbeat signal when the signal component exists within a second predetermined frequency range and during a predetermined time frame, and

determines that at least one of the potential heartbeat signals is a heartbeat signal of a person when the signal component of each of the two or more of the output signals includes a waveform of a seated person and is determined to be a potential heartbeat signal.

2. The heartbeat detecting apparatus according to claim 1, further comprising:

a filter portion eliminating another signal component, existing within a frequency range of a vehicle vibration, from the output signals of the piezoelectric sensors.

3. A heartbeat detecting apparatus comprising:

a plurality of piezoelectric sensors providing output signals;

a seat containing the plurality of piezoelectric sensors;

each output signal including a signal component;

a signal processing device that executes a frequency analysis separately on the respective output signals to provide a result; and

a determining device that

determines that the signal component of each of two or more of the output signals include a waveform of a seated person indicating that a person is seated on the seat, based on a result of the frequency analysis,

determines that the signal component of each of two or more of the output signals is a potential heartbeat signal when the signal component exists within a predetermined frequency range and during a predetermined time frame, and

determines that at least one of the potential heartbeat signals is a heartbeat signal of a person when the signal components of each of the two or more of the output signals includes a waveform of a seated person and are determined to be potential heartbeat signals.

4. The heartbeat detecting apparatus according to claim 3, further comprising:

a filter portion eliminating another signal component, existing within a frequency range of a vehicle vibration, from the output signals of the piezoelectric sensors.

5. A heartbeat detecting apparatus comprising:

a first piezoelectric sensor and a second piezoelectric sensor providing a first output signal and a second output signal, respectively;

a seat containing the first piezoelectric sensor and the second piezoelectric sensor;

the first output signal including a first signal component, and the second output signal including a second output component;

a signal processing device that executes a frequency analysis separately on the respective output signals to provide a result; and

a determining device determines that a first potential heartbeat signal is a heartbeat signal of the human body when

based on the result of the frequency analysis, each of the first signal component and the second signal component includes a waveform that exists within a first predetermined frequency range and within a predetermined amplitude range indicative that a person is seated on the seat, and

the second potential heartbeat signal extracted from the second signal component, which exists within a second predetermined frequency range, exists during a predetermined time frame before or after a peak time of the first potential heartbeat signal, which is extracted from the first signal component and exists within the second predetermined frequency range.

6. The heartbeat detecting apparatus according to claim 5, further comprising:

a filter portion eliminating another signal component, existing within a frequency range of a vehicle vibration, from the output signals of the piezoelectric sensors.

7. A heartbeat detecting apparatus comprising:

a first piezoelectric sensor and a second piezoelectric sensor providing a first output signal and a second output signal, respectively;

a seat containing the first piezoelectric sensor and the second piezoelectric sensor;

the first output signal including a first signal component, and the second output signal including a second output component;

a signal processing device that executes a frequency analysis separately on the respective output signals to provide a result; and

a determining device determines that a second potential heartbeat signal is a heartbeat signal of the human body when

based on the result of the frequency analysis, each of the first signal component and the second signal component includes a waveform that exists within a first predetermined frequency range and within a predetermined amplitude range indicative that a person is seated on the seat, and

the second potential heartbeat signal extracted from the second signal component, which exists within a second predetermined frequency range, exists during a predetermined time frame before or after a peak time of the first potential heartbeat signal, which is extracted from the first signal component and exists within the second predetermined frequency range.

8. The heartbeat detecting apparatus according to claim 7, further comprising:

a filter portion eliminating another signal component, existing within a frequency range of a vehicle vibration, from the output signals of the piezoelectric sensors.

9. A heartbeat detecting apparatus comprising:

a plurality of piezoelectric sensors providing output signals;

a seat containing the plurality of piezoelectric sensors;

each output signal including a signal component;

a signal processing device that executes a frequency analysis separately on the respective output signals; and

a determining device that

determines that the signal component of each of two or more of the output signals includes a waveform of a seated person indicating that a person is seated on the seat, based on the result of the frequency analysis, when the signal component exists within a first predetermined frequency range and within a predetermined amplitude range,

determines that the signal component of each of the two or more output signals is a potential heartbeat signal when the signal component exists within a second predetermined frequency range and during a predetermined time frame,

determines that each of the potential heartbeat signals is a heartbeat signal of a person when the signal components of each of the two or more of the output signals includes a waveform of a seated person and are determined to be potential heartbeat signals;

provides a point to a base piezoelectric sensor and to another piezoelectric sensor whenever the heartbeat signal detected by the other piezoelectric sensor exists during a predetermined time frame before or after a peak time of the heartbeat signal detected by the base piezoelectric sensor, so that points are accumulated by each of the piezoelectric sensors, and

outputs the heartbeat signal of the of the piezoelectric sensor in which the highest number of points is accumulated.

10. The heartbeat detecting apparatus according to claim 9, further comprising:

a filter portion eliminating another signal component, existing within a frequency range of a vehicle vibration, from the output signals of the piezoelectric sensors.