PULSE WAVE MEASUREMENT APPARATUS AND PROGRAM

• US 20130204143A1
• Filed: 01/07/2013
• Published: 08/08/2013
• Est. Priority Date: 02/02/2012
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: NARUSAWA, Atsushi
• Application Number:
  US13/735,492
• Publication Number:
  US 20130204143A1
• Time in Patent Office: Days
• US Class Current: 600/479
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

A pulse wave measurement apparatus includes a light emitting device that applies light to a measurement position at which a pulse wave is measured, and a plurality of light receiving devices that output measurement signals based on the amount of received light which is applied from the light emitting device and is reflected from the measurement position. The control unit of the pulse wave measurement apparatus performs the independent component analysis on the measurement signals output from the plurality of light receiving devices, and calculates the weighting factors of each component when each of the measurement signals is divided into a plurality of components. The control unit calculates the dispersion of the calculated weighting factors for each component, and specifies a component in which the calculated dispersion is the smallest. The control unit generates pulse wave information indicative of the pulse wave based on the specified component.

Claims

1. A pulse wave measurement apparatus comprising:

a plurality of light receiving units that output measurement signals each indicative of a received amount of light which is irradiated to a measurement position where pulse waves are measured and passes through or is reflected from the measurement position;

an independent component analysis unit that performs an independent component analysis on the measurement signals which are output from the plurality of light receiving units, divides each of the measurement signals into a plurality of components, and calculates weighting factors of each of the plurality of components;

a dispersion calculation unit that calculates a value indicative of a degree of dispersion of values of the weighting factors which are calculated by the independent component analysis unit for each of the plurality of components;

a component specification unit that specifies a component of the plurality of components whose value indicative of the degree of dispersion calculated by the dispersion calculation unit satisfies a predetermined condition; and

a pulse wave information generation unit that generates pulse wave information indicative of the pulse waves using the component specified by the component specification unit.

2. The pulse wave measurement apparatus according to claim 1,

wherein the pulse wave information generation unit extracts the component specified by the component specification unit by performing an operation using the weighting factors calculated by the independent component analysis unit on the measurement signals which are output from the plurality of light receiving units, and generates the pulse wave information indicative of the pulse waves based on the extracted component.

3. The pulse wave measurement apparatus according to claim 2,

wherein the component specification unit specifies a component whose value indicative of the degree of dispersion calculated by the dispersion calculation unit is the smallest.

4. The pulse wave measurement apparatus according to claim 2,

wherein the component specification unit specifies a component whose value indicative of the degree of dispersion calculated by the dispersion calculation unit is within a predetermined range.

5. The pulse wave measurement apparatus according to claim 2,

wherein, when the plurality of components are specified by the component specification unit, the pulse wave information generation unit generates the plurality of specified components, and generates the pulse wave information based on the sum of the plurality of generated components.

6. The pulse wave measurement apparatus according to claim 1, further comprising:

a measurement signal specification unit that specifies a measurement signal whose value of the weighting factor of the component specified by the component specification unit satisfies the predetermined condition from among the measurement signals output from the plurality of light receiving units,

wherein the pulse wave information generation unit generates the pulse wave information indicative of the pulse waves based on the measurement signal specified by the measurement signal specification unit.

7. The pulse wave measurement apparatus according to claim 6,

wherein the component specification unit specifies a component whose value indicative of the degree of dispersion calculated by the dispersion calculation unit is greatest.

8. The pulse wave measurement apparatus according to claim 7,

wherein the measurement signal specification unit specifies a measurement signal whose value of the weighting factor of the component specified by the component specification unit is smallest.

9. The pulse wave measurement apparatus according to claim 6,

wherein the pulse wave information generation unit removes the component specified by the component specification unit from the measurement signal specified by the measurement signal specification unit, and generates the pulse wave information based on the measurement signal from which the component is removed.

10. A program causing a computer to perform:

receiving measurement signals from a plurality of light receiving units that output the measurement signals each indicative of a received amount of light which is irradiated to a measurement position where pulse waves are measured, and passes through or is reflected from the measurement positions;

performing an independent component analysis on the measurement signals which are output from the plurality of light receiving units, dividing each of the measurement signals into a plurality of components, and calculating weighting factors of each of the plurality of components;

calculating a dispersion value indicative of a degree of dispersion of values of the weighting factors which are calculated in the independent component analysis for each of the plurality of components;

specifying a component of the plurality of components whose value indicative of the degree of dispersion calculated in the calculating of the dispersion value satisfies a predetermined condition; and

generating pulse wave information indicative of the pulse waves using the component specified in the specifying of the component.