Pulse wave sensor and pulse rate detector

• US 20020188210A1
• Filed: 05/23/2002
• Published: 12/12/2002
• Est. Priority Date: 06/11/2001
• Status: Abandoned Application

• Current Assignee: Watex Co., Ltd.
• Original Assignee: Watex Co., Ltd.
• Inventors: Aizawa, Nobuyuki
• Application Number:
  US10/152,818
• Publication Number:
  US 20020188210A1
• Time in Patent Office: Days
• US Class Current: 600/503
• CPC Class Codes: A61B 5/02433 for infrared radiation
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient

Abstract

A pulse wave sensor for detecting a pulse wave by detecting light output from a light emitting diode and reflected from the artery of a wrist of a subject, the sensor comprising four photodetectors disposed around the light emitting diode symmetrically on a circle concentric to the light emitting diode, and a pulse rate detector comprising the pulse wave sensor and means of computing the pulse rate of a subject based on the output of the pulse wave sensor.

Claims

1. A pulse wave sensor for detecting a pulse wave by detecting light output from a light emitting diode and reflected from the artery of a wrist of a subject, the sensor comprising at least three photodetectors disposed around the light emitting diode.

2. The pulse wave sensor of claim 1, wherein a near infrared LED is used as the light emitting diode.

3. The pulse wave sensor of claim 1, wherein the photodetectors are disposed at an equal distance from the light emitting diode.

4. The pulse sensor of claim 1, wherein cavities are formed in a contact face between a holder for holding the light emitting diode and the photodetectors and the wrist, the light emitting face of the light emitting diode and the light receiving faces of the photodetectors are disposed at respective predetermined distances from the contact face, and the sectional forms of the cavities are tapered such that their widths increase toward the contact face.

5. The pulse wave sensor of claim 1, wherein a transparent plate-like member is provided on a portion including at least the light emitting face and the light receiving faces of the contact face.

6. A pulse rate detector comprising the pulse wave sensor of claim 1 and means of computing the pulse rate of a subject based on the output of the pulse wave sensor.

7. The pulse rate detector of claim 6 which comprises a transmitter for transmitting the measured pulse rate data.