End device

• US 20070088225A1
• Filed: 07/21/2006
• Published: 04/19/2007
• Est. Priority Date: 10/17/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamashita, Shunzo, Ono, Goichi, Tanaka, Takeshi
• Application Number:
  US11/490,180
• Publication Number:
  US 20070088225A1
• Time in Patent Office: Days
• US Class Current: 600/503
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/681 Wristwatch-type devices

Abstract

An end device attachable to the body and containing a heartbeat detector capable of low-power operation. The end device includes a light receiver element and current-to-voltage converter and an amplifier to amplify the output voltage from the current-to-voltage converter and a microcomputer; and the electrical current flowing in the light receiver element from which a specified current is subtracted, is input to the current-to-voltage converter, and the microcomputer CPU detects the heartbeat based on the signal from the amplifier.

Claims

1. An end device attachable to the body comprising:

a light emitter element;

a light receiver element to receive scattered light and reflected light from the light emitter element, and convert that light into an electrical current according to intensity of the received light;

a current-to-voltage converter circuit;

an amplifier circuit for amplifying the output voltage from the current-to-voltage converter circuit; and

a microcomputer,

wherein the current-to-voltage converter circuit is input with an electrical current flowing in the light receiver element from which a specified current is subtracted, and

the microcomputer then detects the heartbeat based on the signal from the amplifier circuit.

2. An end device according to claim 1, wherein a specified amount of current is set based on the amount of current flowing when the light receiver element receives scattered light and reflected light emitted from the light emitter element, before the operation to detect the heartbeat by a microcomputer in a terminal attached to the body.

3. An end device according to claim 2, wherein a specified amount of current is rewritten based on the amount of current flowing when the light receiver element receives scattered light and reflected light emitted from the light emitter element, during the heartbeat detection operation by the microcomputer in a terminal attached to the body.

4. An end device according to claim 1, including a wristband, wherein the end device is attachable to the arm of a human body by the wristband.

5. An end device according to claim 1, wherein

the microcomputer includes a first operating mode and a second operating mode,

the first operating mode operates at a higher frequency than the second operating mode, and

the microcomputer operates the second operating mode for controlling the light emitter element and reading the signal from the amplifier circuit, and operates the first operating mode to detect the heartbeat based on the signal from the amplifier circuit.

6. An end device according to claim 1, wherein

the light emitting element includes multiple light emitting sources, and

the multiple light emitting sources are all capable of emitting infrared light on the same wavelength.

7. An end device according to claim 1, including a wireless communication device, wherein the wireless communication device transfers the detected heartbeat information to the server.