Patient monitoring finger ring sensor

• US 5,964,701 A
• Filed: 10/24/1997
• Issued: 10/12/1999
• Est. Priority Date: 10/24/1996
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Chang, Kuo Wei, Siu, Kai-Yeung Sunny, Asada, Haruhiko H., Yang, Boo-Ho
• Primary Examiner(s): Nasser, Robert L.
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US08/957,789
• Time in Patent Office: 718 Days
• Field of Search: 128/903, 600/300, 600/301, 600/322, 600/483, 600/561, 600/549
• US Class Current: 600/300
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A monitoring system for monitoring the health status of a patient and transmitting to a remote receiver a signal, based on measured physiological parameters. A sensor is incorporated in a finger ring or other article of apparel so as to monitor skin temperature, blood flow, blood constituent concentration, or pulse rate of the patient. The data are encoded for wireless transmission by mapping a numerical value associated with each datum to a pulse emitted after a delay of a specified duration following a fiducial time. Multiple ring bands and sensor elements may be employed for deriving three-dimensional dynamic characteristics of arteries and tissue of the finger.

Claims

1. A monitoring system for monitoring the health status of a patient, comprising:

a. a finger ring to be worn by the patient, the finger ring comprising;

i. at least one sensor for providing a signal based on at least one of skin temperature, blood flow, blood constituent concentration, and pulse rate of the patient;

ii. a transmitter for converting the signal to a wave; and

iii an accelerometer disposed within the finger ring for removing signal artifacts due to finger motion;

b. at least one receiver for receiving the wave from the finger ring; and

c. a controller for analyzing the wave and determining an abnormal health status.

2. A monitoring system according to claim 1, wherein the controller further includes a means for determining the location of the patient.

3. A monitoring system according to claim 1, wherein the wave is a radio wave.

4. A monitoring system according to claim 1, wherein the wave is a light wave.

5. A monitoring system according to claim 1, wherein the wave is an ultrasound wave.

6. A monitoring system according to claim 1, wherein the sensor includes a temperature sensor for measuring skin temperature.

7. A monitoring system according to claim 1, wherein the sensor includes an optical sensor for measuring at least one of the blood flow, blood constituent concentration, and pulse rate of the patient.

8. A monitoring system according to claim 7, wherein the optical sensor comprises a modulated source and synchronous detector.

9. A monitoring system according to claim 7, wherein the sensor comprises an optical source and an optical detector.

10. A monitoring system according to claim 9, wherein the optical source has a wavelength substantially corresponding to the isobestic point of hemoglobin and oxygenated hemoglobin.

11. A monitoring system according to claim 9, wherein the optical source is a light emitting diode.

12. A monitoring system according to claim 7, wherein the optical sensor comprises a plurality of optical sources employing temporal and spatial modulation.

13. A monitoring system according to claim 1, wherein the at least one sensor is an electrical impedance plethysmograph.

14. A monitoring system for monitoring the health status of a patient, comprising:

a. a monitor having a first and a second band to be worn by the patient on a single finger, the monitor comprising;

i. at least one sensor disposed on the first band for providing a first signal based on at least one of skin temperature, blood flow, blood constituent concentration, and pulse rate of the patient;

ii. at least one sensor disposed on the second band for providing a second signal based on at least one of skin temperature, blood flow, blood constituent concentration, and pulse rate of the patient; and

b. a controller for analyzing the first and second signals and determining a physiological characteristic of the patient.

15. A monitoring system according to claim 14, wherein the physiological characteristic is one of the group of arterial blood flow, hematocrit, and blood oxygen saturation.

16. A monitoring system according to claim 14, further comprising:

a. a transmitter for converting the first and second signals to a wave; and

b. at least one receiver for receiving the wave from the monitor.