Invasive FTIR blood constituent testing

• US 5,079,421 A
• Filed: 12/04/1990
• Issued: 01/07/1992
• Est. Priority Date: 04/19/1990
• Status: Expired due to Fees

• Current Assignee: Integ Incorporated (Johnson & Johnson)
• Original Assignee: Inomet, Inc.
• Inventors: Knudson, Mark B., Shapland, James E.
• Primary Examiner(s): Fields, Carolyn E.
• Assistant Examiner(s): BEYER, JAMES
• Application Number:
  US07/621,823
• Time in Patent Office: 399 Days
• Field of Search: 356/39, 356/346, 250/343, 128/634, 128/633, 128/664
• US Class Current: 250/343
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/6817 Ear canal

Abstract

An apparatus is disclosed for measuring a blood constituent. In a preferred embodiment, the apparatus includes a semipermeable membrane for defining a volume with a flexible membrane disposed on one end and with a light source disposed on an opposite end. The flexible membrane flexes to become the moving mirror in an FTIR system.

Claims

1. An apparatus for determining a level of a constituent in a body fluid contained within a body tissue, said apparatus comprising:

volume defining means for defining a bounded volume containing said body fluid, said volume defining means sized to be received within an anatomical space and having means to admit said fluid from said space into said bounded volume;

a light source extending into said bounded volume for directing a test beam through said fluid within said volume;

a flexible membrane disposed within said volume and disposed to reflect said test beam, said flexible membrane selectively movable within said bounded volume when said volume defining means is received within said space.

2. An apparatus according to claim 1 wherein said volume defining means includes a semipermeable membrane having first and second ends;

said light source including a light wave guide disposed within said first end;

said flexible membrane disposed on said second end.

3. An apparatus for determining a level of a constituent in a body fluid contained within a body tissue, said apparatus comprising:

volume defining means for defining a bounded volume containing said body fluid, said volume defining means including a semipermeable membrane having first and second ends;

a light source extending into said bounded volume for directing a test beam through said fluid within said volume, said light source including a light wave guide disposed within said first end;

a flexible membrane disposed within said volume on said second end and disposed to reflect said test beam, said flexible membrane being a piezoelectric film flexible in response to a change in a charge across said membrane.

4. An apparatus for determining a level of a constituent in a body fluid contained within a body tissue, said apparatus comprising:

volume defining means for defining a bounded volume containing said body fluid, said volume defining means including a semipermeable membrane having first and second ends;

a light source extending into said bounded volume for directing a test beam through said fluid within said volume, said light source including a light wave guide disposed within said first end;

a flexible membrane disposed within said volume on said second end and disposed to reflect said test beam, said flexible membrane selected to be flexible in response to an application of energy on said membrane.

5. An apparatus for determining a level of a constituent in a body fluid contained within a body tissue, said apparatus comprising:

volume defining means for defining a bounded volume containing said body fluid;

a light source extending into said bounded volume for directing a test beam through said fluid within said volume;

a flexible membrane disposed within said volume and disposed to reflect said test beam;

said volume defining means, said light source and said flexible membrane are included in a Fourier transform infrared spectrometric system with said flexible membrane being a moving mirror in said system.