Blood constituent measuring apparatus

• US 5,417,206 A
• Filed: 10/21/1993
• Issued: 05/23/1995
• Est. Priority Date: 10/26/1992
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kaneyoshi, Akio
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US08/139,015
• Time in Patent Office: 579 Days
• Field of Search: 128/760, 128/771, 128/632, 128/637, 604/313
• US Class Current: 600/573
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/441 Skin evaluation, e.g. for skin disorder diagnosis
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K

Abstract

A sampling cell (1) sucks body fluid, which is suction effusion fluid (SEF), into a passage by decompressive suction. At this time, the inside of the passage is under reduced pressure and accordingly the SEF contains a large amount of bubbles of oxygen and other gases. When, in this state, first opening/closing means (20, 21) provided in part of the passage are closed and third opening/closing means (25) is opened to bring the passage filled with the SEF into communication with the atmosphere, the gases contained in the SEF are discharged into the atmosphere. After that, the SEF in the passage, cleared of the gases, is supplied together with buffer solution to measuring means (7). Therefore, the SEF to be fed to the measuring means (7) can be supplied always in a fixed quantity.

Claims

1. A blood constituent measuring apparatus for measuring blood constituents in suction effusion fluid (SEF) obtained from the surface of skin deprived of the Keratinous layer, comprising:

a sampling cell having a head which is brought in close contact with the skin during operation of said blood constituent measuring apparatus, an accumulating member which has a passage connected to said head to accumulate the SEF obtained by sucking the surface of the skin in a decompressed state via said head, and a tube which is connected to said passage and is used to generate said decompressed state;

a first valve which is deposed between said head and said accumulating member;

a second valve which is connected along said tube;

a third valve which is connected to said tube between said accumulating member and said second valve for discharging gas contained in the SEF accumulated in said passage through said third valve into a decompressed atmosphere; and

measuring means for measuring a blood constituent in the SEF accumulated in said passage by combining the SEF with a buffer solution;

wherein said first and second valves open and said third valve closes while the SEF is sucked from the skin in said decompressed state, and said first and second valves close and said third valve opens to decompress said passage to discharge the gas contained in the SEF into the decompressed atmosphere.

2. The blood constituent measuring apparatus, as claimed in claim 1, wherein said accumulating member rotates in said sampling cell to connect said passage to said measuring means.

3. The blood constituent measuring apparatus, as claimed in claim 1, wherein said first, second and third valves consist of electromagnetic valves, and wherein said apparatus further comprises control means for controlling said electromagnetic valves.

4. The blood constituent measuring apparatus, as claimed in claim 1, wherein said measuring means includes a sensor for detecting a concentration of glucose in said SEF.

5. The blood constituent measuring apparatus, as claimed in claim 4, wherein said buffer solution contains a constituent for assisting said sensor in detecting the glucose.