Apparatus for measuring electrochemical activity

• US 4,436,610 A
• Filed: 12/13/1982
• Issued: 03/13/1984
• Est. Priority Date: 12/15/1980
• Status: Expired due to Term

• Current Assignee: Transidyne General Corporation (Customedix Corporation)
• Original Assignee: Transidyne General Corporation (Customedix Corporation)
• Inventors: Sarrine, Robert J., Enzer, Steven E.
• Primary Examiner(s): Tung, T.
• Application Number:
  US06/449,336
• Time in Patent Office: 456 Days
• Field of Search: 204/195 R, 204/195 G, 204/195 M, 204/195 B, 204/1 T, 204/1 H, 204/400, 204/408, 204/409, 204/415, 204/420, 204/433, 422/61, 422/68, 422/55, 422/98
• US Class Current: 204/400
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80

Abstract

Apparatus is disclosed for measuring the electrochemical activity of a liquid, for example, the hydrogen ion activity or pH value of blood. A disposable cartridge includes spaced indicating and reference electrodes which develop electrical properties as a function of the electrochemical activity. The cartridge carries a capsule containing an electrolyte solution. A machine for measuring the electrochemical activity includes a socket in a pivoting door for receiving the cartridge. When the door is pivoted into a closed position, the capsule is automatically crushed thereby covering the electrodes with the solution. The breaking of the capsule triggers an electronic measurement of the resultant electrical properties that develop between the two electrodes. This calibration factor is stored and used to compute the electrochemical characteristics of the sample when it is introduced into the cartridge to cover the indicating electrode. In one embodiment a photocell arrangement emits light which is absorbed by the sample so as to automatically trigger the final measurement when the sample is in contact with the indicating electrode. The cartridge is heated to a predetermined temperature to insure the accuracy of the measurement. Preferably, the socket assembly includes heater pads on opposing printed circuit boards which come into contact with the cartridge when the door is closed. The cartridge has a thermally conductive insert adjacent the tip of the indicating electrode which is contacted by a sensor in the socket to provide signals to a microcomputer which is adapted to control the measurement process. The heater system is selectively disabled by the microcomputer to insure the accuracy of the measurement.

Claims

1. In a device for measuring electrochemical activity of a liquid, said device having spaced indicating and reference electrodes, and means for introducing an electrolyte solution to cover the electrodes wherein said electrochemical activity is determined by the electrical properties developed between the electrodes in response to the indicating electrode being contacted with the liquid, the improvement comprising:

a generally rectangular thin walled transparent housing having a generally U-shaped hollowed out portion therein terminating in adjacent open ended trough and throat portions in an upper surface of the housing, said electrodes having tips disposed in said hollowed out portion, a breakable ampule containing the electrolyte solution, rigid means transverse to the legs of said hollowed out portion and located adjacent to the lower portion of the trough supporting said ampule a tape for holding the ampule in the trough.

2. The improvement of claim 1 wherein said rigid means is defined by at least one pointed cross bar member to aid in breaking the ampule when external force is applied thereto.

3. The improvement of claim 1 wherein said indicating electrode is a transparent pH sensitive glass rod.

4. The improvement of claim 1 which further comprises thermally conductive means including an insert of resilient material formed in the housing adjacent to the tip of the indicating electrode adapted for receipt of a sensor for sensing the temperature of the cartridge.

5. The improvement of claim 1 which further comprises electrically conductive means transversely mounted in said housing for making electrical contact with said electrodes through one side of said housing.

6. The improvement of claim 1 wherein said housing includes ridges projecting from opposite sides of the housing, each ridge being of different cross sectional dimension to assist in correctly orienting the housing with respect to an external socket.

7. The improvement of claim 6 which further comprises a socket for receiving said housing, said socket including guideways of different cross sectional area corresponding with the ridges on the housing.

8. In a device for measuring electrochemical activity of a liquid, said device having spaced indicating and reference electrodes, and means for introducing an electrolyte solution to cover the electrodes wherein the electrochemical activity is determined by the electrical properties developed between the electrodes in response to the indicating electrode being contacted with the liquid, the improvement comprising:

a generally rectangular thin walled transparent plastic housing having upper and lower ends, flat major faces, and opposing sides, a trough formed in and opening towards the upper end, lower portions of the trough including a pair of spaced pointed cross bar members;

a glass ampule containing electrolyte solution resting on the cross bar members and presenting an outer surface generally parallel to the upper end of the housing;

a throat formed in the upper end of the housing adjacent the trough and adapted to receive the liquid to be measured;

a generally U-shaped hollowed out portion bridging the trough and throat;

said indicating electrode having a tip projecting into a leg of the hollowed out portion beneath the throat;

first thermally conductive means formed in one major face of the housing adjacent the tip of the indicating electrode and adapted for receiving an external temperature sensor;

first electrically conductive means formed in said major face of the housing for making electrical contact with the indicating electrode, said reference electrode having a tip projecting into another leg of the hollowed out portion, second electrically conductive means in said major face for making electrical contact with said reference electrode, a tape on the end face of the housing for holding the ampule in the trough, and ridges of different cross sectional dimensions on opposite sides of the housing adapted to assist in correctly orienting the housing with respect to an external socket.