Blood leak detector

• US 3,900,396 A
• Filed: 03/22/1974
• Issued: 08/19/1975
• Est. Priority Date: 03/22/1974
• Status: Expired due to Term

• Current Assignee: Rene G. Lamadrid
• Original Assignee: Rene G. Lamadrid
• Inventors: Lamadrid, Rene G.
• Primary Examiner(s): Granger, Theodore A.
• Application Number:
  US05/453,751
• Time in Patent Office: 515 Days
• Field of Search: 210/85,22,94,96,321 73/61.4 250/573,574,575,576,565
• US Class Current: 210/94
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 2205/3313 used specific wavelengths

Abstract

A blood leak detector for use with artificial kidney machines. A transparent conduit through which dialysate circulates extends through a block. The block contains a lamp whose light passes through a first channel in the block transversely intersecting the conduit and a second channel in the block at an angle to the first channel and about the same length, avoiding the conduit. Identical 550-560 nm filters and photovoltaic cells are provided at the ends of the channels. The channels provide relatively wide dispersion angles. Circuitry is provided to measure the differential response of the photovoltaic cells and express this in terms of a voltage. An excessive difference between this voltage and a reference voltage will operate an alarm or emergency device. An adjustable light-obstructing screw is provided in the second channel for purposes of calibration.

Claims

1. IN AN ARTIFICIAL KIDNEY MACHINE, A BLOOD LEAKAGE DETECTOR COMPRISING A TRANSPARENT FLOW CONDUIT CONTAINING DEALYSATE FROM THE ARTIFICIAL KIDNEY MACHINE, AN OPAQUE BLOCK OF HEATABSORBING MATERIAL HABING A BORE CLOSELY RECIEVING SAID CONDUIT, SAID BLOCK BEING FORMED WITH A PAIR OF INTERSECTING DIVERGENT LIGHT PASSAGES, ONE OF SAID PASSAGES TRAVERSING SAID CONDUIT SUBSTANTIALLY PERPENDICULARLY WHERETO AND THE OTHERR BEING CLEAR OF THE DONDUIT AND DEFINING AN INDEPENDENT CLEAR REFERENCE PASSAGE, A LIGHT SOURCE MOUNTED IN THE BLOCK AT THE INTERSECTION OF SAID PASSAGES, RESPECTIVE PHOTOSENSITIVE ELEMENTS MOUNTED IN THE BLOCK AT THE END PORTION OF SAID PASSAGES, AND

2. The artificial kidney machine of claim 1, and wherein said photosensitive elements comprise photovoltaic cells generating currents in accordance with the intensities of the light reaching them through said passages, and wherein said alarm circuit means includes means to respond to the difference between the currents generated in said cells.

3. The artificial kidney machine of claim 2, and respective filters mounted in the block adjacent to and ahead of the photovoltaic cells, said filters being identical and being of a type passing peak absorption wavelengths of oxygenated hemoglobin.

4. The artificial kidney machine of claim 3, and wherein said filters are of a type passing between approximately 540 and approximately 570 nm.

5. The artificial kidney machine of claim 4, and adjustable light-obstructing means in said reference passage for calibrating the detector.

6. The artificial kidney machine of claim 5, and wherein said adjustable light-obstructing means comprises a member threaded through the wall of said reference passage and projecting into the reference passage.

7. The artificial kidney machine of claim 6, and wherein said source is located at a point such that it is substantially at the focal distance from the equivalent lens defined by the conduit and its contents.

8. The artificial kidney machine of claim 7, and wherein said adjustable light-obstructing means comprises a screw threadedly engaged through the wall of said reference passage.

9. The artificial kidney machine of claim 8, and wherein said screw is located adjacent the intersection of said passages.

10. The artificial kidney machine of claim 9, and means to adjust the position of the light source in the block so as to locate the light source substantially at the intersection of the optical axes of said passages.