Sequential thermography fluid flow indicator

• US 4,548,516 A
• Filed: 12/24/1984
• Issued: 10/22/1985
• Est. Priority Date: 12/24/1984
• Status: Expired due to Term

• Current Assignee: Tomasz K. Helenowski
• Original Assignee: Tomasz K. Helenowski
• Inventors: Helenowski, Tomasz K.
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Will, Thomas B.
• Application Number:
  US06/686,094
• Time in Patent Office: 302 Days
• Field of Search: 374/135, 374/138, 374/147, 374/148, 128/691, 128/692, 128/736, 604/8, 604/9, 73/204
• US Class Current: 374/135
• CPC Class Codes: A61B 5/028 by thermo-dilution

Abstract

An apparatus for indicating the fluid flow through implanted shunts by temperature sensing. The sensor comprises a series of thermistors carried by a flexible substrate mounted on a rigid support. The sensors are placed in external proximity to a section of the implanted shunt and by varying the temperature of the fluid proceeding the test section, the apparatus will determine the rate of flow therethrough. Each thermistor is connected by conductors to scaling and amplification circuitry for input into a computer system.

Claims

1. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt through thermal comparisons comprising,

(a) a probe having a rigid base layer, an intermediate layer of resilient material and a flexible circuit board,

(b) an aligned series of temperature sensing elements carried by the exposed surface of said circuit board and adapted to be placed in linear alignment with the embedded shunt for progressively sensing a temperature change in the fluid as its flows through the shunt,

(c) a pair of temperature sensitive elements carried by said circuit board to either side of said aligned series of temperature sensitive elements for sensing the temperature of an adjacent area of the embedded shunt so as to establish a reference temperature source,

(d) conduit means connecting all of said temperature sensing elements to an information gathering and analysis source, and

(e) said information gathering and analysis source registering and indicating the progressive change in temperature of the fluid as it flows through the embedded shunt and for calculating the rate of flow by said progressive temperature variances.

2. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 1 wherein said series of temperature sensing elements and said pair of temperature sensing elements are thermistors having exposed thermal conductive heads.

3. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 1 wherein said conduit means is a ribbon cable consisting of individual conductive lines, one for each temperature sensitive element.

4. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 1 wherein said conduit means is a ribbon cable consisting of individual conductive lines, one for each thermistor.

5. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 1 wherein said information gathering and analysis source includes a computer adapted to analyze the sensed temperature changes in the fluid in the shunt as it flows beneath the aligned temperature sensing elements and to calculate the rate of flow of such fluids in the shunt.

6. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 5 wherein said series of temperature sensing elements and said pair of temperature sensing elements are thermistors having exposed thermal conductive heads.

7. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 5 wherein said conduit means is a ribbon cable consisting of individual conductive lines, one for each temperature sensitive element.

8. An apparatus for non-invasively determining the rate of flow of fluids in an embedded shunt as defined by claim 4 wherein said information gathering and analysis source includes a computer adapted to analyze the sensed temperature changes in the fluid in the shunt as it flows beneath the aligned thermistors and to calculate the rate of flow of such fluids in the shunt.

9. A method for non-invasively determining the rate of flow of fluids in an embedded shunt by thermal comparison comprising sensing the temperature of a mass adjacent to the embedded shunt for determining a base temperature reference, sensing the temperature of the fluid in the shunt and comparing such sensed temperature to the base temperature reference, reducing the temperature of the shunt as well as the fluid therein at a point preceeding it'"'"'s temperature sensing, and subsequently progressively sensing the changed temperature of the fluid flowing in the shunt and analyzing the progressively changing temperatures of the fluid as it flows through the shunt for determining its rate of flow.

10. A method for non-invasively determining the rate of flow of fluids in an embedded shunt by thermal comparison as defined by claim 9 wherein the temperature sensors are thermistors.