Temperature sensing system with retrograde sensor

• US 20050159673A1
• Filed: 03/14/2005
• Published: 07/21/2005
• Est. Priority Date: 08/12/2002
• Status: Active Grant

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Radiant Medical, Inc. (Asahi Kasei Corporation)
• Inventors: Machold, Timothy R., Dae, Michael W., Stull, Paul M.
• Granted Patent: US 7,407,487 B2
• Time in Patent Office: Days
• US Class Current: 600/549
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/6851 Guide wires
• CPC Class Codes: A61B 5/6853 with a balloon

Abstract

A temperature sensing system and method for determining a patient'"'"'s core body temperature by measuring the temperature of the patient'"'"'s blood at a location in a vessel lumen retrograde of an insertion point of a temperature sensor or sensors into the vessel lumen.

Claims

1. A temperature sensing system for determining the core body temperature of a patient by measuring the temperature of body fluid flowing within a body lumen, comprising:

a sheath having a proximal end having a proximal opening, a distal end region having a distal opening disposed at a distal tip of the distal end region, and a lumen therebetween;

a probe configured to be inserted into the proximal opening of the sheath into the lumen of the sheath, the probe having a proximal end region and a distal end region having a distal tip having at least one temperature sensor mounted thereon, the probe also having a bend located adjacent between the proximal end region and the distal end region, the distal tip having a first position before the distal region is inserted in the lumen of the sheath and a second, compressed position when the distal region is inserted into the lumen of the sheath;

whereby the distal end region of the probe returns to its first position when the distal tip of the distal end region is advanced beyond the distal opening of the sheath, and wherein the distal tip and temperature sensor may be moved to a position retrograde of the distal end opening of the sheath relative to the flow of blood in the body lumen by withdrawing at least a portion of the proximal end region of the probe from the sheath.

2. The system of claim 1, wherein the sheath has a first portion having an inserted length;

and wherein the distal end region of the probe has a length that is longer than the inserted length of the sheath.

3. The system of claim 1, wherein the at least one temperature sensor is a thermistor.

4. The system of claim 1, wherein the least one temperature sensor is a thermocouple.

5. The system of claim 1, wherein the at least one temperature sensor is housed in a thermally conductive, electrically insulative material.

6. The system of claim 1 further comprising a controller unit configured to receive temperature signals representative of a temperature of the body fluid from the at least one temperature sensor, and also for providing indications representative of the temperature, and a coupler for coupling the at least one temperature sensor to the controller unit.

7. The system of claim 1, further comprising a heat exchange catheter having a heat exchange region.

8. The system of claim 6, further comprising a heat exchange catheter having a heat exchange region.

9. The system of claim 8, wherein the heat exchange region has a temperature that is controlled by the controller in response to the temperature signals.

10. An apparatus for assisting in locating a temperature probe for measuring the temperature of a body fluid flowing within a body lumen at a position upstream of the insertion of the temperature probe into the body lumen, comprising:

a sheath having a proximal end having a proximal opening and a distal region having a distal opening disposed at a distal tip of the distal region, and a lumen extending between the proximal opening and the distal opening;

an introducer tuber configured to be inserted through the proximal opening of the sheath and advanced through the lumen of the sheath and out of the distal opening of the sheath, the introducer tube having a proximal end having a proximal opening and a flexible distal region having a distal opening disposed at a distal tip of the distal region of the introducer tube and a lumen extending between the proximal opening and the distal opening, the flexible distal region of the introducer tube having a curved normal state having a selected curvature and a straightened state having a different curvature when the flexible distal region of the introducer tube is inserted into and advanced through the lumen of the sheath.

11. A system for measuring the temperature of a body fluid flowing within a body lumen at a location upstream of the insertion of a temperature probe into the body lumen, comprising:

a sheath having a proximal end having a proximal opening and a distal region having a distal opening disposed at a distal tip of the distal region, and a lumen extending between the proximal opening and the distal opening;

an introducer tube configured to be inserted through the proximal opening of the sheath and advanced through the lumen of the sheath and out of the distal opening of the sheath, the introducer tube having a proximal end having a proximal opening and a flexible distal region having a distal opening disposed at a distal tip of the distal region of the introducer tube and a lumen extending between the proximal opening and the distal opening, the flexible distal region of the introducer tube having a curved normal state having a selected curvature and a straightened state having a different curvature when the flexible distal region of the introducer is inserted into and advanced through the lumen of the sheath; and

a temperature probe configured to be inserted and advanced through the lumen of the introducer tube, the temperature probe having a proximal end and a distal end, the distal end having a temperature sensor disposed thereon.

12. A system for measuring the temperature of a body fluid flowing within a body lumen at a location upstream of the insertion of a temperature probe into the body lumen, comprising:

a temperature probe formed from a material having a memory, the temperature probe also having a proximal end, an intermediate region having a curved state resulting from a bend formed therein and a distal region, the distal region having a distal tip with a temperature sensor mounted thereon; and

a sheath adapted for insertion into a body lumen, the sheath having a proximal end and a distal end, the sheath also having a central lumen and a side lumen separated by an inner wall,

the central lumen having a proximal opening disposed at the proximal end of the sheath and a distal opening disposed at the distal end of the sheath,

the side lumen having an outer wall defining the lumen and also having a proximal opening sized to receive the temperature probe, the inner and outer walls of the side lumen being sufficiently stiff to cause the bend in the intermediate region of the temperature probe to straighten sufficiently to allow the temperature probe to be advanced through the side lumen, the side lumen also having a distal opening disposed in the outer wall of the side lumen, the side lumen being terminated by an end wall located adjacent to the distal opening in the outer wall and configured to direct the temperature probe through the distal opening in the outer wall of the lumen, the end wall and the memory material of the temperature probe cooperating to return the intermediate region to the curved state such that further advancement of the temperature probe through the side lumen results in the distal tip of the temperature probe being positioned proximal to the distal opening in the outer wall of the side lumen.

13. A system for measuring the temperature of a body fluid flowing within a body lumen at a location upstream of the insertion of a temperature probe into the body lumen, comprising:

a temperature probe having a proximal end, an intermediate region having a bend formed therein and a distal region, the distal region having a distal tip with a temperature sensor mounted thereon; and

a sheath adapted for insertion into a body lumen, the sheath having a proximal end and a distal end, the sheath having

a central lumen having a proximal opening disposed at the proximal end of the sheath and a distal opening disposed at the distal end of the sheath,

a capture tube disposed at the distal end of the sheath, the capture tube having a distal opening, a proximal opening, and a lumen extending therebetween, the lumen having a length, the length selected to receive and protect the distal tip and at least a portion of the distal region of the temperature probe when the sheath and temperature probe are inserted into a body lumen and also selected so that retracting the proximal end of the temperature probe from the sheath causes the distal tip of the temperature probe to move in a proximal direction, moving the distal tip out of the proximal opening of the capture tube to a desired location proximal to the proximal opening of the capture tube.

26. The system of claim 13, wherein the proximal end of the temperature probe extends into the distal end of the sheath and through the central lumen.

14. A system for measuring the temperature of a body fluid flowing within a body lumen at a location upstream of the insertion of a temperature probe into the body lumen, comprising:

a sheath adapted to be inserted through a wall of a vessel into a vessel lumen, the sheath having a proximal end having a proximal opening disposed therein and an distal end having a distal opening disposed therein; and

a flexible temperature probe having a proximal portion and a proximal end and a distal end, the distal end of the proximal portion having a temperature sensor mounted thereon, the flexible temperature probe also having a detachable portion having a proximal end and a distal end, the distal end of the detachable portion attached to the distal end of the proximal portion through a break away portion.

15. The system of claim 14, wherein the break away portion is formed from a blood soluble material.

16. A method of measuring the temperature of a body fluid flowing through a body lumen of a patient at a location upstream of an insertion point of the a temperature probe, comprising:

inserting a sheath having a proximal end having a proximal opening, a distal end region having a distal opening disposed at a distal tip of the distal end region, and a lumen extending therebetween at least partially within the body lumen;

inserting a probe formed from a material having a memory into the proximal opening of the sheath, the probe having a non-compressed state and a compressed state, the probe also having a proximal region and a distal region connected by an intermediate, curved region, the distal region having a distal tip with at least one temperature sensor mounted thereto, such that when the probe is inserted into the proximal opening of the sheath, the intermediate, curved region of the probe is inserted into the sheath before the proximal or distal regions of the probe;

advancing the probe through the lumen of the sheath causing the probe to have the compressed state;

further advancing the probe through the lumen of the sheath until the distal end of the distal region passes through the distal opening of the sheath, whereupon probe returns to less compressed state and the distal tip moves away from the proximal region of probe;

positioning the temperature sensor in a location upstream of the distal opening of the sheath by retracting the proximal region of the temperature probe from the sheath; and

measuring the temperature of the fluid flowing through the lumen of the vessel.

17. A temperature sensing system for determining the core body temperature of a patient by measuring the temperature of body fluid flowing within a body lumen, comprising:

an introducer sheath having a proximal opening, a distal end region having a distal opening disposed at a distal tip of the distal end region, and a lumen therebetween, the lumen having a diameter at the distal opening;

a temperature probe, the probe having a proximal region and a distal region having a distal tip having at least one temperature sensor mounted thereon, the probe also having a bend located between the proximal region and the distal region, the probe also having a compressed configuration and an uncompressed configuration, the compressed configuration comprising the distal region of the probe compressed at the bend so that the distal region is located adjacent the proximal region so that the two regions form a compressed diameter less than the diameter of the lumen diameter, the uncompressed configuration comprising a configuration wherein the distal region is spaced farther apart from the proximal region a distance greater than the diameter of the lumen diameter at the distal opening, the probe biased at the bend to the uncompressed configuration;

whereby, when the probe is in the compressed configuration, the probe may be inserted and advanced through the lumen bend first, and when advanced until the distal tip is advanced beyond the distal opening, the probe will move from the compressed configuration to the uncompressed configuration and when the probe assumes the uncompressed configuration, the distal tip will be spaced from the proximal region a distance greater than the diameter of the lumen opening such that when the probe is withdrawn, the distal tip does not re-enter the lumen opening but moves retrograde of the lumen opening relative to the flow of blood in the vessel.

18. The system of claim 17, wherein the temperature probe includes a plurality of temperature sensors.

19. A temperature sensing system for determining the core body temperature of a patient by measuring the temperature of body fluid flowing within a body lumen, comprising;

an introducer sheath having a proximal opening, a distal region having a distal opening disposed at a distal tip of the distal region, and a first lumen therebetween, the lumen having a diameter at the distal opening, the sheath also including a second lumen, the second lumen terminating short of the distal tip of the sheath at a side opening, the second lumen having a wall forming at the side opening a ramp inclined toward the proximal opening of the sheath;

a temperature probe having a proximal region and a distal region, the distal region having a distal tip having at least one temperature sensor mounted thereon, the probe having a diameter smaller than the diameter of the second lumen;

whereby the probe may be advanced through the second lumen and the distal tip of the probe is directed by the ramp in a direction retrograde of the probe relative to the flow of body fluid past the sheath within the body lumen.

20. A temperature sensing system for determining the temperature of a target tissue of patient by measuring the temperature of body fluid flowing with a body lumen, comprising;

an introducer sheath having a proximal opening, a distal end region having a distal opening disposed at a distal tip of the distal end region, and a lumen therebetween, the lumen having a diameter at the distal opening;

a temperature probe having a proximal region and a distal region having a distal tip having at least one temperature sensor mounted thereon, the temperature probe configured so that when inserted into the introducer sheath and advanced into the body fluid flowing within the body lumen, the temperature probe is located retrograde of the distal end region of the introducer sheath.

21. The system of claim 20, wherein the temperature probe has a distal tip and a breakable section distal of the distal tip and a pull wire distal of the breakable section, the probe configured so that the probe may be advanced through the introducer sheath with the distal tip, breakable section and pull wire located external to the introducer sheath before insertion of the introducer sheath into the patient.

22. The system of claim 21, wherein the breakable section is weaker than the probe so than when a force is applied to the pull wire, the breakable section separates from the probe.

23. The system of claim 21, wherein the breakable section is biodegradable so that when the introducer is inserted into the body lumen, the body fluid degrades the breakable section and the pull wire may be separated from the probe.

24. The system of claim 20, wherein the distal region of the probe is biased away from the introducer sheath.

25. An apparatus for assisting in locating a temperature probe for measuring the temperature of a body fluid flowing within a body lumen at a position retrograde from a distal opening of a lumen of an introducer, comprising:

a deployment catheter having a proximal end having a proximal opening and a distal region having a distal opening disposed at a distal tip of the distal region, and a lumen defined by a wall extending between the proximal opening and the distal opening, the distal region being expandable from a compressed state when the distal region is disposed within the lumen of the introducer, and also having an expanded state when the distal region is advanced beyond the distal opening of the introducer, the distal region also having a guide tube disposed on an inner surface of the wall, the distal region having a proximal portion having an opening extending through the wall of the proximal portion of the distal region, the opening providing a pathway between the lumen of the deployment catheter and an exterior of the deployment catheter when the distal region is in the expanded state;

a probe having a proximal region, a bend region and a distal region, the distal region of the probe having a distal tip, the distal tip and distal region of the probe extending through the guide tube such that the bend region is disposed distal of the guide tube and the distal region is disposed proximal of the guide tube; and

a temperature sensor disposed on the distal tip of the probe.