Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Thermal applicators
Reexamination Certificate
1999-03-31
2001-09-18
Dvorak, Linda C. M. (Department: 3739)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Thermal applicators
C600S020000
Reexamination Certificate
active
06290717
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to methods and apparatus for cooling patients for therapeutic purposes, and more particularly to systems for measuring temperature in a patient to provide a feedback control signal for controlling a cooling catheter.
BACKGROUND
It has been discovered that the medical outcome for a patient suffering from severe brain trauma or from ischemia caused by stroke or heart attack is degraded if the patient's body temperature rises above normal (38° C.). It is further believed that the medical outcome for many such patients might be significantly improved if the patients were to be cooled relatively quickly to around 32° C. for a short period, e.g., 24-72 hours. Apart from the therapeutic benefits of hypothermia, the outcomes for brain trauma or ischemia patients that develop fevers is worse than for patients that do not develop fevers. Consequently, temperature management for such patients is important, even when hypothermia is not to be used to treat the patients.
The affected organ, in any case, is the brain. Accordingly, systems and methods have been disclosed that propose cooling blood flowing to the brain through the carotid artery. An example of such systems and methods is disclosed in co-pending U.S. patent application Ser. No. 09/063,984, filed Apr. 21, 1998, owned by the present assignee and incorporated herein by reference. In the referenced application, various catheters are disclosed which can be advanced into a patient's carotid artery and through which coolant can be pumped in a closed circuit, to remove heat from the blood in the carotid artery and thereby cool the brain. The referenced devices have the advantage over other methods of cooling (e.g., wrapping patients in cold blankets) of being controllable, relatively easy to use, and of being capable of rapidly cooling and maintaining blood temperature at a desired set point.
As recognized in co-pending U.S. patent application Ser. No. 09/133,813, filed Aug. 13, 1998, owned by the present assignee and incorporated herein by reference, the above-mentioned advantages in treating brain trauma/ischemic patients by cooling can also be realized by cooling the patient's entire body, i.e., by inducing systemic hypothermia. The advantage of systemic hypothermia is that, as recognized by the present assignee, to induce systemic hypothermia a cooling catheter or other cooling device need not be advanced into the blood supply of the brain, but rather can be easily and quickly placed into the relatively large vena cava of the central venous system.
Moreover, since many patients already are intubated with central venous catheters for other clinically approved purposes anyway, providing a central venous catheter that can also cool the blood, if only to manage temperature and thereby ameliorate fever spikes, requires no additional surgical procedures for those patients. A cooling central venous catheter is disclosed in the present assignee's co-pending U.S. patent application Ser. No. 09/253,109, filed Feb. 19, 1999 and incorporated herein by reference.
To supply coolant such as saline to the above-disclosed catheters, a cooling system such as the present assignee's system disclosed in co-pending U.S. patent application Ser. No. 09/220,897, filed Dec. 24, 1998 and incorporated herein by reference, can be used to remove heat from the coolant and return the coolant to the catheter in a closed loop heat exchange system. An alternate system is the thermoelectric cooler (TEC)-based system owned by the present assignee and disclosed in co-pending U.S. patent application Ser. No. 09/260,950, filed Mar. 2, 1999, also incorporated herein by reference. In any case, a cooling system controller preferably maintains temperature at a desired setpoint, be it normothermic or hypothermic. As recognized herein, to facilitate such temperature maintenance, it is necessary to measure patient temperature.
As understood by the present invention, esophageal temperature is a preferred parameter to use because it is more sensitive to body core temperature changes than, e.g., rectal temperature. As also understood by the present invention, for ease of use and to avoid burdensome sterilization procedures, the portion of an esophageal temperature sensor that is advanced into a patient should be disposable. Portions not in contact with the patient, however, need not be disposable. The present invention is provided with these considerations in mind.
SUMMARY OF THE INVENTION
A temperature probe for a therapeutic cooling catheter system includes an elongated probe body that has a distal end and a proximal end, and that is configured for being advanced into a patient with the distal end located in the patient's body and the proximal end located outside the patient's body. First and second temperature sensors, preferably thermistors, are located at or near the distal end of the probe body for generating respective first and second temperature signals. Also, a probe connector is located at or near the proximal end of the probe body, and a reusable interconnect cable has a cable connector configured for engaging the probe connector and at least one controller connector electrically connected to the cable connector and engageable with a controller.
In a preferred embodiment, the probe body is configured for advancement into a patient's esophagus. Also in the preferred embodiment, the probe connector snappingly engages the cable connector. One of the connectors preferably is a male telephone connector and the other connector is a female telephone connector. More specifically, the preferred probe connector includes an outwardly biased pivot arm and the cable connector includes a socket including at least one retainer rail, and the arm snappingly engages the rail when the probe connector is advanced into the cable connector. The arm of the probe connector extends beyond the cable connector when the probe connector is fully engaged with the cable connector, with the arm being manipulable to cause the arm to clear the rail and thereby permit disengagement of the probe connector from the cable connector.
As disclosed in greater detail below, the cable includes first and second controller segments terminating in respective first and second controller connectors. Each controller connector is engageable with the controller. The controller connectors can be phone plugs.
With further regard to the controller, the first temperature sensor generates a control feedback signal that is useful by the controller for controlling a heat exchanger. Also, the second temperature sensor generates an alarm feedback signal useful by the controller for generating an alarm signal. The system is disclosed in combination with a heat exchange catheter in closed loop fluid communication with the heat exchanger.
In another aspect, a controller includes a program of instructions for undertaking method acts for controlling a heat exchanger. These acts includes receiving, from first and second temperature sensors, respective first and second patient esophageal temperature signals. Also, the method acts includes controlling a heat exchanger for a cooling catheter in response to at least the first signal, and generating an alarm signal when the second signal reaches a predetermined setpoint.
In still another aspect, an esophageal temperature sensing apparatus includes first and second temperature sensors supported by a disposable probe body. The probe body is configured for advancing the sensors into a patient's esophagus, with the proximal end of the probe body remaining outside the patient's body at all times. A male or female telephone probe connector is at the proximal end, and an interconnect cable having a female or male telephone cable connector is selectively snappingly engageable with the probe connector. Moreover, a controller connector is engageable with a controller of a closed circuit cooling catheter heat exchange system. As set forth below, the interconnect cable establishes electri
Alsius Corporation
Dvorak Linda C. M.
Kearney R.
Rogitz John L.
LandOfFree
Temperature probe and interconnect cable for hypothermia... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Temperature probe and interconnect cable for hypothermia..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature probe and interconnect cable for hypothermia... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2447931