US 20090044849 A1
A catheter comprising a catheter sleeve and a micro-thermocouple adapted to move within the sleeve, wherein the micro-thermocouple includes a first insulated conductor, wherein the first conductor has a diameter ranging from around 0.00009 inches to 0.005 inches, a second insulated conductor, and a coupled region including a bare region of the first insulated conductor coupled to a bare region of the second insulated conductor and an electrically insulative cover.
1. An catheter, comprising:
a catheter sleeve; and
a micro-thermocouple adapted to move within the sleeve,
wherein the micro-thermocouple includes:
a first insulated conductor, wherein the first conductor has a diameter ranging from around 0.00009 inches to 0.005 inches,
a second insulated conductor, and
a coupled region including a bare region of the first conductor coupled to a bare region of the second conductor and an electrically insulative cover.
2. The catheter of
3. The catheter of
4. The catheter of
5. The catheter of
6. The catheter of
7. The catheter of
8. The catheter of
9. The catheter of
10. The catheter of
11. The catheter of
12. The catheter of
The present application is a continuation of U.S. patent application Ser. No. 12/077,316, filed Mar. 17, 2008, the specification of which is incorporated herein by reference in its entirety, which is a continuation of U.S. patent application Ser. No. 10/391,531, filed Mar. 17, 2003, and issued Apr. 22, 2008 as U.S. Pat. No. 7,361,830, the specification of which is incorporated herein by reference in its entirety.
Pursuant to 35 U.S.C. § 119(e), this patent application claims the benefit of related U.S. Provisional Application No. 60/366,435 filed Mar. 21, 2002, which is hereby incorporated by reference in its entirety.
This patent application relates to thermocouple devices, and in particular, to a thermocouple device produced by encapsulating a thermocouple junction with a heat-shrinkable polymer coating.
A thermocouple is a bimetal junction that provides a voltage proportional to temperature. Temperature probes are often formed using thermocouples. Many applications requiring temperature probes require extremely small size.
One application for extremely small temperature probes is in the medical device industry; especially for use in catheters. For example, ablation catheters are used in non-invasive treatment of heart abnormalities. The ablation catheter is able to identify abnormal tissue growth and uses heat to remove the tissue causing the additional conduction paths. Thermal feedback is required when removing the tissue to prevent blood clotting or blood boiling during the procedure. In using a temperature probe to provide this feedback, the probe must be small enough to get as near an ablation electrode as possible. Also, when used in catheters, it is desirable that a temperature probe not rupture a catheter sleeve by tearing or abrasion. Further, a probe should be electrically insulated to allow in vivo operation.
It is apparent that uses for extremely small temperature probes beyond the medical field are possible. An extremely small probe would be useful in any field where a measurement of a localized temperature variation is desired, such as for example, the field of electronics.
What is needed is an insulated thermocouple device of extremely small size.
This document discusses a catheter with an insulated micro-thermocouple device of extremely small size. The catheter comprises a catheter sleeve and the micro-thermocouple adapted to move within the sleeve, wherein the micro-thermocouple includes a first insulated conductor having a diameter ranging from around 0.00009 inches to 0.005 inches, a second insulated conductor, and a coupled region including a bare region of the first insulated conductor coupled to a bare region of the second insulated conductor and an electrically insulative cover.
This summary is intended to provide an overview of the subject matter of the present application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the subject matter of the preset patent application.
In the drawings like numerals refer to like components throughout the several views.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and specific embodiments in which the invention may be practiced are shown by way of illustration. It is to be understood that other embodiments may be used and structural changes may be made without departing from the scope of the present invention.
As stated previously, the present application is concerned with materials and techniques used to create a sealed thermocouple of extremely small size.
The length (l) 160 of the resultant seal 150 is within the range of about 0.05 inches to 0.5 inches. The overall length (L) 165 of the micro-thermocouple 100 is within the range of about 20 inches to 78 inches. One embodiment of the micro-thermocouple 100 uses polyethylene terephthalate (PET) as the polymer material. Another embodiment uses fluorinated ethylene propylene (FEP). The seal 150 is moisture resistant and electrically insulating. The insulation resistance of the seal is greater than 100 Mega-ohms when measured at 50 Volts (DC).
Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose could be substituted for the specific example shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is intended that this invention be limited only by the claims and the equivalents shown.