Patent Application
20080097421
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
Referring now to
In addition, the elongate body 14 may include a guidewire lumen 20 extending along at least a portion of the length of the elongate body 14 for over-the-wire applications, where the guidewire lumen 20 may define a proximal end and a distal end. The guidewire lumen 20 may be movably disposed within at least a portion of the elongate body 14 such that the distal end of the guidewire lumen 20 extends beyond the and out of the distal portion of the elongate body 14.
The medical device 10 of the present invention may further include a thermal element for providing thermal energy to a desired tissue region, such as an expandable element 22 at least partially disposed on the elongate catheter body, a fixed-volume body or other fluid receptacle, an RF electrode (not shown), or the like. The expandable element 22 may include a balloon or other expandable structure, which may define a proximal end coupled to the distal portion of the elongate body 14 of the catheter, while further defining a distal end coupled to the tip portion and/or the distal end of the guidewire lumen 20. In addition, the expandable element 22 may have any of a myriad of shapes, and may further include one or more material layers providing for puncture resistance, radiopacity, or the like. The expandable element 22 may be in communication with the fluid injection and exhaust lumens of the medical device 10 as described above, i.e., a fluid flow path may provide an inflation fluid, such as a cryogenic fluid or the like, to the interior of the expandable element 22.
Now referring to
The one or more thermocouple elements 24 of the thermocouple array may include an insulation 26 covering at least a portion of the thermocouple elements 24, where portions of the insulation are removed at desired locations for providing a temperature measurement at that particular position. In addition, the thermocouple array may be at least partially disposed on either an interior or exterior portion of the expandable element 22. Should the medical device 10 include multiple expandable elements or an expandable element 22 having multiple layers, the thermocouple array may be positioned and/or integrated between the multiple expandable elements or layers. Where the thermocouple array is not directly exposed to or otherwise able to contact the tissue being treated, the thermal properties of an intervening material layer may be used to extrapolate or otherwise calculate the actual thermal characteristics of the surface of the medical device and/or the tissue given the measurements or indications provided by the thermocouple array. The thermocouple array may be situated about the expandable element 22 of the medical device such that the plurality of temperature measurement positions extends across a significant portion of the surface area of the expandable element 22 or thermal element, thereby providing numerous reference points for monitoring and/or controlling the thermal characteristics of the medical device when in contact with and/or thermally affecting a tissue region.
Again referring to
The handle 28 may also include connectors that are matable directly to a fluid supply/exhaust and control unit or indirectly by way of one or more umbilicals for providing fluid communication with the elongate body 14. In the system illustrated, the handle 28 is provided with a first connector 34 that is matable with a co-axial fluid umbilical (not shown) and a second connector 36 that is matable with an electrical umbilical (not shown) that can further include an accessory box (not shown). The first and second connectors may provide fluid, mechanical, and/or electrical communication between portions of the medical device 10 and the console 12, including providing communication between the console 12 and the thermocouple array of the medical device 10.
The console 12 may house electronics and software for monitoring, controlling and/or recording the characteristics of surgical procedure, including but not limited to the particular thermal environment as indicated by the thermocouple array. The console may further control delivery of a liquid refrigerant under high pressure from a reservoir 38, through an umbilical, to the elongate body and/or the expandable element. The console 12 can also include an apparatus for recovery of expanded refrigerant vapor from the medical device 10 and recompression of the vapor.
In an exemplary use of a system including the medical device 10 of the present invention, the medical device 10 may be positioned in proximity to a tissue region for application of thermal energy thereto. Once the desired positioning has been achieved, the application of thermal energy via the medical device 10 may begin. The thermal energy may include providing a coolant flow through the medical device 10 to the expandable element 22 to impart cryogenically ablative temperatures to the tissue, or may alternatively include a heating element such as an RF electrode or the like for effectively heating the tissue to the desired temperature. Irrespective of the thermal modality in use, the thermocouple array may provide an indication of the thermal characteristics existing on the surface of the tissue region, on the surface of the medical device, and/or the region in between, if any. The information provided by the thermocouple array may be communicated to the console and provided to an operating physician. The particular measurements provided by the thermocouple array may be individualized, i.e., a particular measured value may be provided for each temperature measurement point of the thermocouple array, with the information being provided to a physician in an appropriate format, such as a graphical indication of the temperature across the surface of the medical device 10 or the like. As the thermocouple array may be disposed about a substantial portion of the surface area of the thermal element, a more complete, accurate, and enhanced assessment is available of the thermal interaction between the medical device and the tissue being treated. Accordingly, modifications in the particular amount of thermal energy being provided and/or the positioning of the medical device may be modified in view of the information provided by the thermocouple array, leading to improved operation and treatment results.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
