Leakage-resistant tissue treatment apparatus and methods of using same

1. An apparatus for treating tissue located beneath a skin surface with high frequency energy, the apparatus comprising:

a handpiece;

a treatment tip configured to be removably coupled with the handpiece, the treatment tip including an electrode configured to deliver the high frequency energy to a region of the tissue, a channel for circulating heat transfer fluid proximate to the electrode, and an inlet passage to the channel;

a first conduit inside the handpiece, the first conduit including a tubular sidewall and a lumen inside the tubular sidewall, the lumen configured to be coupled with the inlet passage for transferring the heat transfer fluid from the handpiece to the inlet passage of the treatment tip; and

a septum covering the inlet passage, the septum configured to be pierced by the first conduit to define a first opening for coupling the first conduit with the inlet passage when the treatment tip is coupled to the handpiece and to substantially seal the first opening when the treatment tip is removed from the handpiece to decouple the first conduit from the inlet passage.

2. The apparatus of claim 1 wherein the septum is a membrane composed of an elastomeric material.

3. The apparatus of claim 1 wherein the septum is a membrane composed of a thermoplastic elastomer.

4. The apparatus of claim 1 wherein the septum is a membrane composed of a material having a durometer of about 30 Shore A measured by the ASTM D2240 type A scale and a thickness in a range of about 25 mils to about 35 mils.

5. The apparatus of claim 1 wherein the septum includes a starter opening extending through the septum at a predicted location of the first opening, the starter opening configured to initiate formation of the first opening without tearing the septum.

6. The apparatus of claim 1 wherein the treatment tip includes an outlet passage from the channel, and further comprising:

a second conduit inside the handpiece, the second conduit including a lumen configured to be coupled with the outlet passage for transferring the heat transfer fluid from the inlet passage of the treatment tip to the handpiece.

7. The apparatus of claim 6 wherein the septum covers the outlet passage, and the septum is configured to be pierced by the second conduit to define a second opening to the outlet passage when the treatment tip is coupled to the handpiece and to substantially seal the second opening when the treatment tip is removed from the handpiece.

8. The apparatus of claim 1 wherein the septum is configured to completely seal the first opening when the treatment tip is removed from the handpiece.

9. The apparatus of claim 1 further comprising:

a second conduit inside the handpiece, the second conduit coupled in fluid communication with the first conduit, and the second conduit having a smaller shear modulus than the first conduit; and

a flow control valve inside the handpiece, the flow control valve coupled with the second conduit, and the flow control valve configured to occlude the lumen of the second conduit, when the treatment tip is removed from the handpiece, for reducing leakage of the heat transfer fluid from the first conduit.

10. The apparatus of claim 9 wherein the flow control valve is a pinch valve configured to apply a compressive force to the tubular sidewall of the second conduit to control a flow of the heat transfer fluid through the lumen of the first conduit.

11. The apparatus of claim 10 wherein the tubular sidewall of the second conduit is composed of a material with sufficient flexibility to deform to at least partially reduce a cross-sectional area of the lumen, when the compressive force is applied by the pinch valve, and supply the leakage reduction from the first conduit.

12. A method of operating a tissue treatment apparatus to treat tissue located beneath a skin surface with high frequency energy delivered from an electrode, the method comprising:

attaching a treatment tip carrying the electrode to a handpiece to establish a fluid connection between a lumen of a first conduit in the handpiece and an inlet passage in the treatment tip;

piercing a septum with the first conduit, when attaching the treatment tip to the handpiece to establish the fluid connection, to define a first opening permitting the first conduit to be coupled in fluid communication with the inlet passage;

transferring heat transfer fluid through the lumen of the first conduit to the treatment tip; and

delivering the high frequency energy from the electrode to a region of the tissue to perform a tissue treatment.

13. The method of claim 12 further comprising:

after delivering the high frequency energy, removing the treatment tip from the handpiece; and

when the treatment tip is removed from the handpiece, resiliently closing the first opening in the septum.

14. The method of claim 12 wherein delivering the high frequency energy further comprises:

transmitting the high frequency energy from the electrode through a dielectric substrate by capacitive coupling with the region of the tissue.

15. The method of claim 12 further comprising:

when the treatment tip is attached to the handpiece, establishing a fluid connection between a lumen of a second conduit in the handpiece and an outlet passage in the treatment tip;

piercing the septum with the second conduit, when attaching the treatment tip to the handpiece, to define a second opening permitting the second conduit to be coupled in fluid communication with the outlet passage; and

transferring the heat transfer fluid through the lumen of the second conduit from the treatment tip to the handpiece.

16. The method of claim 15 further comprising:

removing the treatment tip from the handpiece so that the each of the first and second conduits has an open end; and

when the treatment tip is removed from the handpiece, at least partially occluding the lumen of the first conduit and the lumen of the second conduit so that a negligible amount of the heat transfer fluid leaks from the open end of the first conduit and the open end of the second conduit.

17. The method of claim 16 wherein the occlusion of the lumens of the first and second conduits occurs concurrently.

18. The method of claim 12 further comprising:

removing the treatment tip from the handpiece so that the first conduit has an open end; and

when the treatment tip is removed from the handpiece, at least partially occluding the lumen of the first conduit so that a negligible amount of the heat transfer fluid leaks from the open end of the first conduit.