Medical instrument and method of use

• US 8,444,636 B2
• Filed: 01/10/2006
• Issued: 05/21/2013
• Est. Priority Date: 12/07/2001
• Status: Active Grant

• Current Assignee: Tsunami MedTech, LLC
• Original Assignee: Tsunami MedTech, LLC
• Inventors: Shadduck, John H., Hoey, Michael
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US11/329,381
• Publication Number:
  US 20060224154A1
• Time in Patent Office: 2,688 Days
• Field of Search: 606/41, 606 45- 50, 607/96, 607/101, 607/102
• US Class Current: 606/41
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 2018/00619 Welding
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2018/046 in liquid form
• CPC Class Codes: A61B 2018/048 in gaseous form

Abstract

An instrument for thermally-mediated therapies in targeted tissue volumes or for volumetric removal of tissue. In one embodiment, the instrument has an interior chamber that includes a diffuser structure for diffusing a biocompatible conductive fluid that is introduced under high pressure. The interior chamber further includes surfaces of opposing polarity electrodes for vaporizing the small cross-section diffused fluid flows created within a diffuser structure. In one embodiment, the diffuser structure includes a negative temperature coefficient of resistance material between the opposing polarity surfaces. The NTCR structure can self-adjust the lengths of current paths between the opposing polarities to insure complete vaporization of the volume of flow of conductive fluid. The non-ionized vapor phase media is ejected from a working surface of the instrument and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. In another embodiment, the instrument provides voltage means for converting the non-ionized vapor phase media into an ionized media or plasma for applying energy to body structure.

Claims

1. A method for delivering energy to mammalian body structure, comprising:

providing an elongated probe with a proximal end and a working end;

providing a pressurized flow of a non-ionized flow media from at least one port in the working end to the mammalian body structure, wherein a source of the non-ionized flow media is positioned remotely from the working end; and

controlling a pressure of the non-ionized flow media to control a propagation velocity of the flow of the non-ionized flow media;

wherein the non-ionized flow media carries sufficient thermal energy to modify the body structure by at least hydrothermal denaturation of tissue.

2. The method of claim 1 including providing the flow of non-ionized flow media from a needle-like working end into the body structure.

3. The method of claim 1 including providing the flow of non-ionized flow media from the working end into at least one of a body lumen, soft tissue, surface tissue and bone.

4. The method of claim 1 including providing the flow of non-ionized flow media in at least one of a distal direction relative to a probe axis, a proximal direction relative to said axis and substantially perpendicular to said axis.

5. The method of claim 4 including providing the flow of non-ionized flow media from at least one proximally-oriented port into an interior channel in the probe.

6. The method of claim 5 including providing negative pressure aspiration forces to said interior channel in the probe.

7. The method of claim 1 wherein the source of the non-ionized flow media is positioned at least 5 mm;

10 mm and 100 mm from a surface of the working end.