Methods for laser treatment of tissue

• US 5,829,445 A
• Filed: 06/02/1995
• Issued: 11/03/1998
• Est. Priority Date: 09/24/1992
• Status: Expired due to Fees

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Inventors: Martin, Steve W., Shirk, Gerald J.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US08/458,883
• Time in Patent Office: 1,250 Days
• Field of Search: 606/2, 606/3, 606/9, 606/13-16, 128/898, 385/141, 385/142, 385/143, 65/385, 65/387, 65/390, 65/392
• US Class Current: 128/898
• CPC Class Codes: A61B 18/22 the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
• CPC Class Codes: C03B 2201/32 doped with aluminium C03B2201/36 takes precedence
• CPC Class Codes: C03B 2201/40 doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn
• CPC Class Codes: C03B 2201/42 doped with titanium
• CPC Class Codes: C03B 2201/50 doped with alkali metals
• CPC Class Codes: C03B 37/01205 starting from tubes, rods, fibres or filaments C03B37/014 takes precedence
• CPC Class Codes: C03B 37/027 Fibres composed of different sorts of glass, e.g. glass optical fibresC03B37/0253, C03B37/028 take precedence
• CPC Class Codes: C03B 37/15 with heat application, e.g. for making optical fibres fusion-splicing of light guides G02B6/255; treatment of light guides to shape optical elements G02B6/2835, G02B6/2856
• CPC Class Codes: C03C 13/006 Glass-ceramics fibres
• CPC Class Codes: C03C 13/045 Silica-containing oxide glass compositions
• CPC Class Codes: C03C 13/046 Multicomponent glass compositions
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/102 for infrared and ultraviolet radiation

Abstract

A new optical fiber and method of manufacturing the same developed for use with surgical laser systems. The fiber core utilizes an ultra-low expansion (ULE) material. The preferred ULE fiber consists of silicon dioxide core doped with titanium dioxide which is cladded and jacketed for chemical and abrasion resistance. The resulting fiber is stable against degradation due to thermal expansion.

Claims

1. A method for laser treatment of tissue comprising the steps of:

a) providing a laser fiber having a core constructed of silica-titania glass, the core terminating in a tip; and

b) transmitting laser energy through the core to treat tissue, wherein the tip retains its integrity during treatment.

2. The method of claim 1, further comprising the step of contacting tissue with the laser fiber tip.

3. The method of claim 1, further comprising the step of incising the tissue with the laser energy.

4. The method of claim 1, wherein the silica-titania glass exhibits a thermal coefficient of linear expansion of less than about 0.5×

10^-6 /°

C. in temperatures from about 25°

C. to about 700°

C.

5. The method of claim 1, wherein the silica-titania glass is substantially colorless.

6. The method of claim 1, further comprising the steps of:

a) absorbing laser energy in the core proximate the tip; and

b) contacting tissue with the tip to thereby incise the tissue.

7. The method of claim 6, wherein the step of absorbing laser energy further comprises providing a laser absorbing dopant in the core proximate the tip.

8. The method of claim 7, further comprising the step of varying the concentration of the laser absorbing dopant to provide a predetermined level of laser energy absorption.

9. The method of claim 1, wherein the step of providing a laser fiber further comprises providing a laser fiber having a core consisting essentially of silica-titania glass.

10. The method of claim 9, wherein the core comprises a concentration of TiO₂ of about 7.5 percent by weight.

11. A method for laser treatment of tissue comprising the steps of:

a) providing a laser fiber having a core of silica-titania glass exhibiting a thermal coefficient of linear expansion of less than about 0.5×

10^-6 /°

C. in temperatures from about 25°

C. to about 700°

C., the core terminating in a tip; and

b) transmitting laser energy through the core;

c) absorbing laser energy in the core proximate the tip;

d) contacting tissue with the laser fiber tip; and

e) incising the tissue with the laser energy, wherein the tip retains its integrity during treatment.

12. The method of claim 11, wherein the silica-titania glass is substantially colorless.

13. The method of claim 11, wherein the step of providing a laser fiber further comprises providing a laser fiber having a core consisting essentially of silica-titania glass.

14. The method of claim 13, wherein the core comprises a concentration of TiO₂ of about 7.5 percent by weight.