METHOD AND DEVICE FOR LASER LITHOTRIPSY

• US 20100137847A1
• Filed: 12/01/2009
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: Biolitec Unternehmensbeteiligungs II AG
• Original Assignee: CeramOptec Industries Incorporated (Biolitec AG)
• Inventors: Cecchetti, Leonardo, Neuberger, Wolfgang, Cecchetti, Walter
• Granted Patent: US 8,409,176 B2
• Time in Patent Office: Days
• US Class Current: 606/2.500
• CPC Class Codes: A61B 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 18/26 for producing a shock wave, e.g. laser lithotripsy
• CPC Class Codes: A61B 2017/2215 having an open distal end
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/263 the conversion of laser energy into mechanical shockwaves taking place in a liquid

Abstract

A system and method for the destruction/ablation of stones, calculi or other hard substances by means of laser energy is disclosed. As a consequence, several important medical treatments can be performed, especially lithotripsy. The system comprises a diode laser source emitting at least at one wavelength, one or more optical fibers which convey laser radiation to the treatment site and a liquid delivery system used for creating a liquid environment around the stones (calculi). The laser device emits at least one wavelength which is highly absorbed in the surrounding/covering medium, thus causing evaporation and cavitation effects that lead to stone/calculi destruction. Different radiation configurations may be used. In one embodiment continuous radiation is used to create sparkler-less plasma bubbles able to destroy hard substances. In another embodiment high peak power pulsed radiation is used. Wavelengths of 1470 nm, 1940 nm, or 1550 nm are preferred. Additionally it can be applied in combination with another wavelength with medium absorption in water such as 980 nm. In another embodiment a concentric double core fiber is used, in which the ignition radiation is guided in near single mode, inner core and the radiation used to maintain and enhance the pulse is guided into the surrounding second outer core. In another preferred embodiment, the use of multiple optical fibers allows for treating larger stones in a shorter time period. In another preferred embodiment, cooling liquid is supplied to the impact site to further reduce thermal heating of the stone, thus diminishing risks of tissue damage caused by stone fragment anchorage and thermal energy. With these safer and improved methods and system, enhanced lithotripsy treatments can be performed in a shorter treatment time, destroying a wider range of stones with less risk of tissue damage, and less patient and physician stress.

Claims

1. A laser system for the destruction and removal of kidney stones, calculi, etc. (hard substances) from the urinary tract, by a minimally invasive procedure comprising:

a laser, at least one optical fiber, and means to enter the urinary tract;

wherein said laser emits at least one wavelength that is highly absorbed in a medium surrounding said hard substances.

2. The laser system, according to claim 1, wherein said laser emits in a continuous wave mode.

3. The laser system, according to claim 1, further comprising:

means to provide a medium to surround said hard substance prior to lasing, wherein said medium and said laser wavelength are selected to be compatible.

4. The laser system, according to claim 1, wherein said laser is a diode laser, operating at about either 980±

60 nm, 1470±

60 nm, or 1940±

60 nm.

5. The laser system, according to claim 1, wherein said at least one optical fiber has a concentric core structure, wherein one laser wavelength travels in an inner core and a second wavelength is transmitted in an outer core.

6. The laser system according to claim 4, wherein at least two of the preferred wavelengths are employed in combination:

980 nm and 1470 nm;

980 nm and 1940 nm or 1470 nm and 1940 nm.

7. The laser system according to claim 1, wherein one laser is a fiber laser and a second laser is a pump laser for said fiber laser, and wherein beams from both lasers are transmitted by said at least one optical fiber.

8. The laser system according to claim 7, wherein said at least one optical fiber has a concentric core structure, wherein said fiber laser wavelength travels in an inner core and a pump laser wavelength is transmitted in an outer core.

9. The laser system according to claim 7, wherein said fiber laser emits at about 1550 nm, and said pump laser emits at either about 915-980 nm or at about 1480 nm.

10. The laser system, according to claim 1, wherein multiple optical fibers are employed, arranged around said target hard substance to speed up its destruction.

11. The laser system according to claim 7, wherein multiple optical fibers are employed, arranged around said target hard substance to speed up its destruction.

12. The laser system according to claim 3, wherein said medium delivery means is used to provide a cooling fluid to the treatment site.

13. A minimally invasive method for laser lithotripsy, using a laser system, according to claim 1, to create sparkless plasma bubbles which destroy hard substance obstructions in a urinary tract in a fast, safe, efficient manner.

14. The method for laser lithotripsy, according to claim 13, wherein a cooling fluid is aimed at a target hard substance to reduce danger of tissue damage from thermal energy or severe fragmentation/anchorage of said destroyed obstruction.