Tailored laser pulses for surgical applications

Patent metadata

Field	Value
Publication number	US-10893906-B2
Application number	US-201715723700-A
Country	US
Kind code	B2
Filing date	Oct 3, 2017
Priority date	Oct 4, 2016
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A laser system may include a controller configured to direct a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, and a lasing medium configured to output a quasi-continuous laser pulse in response to the optical pumping. The plurality of temporally spaced-apart electrical pulses may include (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, and (b) multiple second electrical pulses following the first electrical pulse. The quasi-continuous laser pulse is output in response to the multiple second electrical pulses.

First claim

We claim:

1. A laser system, comprising:
a controller configured to direct a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium; and

a lasing medium configured to output a quasi-continuous laser pulse in response to the optical pumping, the plurality of temporally spaced-apart electrical pulses including (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, wherein the first electrical pulse is a single pre-pulse, and (b) multiple second electrical pulses following the first electrical pulse, wherein the quasi-continuous laser pulse is output in response to the multiple second electrical pulses.

2. The system of claim 1 , wherein the lasing medium includes one of Ho:YAG, Tm:YAG, Tm:Ho:YAG, Er:YAG, Er:YLF, Nd:YAG, Tm-fiber laser, and CTH:YAG.

3. The system of claim 1 , wherein each electrical pulse of the multiple second electrical pulses has an electrical pulse duration between 10-1000 μs, and wherein a spacing between adjacent electrical pulses of the multiple second electrical pulses is between 10-300 μs.

4. The system of claim 1 , wherein a laser pulse duration of the quasi-continuous laser pulse is between 250 μs to 10 ms.

5. The system of claim 1 , wherein a power of the quasi-continuous laser pulse is between 100 W to 1 KW, wherein at least one characteristic of the second electrical pulses is different from a same characteristic of the first electrical pulse, and wherein the second electrical pulses include a plurality of temporally spaced apart laser pulses having a frequency greater than or equal to 1 kHz.

6. The system of claim 1 , wherein at least one of (i) duration, (ii) pulse-pulse spacing, and (iii) magnitude of a first set of pulses of the multiple second electric pulses is different from a second set of pulses of the multiple second electric pulses.

7. The system of claim 1 , wherein the quasi-continuous laser pulse includes a plurality of temporally spaced apart laser pulses having a frequency greater than or equal to 1 kHz.

8. The system of claim 1 , wherein the first electrical pulse is configured to excite the lasing medium to an energy level above 80% of the lasing threshold and below the lasing threshold.

9. The laser system of claim 1 , wherein durations of the second electrical pulses are different from a duration of the first electrical pulse, and wherein the quasi-continuous laser pulse is a single continuous waveform.

10. A method of using a laser system having a lasing medium to fragment a stone within a body cavity, comprising:
directing a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, the plurality of temporally spaced-apart electrical pulses including (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, wherein the first electrical pulse is a single pre-pulse, wherein the first electrical pulse is a single pre-pulse, and (b) multiple second electrical pulses following the first electrical pulse, wherein durations of the second electrical pulses are different from a duration of the first electrical pulse, and wherein the second electrical pulses include a plurality of temporally spaced apart laser pulses having a frequency greater than or equal to 1 kHz; and
outputting a quasi-continuous laser pulse from the lasing medium in response to the multiple second electrical pulses toward the stone to fragment the stone.

11. The method of claim 10 , wherein each electrical pulse of the multiple second electrical pulses has an electrical pulse duration between 10-1000 μs, and wherein a spacing between adjacent electrical pulses of the multiple second electrical pulses is between 10-300 μs.

12. The method of claim 10 , wherein a laser pulse duration of the quasi-continuous laser pulse is between 250 μs to 10 ms, and a power of the quasi-continuous laser pulse is between 100 W to 1 KW.

13. The method of claim 10 , wherein the quasi-continuous laser pulse is one of (a) a single laser pulse having a continuous waveform, or (b) a plurality of temporally spaced apart laser pulses having a frequency greater than or equal to 1 kHz.

14. The method of claim 10 , wherein the lasing medium includes one of Ho:YAG, Tm:YAG, Tm:Ho:YAG, Er:YAG, Er:YLF, Nd:YAG, Tm-fiber laser, and CTH:YAG, and wherein the first electrical pulse is configured to excite the lasing medium to an energy level above 80% of the lasing threshold and below the lasing threshold.

15. The method of claim 10 , wherein at least one of (i) duration, (ii) pulse-pulse spacing, and (iii) magnitude of a first set of pulses of the multiple second electric pulses is different from a second set of pulses of the multiple second electric pulses.

16. A method of using a laser system having a lasing medium to fragment a stone, comprising:
directing a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, the plurality of temporally spaced-apart electrical pulses including (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, wherein the first electrical pulse is a single pre-pulse, and (b) multiple second electrical pulses following the first electrical pulse, wherein a first pulse of the multiple second electrical pulses increases the energy level of the lasing medium above the lasing threshold; and
outputting a quasi-continuous laser pulse from the lasing medium in response to the multiple second electrical pulses, wherein the quasi-continuous laser pulse is output toward the stone to fragment the stone, wherein the quasi-continuous laser pulse is one of (a) a single laser pulse having a continuous waveform, or (b) a plurality of temporally spaced apart laser pulses having a frequency greater than or equal to 1 kHz,
wherein durations of at least one of the second electrical pulses are longer than a duration of the first electrical pulse.

17. The method of claim 16 , wherein each electrical pulse of the multiple second electrical pulses has an electrical pulse duration between 10-1000 μs, and wherein a spacing between adjacent electrical pulses of the multiple second electrical pulses is between 10-300 μs.

18. The method of claim 16 , wherein the quasi-continuous laser pulse is a single laser pulse having a continuous waveform and having a laser pulse duration between 250 μs to 10 ms and a power between 100 W to 1 KW.

19. The method of claim 16 , wherein the lasing medium includes one of Ho:YAG, Tm:YAG, Tm:Ho:YAG, Er:YAG, Er:YLF, Nd:YAG, Tm-fiber laser, and CTH:YAG, and wherein the first electrical pulse is configured to excite the lasing medium to an energy level above 80% of the lasing threshold and below the lasing threshold.

20. The method of claim 16 , wherein at least one of (i) duration, (ii) pulse-pulse spacing, and (iii) magnitude of a first set of pulses of the multiple second electric pulses is different from a second set of pulses of the multiple second electric pulses.

Assignees

• Boston Scient Scimed Inc

Inventors

• Falkenstein Werner
• Schubert Michael
• Dittmar Stephan
• Butsch Anna
• Kremser Thomas

Classifications

• H01S3/1024

  for pulse generation · CPC title

• H01S3/093

  focusing or directing the excitation energy into the active medium · CPC title

• H01S3/10038

  Amplitude control · CPC title

• A61B2017/00176

  Two pulses, e.g. second pulse having an effect different from the first one · CPC title

• H01S3/1312

  by controlling the optical pumping · CPC title