Laser modulation for coagulation

Patent metadata

Field	Value
Publication number	US-9445871-B2
Application number	US-201514920462-A
Country	US
Kind code	B2
Filing date	Oct 22, 2015
Priority date	Mar 27, 2009
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An apparatus has a pump module providing pump energy, a resonator and a controller. The resonator includes a gain medium receiving the pump energy from the pump module and producing light; reflective surfaces reflecting light produced by the gain medium back toward the gain medium; and a variable light attenuator receiving light produced by the gain medium. The controller controls the amount of light attenuated by the variable light attenuator such that the apparatus emits windows of pulses of laser light at spaced time intervals, each window containing a plurality of pulses of laser light and each interval between windows being larger than an interval between pulses within a window. The emitted windows of pulses of laser light heat tissue to a temperature that causes coagulation without vaporization.

First claim

What is claimed is:

1. A medical laser system comprising:
a pump module providing a pump energy;
a resonator comprising:
a gain medium receiving the pump energy and producing a light;
at least two at least partially reflective surfaces reflecting the light produced by the gain medium back toward the gain medium;
a variable light attenuator receiving the light produced by the gain medium; and
a controller that provides a first driver signal to the variable light attenuator to control an amount of the light attenuated by the variable light attenuator such that the system emits a first laser light including a plurality of windows of laser light at spaced time intervals, each of the plurality of windows containing a plurality of pulses of laser light, wherein an interval between each of the plurality of windows is larger than an interval between each of the plurality of pulses, and each successive one of the plurality of pulses has a magnitude greater than a magnitude of a preceding one of the plurality of pulses.

2. The system of claim 1 , wherein a duration of each of the plurality of windows of laser light and a duration of the intervals between each of the plurality of windows are such that the first laser light does not cause vaporization of tissue.

3. The system of claim 2 , further comprising a user input device that allows the user to select between a vaporization mode and a coagulation mode,
wherein, when the user selects the vaporization mode, the controller provides a second driver signal to the variable light attenuator such that the system emits a second laser light including a continuous train of pulses of laser light to vaporize tissue, and
wherein, when the user selects the coagulation mode, the controller provides the first driver signal such that the system emits the first laser light to coagulate tissue.

4. The system of claim 1 , wherein, when the variable light attenuator attenuates more light, the system emits less of the first laser light.

5. The system of claim 4 , wherein the controller comprises:
a driver producing the first driver signal, the driver having an input for turning the first driver signal on and off, such that, when the first driver signal is on, the light attenuator attenuates more light than when the first driver signal is off and
a timer coupled to the input of the driver for turning the first driver signal on and off, the timer providing a cyclical timer signal in a first mode of operation and a static timer signal in a second mode of operation, the timer having a frequency input that defines the frequency of the cyclical timer signal and a duration input that defines a length of time that the timer signal turns the first driver signal off during the cyclical timer signal.

6. The system of claim 5 , wherein the static timer signal turns the first driver signal on.

7. The system of claim 6 , wherein the driver further comprises a magnitude input that receives a magnitude value used to set the magnitude of the first driver signal, and the system further comprises a processor executing computer-executable instructions that cause the processor to lower the magnitude value so that the overall shape of each of the plurality of pulses is triangular.

8. The method claim 4 , wherein the overall shape of each macropulse is triangular.

9. A method comprising:
powering a medical laser system including a pump module, a resonator, a variable light attenuator, and a controller;
receiving, with the controller, a first input indicating that the system is to be placed in a vaporization mode;
providing, with the controller, a first driver signal based on the first input;
receiving, with the variable light attenuator, the first driver signal;
emitting, with the system, a first laser light including a continuous series of micropulses of laser light;
receiving, with the controller, a second input indicating that the system is to be placed in a coagulation mode;
providing, with the controller, a second driver signal based on the second input;
receiving, with the variable light attenuator, the first driver signal; and
emitting, with the system, a second laser light including a series of macropulses of laser light at spaced time intervals, each macropulse comprising a series of micropulses of laser light, wherein a time interval between each macropulse is longer than a time interval between each micropulse, and each successive micropulse has a magnitude greater than a magnitude of a preceding pulse.

10. The method of claim 8 , wherein a duration of each macropulse and the time interval between each macropulse are such that the second laser light is insufficient for performing tissue vaporization.

11. The method of claim 10 , wherein the duration of each macropulse is between 5 and 30 milliseconds.

12. The method of claim 11 , wherein the time interval between each macropulse is 60 milliseconds.

13. The method of claim 9 , wherein the series of micropulss have the same frequency as the continuous series of micropulses.

14. The method of claim 9 , wherein the series of micropulses occur with the same peak intensity as the continuous series of micropulses of the coagulation mode.

15. The method of claim 9 , further comprising using an interface to set a first power level for the first laser light and a second power level for the second laser light.

16. The method of claim 9 , wherein each micropulse within the series of micropulses occur with a frequency of 15 kHz.

17. A method comprising:
positioning a delivery tip of a medical laser system adjacent a tissue, the system including:
a pump module;
a resonator including a gain medium and a variable light attenuator; and
a controller including a driver;

providing, with the driver, a first driver signal to the variable light attenuator; and
emitting, through the delivery tip, a first laser light including a series of macropulses at spaced time intervals, each macropulse comprising a series of micropulses, wherein a time interval between each macropulse is longer than a time interval between each micropulse, and each successive micropulse has a magnitude greater than a magnitude of a preceding micropulse.

18. The method of claim 17 , wherein the first laser light is configured for tissue coagulation.

19. The method of claim 18 , further comprising:
providing, with the driver, a second driver signal to the variable light attenuator; and
emitting, through the delivery tip, a second laser light including a continuous series of micropulses.

Assignees

• Ams Res Llc
• Boston Scient Scimed Inc

Inventors

• Kang Hyun Wook
• Nemeyer Raymond Adam
• Hodel Michael Ray

Classifications

• A61B2017/00154

  pulsed · CPC title

• H01S3/10038

  Amplitude control · CPC title

• H01S3/1643

  YAG · CPC title

• A61B18/20 Primary

  using laser · CPC title

• H01S3/1068

  using an acousto-optical device · CPC title