Ablative material removal with a preset removal rate or volume or depth

• US 20060064079A1
• Filed: 08/11/2004
• Published: 03/23/2006
• Est. Priority Date: 08/11/2003
• Status: Active Grant

• Current Assignee: Rayd LLC, University of Central Florida Research Foundation Inc. (State University System of Florida)
• Original Assignee: Raydiance, Inc. (Coherent Corp.)
• Inventors: Stoltz, Richard, Delfyett, Peter J.
• Granted Patent: US 7,367,969 B2
• Time in Patent Office: Days
• US Class Current: 606/10
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy

Abstract

The present invention includes a method of surgical material removal from a body by optical-ablation with controlled pulse energy from an amplifier including inputting an ablation-threshold-pulse-energy-for-material-being-ablated signal; controlling the energy of a pulse and the pulse repetition rate and by knowing the type of material being removed, the system can control the removal to predetermined rate and, thus knowing the removal rate, it can know how long to run to stop at the predetermined volume.

Claims

1. A method of surgical material removal from a body by optical-ablation with controlled pulse energy from a fiber amplifier, comprising:

inputting an ablation-threshold-pulse-energy-for-material-being-ablated signal;

generating a series of wavelength-swept-with-time pulses using an optical oscillator;

controlling pulse energy based on the ablation-threshold-pulse-energy-for-material-being-ablated signal either by selecting pulses from the oscillator generated series of wavelength-swept-with-time pulses, wherein the fraction of pulses selected can be controllably varied to give a selected pulse repetition rate that is a fraction of the oscillator repetition rate, or by passing electrical current through at least one pump diode to generate pumping light, optically pumping the fiber amplifier with the pumping light, and controlling pump diode current;

amplifying the wavelength-swept-with-time pulse with the fiber-amplifier;

time-compressing the amplified pulse and illuminating a portion of the body with the time-compressed optical pulse, whereby controlling the pulse selection and/or the pump diode current controls the pulse energy; and

determining a volumetric removal rate from the pulse energy and the threshold-pulse-energy-for-material-being-ablated signal.

2. The method of claim 1, wherein a volume of material to be ablated is inputted and ablation is performed for a length of time to remove that volume at the volumetric removal rate.

3. The method of claim 1, wherein the ablation-threshold-pulse-energy-for-material-being-ablated signal is inputted by a multi-position selector switch indicating classes of materials, which is set to one of the classes and directly or indirectly selects a volume removal per pulse by an average pulse having an energy in the range of between about 2.5 and about 3.6 times ablation threshold for the selected class.

4. The method of claim 1, wherein the oscillator, amplifier and compressor are within a man-portable system.

5. The method of claim 1, wherein the compression is done in an air-path between gratings compressor.

6. The method of claim 1, wherein the compressed optical pulse has a sub-picosecond duration.

7. The method of claim 1, wherein the oscillator pulse has a duration between about 10 picoseconds and about one nanosecond.

8. The method of claim 1, wherein the ablation is from an outside surface of the body.

9. The method of claim 1, wherein the ablation is done inside of the body.

10. The method of claim 1, wherein more than one amplifiers are used in a mode where amplified pulses from one amplifier are delayed to arrive one or more nanoseconds after those from any other amplifier, to allow control of ablation rate independent of pulse energy.

11. The method of claim 1, wherein the pulse energy applied to the body is between about 2.5 and about 3.6 times ablation threshold of the body portion being ablated.

12. The method of claim 1, wherein a depth of material to be ablated is inputted and ablation is performed for a length of time to remove material to that depth from an area being ablated at the volumetric removal rate.

13. A method of material removal from a body by optical-ablation with controlled pulse energy from an optical amplifier, comprising:

inputting an ablation-threshold-pulse-energy-for-material-being-ablated signal;

generating a series of wavelength-swept-with-time pulses using an optical oscillator;

controlling pulse energy based on the ablation-threshold-pulse-energy-for-material-being-ablated signal to between 2.5 and 3.6 times ablation threshold;

amplifying the wavelength-swept-with-time pulse with the amplifier;

time-compressing the amplified pulse and illuminating a portion of the body with the time-compressed optical pulse, whereby controlling the pulse selection and/or the pump diode current controls the pulse energy; and

determining a volumetric removal rate from the pulse energy and the pulse-energy-for-material-being-ablated signal.

14. The method of claim 13, wherein a volume of material to be ablated is inputted and ablation is performed for a length of time to remove that volume at the volumetric removal rate.

15. The method of claim 13, wherein the ablation-threshold-pulse-energy-for-material-being-ablated signal is inputted by a multi-position selector switch indicating classes of materials, which is set to one of the classes and directly or indirectly selects a volume removal per pulse by an average pulse having an energy in the range of about 2.5 and about 3.6 times ablation threshold for the selected class.

16. The method of claim 13, wherein a depth of material to be ablated is inputted and ablation is performed for a length of time to remove material to that depth from an area being ablated at the volumetric removal rate.