Method for stabilizing delivered laser energy

• US 7,836,893 B2
• Filed: 03/09/2005
• Issued: 11/23/2010
• Est. Priority Date: 03/15/2004
• Status: Active Grant

• Current Assignee: Amo Manufacturing Usa, Llc (Johnson & Johnson)
• Original Assignee: Amo Manufacturing Usa, Llc (Johnson & Johnson)
• Inventors: Holliday, Keith
• Primary Examiner(s): Farah; Ahmed M
• Application Number:
  US11/077,173
• Publication Number:
  US 20050203494A1
• Time in Patent Office: 2,085 Days
• Field of Search: 606 4- 6, 606 8- 12, 607 88- 94, 128/898, 356213-236, 219/121.6, 219/121.61, 219/121.62
• US Class Current: 128/898
• CPC Class Codes: A61F 2009/00848 based on wavefront
• CPC Class Codes: A61F 2009/00855 Calibration of the laser system
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00804 Refractive treatments
• CPC Class Codes: A61F 9/00819 with photoablatable masks

Abstract

Systems and methods provide for stabilizing the amount of laser energy delivered to a target from a laser device. Generally, delivered laser energy is measured over multiple laser pulses or over time in the case of a constant wave laser. A decrease is then calculated in the delivered energy, the decrease being caused by accumulation of one or more substances, such as ozone, along the laser beam delivery path due to passage of the laser beam along the path. Using this calculated decrease, a laser device may be adjusted to compensate for the decrease in delivered energy due to the accumulated substance(s), thus stabilizing the amount of energy delivered to the target.

Claims

1. A method for stabilizing an amount of laser energy delivered to a target by a laser generating device of a laser eye treatment system, the method comprising:

measuring the amount of delivered laser energy arriving at or near a target from the laser generating device of the laser eye treatment system over a period of time;

calculating a decrease in the amount of delivered energy over time caused by passage of the laser energy along a delivery path, which causes an accumulation of at least one substance along the delivery path, the substance impeding subsequent passage of the laser energy; and

adjusting the laser generating device to compensate for the decrease to stabilize the amount of delivered laser energy arriving at the target by increasing an amount of laser energy provided from the laser generating device over the time to compensate for the accumulation of the at least one substance along the delivery path.

2. A method as in claim 1, wherein measuring the amount of delivered laser energy comprises measuring with a laser energy meter positioned at or near the target.

3. A method as in claim 2, wherein the laser energy meter is positioned on an opposite side of a partially transparent lens or mirror from the target.

4. A method as in claim 1, wherein measuring the amount of delivered laser energy comprises measuring delivered energy of multiple pulses of laser energy.

5. A method as in claim 1, wherein measuring the amount of delivered laser energy comprises measuring delivered energy of a continuous wave (CW) of laser energy.

6. A method as in claim 1, wherein the at least one substance comprises ozone, and wherein passage of the laser energy along the delivery path causes an amount of oxygen to be converted to ozone.

7. A method as in claim 1, wherein calculating the decrease in the amount of delivered energy comprises calculating a decrease in delivered energy of a pulse of laser energy compared to an immediately previously fired pulse of laser energy.

8. A method as in claim 7, wherein calculating the decrease comprises:

calculating an amount of decrease caused by accumulation of one or more substances in the delivery path of the laser energy; and

reducing the amount of the decrease caused by the accumulation by a factor of time between pulses of the laser energy, which time allows for dissipation of the substance(s).

9. A method as in claim 1, wherein the laser generating device is adjusted to compensate for accumulation of ozone along the delivery path.

10. A method as in claim 1, wherein adjusting the laser generating device further comprises reducing any increases in the amount of provided laser energy to compensate for time between pulses of laser energy, which time allows for dissipation of the substance(s).

11. A method as in claim 1, wherein the measuring, calculating and adjusting steps are performed during a calibration procedure for the laser generating device.

12. A method as in claim 11, further comprising performing a laser eye surgery procedure with the laser generating device after the calibration procedure.

13. A method as in claim 1, further comprising directing laser energy from the laser generating device toward the target.

14. A method as in claim 13, wherein the directed laser energy comprises pulsed laser energy.

15. A method as in claim 13, wherein the directed laser energy comprises continuous wave (CW) laser energy.