Vacuum sense control for phaco pulse shaping

• US 8,366,728 B2
• Filed: 05/17/2012
• Issued: 02/05/2013
• Est. Priority Date: 08/01/2006
• Status: Active Grant

• Current Assignee: Johnson & Johnson Surgical Vision, Inc. (Johnson & Johnson)
• Original Assignee: Abbott Medical Optics Incorporated (Johnson & Johnson)
• Inventors: Staggs, James W
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): CARPENTER, WILLIAM R
• Application Number:
  US13/473,959
• Publication Number:
  US 20120226221A1
• Time in Patent Office: 264 Days
• Field of Search: 606/107, 606/167, 606/169, 604/19, 604/22, 604/27, 604/28, 604/30, 604/93.01, 604/118
• US Class Current: 606/169
• CPC Class Codes: A61F 9/00745 using mechanical vibrations, e.g. ultrasonic
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/774 Handpieces specially adapted for providing suction as well as irrigation, either simultaneously or independently
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2210/0612 Eyes
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A method and apparatus for precisely controlling particle movement relative to a phacoemulsification needle tip is provided. The design monitors actual vacuum present and calculates a pulse shape amplitude waveform proportional to the amount of measured vacuum. An increase in vacuum indicates that the handpiece/needle is becoming occluded by a large particle. The present design determines whether additional power is required to bump or move a large particle away from the needle tip. The present design may employ a control loop that senses and continuously monitors vacuum. The design may dynamically vary the amount of ultrasonic energy delivered to the surgical area in response to the observed actual vacuum, and can actively vary the amount of power delivered to the surgical area based on the size of the particle and the resultant vacuum realized.

Claims

1. A method for applying ultrasonic energy to a device used in a surgical region,

comprising:

monitoring actual vacuum pressure level at the surgical region;

dynamically calculating a pulse shape amplitude (PSA) level based on monitored actual vacuum pressure level;

generating a PSA waveform based on said dynamically calculating;

summing a predetermined wave shape with the PSA waveform to produce a PSA wave shape; and

delivering said PSA wave shape to a handpiece.

2. The method of claim 1, wherein said monitoring actual vacuum pressure level occurs using a device separate from the handpiece.

3. The method of claim 1, wherein said handpiece comprises a needle that vibrates based on the PSA wave shape received from said delivering.

4. The method of claim 1, wherein dynamically calculating comprises assessing based on actual sensed aspiration vacuum pressure multiplied by maximum pulse amplitude minus minimum pulse amplitude and divided by maximum sensed aspiration vacuum pressure;

added to minimum pulse amplitude.

5. The method of claim 1, wherein the delivering tends to induce transient cavitation within the surgical region.

6. The method of claim 1, wherein monitoring actual pressure level occurs using a first aspiration device.

7. The method of claim 1, wherein said dynamically calculating, generating, summing, and delivering is repeated, thereby delivering multiple pulses each comprising an individual pulse shape formed based on actual sensed aspiration vacuum pressure.