Pneumatic controls for ophthalmic surgical system

• US 5,417,246 A
• Filed: 09/27/1993
• Issued: 05/23/1995
• Est. Priority Date: 10/27/1989
• Status: Expired due to Term

• Current Assignee: American Cyanamid Co (Pfizer Inc.)
• Original Assignee: American Cyanamid Co (Pfizer Inc.)
• Inventors: Perkins, James T., Painter, John A., Appelbaum, Peter F.
• Primary Examiner(s): Fox, John C.
• Application Number:
  US08/127,921
• Time in Patent Office: 603 Days
• Field of Search: 137/870, 137/871, 137/883, 91/47
• US Class Current: 137/870
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 2017/00544 pneumatically
• CPC Class Codes: A61B 2017/00973 pedal-operated
• CPC Class Codes: A61B 2090/306 using optical fibres
• CPC Class Codes: A61F 9/00745 using mechanical vibrations, e.g. ultrasonic
• CPC Class Codes: A61F 9/013 Instruments for compensation of ocular refraction A61F9/008 takes precedence; Instruments for use in cornea removal, for reshaping or performing incisions in the cornea
• CPC Class Codes: A61M 1/72 Cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 1/804 using Laval or Venturi jet pumps
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: Y10T 137/2544 Supply and exhaust type
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/8376 Combined
• CPC Class Codes: Y10T 137/87772 With electrical actuation
• CPC Class Codes: Y10T 137/87877 Single inlet with multiple distinctly valved outlets
• CPC Class Codes: Y10T 137/87885 Sectional block structure

Abstract

A pneumatic control system for providing pressurized air and vacuum to ophthalmic microsurgical instruments. The pneumatic system is constructed in a drawer assembly to allow it to be readily inserted into or removed from a modularly constructed cabinet of a microsurgical control console. In addition, the pneumatic system improves upon existing pneumatic control systems by providing a third mode of microscissors operation from a single-pneumatic port. The third mode is made possible by a high speed three-way solenoid control valve which provides rapid pulses of air to the pneumatic port. A second improvement involves the use of a pneumatic pressure transducer to monitor pneumatic pressure being supplied to the pneumatic system in order to recognize non-hazardous transient drops in air pressure which can occur under certain normal operating conditions. A third improvement relates to the use of an intraocular pressure accumulator downstream from a final solenoid-operated pinch valve, which reduces fluctuations in air pressure and has other advantages.

Claims

1. An improved intraocular pressure system of the type powered by a source of compressed gas and including at least one pressure regulator means for limiting gas pressure to a predetermined maximum value, first electromagnetically-actuated valve means for controlling flow of the compressed gas from the source to a location where such gas is put to use, and a second electromagnetically-actuated valve means for controlling flow of the compressed gas from the location to atmosphere to reduce pressure at such location, the improvement comprising:

third electromagnetically-actuated valve means for interrupting flow from the first valve means to the location; and

variable volume gas reservoir means for accumulating additional compressed gas for later use, the reservoir means being located downstream of the first and third valve means.

2. A control system as in claim 1, wherein the first and third valve means are each two-way normally-closed solenoid-operated spring-returned valves, and the second valve is a two-way normally-open solenoid-operated spring-returned valve.

3. A control system as in claim 2, further comprising a transducer for measuring the pressure level achieved at the location.

4. A control system as in claim 1, wherein the variable volume gas reservoir means includes a collapsible pliable bladder.

5. A control system as in claim 1, wherein the first, second and third valves are in fluid communication with a common node, and the control system further comprises a fluid passage between the common node and the second valve having an orifice of predetermined diameter in the range of about 0.010 inch to about 0.35 inch.