Handpiece drive apparatus for powered surgical scissors

• US 5,020,535 A
• Filed: 12/21/1987
• Issued: 06/04/1991
• Est. Priority Date: 09/26/1985
• Status: Expired due to Term

• Current Assignee: Alcon Manufacturing Limited (Alcon Incorporated)
• Original Assignee: Alcon Laboratories Incorporated (Alcon Incorporated)
• Inventors: Parker, Donald A., Rogers, Wayne W.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US07/136,208
• Time in Patent Office: 1,261 Days
• Field of Search: 128/305, 128/318, 128/755, 128/303 R, 128/1 R
• US Class Current: 606/174
• CPC Class Codes: A61B 2017/00544 pneumatically
• CPC Class Codes: A61F 9/00736 Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments A61F9/008 takes precedence
• 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 1/784 by filtering, sterilising or disinfecting the exhaust air, e.g. swellable filter valves
• 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

Abstract

There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a pneumatic system for driving pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor.

Claims

1. An apparatus for driving scissors blades comprising:

a body for providing support and having a bore providing access to the inside of the body;

a sliding rod inside said body having a projecting portion which is housed in and guided by said bore and having a dimension relative to said bore so as to be slidably coupled to said body, said sliding rod having an annular shoulder;

a biasing means for biasing said sliding rod to a predetermined position in said body and resisting movement of said rod with linearly increasing force as a function of distance of movement;

a chamber having an inlet for receiving pressurized fluid and having a movable wall coupled to said sliding rod so as to move said rod in said bore when the pressure of said pressurized fluid is sufficient to cause movement of said movable wall;

control transducer means for indicating the desired blade movement of said scissors;

computer means coupled to said control transducer means for reading the desired blade movement from said control transducer and for converting said desired blade movement to a digital number and for digitally scaling said digital number according to a constant which may be altered to generate scaled blade movement data and for converting the scaled blade movement data to an analog blade movement signal;

electrically operated valve means having a fluid inlet for coupling to a source of pressurized fluid having a constant pressure, and having an electrical control input coupled to receive said analog blade movement signal, for converting said flow of said pressurized fluid to a flow having a variable flow rate which is a function of an electrical characteristic of said analog blade movement signal; and

conversion means including a cavity having a controlled leak rate and an inlet coupled to receive said flow of pressurized fluid from said electrically operated valve means and having a pressure outlet coupled to said inlet of said chamber, said conversion means for converting said variable flow rate of pressurized fluid to a corresponding variable pneumatic pressure having variations which track the variations in said flow rate and applying said variable pneumatic pressure to said inlet for pressurized fluid via said pressure outlet.

2. An apparatus for driving scissors blades under the influence of pneumatic pressure comprising:

a body;

a sliding rod housed in said body;

means for providing a path for sliding of said rod in said body and for guiding and supporting said rod without imposing excessive friction;

means for biasing said rod against sliding in one direction;

pneumatic-to-mechanical conversion means having a pneumatic inlet for receiving pressurized fluid for converting the pneumatic pressure of said fluid into sliding motion of said sliding rod including a sealed chamber with a movable wall coupled to said sliding rod, said chamber expanding by movement of said movable wall when under the influence of higher than atmospheric pressure thereby causing the movement of said sliding rod;

a movable control;

pneumatic drive means coupled to said control and to said pneumatic inlet and coupled to a source of pressurized fluid, for reading the position of said control and for causing said pressurized fluid to be coupled to said pneumatic inlet at a pressure which is a substantially linear function of the position of said control;

and wherein said pneumatic drive means further comprises;

electronic means for reading the position of said control and for coupling to said source of pressurized fluid for converting the flow from said source of pressurized fluid into a flow having a flow rate which is linearly proportional to said position to said control;

a flow-to-pressure conversion means having a fluid inlet for receiving said flow of pressurized fluid from said electronic means and having a chamber coupled to receive said flow of pressurized fluid, said chamber having an outlet acting to provide a controlled leak rate of said pressurized fluid from said chamber thereby converting said flow of pressurized fluid from said electronic means to a pressure which corresponds to the flow rate of said pressurized fluid, and said chamber having a pneumatic pressure outlet coupled to said pneumatic inlet of said pneumatic-to-mechanical conversion means, said flow-to-pressure conversion means converting the flow rate of said pressurized fluid to a corresponding pressure and coupling said pressure to said pneumatic pressure outlet.

3. An apparatus for driving scissors blades under the influence of pneumatic pressure comprising:

a body;

a sliding rod housed in said body;

means for providing a path for sliding of said rod in said body and for guiding and supporting said rod without imposing excessive friction;

means for biasing said rod against sliding in one direction;

pneumatic-to-mechanical conversion means having a pneumatic inlet for receiving pressurized fluid for converting the pneumatic pressure of said fluid into sliding motion of said sliding rod including a sealed chamber with a movable wall coupled to said sliding rod, said chamber for expanding by movement of said movable wall under the influence of higher than atmospheric pressure thereby causing movement of said sliding rod;

a movable control;

pneumatic drive means coupled to said control and to said pneumatic inlet and for coupling to a source of pressurized fluid, for reading the position of said control and for causing said pressurized fluid to be coupled to said pneumatic inlet at a pressure which is a substantially linear function of the position of said control;

wherein said pneumatic drive means further comprises;

electronic means for reading the position of said control and for generating an output electrical signal which has an amplitude which is linearly proportional to said position;

a port for coupling to said source of pressurized fluid;

linear, electrically operated valve means having an electrical input coupled to said output electrical signal from said electronic means and having a gas inlet coupled to said port for coupling to said source of pressurized fluid and having a fluid outlet, said valve means for modulating the flow rate of fluid flowing out said fluid outlet in proportion to an electrical characteristic of said output electrical signal from said electronic means,

a flow-to-pressure conversion cavity means having a fluid inlet coupled to said fluid outlet of said valve means for receiving the flow of pressurized fluid and having a chamber coupled to receive the flow of pressurized fluid, said chamber having an outlet acting to provide a controlled leak rate thereby converting the flow of pressurized fluid to a pressure which corresponds to the flow rate of said pressurized fluid, said chamber having a pneumatic pressure outlet coupled to said pneumatic inlet of said pneumatic -to-mechanical conversion means, said flow-to-pressure conversion cavity means converting the flow rate of said pressurized fluid to a corresponding pressure and coupling said pressure to said pneumatic pressure outlet.