Handpiece drive apparatus for powered surgical scissors

• US 4,768,506 A
• Filed: 09/26/1985
• Issued: 09/06/1988
• 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:
  US06/780,689
• Time in Patent Office: 1,076 Days
• Field of Search: 128/305, 128/318, 128/755, 128/303 R, 604/22
• 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 having a round cross section at any cross section normal to the longitudinal axis of said body and comprised of two mating halves which may be attached and detached from each other, said body for providing support for said scissors blades and having a chamber having first and second sections therein in fluid communication with each other and a bore providing access to the inside of the body and to at least said first section of said chamber, said body having tool attachment means through which said bore passes, said tool attachment means for providing easy attachment or detachment of said scissor blades or other surgical tools without the need to disassemble said body;

a sliding rod slidably coupled to the inside of said body via a projecting portion which projects through and is guided by said bore and which passes through said tool attachment means so as to engage the driving mechanism of any tool attached to said tool attachment means, said projecting portion having a dimension relative to the diameter of said bore so as to provide a fit which is loose enough so as to not generate excessive friction when said projecting portion slides in said bore, said sliding rod having an annular shoulder having first and second surfaces;

a spring housed in said first section of said chamber and engaging said first surface of said shoulder so as to bias said sliding rod so as to tend to move to a predetermined position in said body absent the effect of other forces acting upon said sliding rod;

a flexible, non metallic, autoclavable diaphragm mechanically affixed in sealing engagement with the walls of said second section of said chamber and mechanically affixed in sealing engagement with said second surface of said annular shoulder of said sliding rod so as to form a flexible movable wall of said second section of said chamber;

an inlet for coupling via a hose to a source of pressurized air, said inlet being in fluid communication with said second section of said chamber, said inlet extending parallel to the longitudinal axis of said body in such a manner that said body may be turned in the user'"'"'s hand to any angle without interference by any hose coupled to said inlet;

adjustment means for limiting the range of movement of said sliding rod to a user selected maximum;

and further comprising a footswitch and first means for introducing pressurized air into said inlet having a periodic pressure variation over time with a frequency which is set by a user by manipulation of said footswitch in a multicut mode, and second means for introducing pressurized air into said inlet having a pressure which is proportional to the amount of depression of said footswitch by said user in a proportional cut mode, and further comprising mode control means coupled to said first and second means for switching upon user command between said multicut and proportional cut modes and activating either said first means or said second means depending upon which mode is selected.

2. An apparatus for driving scissors blades comprising:

a body having a round cross section at any cross section normal to the longitudinal axis of said body and comprised of two mating halves which may be attached and detached from each other, said body for providing support for said scissors blades and having a chamber having first and second sections therein in fluid communication with each other and a bore providing access to the inside of the body and to at least said first section of said chamber, said body having tool attachment means through which said bore passes, said tool attachment means for providing easy attachment or detachment of said scissor blades or other surgical tools without the need to disassemble said body;

a sliding rod slidably coupled to the inside of said body via a projecting portion which projects through and is guided by said bore and which passes through said tool attachment means so as to engage the driving mechanism of any tool attached to said tool attachment means, said projecting portion having a dimension relative to the diameter of said bore so as to provide a fit which is loose enough so as to not generate excessive friction when said projecting portion slides in said bore, said sliding rod having an annular shoulder having first and second surfaces;

a spring housed in said first section of said chamber and engaging said first surface of said shoulder so as to bias said sliding rod so as to tend to move to a predetermined position in said body absent the effect of other forces acting upon said sliding rod;

a flexible, non metallic, autoclavable diaphragm mechanically affixed in sealing engagement with the walls of said second section of said chamber and mechanically affixed in sealing engagement with said second surface of said annular shoulder of said sliding rod so as to form a flexible movable wall of said second section of said chamber;

an inlet for coupling via a hose to a source of pressurized air, said inlet being in fluid communication with said second chamber, said inlet extending parallel to the longitudinal axis of said body in such a manner that said body may be turned in the user'"'"'s hand to any angle without interference by any hose coupled to said inlet;

adjustment means for limiting the range of movement of said sliding rod to a user selected maximum;

and further comprising a footswitch position sensor and means coupled to said footswitch position sensor for introducing pressurized air into said second chamber having a pressure which is proportional to the amount of displacement of said footswitch position sensor operated by a user;

wherein said means for introducing pressurized air includes a microprocessor means for reading the position of the footswitch position sensor and for calculating the fraction of total displacement which then exists on the footswitch position sensor and for multiplying this fraction times a constant, and for sending the result to a D/A converter means for converting the number so calculated to an analog signal which controls a linear valve means for modulating a flow of pressurized air in proportion to the amplitude of said analog signal, said linear valve means pneumatically coupling said modulated flow of pressurized air to a jewelled orifice means for converting the flow volume of pressurized air to a pneumatic pressure signal which has a pressure which is proportional to the flow volume, said jewelled orifice having a pneumatic line from the chamber of said jewelled orifice to said second chamber.

3. An apparatus for driving scissors blades comprising:

a body having a round cross section at any cross section normal to the longitudinal axis of said body and comprised of two mating halves which may be attached and detached from each other, said body for providing support for said scissors blades and having a chamber having first and second sections therein in fluid communication with each other and a bore providing access to the inside of the body and to at least said first section of said chamber, said body having tool attachment means through which said bore passes, said tool attachment means for providing easy attachment or detachment of said scissor blades or other surgical tools without the need to disassemble said body;

a sliding rod slidably coupled to the inside of said body via a projecting portion which projects through and is guided by said bore and which passes through said tool attachment means so as to engage the driving mechanism of any tool attached to said tool attachment means, said projecting portion having a dimension relative to the diameter of said bore so as to provide a fit which is loose enough so as to not generate excessive friction when said projecting portion slides in said bore, said sliding rod having an annular shoulder having first and second surfaces;

a spring housed in said first section of said chamber and engaging said first surface of said shoulder so as to bias said sliding rod so as to tend to move to a predetermined position in said body absent the effect of other forces acting upon said sliding rod;

a flexible, non metallic, autoclavable diaphragm mechanically affixed in sealing engagement with the walls of said second section of said chamber and mechanically affixed in sealing engagement with said second surface of said annular shoulder of said sliding rod so as to form a flexible movable wall of said second section of said chamber;

an inlet for coupling via a hose to a source of pressurized air, said inlet being in fluid communication with said second section of said chamber, said inlet extending parallel to the longitudinal axis of said body in such a manner that said body may be turned in the user'"'"'s hand to any angle without interference by any hose coupled to said inlet;

adjustment means for limiting the range of movement of said sliding rod to a user selected maximum;

and further comprising a footswitch and first means for introducing pressurized air into said inlet having a periodic pressure variation over time with a frequency which is set by a user by manipulation of said footswitch in a multicut mode, and second means for introducing pressurized air into said inlet having a pressure which is proportional to the amount of depression of said footswitch by said user in a proportional cut mode, and further comprising mode control means coupled to said first and second means for switching upon user command between said multicut and proportional cut modes and activating either said first means or said second means depending upon which mode is selected;

and wherein said means for introducing pressurized air includes a microprocessor means for reading the fraction of total displacement of a footswitch position sensor and for calculating a cut frequency by taking the fraction so read and multiplying it by a constant and for storing the result in memory, and from time to time reading this result in memory and calculating a step size by which to increase or decrease the pneumatic pressure to said apparatus for driving scissors blades, and for converting this step size to a number which is sent to a digital to analog converter means for converting said number to an analog signal which is coupled to a linear valve means for converting said analog signal to a flow of pressurized air having a flow volume which is proportional to the amplitude of said analog signal, said flow volume being coupled to a jewelled orifice means for converting the volume of air flow into a corresponding pressure level, said jewelled orifice having a pneumatic line coupled from the chamber of said jewelled orifice to said inlet.

4. An apparatus for providing pneumatic drive for a scissors 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;

means having an inlet for converting pneumatic pressure into sliding motion of said sliding rod including a flexible, non metallic, autoclavable diaphragm used to expand under the influence of higher than atmospheric pressure where said expansion is coupled to said rod to create said sliding motion;

a footswitch;

first means for introducing pressurized air into said inlet having a periodic pressure variation over time with a frequency which is set by a user by manipulation of said footswitch in a multicut mode;

second means for introducing pressurized air into said inlet having a pressure which is proportional to the amount of depression of said footswitch by said user in a proportional cut mode;

mode control means coupled to said first and second means for switching upon user command between said multicut and proportional cut modes and activating either said first means or said second means depending upon which mode is selected.

5. An apparatus for pneumatically driving a scissors comprising:

a body means for providing support;

a moving member movably coupled to said body in such a manner as to not suffer excessive friction during relative movement between said moving member and said body;

pressure conversion means for converting pneumatic pressure into movement of said moving member of a distance proportional to the amount of pneumatic pressure applied;

a footswitch;

first means for introducing pressurized air into said pressure conversion means having a periodic pressure variation over time with a frequency which is set by a user by manipulation of said footswitch in a multicut mode;

second means for introducing pressurized air into said pressure conversion means having a pressure which is proportional to the amount of depression of said footswitch by said user in a proportional cut mode;

mode control means coupled to said first and second means for switching, upon user command, between said multicut and proportional cut modes and activating either said first means or said second means depending upon which mode is selected; and

wherein said first means for introducing pressurized air includes a microprocessor means for reading the fraction of total displacement of a footswitch position sensor and for calculating a cut frequency by taking the fraction so read and multiplying it by a constant and for storing the result in memory, and from time to time reading this result in memory and calculating a step size by which to increase or decrease the pneumatic pressure to said apparatus for driving scissors blades, and for converting this step size to a number which is sent to a digital to analog converter means for converting said number to an analog signal which is coupled to a linear valve means for converting said analog signal to a flow of pressurized air having a flow volume which is proportional to the amplitude of said analog signal, said flow volume being coupled to a jewelled orifice means for converting the volume of air flow into a corresponding pressure level, said jewelled orifice having a pneumatic line coupled from the chamber of said jewelled orifice to said inlet; and

wherein said second means for introducing pressurized air includes a microprocessor means for reading the position of the footswitch position sensor and for calculating the fraction of total displacement which then exists on the footswitch position and for multiplying this fraction times a constant, and for sending the result to a D/A converter means for converting the number so calculated to an analog signal which controls a linear valve means for modulating a flow of pressurized air in proportion to the amplitude of said analog signal, said linear valve means pneumatically coupling said modulated flow of pressurized air to a jewelled orifice means for converting the flow volume of pressurized air to a pneumatic pressure signal which has a pressure which is proportional to the flow volume, said jewelled orifice having a pneumatic line from the chamber of said jewelled orifice to said second chamber; and

further comprising feedback means in said pressure conversion means for monitoring the actual pressure acting on said moving member and comparing the actual pressure to the desired pressure as calculated by the microprocessor means and for generating an error signal and further comprising means for converting said error signal to a change in the flow of pressurized air through said linear valve means in a manner to tend to bring the actual pressure closer to said desired pressure.