MXPA99005015A - Control system for one piece manual delicuefacc - Google Patents

Abstract

A control system for a manual liquefaction part, which uses the output of a surgical console to generate a control signal for a radio frequency (RF) amplifier. The output of the RF amplifier is used to drive the heating element of the manu

Description

CONTROL SYSTEM FOR ONE PIECE MANUAL LIQUEFACTION BACKGROUND OF THE INVENTION This invention relates, generally, to the field of cataract surgery and, more particularly, to a control system for a manual part to practice the cataract removal liquefaction technique. The human eye, in its simplest terms, functions to supply vision, transmitting light through a clear external portion, named the cornea, and focusing the image through the lens on the retina. The amount of the focused image depends on many factors, including the size and configuration of the eye and the transparency of the cornea and the lens. When age or diseases cause the lens to become less transparent, vision deteriorates due to the diminished light that can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. An accepted treatment for this condition is the surgical removal of the lens and the replacement of lens function by an artificial intraocular lens ("IOL").

In the United States of America, most cataract lenses are removed by a surgical technique called phacoemulsification. During this procedure, a thin phacoemulsive cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquefies or emulsifies the lens, so that it can be sucked out of the eye. The diseased lens, once removed, is replaced by an artificial lens. A typical ultrasonic surgical device, suitable for ophthalmic procedures, consists of an ultrasonically driven handpiece, an attached cutting point, and an irrigation cuff and an electronic control console. The manual piece assembly is attached to the control console by an electrical cable and flexible pipes. Through the electric cable, the console varies the power level transmitted by the handpiece to the attached cutting tip and the flexible tubing supplies the irrigation fluid and drives the aspiration of the fluid from the eye through the handpiece assembly. The operative part of the manual piece is a hollow resonance bar, placed centrally, or horn, directly attached to a set of piezoelectric crystals. The crystals provide the required ultrasonic vibration, necessary to drive both the horn and the attached cutting tip during phacoemulsification and are controlled by the console. The glass / horn assembly is suspended within the hollow body or cover of the handpiece by flexible assemblies. The handpiece body terminates in a reduced diameter portion or nasal cone at the distal end of the body. The nose cone is screwed externally to accept the irrigation sleeve. Similarly, the horn auger internally threads at the distal end to receive the external threads of the cutting tip. The irrigation sleeve also has an internally threaded bore, which is screwed into the external threads of the nose cone. The cutting tip is adjusted so that the tip projects only for a predetermined amount, past the open end of the irrigation sleeve. Ultrasonic handpieces and cutting tips are described more fully in US Pat. Nos. 3,589,363; US 4,223,676; US 4,246,902; US 4,493,694; US 4,515,583; US 4,589,415; US 4,609,368; US 4,869,715; US 4,922,902; USES 4,989,583; US 5,154,694 and US 5,359,996, the complete contents of which are incorporated herein by reference. During use, the ends of the cutting tip and the irrigation sleeve are inserted into a small incision of predetermined width in the cornea, sclera or other location. The cutting tip is vibrated ultrasonically along its longitudinal axis inside the irrigation sleeve by the glass-driven ultrasonic horn, thus emulsifying the selected tissue in situ. The hollow hole of the cutting tip communicates with the hole in the horn, which in turn communicates with the suction line from the hand piece to the console. A source of reduced pressure or vacuum in the console drives or sucks the emulsified tissue from the eye through the open end of the cutting tip, the cutting tip and the horn holes and the suction line and into the collection device. The suction of the emulsified tissue is aided by an abundant or irritant saline solution, which is injected into the surgical site through a small annular gap, between the inner surface of the irrigating sleeve and the cutting tip. Recently, a new technique of cataract removal has been developed, involving the injection of hot water (approximately 45 to 105 ° C) or a saline solution, to liquefy or gel the hard core of the lens, thus making it possible to aspirate the lens liquefied from the eye. The aspiration is carried out with the injection of the heated solution and the injection of a relatively cold solution, thus rapidly cooling and removing the heated solution. This technique is described more fully in U.S. Pat. No. 5,616,120 (Andrew, et al.), The entire contents of which are incorporated herein by reference. The apparatus disclosed in the publication, however, heats the solution separately from the surgical handpiece. Controlling the temperature of the heated solution can be difficult, because the fluid lines feeding the handpiece are typically up to two meters long, and the heated solution can be considerably cooled as it travels along the length of the pipe. Therefore, the need continues for a surgical manual piece that can internally heat the solution used to carry out the liquefaction technique.

Brief Summary of the Invention The present invention is an improvement over the prior art, by the provision of a control system for a manual liquefaction part. The system uses the output from a surgical console to generate a control signal for an RF amplifier. The output from the RF amplifier is used to drive the heating element of the handpiece. Therefore, an object of the present invention is to provide a surgical console control system. Another object of the present invention is to provide a surgical console control system that generates a control signal for an RF amplifier. Another objective of the present invention is to provide a surgical console control system that supplies a pulse signal for a manual liquefaction part. These and other objects and advantages of the present invention will become apparent from the detailed description and the claims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front, top, left, perspective view of the hand piece of the present invention; Figure 2 is a rear, top, right, perspective view of the hand piece of the present invention; Figure 3 is a cross-sectional view of the hand piece of the present invention, taken along a plane passing through the irrigation channel; Figure 4 is a cross-sectional view of the hand piece of the present invention, taken along a plane passing through the suction channel; Figure 5 is an enlarged partial cross-sectional view of the hand piece of the present invention, taken in the circle 5 in Figure 4; Figure 6 is an enlarged, partial cross-sectional view of the hand piece of the present invention, taken in the circle 6 in Figure 3; Figure 7 is an enlarged cross-sectional view of the hand piece of the present invention, taken on the circle 7 in Figures 3 and 4, and showing a boiler pump of resistances; Figure 8 is a schematic, cross-sectional view of a boiler pump of the heating element, which can be used with the present invention; Figure 9 is a partial cross-sectional view, with separate parts, of a modality of the hand piece of the present invention; and Figure 10 is a block diagram of a control system that can be used with the hand piece of the present invention.

Detailed Description of the Invention The hand piece 120 of the present invention generally includes a body 12 and an operative tip 16. This body 12 generally includes an external lumen 18 for irrigation and the suction attachment 20. The body 12 is similar in construction to the phacoemulsification handpieces, well known in the art, and can be made of plastic, titanium or stainless steel. As best seen in Figure 6, the operating tip 16 includes the tip / cap sleeve 26, the needle 28 and the lumen 30. This sleeve 26 can be any suitable phacoemulsification tip / cap, commercially available, or the Sleeve 26 can be incorporated into other tubes as a multi-lumen tube. Needle 28 can be any commercially available phacoemulsification hollow cutting tip, such as the TURBOSONICS tip, available from Alcon Laboratories, Inc., Fort Worth, Texas. The lumen 30 can be any pipe with a suitable dimension, to be mounted inside the needle 28, for example a 29-gauge hypodermic needle line. As best seen in Figure 5, the lumen 30 is free at the distal end and is connects to the pump chamber 42 at the proximal end. The lumen 30 and the pump chamber 42 can be sealed in a fluid-tight manner by any suitable means, having a relatively high melting point, such as silver solder. The fitting 44 holds the lumen 30 within the bore 48 of the suction horn 46. This hole 48 communicates with the accessory 20, which is rotatably mounted on the horn 46 and sealed with the 0-ring seal 50, to form a suction path through the horn 46 and the external fitting 20 The horn 46 is held within the body 12 by the seal 56 of O-ring, to form the irrigation lumen 52, which communicates with the irrigation lumen 18 at the door 54. As best seen in Figure 7, in a first embodiment of the present invention, the pump chamber 42 contains a relatively large pumping tank 43, which is sealed at both ends by the electrodes 45 and 47. Electrical power is supplied to the electrodes 45 and 47 by insulated wires 49 and 51, respectively. During use, surgical fluid (eg, saline irrigation solution) enters reservoir 43 through port 55, lumen 34 and check valve 53. The electrical current (preferably RFAC) is delivered to and through the electrodes 45 and 47, due to the conductive nature of the surgical fluid. As the current flows through the surgical fluid, this surgical fluid boils. As this surgical fluid boils, it rapidly expands out of the pump chamber 42 through the door 57 and into the lumen 30 (the check valve 53 prevents the expanding fluid from entering the lumen 34). Bubbles of the expansion gas push the surgical fluid into the lumen 30 downstream of the pump chamber 42 forward. Subsequent pulses of the electric current form sequential gas bubbles that move the surgical fluid down to the lumen 30. The size and pressure of the fluid pulse obtained by the pump chamber 42 can vary varying the length, time and / or power of the electrical pulse sent to the electrodes 45 and 47 and varying the dimensions of the reservoir 43. Furthermore, the surgical fluid can be preheated before entering the pumping chamber 42. The pre-heating of the surgical fluid will decrease the power required by the chamber of pumping 42 and / or will increase the speed at which the pressure pulses can be generated. While various embodiments of the hand piece of the present invention are described, any hand piece that produces a suitable pulse force, time and frequency of lifting, can also be used. For example, any suitable hand piece that produces a pulse force of pressure between 0.03 and 3.0 grams, with a rise time between 1 and 3,000 grams / second and a frequency between 1 and 200 Beam, may be used, being most preferred between 10 and 100 Do. The pulse force of pressure and frequency can vary with the hardness of the material being removed. For example, the inventors have found that a lower frequency with a higher pulse force is more efficient in undoing and removing relatively hard nuclear material, with a higher frequency and a lower pulse force being useful in removing the epinuclear and cortical material more soft. The infusion pressure, suction flow rate and vacuum limit are similar to current phacoemulsification techniques. As seen in Figure 8, the fluid in the reservoir 143 in the pump chamber 142 can also be heated by the use of the heating element 145, which is internal to the reservoir 143. The heating element 145 can be, for example , a coil of stainless steel wire of 76.2 microns in diameter, to which power is supplied by the power source 147. The size and pressure of the fluid pulse obtained by the pump chamber 142 may vary by varying the length of the electrical pulse sent to the element 145 by the source 147 of power and varying the dimensions of the reservoir 143. As seen in Figure 10, one embodiment of the control system 300 for use in operating the hand piece 310 includes the control module 347, the RF amplifier 312 of gain of power and the function generator 314. The power is supplied to the RF amplifier 312 by a DC power supply 316, which is preferably a DC isolated power supply, operating at several hundred volts, but specifically at ± 200 volts. The control module 347 can be any microprocessor, microcontroller, computer or digital logic controller and can receive input from the operator input device 318. The function generator 314 supplies the electric waveform in kilohertz to the amplifier 312 and operates preferably at 450 KHz to help minimize corrosion. During use, the control module 347 receives the input from the surgical console 320. The console 320 can be any commercially available surgical control console, such as the surgical system LEGACY® SERIES TWENTY THOUSAND®, available from Alcon Laboratories, Inc. ., Fort Worth, Texas. The console 320 is connected to the hand piece 310 through the irrigation line 322 and the suction line 324, and the flow through the lines 322 and 324 is controlled by the user by means of a foot switch 326. The information of the irrigation and suction flow rate in the hand piece 310 is provided to control the module 347 by the console 320 via the interface 328, which can be connected to the control door of the manual ultrasound part in the console 320 or any other exit door. The control module 347 uses the information of the foot switch 326 provided by the console 320 and the operator input from the input device 318 to generate two control signals 330 and 332. The signal 332 is used to operate the valve 334 of step, which controls the surgical fluid flowing from the fluid source 336 to the hand piece 310. The fluid from the source 336 is heated in the manner described herein. The signal 330 is used to control the function generator 314. Based on the signal 330, the function generator 314 supplies a waveform at the frequency selected by the operator and the amplitude determined by the position of the foot switch 326 to the RF amplifier 312, which is amplified to advance the form of power wave to the hand piece 310 to create pressurized pulses of the heated surgical fluid. As best seen in Figures 3, 4 and 7, the surgical fluid can be delivered to the pumping chamber 43 through the lumen 34 or, as seen in Figure 8, a surgical fluid can be delivered to the chamber. pumping 243 through lumen 234 of the irrigation fluid, which branches to the main irrigation lumen 235, supplying cold surgical fluid to the operative site. As seen in Figure 9, the aspiration lumen 237 can be contained internally in the handpiece 10. Any number of methods can be employed in order to limit the amount of heat produced in the eye. For example, the working cycle of the pulse train of the heated solution can be varied so that the total amount of the heated solution introduced into the eye does not vary with the pulse rate. Alternatively, the suction flow rate can vary as a function of the pulse frequency, so as the pulse rate increases, the suction flow rate will increase proportionally. This description was provided for the purpose of illustration and explanation. It will be apparent to those skilled in the pertinent art that changes and modifications can be made to the invention described above, without departing from the scope or spirit. For example it will be recognized by one skilled in the art that the present invention can be combined with ultrasonic and / or rotary cutting tips to increase their performance.

Claims (6)

1. CLAIMS 1. A control system for a manual liquefaction part, which comprises: a) a control module, capable of generating a control signal; b) a function generator, which receives the control signal, this function generator is capable of generating a waveform in response to the control signal; and c) an amplifier, which receives the waveform, this amplifier is capable of amplifying the waveform to provide a power waveform to the manual liquefaction, pumping part.
2. 2. The control system of claim 1, wherein the control module is a microprocessor.
3. 3. The control system of claim 1, wherein the function generator operates at about 450 KHz or more.
4. 4. The control system of claim 1, wherein the amplifier is a radio frequency (RF) amplifier.
5. 5. A control system for a manual piece, which comprises: a) a microprocessor, capable of generating a control signal; b) a function generator, which receives the control signal, this function generator is capable of generating a waveform in response to the control signal; and c) an RF amplifier, which receives the waveform, this amplifier is capable of amplifying the waveform to supply a power waveform output to the manual liquefying part.
6. 6. The control system of claim 5, wherein the function generator operates at 450 KHz.