MXPA00010015A - Torsional ultrasound handpiece - Google Patents

Abstract

A handpiece (10) suitable for use in ophthalmic phacoemulsification surgery is provided with an ultrasonically driven cutting tip (16), comprising an ultrasound horn (18) having longitudinally vibrating piezoelectric elements. To obtain oscillatory or torsional movement as well as longitudinal movement, a series of generally parallel, circumferentially disposed, diagonal slits (20) is provided in the ultrasonic horn. The slits translate longitudinal vibrations into oscillatory or torsional vibrations.

Description

TORSIONAL ULTRASOUND HANDPIECE This invention relates to ultrasonic devices and more particularly to an ophthalmic phacoemulsification hand piece. Background of the Invention A typical ultrasonic surgical device suitable for ophthalmic procedures, consists of an ultrasonically directed hand piece, a connected hollow cutting tip, an irrigation sleeve and an electronic control console. The handpiece structure is connected to the control console by an electrical cable and flexible pipes. Through the electric cable, the console varies the energy level transmitted by the handpiece to the connected cutting tip and the flexible tubing supplies irrigation fluid to and extract suction fluid from the eye through the handpiece structure . The operative part of the hand piece is a hollow resonating horn or bar located centrally, directly connected to a set of piezoelectric crystals. The crystals provide the required ultrasonic vibration necessary to direct both the tube and the cutting tip connected during phacoemulsification and are controlled by the console. The glass / horn structure is suspended within the body or cover of the handpiece at its nodal points by relatively inflexible mounts. The handpiece body ends in a portion of reduced diameter or tip in • the far end of the body. The tip is externally threaded to accept the irrigation sleeve. Likewise, the perforation of the tube is internally threaded at its distal end to receive the external threads of the cutting tip. The irrigation sleeve has an internally threaded hole that is screwed into the external threads of the tip. The cutting tip is adjusted such that only a predetermined amount is projected beyond the open end of the irrigation sleeve. When it is used to perform phacoemulsification, the ends of the cutting tip and the irrigation cuff are inserted into a small incision of predetermined width in the cornea, sclera, or other location in the tissue of the eye in order to gain access to the anterior chamber of the eye. eye. The cutting tip is vibrated ultrasonically on its longitudinal axis within the irrigation sleeve by the glass-guided ultrasonic horn, thereby emulsifying the selected tissue in situ before contact. The hollow perforation of the cutting tip communicates with the perforation in the tube that in turn communicates with the suction line of the handpiece to the console. A source of vacuum or reduced pressure in the console removes or aspirates the emulsified tissue from the eye through the open end of the • Cutting tip, perforation of the cutting tip, perforation of the tube and the suction line and towards the collection device. Aspiration of emulsified tissue aids in a saline or irrigant wash solution that is injected into the surgical site through the small annular space between the inner surface of the irrigation sleeve and the • outer surface of the cutting tip. There have been previous attempts to combine ultrasonic longitudinal movement of the cutting tip with rotational or oscillatory movement of the tip, see the patents of the U.S.A. Nos. 5,222,959 (Anis), 5,722,945 (Anis, and collaborators and 4,504,264 (Kelman), all the contents of which are incorporated herein by reference.

These previous attempts have used electric motors to provide the rotation in the tip that requires O-rings or other seals that may fail in addition to the added complexity and possible failure of the engines. Accordingly, there continues to be a need for a reliable ultrasonic oscillating hand piece. 25 Brief Summary of the Invention The present invention improves upon prior art ultrasonic devices by providing a hand piece having a set of • longitudinally vibratory piezoelectric elements. To obtain oscillatory or torsional movement, a series of parallel, diagonal grooves is provided circumferentially around the ultrasonic horn. The grooves transfer longitudinal vibrations in oscillatory or torsional vibrations. Accordingly, an object of the present invention is to provide an ultrasound handpiece that has both longitudinal and torsional movement. An additional objective of the present; invention is to provide an ultrasound hand piece with a tube having a series of diagonal slots to produce torsional movement. Other objects, features and advantages of the present invention will be apparent with reference to the drawings and the following description of the drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view of the ultrasonic horn that can be employed with the handpiece of the present invention. Figure 2 is a cross-sectional view of the ultrasonic horn that can be used with the handpiece of the present invention taken on line 2-2 of Figure 1. Figure 3 is a perspective view of the Ultrasonic horn that can be used with the handpiece of the present invention. Figure 4 is a perspective view of the handpiece of the present invention. Figure 5 is a block diagram of a first controller circuit that can be employed with the present invention. Figure 10 is a block diagram of a second controller circuit that can be employed with the present invention. Detailed Description of the Invention As best seen in Figure 4, the handpiece 10 of the present invention generally includes a hand piece cover 12, infusion sleeve 14 and cutting tip 16. As best seen in the Figures 1 to 3, the hand piece 10 contains the ultrasonic trunnion 18. The handpiece 10 generally contains at least one pair of piezoelectric crystals (not shown) coupled to the trunnion 18, to create longitudinal vibratory movement in the trumpet 18 when it is excite the crystals. The materials used for and construction of the handpiece 10 and the horn 18 (except for the slots 20) are well known to those skilled in the art. See, for example, US Pat. Do not. • 4,169,984 (Parisi), 4,515,583 (Sorich), 4,989,588 (Kubota, et al.) And 5,359,996 (Hood), all the contents of which are hereby incorporated by reference. The horn 18 contains a series of circumferential, generally parallel, diagonal slots 20 near the distal end 22 of the horn 18. The angle of the slots 20 is preferably about 45 ° to the longitudinal axis of the horn 18, which is the main stress angle for the tube 18, but any angle can be used between 10 ° and 80 °, being preferred between 45 ° and 60 °. As a person with skill in the specialty will recognize, the exact location, number and tameiño of slots 20 required to convert the longitudinal movement of the crystals to torsional or oscillatory movement of the distal end 22 of the horn 18, will vary depending on the amount of torsional movement desired. Speaking in In general, efficient conversion will occur with slots 20 between .00254 cm (.001 inch) and 1.016 cm (0.4 inch) in depth. In addition, the slots 20 do not need to be parallel to each other. As seen in Figure 5, the generator ultrasound 26 employs a broad spectrum source to generate at least one component of the signal that directs an ultrasonic handpiece ("the control signal"). The broad spectrum source can be programmable and from this • way is easily adjustable by varying certain feed information that is supplied to the source. However, a fixed spectrum source can also be used without difficulty. A digital signal processor ("DSP" = Digital Signal Processor) of Fast Fourier Transform ("FFT" = Fast Fourier Transform) can be used to analyze the response of the handpiece 10 to the • wide-spectrum component of the control signal. In real-time applications, the FFT DSP output is used to generate built-in control parameters within an appropriate feedback signal, which is feeds the circuits that generate the control signal in order to alter aspects of the control signal. As will be seen in Figure 6, the ultrasound generator 26 can also employ a conventional signal processor to analyze the response of the hand piece 10 to the signal of control. The term "control signal" as used herein encompasses at least one signal useful only for energizing an ultrasonic handpiece, a signal useful only for adjusting or calibrating a handpiece, and a combination of this power signal and this signal of adjustment or calibration.

As illustrated in Figure 5, the wide-spectrum signal source 28 generates the control signal 4 which is combined with the control signals 5 and 6 of the • single torsional frequency source 30 and longitudinal single frequency source 32 respectively in amplifier 34. Amplifier 34 supplies control signal 36 to handpiece 10 and to FFT DSP 38. The DSP 38 FFT also receives the signal of feedback 40 of the handpiece 10. FFT DSP 38 processes the control signal 36 and the feedback signal 40 in the form that is • 'more fully described in the U.S. patent application. of common property Serial No. 08 / 769,257 (corresponding to PCT patent application No. PCT / US97 / 15952), all the contents of which hereby incorporated by reference, to determine the operating characteristics of the handpiece 10. FFT DSP 38 determines the electrical response of the handpiece 10 in the broad-spectrum signal 4 and provides the signal 42 to the DSP 39 which generates signals of Adjustment 60 and 61 to adjust the frequencies and / or output voltage of the sources 32 and 30, respectively in order to adjust the control signals 5 and 6. As illustrated in Figure 6, two conventional control signal sources, such as those described in the US patent. No. 5,431,664, all the contents of which are hereby incorporated by reference, or the patent application of the U.S. Serial No. 08 / 769,257 (corresponding to the patent application • from PCT No. PCT / US97 / 15952), can be used. For example, the source 44 can generate the control signal 45 for the torsional crystals 18 and the source 46 can generate the control signal 47 for the longitudinal crystals 20. The control signals 45 and 47 are combined in the amplifier 134 and direct the signal 136 supplied to the hand piece 110. The signal of • feedback of the handpiece 140 is filtered through the separator 48 to provide adjustment signals 50 and 52 to the sources 44 and 46. The separator 48 can be any number of analog or digital devices commercially available such as low pass or high pass filters or heterodyne receiver. While certain embodiments of the present invention have been described above, these descriptions are given for the purpose of illustration and explanation. Variations, changes, modifications and separations of the systems and methods described above can be adopted without departing from the scope or spirit of the present invention.

Claims (3)

1. CLAIMS 1. An ultrasound surgical hand piece, characterized in that it comprises: a) a piece cover • hand; b) an ultrasound tube supported within the cover, the tube contains a plurality of circumferential, diagonal grooves, dimensioned and spaced to produce torsional in the tube in response to longitudinal vibration of the tube; and c) a cutting tip mounted on the tube distant from the slots.
2. 2. The hand piece of claim 1, characterized in that the horn has a longitudinal axis and the slots are arranged at an angle between 10 degrees and 80 degrees with respect to the longitudinal axis.
3. 3. The hand piece of claim 2, characterized in that the slots are arranged at an angle between 45 degrees and 60 degrees with respect to the longitudinal axis.