Ultrasonsically vibrated surgical cutting instrument

Abstract

An improved ultrasonically vibrated surgical cutting instrument for cutting soft tissues without stretching the same during the cutting hereof having an ultrasonic frequency generator, a transducer connected to said ultrasonic frequency generator for creating a vibratory motion and having a vibrator in communication with the transducer, and a double blade knife with one of the blades adapted to move in a longitudinal direction along the motion of the vibrator and the other blade fixed to prevent deflection of the cutting blade during the cutting operation and retaining the tissue against the cutting edge such that when the sharp edge of the knife blades touch soft tissues the knife blades will cut the soft tissues without stretching the membrane.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation in part application to my copending application Ser. No. 386,867 for a Surgical Instrument filed Aug. 9, 1973, now abandoned.

Description

BACKGROUND OF THE INVENTION

1. Field of the Search.

This invention relates to an ultrasonically vibrated surgical cutting instrument for cutting soft tissues and more particularly to an ultrasonically vibrated surgical cutting instrument having two knife blades.

2. Prior Art.

Heretofore, it has been known that in an effort to cut soft tissues, for example, in the eye, the weight of a surgical knife cutting soft tissues tends to stretch the tissues such that after it has been severed the tissue does not return to its normal pre-severed size until a substantial time has elapsed, or may be permanently torn from adjacent tissues. It has been found that the reason for the stretching was due to the necessary weight which had to be placed on the soft tissue in order for the sharp surgical edge of the knife to engage the tissue to permit the commencement of the cutting. The weight of the knife coupled with the pressure applied by the surgeon was sufficient to depress the tissue and thereby stretch the same providing a somewhat deformed tissue after the severance had been made. Varying types of extremely sharp blades of very thin material have been used but none to the satisfaction of the surgical profession and particularly those concerned with intro-ocular surgery in ophthamology.

The ultrasonically vibrated surgical cutting instrument was developed to solve this problem. The blade vibrates as a result of longitudinal vibrations injected therein from the driving element. Because of the rapid oscillations of the blade much less pressure is applied in the cutting operation than with the ordinary knife.

While less pressure was needed to make the incision using the ultrasonically vibrated surgical cutting instrument, the prior art devices are limited to a single bladed knife. A problem developes when the single knife blade encounters increased resistance to cutting. There is a tendency for very thin blades to deflect or stray from the line along which the surgeon wishes to cut. Single blades lack the ability to stabilize the tissue being cut as well as the method using a second adjacent blade. In the case of delicate operations, it is imperative that the knife blade be prevented from deflecting to prevent damaging tissue adjacent to the incision, and that the tissue be cut smoothly without stretching.

OBJECTS OF THE PRESENT INVENTION

It is the general object of the present invention to avoid and overcome the foregoing and other difficulties which will become apparent as the description proceeds by providing an ultrasonically vibrated surgical cutting instrument which has two knife blades, one of which is fixed and the other of which is free to vibrate.

Another object of the present invention is to provide an ultrasonically vibrated surgical cutting instrument having two knife blades, in which the fixed blade prevents the moveable blade from deflecting from desired cutting line.

Yet another object of the present invention is to provide an ultrasonically vibrated surgical cutting instrument which is of a simplified construction and can be economically produced.

SUMMARY OF THE INVENTION

The objects of the present invention have been achieved by providing a surgical cutting instrument for use in cutting soft tissues without stretching the tissues during the cutting operation being provided with ultrasonic frequency generator, a transducer in communication with said ultrasonic frequency generator, a vibrating anvil in communication with said transducer and adopted to vibrate along the longitudinal axis thereof, and a double blade knife, one of the knife blades being in communication with said vibrating anvil so that said knife blade will move along the longitudinal axis thereof, while the other blade remains fixed and prevents said moveable blade from deflecting from a desired cutting line.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention reference should be had to the accompanying drawing wherein like numerals of reference indicate similar parts throughout the respective views and wherein:

FIG. 1 is a profile view of the improved ultrasonically vibrated surgical cutting instrument in accordance with the present invention.

FIG. 2 is a partial sectional view at an enlarged scale along line 2--2 in FIG. 1.

FIG. 3 is a sectional view at an enlarged scale along line 3--3 in FIG. 1.

FIG. 4 is a sectional view of an alternative knife blade construction.

FIG. 5 is a sectional view of the relationship of the two knife blades at a greatly enlarged scale.

FIG. 6 is a sectional view along line 6--6 of FIG. 2.

FIG. 7 is a sectional view along line 7--7 of FIG. 2.

FIG. 8 is a partial view, at an enlarged scale, of an alternative knife blade construction.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, the ultrasonically vibrated surgical cutting instrument is generally indicated by the reference numeral 10. The basic concept of an ultrasonically vibrated surgical cutting instrument is old in the art and will not be discussed in detail herein. Basically, the frequencies developed by an ultrasonic generator are connected to vibratory mount by a transducer. A vibrating anvil in communication with the transducer transmits the vibratory motion to the knife blade of the cutting instrument. The surgical cutting instrument 10, has two knife blades 11 and 12 which will be described hereinafter in further detail.

As shown in FIG. 2, the ultrasonically vibrated surgical cutting instrument 10 has a housing within which the abovementioned ultrasonic generator, transducer and vibratory anvil are located. Because the present invention is adapted to be used on a conventional ultrasonically vibrated cutting instrument, the details of the ultrasonic generator, transducer, and vibrating anvil are not shown. Only a portion of the vibrating anvil is shown and is identified with the reference numeral 14.

As the open end of housing 13 is a retaining collar 15, the retaining collar 15 is mounted to the housing 13 so that it is free to rotate thereon. The projection 16 at the end 17 of the retaining collar 15 cooperates with a channel 18 in the end of the housing 13 and is retained therein by the retaining projection 19.

The end portion 20 of the ultrasonically vibrated surgical cutting instrument 10 is releasably secured to the housing 13 by means of the retaining collar 15. Threads 21 on the end 22 of the end portion 20 cooperate with threads 23 on the retaining collar 15. For reasons which will become apparent hereinafter, the end portion 20 will be drawn towards the housing 13 and become secured thereto. When the retaining collar 15 is rotated in the opposite direction, the end portion 20 is drawn away from the housing 13 and can be removed from the retaining collar 15.

The end portion 20 has a passageway 24 therethrough within which the connecting bar 25 is free to pass. The connecting bar 25 is releasably secured at its one end to the vibrating anvil 14. On the other end of the connecting bar 25 is mounted one of the knife blades 11. Releasably mounted to the end of the end portion 20 is a second blade 12. Blade 11 is the moveable knife blade and blade 12 is the fixed knife blade.

It is imperative that during the cutting operation the two blades do not separate. In delicate surgical operations, the surgeon must be sure that he is making the incision along the exact line that he intends to avoid damaging surrounding tissue.

The two knife blades 11 and 12 are designed to prevent them from separating during the actual cutting operation. As shown in FIG. 3, the moveable knife blade 11 has a keyway 26 cut therein. The fixed knife blade 12 has a projection 27 which cooperates with the keyway 26 to keep the two knife blades in a close operating relationship. To further prevent separation of the knife blades, the moveable knife blade 11 has a downward extension 28 which extends over the top of the fixed knife blade 12. This downward extension 28 of knife blade 11 biases knife blade 11 against knife blade 12 so that the inside surface 29 of the knife blade 11 and the inside surface 30 of the knife blade 12 meet only at the tip 31 where the cutting edge 32 is formed. This biasing action also has the effect of limiting the friction effects between the blades.

An alternative construction for the knife blades is shown in FIG. 4. The downward extension 33 of the knife blade 11 has an upward projection 34 which cooperates with the downward projection 35 on the knife blade 12 to further prevent the knife blades 11 and 12 from separating during the cutting action.

In addition to the structure of the knife blades, the passageway 24 and the connecting bar 25 are also designed to prevent the knife blades from separating. As shown in FIG. 6, the clearance 36 between the connecting bar 25 and the walls of the passageway 24 is at a minimum to prevent the separation. In addition, as shown in FIG. 7, a projection 37 from the wall 38 of the passageway 24 cooperates with a groove 39 in the connecting bar 25 to limit the excessive movement of the connecting bar 25 and thus preventing separation of the knife blades.

In FIG. 8, an alternative knife blade construction is shown. Either or both of the knife blades may be serrated, to enhance the cutting operation, along the cutting edge.

In view of the need to change knife blades after each operation, to maintain sterile conditions, the knife blades 11 and 12 are removeable from the vibrating anvil 14 and end portion 20 respectively. To facilitate removal of the moveable knife blade 11 and connection bar 25, the end portion 20 of the surgical cutting instrument 10 is releasably secured to the housing 13 by means of the retaining collar 15 as hereinabove described. The end 40 of the connecting bar 25 may releasably engage the vibrating anvil 14 by an conventional means such as a close tolerance press fit or by means of screw threads. As noted hereinabove, the fixed knife blade 12 is releasably secured to the end portion 20 and can be removed therefrom while the end portion is removed from the housing.

In summary, I have provided a surgical instrument for the cutting of very delicate soft tissues using an ultrasonically controlled surgical cutting blade which will permit the cutting of the soft tissues without the stretching of the tissues per se, having a moveable knife blade and a fixed knife blade which maintains the moveable blade along the desired cutting line.

While in accordance with the patent statutes a preferred and alternative embodiment are shown in detail, it should be particularly understood that the invention is not limited thereto or thereby.

Claims

I claim:

1. An improved ultrasonically vibrated surgical cutting instrument having an ultrasonic frequency generator, a transducer in communication with said ultrasonic frequency generator for converting ultrasonic energy to vibratory energy and a vibrating anvil in communication with said transducer for providing vibrations wherein the improvement comprises a fixed knife blade, a moveable knife blade in communication with said fixed knife blade and said vibrating anvil and means for preventing said moveable knife blade from separating from said fixed knife blade during the cutting operation so that said fixed knife blade prevents said moveable knife blade from deflecting during the cutting operation.

2. The device in accordance with claim 1 wherein said preventive means comprises a keyway in said moveable knife blade, a projection on said fixed knife blade in communication with said keyway, and a projection on said moveable knife blade in communication with said fixed knife blade to bias said moveable knife blade against said fixed knife blade.

3. The device in accordance with claim 2 wherein said moveable knife blade has a serrated cutting edge.

4. The device in accordance with claim 3 wherein said fixed knife blade has a serrated cutting edge.