Ultrasonic Surgical Instrument

Abstract

Surgical instrument using ultrasonic energy which are to operate upon tissue including arrangements for shielding ultrasonic transducer probe to prevent energy from being radiated into unwanted areas which also include provisions for applying irrigation fluid and/or suction pressure to desired locations within the operating field.

Description

This invention relates to surgical instruments and more particularly to surgical instruments using ultrasonic energy which are designed for operating on tissue, for example, to remove pieces of tissue from a larger mass. In prior U.S. Pat. No. 3,589,363, which I am one of the co-inventors, instruments of this general type are disclosed in which the probe end of an ultrasonic transducer is designed to be inserted through an incision into an operating field. The tip of the probe is to come in direct contact with tissue in the operating field and the ultrasonic energy radiated from the probe tip acts to remove particles of tissue from a larger tissue mass and to withdraw these particles from the operating field by means of a suction system. The removal of the tissue particles from the mass is generally accomplished by the ultrasonic energy which acts to emulsify the tissue, that is, to act upon a portion of the tissue to heat it by ultrasonic energy so that the tissue particles will break away from the larger body.

In the instruments disclosed in the aforesaid patent, a shield of a silicone composition is provided around a portion of the transducer probe to provide a passage for fluid to be introduced in the proximity of the operating field and to prevent the vibrator from rubbing against the walls of the incision or other parts of the body being operated upon. In the instruments of the patent, an arrangement is also provided for conveying suction pressure through the center of the transducer probe and irrigation fluid in a passage between the outer surface of the probe and the inner surface of the silicone shield. Since the suction pressure is applied directly through the center of the probe and the irrigation fluid also exits through the probe tip, this limits the usefulness of the instrument in the sense that the probe must be aimed directly at the tissue for the suction pressure and irrigation fluid to be effective. In many cases, this is neither desirable nor possible. In accordance with the teachings of the aforesaid patent, the tissue to be removed is to be brought directly into contact with the tip of the transducer probe. Here again, this has been found to be undesirable in many cases since portions of the tissue directly adjacent those in contact with the tip of the probe can become heated and possibly damaged.

The present invention relates to an improved ultrasonic surgical instrument. In accordance with the invention, a number of attachments are provided for use with an ultrasonic transducer, each attachment having an arrangement such that a shield of metallic material can be placed around the probe and held in concentric relationship therewith. This provides an effective shield against unwanted radiation of the ultrasonic energy. In addition, the attachements are such so as to be able to provide irrigation fluid or suction pressure, either individually or in combination, at desired points within the operating field, not necessarily in front of the probe. The attachments are also capable of providing suction pressure to draw the tissue to be removed adjacent the tip of the probe but hold it out of direct contact. In addition, an arrangement is provided for efficiently removing from the operating field those particles which have been cut from the tissue mass by a combined suction and pressure flow.

It is therefore an object of the present invention to provide ultrasonic instruments for removal of tissue in which unwanted radiation of ultrasonic energy can be controlled.

An additional object is to provide ultrasonic instruments in which the energy can be applied to a given localized area with the selective application of irrigation fluid and/or suction pressure at any desired portion within the operating field.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings, in which:

FIG. 1 is a plan view, taken partially in cross-section of a transducer useful with the present invention and a partial block diagram showing of the auxiliary equipment;

FIG. 2 is a fragmentary view of the front of the transducer, partially cut away and partially in cross-section showing a shield in accordance with the invention;

FIGS. 2A and 2B are fragmentary views shown partly broken away, of modifications of the transducer tip and shield;

FIG. 3 is a fragmentary view of the front of the transducer partially cut away and partially in cross-section showing a transducer modified for receiving irrigation fluid or suction pressure;

FIG. 4 is a fragmentary view of a portion of a transducer partly cut away and partly in cross-section showing another embodiment of the invention for using both irrigation fluid and suction pressure;

FIG. 4A is an enlarged fragmentary view of the end portion of the tip of the instrument of FIG. 4 showing a modification thereof;

FIG. 5 is a fragmentary view, taken partly in cross-section and partly broken away, of a further modification of the invention showing an external irrigation;

FIG. 5A is an enlarged fragmentary view of the tip of the instrument shown in FIG. 5 and showing a further modification thereof;

FIG. 6 is a fragmentary view, taken partly in cross-section, showing the tip of an instrument incorporating a further modification of the invention having internal irrigation;

FIG. 7 is a plan view of a further embodiment of the invention shown partly broken away and partly in cross-section; and

FIG. 7A is an enlarged view of the front portion of the tip of the instrument of FIG. 7.

Referring to FIG. 1, a typical transducer 10 for use with the subject invention is shown. While a magnetostructure type transducer is described, it should be understood that a piezoelectric type also may be utilized. The transducer includes the usual stack of laminations 12 of magnetostrictive material which are fastened together, such as by brazing, at one end 11. The stack 12 is to have coil of wire (not shown) placed in proximity thereto in a conventional manner to supply excitation energy of a suitable frequency, preferably in the ultrasonic range, from a source 14 over leads 16. Any suitable ultrasonic source may be utilized. The term "ultrasonic energy" is used herein in the broad sense and encompasses energy within the range from 1,000 Hz up to 100,000 Hz. Typical ultrasonic frequencies which are utilized are in the range between 25,000 Hz. 50,000 Hz. The ultrasonic source 14 is shown as having a variable control 15 for setting the frequency and/or the amplitude of power to be supplied to the transducer 10 over the leads 16. If desired, a suitable source of cooling fluid also can be used to cool the laminations 12 and the coil. This would be applied to a housing covering the stack and the coil. Such constructions are conventional in the art and are not further described.

The transducer 10 also includes an acoustic transformer 18 one of whose ends is threaded onto a stud 19 which is attached to the lamination stack 12. The transformer 18 has another set of threads 20 at an intermediate point to which is threaded the housing containing the coil for the stack 12 and the cooling fluid connections. Threads 20 are usually located at a nodal point of transformer 18.

The acoustic transformer 18 is tapered in a manner to achieve a desired impedance transformation between the end of stack 12 and a probe 24. A structure generally designated as 26 is provided between the threads 20 and end of transformer 18 adjacent the probe 24 to act as a mode suppressor and also as a resonator to tune the transformer 18 so that the desired longitudinal vibrations are produced at the free end (tip) of probe 24. Mode suppressor structure 26 has a thread 28 thereon to accept and hold a number of different types of shielding structures to be described below. Threads 28 are preferably located at or near a mode (null) point of the mode suppressor 26.

FIG. 1 also shows a source 30 of irrigation or treatment fluid, which can be of any desired composition, for example a saline solution, to be supplied to the area to be operated on and also a source 32 of suction pressure 32. The respective output conduits 30a and 32a are shown for these two sources. One or both conduits, as is described below, can be connected to the instrument to supply irrigation fluid and/or suction pressure to the area being operated upon.

The two sources 30 and 32 are shown under the control of a switching circuit 34. The switching circuit is operated by the person using the instrument. Any suitable switching circuit can be used, for example, a relay actuated circuit. One or both of the sources 30 and/or 32 can be actuated at a given time as desired. Such circuits are also conventional and no further description thereof is necessary.

As explained in my prior patent, the probe 24 is to be inserted into the tissue area to be operated upon. Where the tissue area is within the eye, a suitable incision is made and the probe inserted through the incision. The ultrasonic energy produced by the transducer 10 is converted into motion at the tip of the probe 24. Some of the energy also is radiated. The combination of the motion and the energy produce the desired effect on the tissue to change its state to a less solid form. This process is generally called emulsification. It has been found that the energy from the probe 24 preferably should be confined to the tip end so that only a predetermined portion of tissue adjacent the tip end will be effected by the instrument. To accomplish this, a shielding arrangement is used for the probe.

FIG. 2 shows a structure for confining the bulk of the ultrasonic energy within the length of probe 24. As shown, a hollow cap 40 is fastened to the threads 28 on the end of resonator 26. An O-ring is located between the inner face of cap 40 and a shoulder in front of threads 28 to provide a fluid-seal. A tubular sleeve 46 is fastened within the front end of cap 40 in the area 47 by an suitable arrangement which is compatible with the materials of both the cap 40 and the sleeve 46. In a preferred embodiment of the invention, both the cap 40 and the sleeve 46 are of stainless steel. Therefore, the construction to mate the two together can be either by welding or some other suitable technique. As should be apparent, the surface area 47 in which the joining of members 40 and 46 takes place provides a high degree of stability for the sleeve 46 so that it can be kept coaxial and concentric with the probe 24.

As seen in FIG. 2, only a small portion 24a of the probe extends beyond the free end of the sleeve 46. The material of shield 46 reflects the radiated ultrasonic energy from the probe 24. Because of this arrangement, ultrasonic energy will only be radiated from this unshielded tip portion 24a of the probe. Therefore, the area of the operational field which come in contact with the shield 46 will experience little or no deleterious effects. It should be noted that the length of the free end 24a beyond the shield 46 can be controlled somewhat by threading or unthreading in the cap 40 to move shield 46 forward or backward.

The shield-probe tip structure of FIG. 2 will have a relatively open pattern of ultrasonic energy radiation in the area beyond shield 46. Also, the tip 24a of the probe can come into contact with the tissue in the operational field. FIG. 2A shows a further arrangement in which a curved portion 47 of shield 46 extends over the front of the probe tip 24a. The extending portion 47 is designed preferably to cover only a portion of the total angle of the tip 24. That is, for example, the included angle of the extending piece 47 can be in the order from 30.degree. to about 27.degree..

Extending shield piece 47 serves two purposes. First of all, spaces the tip 24a of the probe away from the tissue being operated upon. That is, the tip 24a is kept substantially or entirely out of contact with the tissue by piece 47. Secondly, piece 47 confines the radiation of ultrasonic energy only to the open area of tip 24a. That is, little or no energy will be radiated into tissue in the area of the extension piece 47.

FIG. 2B shows another embodiment of the invention in which the shield 46 extends fully over the free end of the tip 24. This arrangement serves to further narrow down the beam of the ultrasonic energy radiated from the tip of probe 24. In addition, it completely prevents the tip 24 from coming into contact with the tissue. This provides an additional safety feature.

The shield structures of FIGS. 2A and 2B can be utilized with the instrument structure of FIG. 2.

FIG. 3 shows another embodiment of the invention which is similar to that as shown in FIG. 2. Here, the cap 40 is modified to have a bore 50 therein which accepts one of the conduits 30a or 32a from the irrigation or suction sources. Bore 50 communicates with an annular chamber 41 defined between the inner surface of cap 40 and the front end of the resonator 26. Irrigation fluid or suction pressure from conduit 30a or 32a passes from chamber 41 through the space, or passage, 25 between probe 24 and sleeve 46. Where irrigation fluid is used, the fluid exits passage 25 adjacent the tip 24a of the probe. This is shown by the arrow. Where suction pressure is used, the tissue to be operated upon will be drawn in towards the passage 25 to the active end 24a of probe 24. Here again, the shield 46 prevents a substantial portion of the ultrasonic energy from radiating into an undesired area.

It should be understood that the structures of FIGS. 2A and 2B can be used with the instrument of FIG. 3 to space the tip 24a from the tissue and/or to confine the radiation of the energy from the tip. In the embodiment of FIG. 3, the shield 46 is also held in spaced relationship from the probe 24 by the mounting arrangement. Where treatment fluid is supplied through the passage 25, the fluid also serves to cool the probe 24 and the shield 46. Both of these elements are heated to an extent by the ultrasonic energy.

FIG. 4 shows a further embodiment of the invention in which the instrument is provided with the capability of handling suction pressure and irrigation fluid at the same time. In the embodiment of FIG. 4 a second bore 54 is formed in the cap 40 and the cap is also formed with an annular space 57 near the front end thereof which communicates with bore 54. The sleeve 46 is attached to cap 40 as in the embodiments of FIGS. 2 and 3 so that the passage 25 between probe 24 and shield 46 is in communication with the annular chamber 41 which in turn is in communication with bore 50. Shield 46 is held in spaced relationship with probe 24.

A second sleeve 59 is attached to the front end of the cap 40 and spaced from the first sleeve 46 to define a second passage 27 therebetween. The second sleeve 59 can also be of the same material as sleeve 46, for example, stainless steel. The space 27 between the two sleeves 46 and 59 is in communication with the second annular chamber 57. Chamber 57 is isolated from chamber 41 by the ring 43 of the cap.

The bore 50 receives one of the two conduits 30a or 32a from the irrigation and suction sources while the bore 54 receives the other conduit. Depending upon which of the bores receives the respective conduit, the irrigation fluid or suction pressure is available in either of the passages 25 or 27. Normally, the irrigation fluid is provided in passage 27. The probe 24 is being cooled through the shield 46 and by the outgoing fluid.

Either of the modified shield structures of FIGS. 2A and 2B can be used with the instrument of FIG. 4.

FIG. 4A shows a modification of the shield structure instrument of FIG 4. Here, a nipple 61 is provided at the front end of the instrument to seal off the exit of passage 27 between the two sleeves 59 and 46. Outer sleeve 59 is provided with a hole 59a adjacent the collar. The remainder of the construction of the instrument of FIG. 4A is the same as that of FIG. 4.

In the instrument of FIG. 4A instead of having the irrigation fluid or suction pressure in the second passage 27 exit at the tip of the instrument, this fluid or suction pressure will exit through the opening 59a. There will be side irrigation or suction of the area being operated upon. Here again, only a small portion of the tip 24a of the probe is exposed and the majority of the tip is shielded against radiation of ultrasonic energy.

In the instrument of FIG. 4A, irrigation fluid is normally supplied through passage 27 and suction pressure through passage 25. Thus, the tissue is drawn toward the tip of probe 24. If desired, the structures of FIGS. 2A and 2B also can be used for the shield 46 of FIG. 4A to space the tissue from the tip of the probe.

In each of the embodiments of FIGS. 4 and 4A, the suction pressure draws the tissue toward the tip of probe 24 where it is acted upon by the ultrasonic energy. Any particles which are formed by the emulsification action are drawn out of the operational field by the suction pressure through passage 25.

FIG. 5 shows a still further embodiment of the invention. The portion of the instrument in the area of cap 40 is substantially similar to that of FIG. 4. Here, an opening 59b provided in the outer sleeve 59 and a curved nipple 66 closes off the passageway 27 between sleeves 46 and 59 at the tip end of the instrument and in front of opening 59b. Thus, the only exit for irrigation fluid applied from conduit 30a into passage 27 is through the opening 59b. The irrigation fluid does not interfere with the substance to be treated by the tip of the probe.

As seen best in FIG. 5A, a portion of 69 of the front of nipple 66 is cut off at an angle to expose the tip of probe 24 and to provide an exit from the inner passage 25 for the suction pressure. The nipple 66 can be fully circular to seal off the entire passage 27 or else, as shown in FIG. 5A, the lower portion of sleeve 59 can be bent, as at 61, and attached to the outer surface of sleeve 46 to provide the fluid seal.

As seen, the irrigation fluid exiting from opening 59b will be to one side of the active area of the tip of probe 24. The suction pressure is available at the front of the tip to draw the tissue to be operated upon toward the probe tip. Radiation of ultrasonic energy is confined substantially to the angled opening 69 by the nipple 66. Also, the nipple 66 prevents tissue from coming into contact with the major portion of the probe tip.

FIG. 5A shows a modification of the instrument of FIG. 5 in that the nipple 66 has been shortened to bring the exit port 59b for irrigation fluid closer to the tip of the instrument. In both of the instruments of FIGS. 5 and 5A, the particles of tissue broken from the larger mass are removed from the operating field via the passage 25.

FIG. 6 shows a further embodiment of the instrument which is similar in many respects to that of FIGS. 5 and 5A. Here, rather than have the hole 95b in the outer sleeve 59 so that the irrigation fluid can exit into the operation field, the outer sleeve 59 is made continuous and a hole 46a is provided in the inner sleeve 56. Nipple 66a closes off passage 27 at the probe tip and the irrigation fluid will exit through port 46a back into passage 25. Passage 25 also receives suction pressure to draw tissue adjacent the exposed tip portion of probe 24. The mixture of irrigation fluid and suction pressure in passage 25 rapidly removes the free tissue particles from the operating field. In addition, some of the irrigation fluid can also leave the tip to enter the operating field.

FIGS. 7 and 7A show a further embodiment of the invention with provisions to control the suction pressure. This instrument has the same cap structure and is similar in some respects to the instrument of FIG. 6. The sleeve 46 has a second opening 46b in addition to the first opening 46a for directing the irrigation fluid from passage 27 to passage 25. Sleeve 59 is sealed at the bent area 61 at the lower portion of the instrument to the rear of exit port 46b. The latter post communicates with passage 25. A nipple 70 with a rounded front end seals off the remainder of passage 27.

A movable sleeve 75, which also can be of stainless steel or other suitable material, is positioned to slide over the outside of sleeve 59. In FIG. 7, the sleeve 75 is shown in a position leaving the opening 46b unobstructed so that the suction pressure applied form opening 46b can bring the tissue into active relationship with probe 24. In FIG. 7A, sleeve 75 is shown in the forward position with the opening 46b blocked.

It should be noted that in the embodiment of FIGS. 7 and 7A, the nipple 70 prevents the tissue from coming into direct contact with the tip of the probe 24. Here again, as in FIG. 6, the particles of tissue are removed rapidly by the combined irrigation fluid and pressure flow.

Each of the embodiments of the invention described above utilize the cap assembly containing the energy shield. The same cap assembly can also have provision for suction and/or irrigation. The cap assemblies are removable so that the same transducer can be used with a number of different assemblies. Each assembly is such that a concentric relationship is maintained between the probe and the shield and also between the shield and another sleeve, the space between the latter two members defining a passage for suction pressure or fluid flow.

In each of the embodiments of the invention the space between the tip 24 and the sleeve 46 provides a safe distance between an active (vibrating) component and an insulating element preventing transmission of ultrasonic energy and rubbing which might generate a prohibitive amount of heat. Also, the use of metallic shield, such as 46, provides effective reflection of the energy back to the probe so that it does not radiate into the object being operated upon.

The cap 40 and O-ring seal 42 also provide a highly effective arrangement for changing shield and suction/irrigation flow configurations. In addition, the O-ring 42 also serves to dampen the vibrations of the probe. The use of the threaded cap also provides a range of adjustment for the shield with respect to how much of the probe tip is to be left uncovered.

It should be understood the instruments disclosed herein have particular advantages when used to emulsify semi-solid material such as the vitreous humor which is found in the eye. Here, the novel suction arrangements will bring the material, which is in a viscous and flowable state, adjacent the tip end of the ultrasonic probe. A portion of the vitreous body is moved toward the tip as the suction pressure is applied and the material moved into active relationship with the tip is emulsified. The tip itself does not have to be moved directly into the area of the body which is to be emulsified. This gives the user of the instrument a safety factor in that he does not have to come close to tissue which is to be left untouched by the ultrasonic energy. A typical of this is where the retina is to be protected during an operation. Where the various fully or partially shielded tips are used, additional protection is provided for the other tissue which is not to be effected by the energy.

Claims

What is claimed is:

1. An ultrasonic energy instrument comprising ultrasonic transducer means including elongated probe means for converting electrical energy into vibratory energy along the length of the probe means to produce movement at the free tip end of said probe means, shield means of substantially rigid metallic material, and means for mounting said shield means around and in spaced relationship to said probe means over a substantial portion without any mechanical connection between the probe means and the shield means of the length thereof to confine the vibrating energy.

2. An instrument as in claim 1 wherein said shield means extends beyond the tip of the probe means.

3. An instrument as in claim 2 wherein said shield means extends completely around the probe for its entire length.

4. Apparatus as in claim 2 wherein said shield means is partially open at the portion which extends beyond the probe tip.

5. An instrument as in claim 1 wherein said means for mounting said shield means to said transducer means comprises first coupling means on said transducer means and mating demountable second coupling means to which said shield means are mounted.

6. An ultrasonic energy instrument comprising ultrasonic transducer means including elongated probe means for converting electrical energy into vibratory energy along the length of the probe to produce movement at the free tip end of said probe means, first coupling means on said transducer means adjacent the attached end of said probe means, second coupling means, an elongated tubular shield means attached to said second coupling means, said coupling means when connected to said first coupling means holding said shield means around and in spaced relationship to said probe means over a substantial portion of the length of said probe means to confine the vibratory energy and leaving a space between said probe means and said shield means and an exit from said space to the exterior of the instrument, and means on said second coupling means for supplying fluid to said space between said probe means and said shield means, said fluid leaving said space from said exit.

7. Apparatus as in claim 6 wherein said fluid is a liquid which flows around the probe means to cool the same.

8. Apparatus as in claim 6 wherein said fluid is a gas.

9. An ultrasonic energy instrument comprising an ultrasonic transducer means including an elongated probe means for converting electrical energy into vibratory energy along the length of the probe means to produce movement at the free tip end of said probe means.

a. first and second tubular sleeve means,

b. means for mounting said first and second tubular sleeve means to said transducer means to hold said first tubular sleeve means in spaced relationship with said probe means over at least a substantial portion of the length thereof to define a first passageway between said probe means and said first tubular sleeve means and to hold said first and second tubular sleeve means in a spaced relationship to define a second passageway therebetween,

c. means for supplying fluid to said first and second passageways, and

d. means for permitting the fluid in each of said passageways to exit therefrom.

10. An instrument as in claim 9 further comprising means for sealing the exit of the second passageway at the tip end of the probe, said second sleeve being formed with an opening in the wall thereof through which the second fluid can exit from the second passageway.

11. An instrument as in claim 10 further comprising means for shielding a substantial portion of the tip of the probe means to hold it out of contact with an object with which the instrument is to be used.

12. An instrument as in claim 9 further comprising means for sealing the exit of the second passageway at the tip end of the probe, said first sleeve being formed with an opening in a wall thereof to provide communication between said first and said second passageways for the second fluid.

13. An instrument as in claim 9 further comprising means for sealing the exit of said first passageway at the tip end of the probe, said first sleeve formed with an opening in the wall thereof to direct the first fluid out of said first passageway at an angle lying off the longitudinal axis of the probe.

14. An instrument as in claim 13 further comprising means for sealing the exit of the second passageway at the tip end of the probe, said first sleeve being formed with an opening in a wall thereof to provide communication between said first and said second passageways for the second fluid.

15. An instrument as in claim 13 further comprising a third sleeve means which is slidable over said second sleeve means to close off the opening in the wall of said first sleeve means.

16. An instrument as in claim 15 further comprising means for sealing the exit of the second passageway at the tip end of the probe, said first sleeve being formed with an opening in a wall thereof to provide communication between said first and said second passageways for the second fluid.

17. An instrument as in claim 16 further comprising means for shielding a substantial portion of the tip of the probe means to hold it out of contact with an object with which the instrument is to be used.

18. An instrument as in claim 13 further comprising means for shielding a substantial portion of the tip of the probe means to hold it out of contact with an object with which the instrument is to be used.

19. The instrument of claim 6 wherein said shield means is of metal.

20. An instrument as in claim 9 wherein said means for mounting said first and second sleeve means comprises a holder to which said sleeve means are attached and mating coupling means on said holder and said transducer means, said means for supplying fluid to said first and second passages including means on said holder for accepting first and second fluids from respective sources.