HK1120388A - Apparatus and methods for the selective removal of tissue using combinations of ultrasonic energy and cryogenic energy - Google Patents

Abstract

Ultrasonic apparatus and method for selective and targeted removal of unwanted tissues are disclosed. The apparatus and methods may utilize combinations of ultrasonic and cryogenic energy for the selective removal of tissue. The apparatus generates and delivers to the tissue both cryogenic and ultrasonic energy either in combination or in sequence and provides resize ablation of unwanted tissue parts and may be used on other body tissues including internal organs.

Description

Apparatus and method for selective removal of tissue using a combination of ultrasonic and cryogenic energy

Background

Technical Field

The present invention relates to the removal of patient tissue, and more particularly, to an apparatus and method for removing tissue using a combination of ultrasonic and cryogenic energy.

Description of the related Art

The human skin is the largest organ of the body and serves as an indicator of various internal and external health related diseases. The skin protects the body from the common physical, chemical and microbial insults to which humans are naturally exposed in their everyday living environment.

Skin disorders are generally defined as diseases affecting the skin. Skin disorders often affect multiple layers of skin. Some common skin diseases include wrinkles, scars, warts, non-metastatic melanoma, basal cell carcinoma and human papilloma virus, as well as various pre-cancerous and cancerous skin growths. Some skin diseases are local growths of the skin caused by viral infections, which are not usually infectious.

Common methods of treating skin disorders include surgical removal, chemical peeling, cryogenic and electronic treatments. These methods often have the disadvantage of damaging surrounding healthy tissue, thereby increasing infection rates, high recurrence rates, and/or substantial pain or discomfort following surgery. Furthermore, many existing methods are complex and inaccurate. The lack of precision in targeting unhealthy tissue can result in the inability to completely remove the necessary harmful tissue and can also result in damage to surrounding healthy skin tissue. Any unhealthy tissue that is not removed can quickly underlie the recurrence of the condition. In addition, the treated tissue may become the point of introduction of infection or contamination due to damage or destruction to surrounding tissue. Accordingly, there is a need for apparatus and methods that target and completely or effectively completely remove diseased tissue without damaging surrounding tissue.

Disclosure of Invention

The present invention relates to devices and methods for selective ablation of unused (unwanted) skin layers. The apparatus and method according to the present invention may meet the above-described needs and also provide additional advantages and improvements that will be recognized by those skilled in the art upon review of the present disclosure.

The apparatus according to the present disclosure delivers ultrasonic and cryogenic energy to skin tissue in combination or sequentially. By this combination or sequential application of ultrasonic and cryogenic energy, unwanted tissue layers can be destroyed and removed. The apparatus may be used to treat diseased or unwanted tissue layers/growths located on or in the superficial layers of the human and animal body. The device can be used to target and selectively resect soft and hard tissues.

An embodiment of a device according to the invention may be a handheld device having a proximal end and a distal end. The proximal end may include a handle so that the device may be grasped and manipulated by the surgeon. An ultrasonic tip may be disposed on the distal end of the device. The ultrasonic tip may include a body, and the body may define one or more cavities. The ultrasonic tip may be cryogenically cooled by delivering a cryogenic fluid from a reservoir into one or more chambers defined by the ultrasonic tip. An ultrasonic transducer may be used to excite the ultrasonic tip. Thus, the ultrasonic tip may be simultaneously cryogenically cooled and excited by the ultrasonic transducer, or may be sequentially cooled and excited by the transducer, so that a simultaneous and sequential combination of cryogenic and ultrasonic energy may be formed at the ultrasonic tip. An ultrasonic tip may then be placed over the target tissue to be removed to deliver the cryogenic and ultrasonic energy to the target tissue to be removed in combination or sequentially.

Cryogenic fluids are typically in the gas or liquid phase. Cryogenic gases or liquids, such as liquid nitrogen, recognized by those skilled in the art may be used. The cryogenic fluid may be delivered to one or more chambers defined by the body of the ultrasonic tip. The cryogenic fluid may be delivered through one or more connecting tubes or other components designed to direct the flow of cryogenic fluid in the chamber. In one aspect, one or more inlet tubes are provided in communication with the chamber for introducing cryogenic fluid into the chamber, and one or more outlet tubes are provided to allow cryogenic fluid to be removed from or flow through the chamber. On the other hand, the internal cavity may be designed close to the distal end of the ultrasonic tip in order to more effectively cool the distal end.

The ultrasonic tip has an ultrasonically active end (ultrasonic end) for delivering ultrasound to the target tissue. This may be applied to the tissue in conjunction with, after, or before application of the cryogenic energy. The cryogenic energy may be applied by direct contact, by an ice ball formed on the ultrasonic tip, or by cryogenic spray emitted from the ultrasonic tip. As used herein, "ice ball" generally refers to the creation of ice particles or chunks, as the use of this term is often associated with cryotherapy. Although the ice particles or pieces herein labeled "ice hockey" may have a circular geometric form, the ice particles or pieces making up the "ice hockey" do not necessarily have a spherical geometric form, as will be recognized by those skilled in the art.

The ultrasonic tip is typically composed of a metal, such as titanium, although the ultrasonic tip may also be composed of plastic or a combination of metal and plastic, as will be recognized by those skilled in the art. An ultrasonic transducer may be used to excite the ultrasonic tip. The ultrasonic tip may be connected to the ultrasonic transducer by an ultrasonic horn (horn). The ultrasonic tip may be detachable from the ultrasonic horn or permanently attached to the ultrasonic horn. The detachable ultrasonic tip may be disposable.

In other aspects, the distal end of the ultrasonic tip may have various geometries, such as sharp-edged (sharp edge), conical, serrated, wavy, flat, rounded, or a combination of shapes. Various shapes may be selected as appropriate for various procedures performed on the tissue. A detachable ultrasonic tip can allow a surgeon to change the geometry of the tip to a suitable geometry during a surgical procedure.

On the other hand, a hole connected to the chamber may be provided on the tip end so that an ice ball may be formed or a cryogenic fluid may be sprayed from the tip end.

The apparatus of the present disclosure may be used to simultaneously and/or sequentially ablate tissue using ultrasonic and cryogenic energy. The simultaneous application of cryogenic and ultrasonic energy may be achieved by supplying cryogenic fluid to the tip, activating the ultrasonic transducer, and then placing the tip in contact with the tissue until the tissue is ablated.

Alternatively, cryogenic energy and ultrasonic energy may be applied sequentially through the apparatus to the tissue to be ablated. For example, sequential application may be initiated by activating the ultrasonic transducer, placing the distal end in contact with the tissue, and then supplying cryogenic fluid to the distal end. The sequence may be reversed such that the sequence is initiated by supplying cryogenic fluid to the tip, placing the tip in contact with the tissue, and then activating the ultrasound transducer. As recognized by those skilled in the art, various combinations of sequential and simultaneous application of cryogenic and ultrasonic energy may be used in an ablation procedure.

Cryogenic energy can be delivered to tissue in different ways, such as by supplying cryogenic fluid to the ultrasonic tip and then placing the tip in direct contact with the tissue. Alternatively, an ice ball on the tip may be placed in contact with the tissue, or cryogenic jets emitted from holes in the tip may be used to transfer cryogenic energy to the tissue.

Combining cryogenic energy with ultrasonic energy can provide several benefits for selective tissue removal procedures. One advantage of a device incorporating aspects of the present invention is that adhesion of the ultrasonic tip to the patient's tissue is avoided. Another advantage of an apparatus incorporating aspects of the present invention is that ultrasonic vibration separates the tissue to be removed from healthy tissue. Another advantage of apparatus incorporating aspects of the present invention is that high intensity ultrasonic energy alone may destroy the target tissue and is supplemented only by the cryogenic effect. Another advantage of apparatus incorporating aspects of the present invention is that less pain is experienced in the procedure due to the pain reduction effect achieved by the application of ultrasonic energy. Another advantage of apparatus incorporating aspects of the present invention is that the application of ultrasonic and cryogenic energy may have an antimicrobial effect on the treated and surrounding tissue. These and other novel aspects of the present invention will become more apparent from the following discussion and the accompanying drawings.

Drawings

FIG. 1 is a general diagrammatic overview of an embodiment of a system for removing tissue that can provide a combination of ultrasonic and cryogenic energy;

FIG. 2 illustrates an embodiment of an ultrasonic tip according to the present invention configured to deliver cryogenic fluid from the exterior directly into the interior of the distal portion of the tip and through a round head orifice (bluntorifice) in the interior;

FIG. 3 illustrates an embodiment of an ultrasonic tip according to the present invention configured to deliver cryogenic fluid through two round-headed holes in the interior;

FIG. 4 illustrates an embodiment of an ultrasonic tip with two separate outer tubes and two inner holes for passing cryogenic medium in and out;

FIG. 5(a) illustrates a cross-sectional front view of an embodiment of an ultrasonic tip with two separate outer tubes and two internal holes for passing cryogenic medium in and out;

FIG. 5(b) illustrates a horizontal cross-section of an embodiment of an ultrasonic tip having two holes;

6(a) through 6(i) illustrate cross-sectional views of embodiments of differently shaped ultrasonic tip end portions;

FIG. 7 illustrates an embodiment of passing cryogenic medium through the transducer and the bore of the ultrasonic tip;

FIG. 8 illustrates a cross-sectional view of an embodiment of an ultrasonic tip with an internal cavity in communication with a hole to a radiation surface;

FIG. 9 illustrates an embodiment of the delivery of cryogenic and ultrasonic energy to tissue through an iceball disposed between the radiation surface and the tissue;

FIG. 10 illustrates an embodiment of the delivery of ultrasonic energy to tissue by cryogenic spray directed at the tissue from a radiation surface;

FIG. 11 illustrates a perspective view of an embodiment of an ultrasonic tip end portion defining a plurality of holes on a radial surface for removing tissue of a body lumen (e.g., vessel, cavity, etc.) from the surrounding and sidewall;

FIG. 12 illustrates an embodiment of an ultrasonic tip having a reverse tapered radiation surface for focusing ultrasonic energy to tissue; and

fig. 13 illustrates an embodiment of an ultrasonic tip having a concave shaped radiation surface for focusing ultrasonic energy to tissue.

Detailed description of the invention

The present invention relates to apparatus for ablating tissue by a combination of ultrasonic and cryogenic energy, and to methods of use of such apparatus. Highly controllable, precise delivery of ultrasonic and cryogenic energy, simultaneously or in different sequences, allows for destruction of unwanted tissue without damaging surrounding tissue.

Fig. 1 shows a general view of an embodiment of the present apparatus 10. The device 10 of the present invention may be a handheld device having a distal ultrasonic tip 1, the distal ultrasonic tip 1 delivering ultrasonic and cryogenic energy to a skin tissue region 9 selected for treatment in combination or sequentially. The ultrasonic tip 1 includes a body defining one or more internal chambers 7 for a cryogenic fluid 20. The cryogenic fluid 20 may be a gas or a liquid, such as liquid nitrogen, as will be recognized by those skilled in the art. Cryogenic fluid 20 may be transferred from source 5 to internal chamber 7 through cryogenic fluid transfer tube 4, cryogenic fluid transfer tube 4 being connected to ultrasonic tip 7 at cryogenic fluid inlet tube 16. The cryogenic fluid inlet tube 16 defines an internal passage 17 connecting the cryogenic fluid transfer tube 4 to the one or more internal chambers 7. The ultrasonic transducer 3 may be connected to the ultrasonic generator 6 by a cable (cable) 11. The ultrasonic tip 1 provides an ultrasonically active tip 14 for delivering ultrasonic and cryogenic energy to the tissue 9 by direct contact, through an iceball 22 shown in fig. 9, or through a cryogenic spray 24 shown in fig. 10.

The ultrasonic tip 1 is typically made of a metal such as titanium. The ultrasonic tip 1 may also be made of plastic and may be disposable. The ultrasonic tip 1 may be excited by an ultrasonic transducer 3. The ultrasonic tip 1 may be connected to an ultrasonic transducer 3 through an ultrasonic horn 2. Those skilled in the art will recognize that the ultrasonic tip 1 may be a separate component that is attachable to the ultrasonic horn 2, or the ultrasonic tip 1 and the ultrasonic horn 2 may be combined into a single component. The ultrasound transducer 3 is typically connected to the ultrasound generator 6 by a cable 11. The ultrasonic transducer generates pulses in accordance with a drive signal generated by the ultrasonic generator 11 and transmitted to the ultrasonic transducer 3 via the cable 11. The drive signal as a function of time may be rectangular, trapezoidal, sinusoidal, or other signal types as recognized by those skilled in the art. The ultrasound frequency may be between 18KHz and 20MHz, or more. The preferred frequency is 20KHz-60KHz and the recommended frequency is 35 KHz. The amplitude of the ultrasonic waves may be between 1 micron and 200 microns, or more.

Figure 2 is an illustration of an ultrasound transducer 3 in which an internal passage 17 defined by a cryogenic fluid inlet tube 16 is connected to an internal cavity 7 defined by the ultrasound tip 1. Fig. 2 also shows a graph of the amplitude of the mechanical vibrations of the ultrasonic horn 2 and the ultrasonic tip 1. The transfer tube 16 is connected to the ultrasonic horn 2 or the ultrasonic tip 1 at a mechanical resonance node 28, which is the point at which the vibration amplitude of the ultrasonic horn 2 or the ultrasonic tip 1 is zero, 28. If the tube 4 is not connected to the ultrasonic horn 2 or ultrasonic tip 1 at the resonant node 28, the intensity of the ultrasonic energy at the distal end 14 is attenuated.

Figure 3 shows the configuration of the ultrasonic tip 1 in which cryogenic fluid is delivered through a lumen 7 having a narrow elongated portion extending toward the tip 14. The number of cavities 7 must be at least one. In some embodiments, more lumens 7 may provide high efficacy cryogenic ablation by increasing surface area. In other embodiments, a narrow elongated portion of the chamber 7 may direct cryogenic fluid to one or more holes 12 on the terminal radiating surface (fig. 8, 9, 10) or on the radial surface (fig. 11).

Figure 4 illustrates an embodiment of the ultrasonic tip 1 having a cryogenic fluid inlet tube 16 and a cryogenic fluid outlet tube 8, the cryogenic fluid inlet tube 16 defining an internal passage 17 connecting the cryogenic fluid transfer tube 4 to the one or more internal chambers 7, the cryogenic fluid outlet tube 8 defining an internal passage 19 to the one or more internal chambers 7. Cryogenic fluid may then be added to the one or more internal chambers 7 through the cryogenic fluid inlet tube 16 and removed from the one or more internal chambers 7 through the cryogenic fluid outlet tube 8, such that cryogenic medium is circulated through the one or more chambers 7 of the ultrasonic tip.

Fig. 5(a) is a side view of the cavity 7 defined by the body 30 of the ultrasonic tip 1. Fig. 5(a) also shows a passage 32 extending through the distal portion of the ultrasonic tip 1 and in fluid communication with the cavity 7, which may increase the efficiency of heat transfer between the ultrasonic tip 1 and the cryogenic medium. The body 30 also defines a plurality of tubular passages 34. The tubular passage 34 diverges from the chamber 7 towards the distal end 14 to allow cryogenic fluid to access the distal end 14 while maintaining the structural integrity of the body 30.

Figure 5(b) shows a cross section of an embodiment of an ultrasonic tip with two chambers 7 for improved circulation of the cryogenic fluid.

Fig. 6(a) to 6(i) are cross-sectional views of different shapes of the tip 14. Fig. 6(a) shows a circular or elliptical tip 14 that can be used to resect a larger area of tissue 9. Fig. 6(b) shows a pointed tapered end 14 which can be used to accurately resect a small area of tissue 9. Fig. 6(c), 6(d), 6(e) and 6(f) show various flattened ends 14 for cutting out local tissue 9. Figure 6(g) shows a serrated tip 14. A disposable plastic cover 26 matching the geometry of the tip 14 can be used to cover the tip as shown in fig. 6 (e).

The various ultrasonic tip 1 geometries shown in fig. 6(h) and 6(i) are particularly designed for ablating unwanted tissue layers within a body lumen, such as a vessel, cavity, or the like. The ultrasonic tip is designed for insertion into a body cavity without damaging surrounding tissue.

Figure 7 illustrates the transfer of cryogenic fluid 20 through an internal chamber 34, the internal chamber 34 passing through the center of the ultrasonic transducer 3, the ultrasonic horn 2, and connecting to one or more chambers 7. This particular embodiment may provide manufacturing advantages that will be recognized by those skilled in the art upon review of the present disclosure.

Figure 8 illustrates a cross-sectional view of the ultrasonic tip 1 having an aperture 12 between the chamber 7 and the distal end 14 such that cryogenic fluid 20 may flow from the chamber 7 through the aperture 12 and out the distal end 14. This type of embodiment allows for the formation of an ice ball 22 on the tip 14 as shown in fig. 9, and/or a cryogenic spray as shown in fig. 10. Cryogenic and ultrasonic energy can then be delivered to tissue 9 through iceball 22 and/or cryogenic spray between tip 14 and tissue 9.

Figure 11 shows a three-dimensional view of an ultrasound tip 1 in which a plurality of holes 12 are provided in the tip 14 for circumferentially ablating the walls and sidewalls of a body lumen (e.g., vessel, cavity, etc.).

Fig. 12 shows a backward taper of tip 14 focusing ultrasonic energy at focal point 44, while fig. 13 shows a concave shape of tip 14 focusing ultrasonic energy at focal point 44.

The device according to the invention can be used to selectively remove unwanted skin tissue, such as warts, fetal masses, pre-cancerous skin growths, tumors, melanomas and scars. In one exemplary technique of using the present apparatus, cryogenic energy and ultrasonic energy are applied simultaneously to the tissue to be ablated. This technique includes supplying cryogenic fluid 20 to the distal end 14, exciting the ultrasonic transducer 3, and then placing the distal end 14 in proximity to and/or in contact with the tissue 9 until the tissue is ablated.

Alternatively, cryogenic energy and ultrasonic energy may be applied sequentially through the apparatus to the tissue to be ablated. For example, sequential application may begin by activating the ultrasound transducer 3, placing the distal end 14 proximate to and/or in contact with the tissue 9, and then supplying cryogenic fluid to the distal end 14. The sequence may also be reversed, in which case the sequence would be initiated by supplying cryogenic fluid 20 to the distal end 14, placing the distal end 14 proximate and/or in contact with the tissue 9, and then activating the ultrasound transducer. In ablating tissue 9, a combination of sequential application of cryogenic energy and ultrasonic energy and simultaneous application of cryogenic energy and ultrasonic energy may be used, as recognized by those skilled in the art.

Cryogenic energy can be delivered to the tissue by supplying cryogenic fluid 20 to the distal end 14 and placing the distal end proximate to the tissue and/or placing the distal end in contact with the tissue 9. Alternatively, an ice ball 22 on the tip 14 may be placed in contact with the tissue, or cryogenic spray 24 from the hole 12 in the tip 14 may be used to deliver cryogenic energy to the tissue.

Although specific embodiments and methods of use have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments and methods shown. It is to be understood that the above description is intended to be illustrative and not restrictive. Combinations of the above embodiments and other embodiments, and combinations of the above methods of use and other methods of use will be apparent to those of skill in the art upon review of the present disclosure. Reference should be made to the appended claims for determining the scope of the present invention and the full scope of equivalents to which such claims are entitled.

Claims (18)

1. An apparatus, comprising:

an ultrasonic tip comprising a body defining a lumen and an internal channel and having a distal end configured to transfer energy between the body and patient tissue, the internal channel extending between an outer surface of the body and the lumen, the internal channel configured to communicate cryogenic fluid to the lumen, the lumen configured to cool the distal end of the body; and

an ultrasonic transducer in communication with the ultrasonic tip to excite the ultrasonic tip.

2. The apparatus of claim 1, wherein the ultrasonic transducer operates at a frequency between 18KHz and 60 MHz.

3. The apparatus of claim 1, wherein the ultrasonic transducer operates at a frequency between 20KHz and 100 KHz.

4. The apparatus of claim 1, wherein the ultrasonic transducer operates at a frequency of about 35 KHz.

5. The apparatus of claim 1, wherein the tip amplitude is between 1 micron and 300 microns.

6. The apparatus of claim 1, wherein the tip amplitude is about 50 microns.

7. The apparatus of claim 1, wherein the tip is rounded.

8. The apparatus of claim 1, wherein the end is rectangular.

9. The apparatus of claim 1, wherein the tip is pointed.

10. The apparatus of claim 1, wherein the distal end of the ultrasonic tip has a sharp edge.

11. The apparatus of claim 1, wherein the distal end of the ultrasonic tip has a serrated edge.

12. The apparatus of claim 1, wherein the ultrasonic tip is concave.

13. The apparatus of claim 1, wherein the body of the ultrasonic tip defines one or more holes, each of the one or more holes connected to the lumen.

14. A method for removing tissue from a patient, comprising:

providing an ultrasonic transducer having an ultrasonic tip, the ultrasonic tip comprising a body defining a cavity and an internal passage and having a distal end configured to transfer energy between the body and patient tissue, the internal passage extending between an outer surface of the body and the cavity, the internal passage configured to communicate a cryogenic fluid into the cavity, the cavity configured to cool the distal end of the body;

flowing cryogenic material through the internal passage into the cavity of the ultrasonic tip;

ultrasonically vibrating the ultrasonic tip; and

contacting the patient tissue to cryogenically treat and deliver ultrasonic energy to the tissue.

15. The method of claim 14, further comprising: the ultrasonic tip is first ultrasonically vibrated, then tissue is brought into contact with the distal end of the ultrasonic tip, and cryogenic energy is excited after the distal end contacts tissue.

16. The method of claim 14, further comprising: flowing a cryogenic material first to the lumen of the ultrasonic tip, then contacting tissue with the distal end of the ultrasonic tip and ultrasonically vibrating the ultrasonic tip.

17. The method of claim 16, further comprising: the distal end of the ultrasonic tip delivers ultrasonic cryogenic energy for ablation to tissue through an iceball disposed between the distal end of the ultrasonic tip and the tissue.

18. The method of claim 16, further comprising: the distal end of the ultrasonic tip delivers ultrasonic cryogenic energy for ablation to tissue by a cryogenic spray disposed between the distal end of the ultrasonic tip and tissue.