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Publication numberUS20100331743 A1
Publication typeApplication
Application numberUS 12/880,821
Publication date30 Dec 2010
Filing date13 Sep 2010
Priority date9 Feb 2004
Also published asUS7794414, US20050187513
Publication number12880821, 880821, US 2010/0331743 A1, US 2010/331743 A1, US 20100331743 A1, US 20100331743A1, US 2010331743 A1, US 2010331743A1, US-A1-20100331743, US-A1-2010331743, US2010/0331743A1, US2010/331743A1, US20100331743 A1, US20100331743A1, US2010331743 A1, US2010331743A1
InventorsRobert A. Rabiner, Bradley A. Hare, Rebecca I. Marciante, Mark J. Varady
Original AssigneeEmigrant Bank, N. A.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus and method for an ultrasonic medical device operating in torsional and transverse modes
US 20100331743 A1
Abstract
The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode. An ultrasonic probe of the ultrasonic medical device is placed in communication with a biological material. An ultrasonic energy source is activated to produce an electrical signal that drives a transducer to produce a torsional vibration of the ultrasonic probe. The torsional vibration produces a component of force in a transverse direction relative to a longitudinal axis of the ultrasonic probe, thereby exciting a transverse vibration along the longitudinal axis causing the ultrasonic probe to undergo both a torsional vibration and a transverse vibration. The torsional vibration and the transverse vibration cause cavitation in a medium surrounding the ultrasonic probe to ablate the biological material.
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Claims(20)
1. An ultrasonic medical device comprising:
an ultrasonic probe comprising a proximal end, a distal end and a longitudinal axis therebetween; and
a transducer coupled to the ultrasonic probe, the transducer being configured to create a torsional vibration along the ultrasonic probe, the ultrasonic probe and the transducer being adapted so that the torsional vibration induces a transverse vibration along a portion of the ultrasonic probe.
2. The ultrasonic medical device of claim 1 wherein the transverse vibration is tuned into coincidence with the torsional vibration along the portion of the ultrasonic probe in which the transverse vibration is induced.
3. The ultrasonic medical device of claim 1 wherein tension to the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration.
4. The ultrasonic medical device of claim 1 wherein bending the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration.
5. The ultrasonic medical device of claim 1 wherein the torsional vibration and the transverse vibration are segregated over the portion of the ultrasonic probe.
6. The ultrasonic medical device of claim 1 wherein the torsional vibration of the ultrasonic probe produces a plurality of torsional nodes and a plurality of torsional anti-nodes along the portion of the ultrasonic probe.
7. The ultrasonic medical device of claim 1 wherein the torsional vibration of the ultrasonic probe causes a rotation and counterrotation along at least the portion of the ultrasonic probe.
8. A medical device comprising:
an elongated, flexible probe comprising a proximal end, a distal end and a longitudinal axis between the proximal end and the distal end;
a transducer coupled to the elongated, flexible probe, the transducer being configured to create a torsional vibration along the longitudinal axis of the elongated, flexible probe when electrical energy is applied to the transducer, the elongate, flexible probe and the transducer being adapted so that the torsional vibration induces a transverse vibration along the longitudinal axis of the elongated, flexible probe.
9. The medical device of claim 8 wherein the transverse vibration is tuned into coincidence with the torsional vibration along at least a portion of the longitudinal axis of the elongated, flexible probe in which the transverse vibration is induced.
10. The medical device of claim 8 wherein tension to the elongated, flexible probe tunes the transverse vibration into coincidence with the torsional vibration.
11. The medical device of claim 8 wherein bending the elongated, flexible probe tunes the transverse vibration into coincidence with the torsional vibration.
12. The medical device of claim 8 wherein bending the elongated, flexible probe shifts a frequency of the elongated, flexible probe causing the transverse vibration to coincide with the torsional vibration.
13. The medical device of claim 8 wherein the torsional vibration and the transverse vibration are superimposed or segregated along the longitudinal axis of the elongated, flexible probe.
14. The medical device of claim 8 wherein the elongated, flexible probe comprises a varying diameter from the proximal end of the elongated, flexible probe to the distal end of the elongated, flexible probe.
15. An ultrasonic probe comprising:
a proximal end;
a distal end that terminates in a probe tip; and
a longitudinal axis between the proximal end and the distal end, wherein the ultrasonic probe supports a torsional vibration and a transverse vibration.
16. The ultrasonic probe of claim 15 wherein the transverse vibration is tuned into coincidence with the torsional vibration along at least a portion of the longitudinal axis of the ultrasonic probe in which the transverse vibration is induced.
17. The ultrasonic probe of claim 15 wherein tension to the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration.
18. The ultrasonic probe of claim 15 wherein bending the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration.
19. The ultrasonic probe of claim 15 wherein bending the ultrasonic probe shifts a frequency of the ultrasonic probe causing the transverse vibration to coincide with the torsional vibration.
20. The ultrasonic probe of claim 15 wherein the ultrasonic probe comprises a varying cross section from the proximal end of the ultrasonic probe to the distal end of the ultrasonic probe.
Description
    RELATED APPLICATIONS
  • [0001]
    This application is a continuation of U.S. application Ser. No. 10/774,898, filed on Feb. 9, 2004, the entirety of which is hereby incorporated herein by reference for the teachings therein.
  • FIELD OF THE INVENTION
  • [0002]
    The present invention relates to ultrasonic medical devices, and more particularly to an apparatus and method of using an ultrasonic probe operating in torsional and transverse modes.
  • BACKGROUND OF THE INVENTION
  • [0003]
    The presence of biological material in various parts of the human body can lead to complications ranging from artery disease, heart attack, stroke and in some cases death. The safe and effective destruction of the biological material that causes these complications is an important endeavor in the medical field. A variety of prior art instruments and methods destroy biological material in the human body.
  • [0004]
    Prior art medical instruments used to destroy biological material in the body suffer from several limitations. Prior art medical instruments are large, making it difficult for medical professionals to utilize them. Prior art medical instruments utilize high power levels that can adversely affect areas surrounding the treatment area and the patient. Procedures using prior art medical instruments are time consuming in comparison with other methods such as surgical excision.
  • [0005]
    Prior art medical instruments have relied on longitudinal vibrations of the tip of the instrument. By creating longitudinal vibrations of the tip, the tip of the prior art medical instrument must contact the biological material and, similar to a jackhammer, remove the biological material through successive motion of the tip of the instrument. In many cases, the prior art instruments operating in a longitudinal mode have a tip having both a small cross sectional area and a small surface area, thereby removing small amounts of biological material and increasing the overall time of the medical procedure.
  • [0006]
    For example, U.S. Pat. No. 4,961,424 to Kubota et al. discloses an ultrasonic treatment device operating in a longitudinal mode that is urged or brought into contact with an area to be treated, with energy delivered to the tip of the device. U.S. Pat. No. 4,870,953 to DonMicheal et al. discloses an intravascular ultrasonic catheter/probe and method for treating intravascular blockage that delivers ultrasonic energy via a bulbous tip of the instrument where the bulbous tip is placed in contact with a blockage. U.S. Pat. No. 5,391,144 to Sakurai et al. discloses an ultrasonic treatment apparatus that includes an instrument operating in a longitudinal mode that emulsifies tissue at the tip of the instrument. Therefore, there remains a need in the art for a device that can safely and effectively destroy a large area of biological material in a time efficient manner.
  • [0007]
    Torsional mode vibration of objects is known in the art. However, the prior art does not describe the torsional mode vibration of a medical device. Further, the prior art requires additional objects to be attached to the prior art instruments, thereby preventing a minimally invasive solution of destroying biological material using torsional mode vibration. For example, U.S. Pat. No. 4,771,202 and U.S. Pat. No. 4,498,025 both to Takahashi disclose a tuning fork using the fundamental vibration of a flexural mode coupled with the fundamental mode of torsion. The fundamental frequency of the torsional mode is adjusted by placing masses near the side edges of the tine tips. U.S. Pat. No. 4,652,786 to Mishiro discloses a torsional vibration apparatus having a plurality of electrodes formed on the two surfaces of a circular member of electrostrictive material. Therefore, there remains a need in the art for an apparatus and a method of destroying biological material that utilizes a medical device that can vibrate in a torsional mode to destroy the biological material in the body in a time efficient manner.
  • [0008]
    The prior art does not provide a solution for destroying biological material in a safe, effective and time efficient manner. The prior art does not provide an effective solution for increasing a surface area for biological material destruction. Prior art ultrasonic instruments are limited in that they require contact between the device and the biological material and only treat the biological material using the tip of the ultrasonic instrument. Therefore, there remains a need in the art for an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode to ablate biological material in a safe, effective and time efficient manner.
  • SUMMARY OF THE INVENTION
  • [0009]
    The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode to treat a biological material. The present invention is an ultrasonic medical device comprising an ultrasonic probe having a proximal end, a distal end and a longitudinal axis therebetween. The ultrasonic medical device includes a transducer for creating a torsional vibration of the ultrasonic probe. A coupling engages the proximal end of the ultrasonic probe to a distal end of the transducer. An ultrasonic energy source engaged to a proximal end of the transducer produces an electrical energy to power the ultrasonic medical device. The torsional vibration of the ultrasonic probe induces a transverse vibration along an active area of the ultrasonic probe, the active area supporting the torsional vibration and the transverse vibration.
  • [0010]
    The present invention is a medical device comprising an elongated, flexible probe comprising a proximal end, a distal end and a longitudinal axis between the proximal end and the distal end. The medical device includes a transducer that converts electrical energy into mechanical energy, creating a torsional vibration along the longitudinal axis of the elongated, flexible probe. A coupling engages the proximal end of the elongated, flexible probe to a distal end of the transducer. An ultrasonic energy source engaged to a proximal end of the transducer provides electrical energy to the transducer. The torsional vibration induces a transverse vibration along the longitudinal axis of the elongated, flexible probe.
  • [0011]
    The present invention is a method of treating a biological material in a body with an ultrasonic medical device comprising: providing an ultrasonic probe having a proximal end, a distal end and a longitudinal axis therebetween; moving the ultrasonic probe to a treatment site of the biological material to place the ultrasonic probe in communication with the biological material; activating an ultrasonic energy source engaged to the ultrasonic probe to produce an ultrasonic energy that is converted into a torsional vibration of the ultrasonic probe; and inducing a transverse vibration in an active area of the ultrasonic probe by the torsional vibration wherein the active area of the ultrasonic probe supports the torsional vibration and the transverse vibration.
  • [0012]
    The present invention is a method of removing a biological material in a body comprising providing an ultrasonic medical device comprising a flexible probe having a proximal end, a distal end and a longitudinal axis between the proximal end and the distal end. The flexible probe is moved in the body and placed in communication with the biological material. An ultrasonic energy source of the ultrasonic medical device is activated to produce an electrical signal that drives a transducer of the ultrasonic medical device to produce a torsional vibration of the flexible probe. The torsional vibration induces a transverse vibration along the longitudinal axis of the ultrasonic probe.
  • [0013]
    The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode. The active area of the ultrasonic probe operating in the torsional mode and the transverse mode is vibrated in a direction not parallel to the longitudinal axis of the ultrasonic probe while equally spaced points along the active area are vibrated back and forth in a short arc in a plane parallel to the longitudinal axis along the active area of the ultrasonic probe. The present invention provides an ultrasonic medical device that is simple, user-friendly, time efficient, reliable and cost effective.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0014]
    The present invention will be further explained with reference to the attached drawings, wherein like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.
  • [0015]
    FIG. 1 is a side plan view of an ultrasonic medical device of the present invention capable of operating in a torsional mode and a transverse mode.
  • [0016]
    FIG. 2 is a side plan view of an ultrasonic probe of the present invention having a uniform diameter from a proximal end of the ultrasonic probe to a distal end of the ultrasonic probe.
  • [0017]
    FIG. 3 is a fragmentary perspective view of an ultrasonic probe of the present invention having a torsional vibration and a transverse vibration along an active area of the ultrasonic probe.
  • [0018]
    FIG. 4 is a fragmentary perspective view of the ultrasonic probe of the present invention undergoing a torsional vibration.
  • [0019]
    FIG. 5A is a fragmentary side plan view of the ultrasonic probe of the present invention undergoing a torsional vibration.
  • [0020]
    FIG. 5B is a graph corresponding to the torsional vibration shown in FIG. 5A.
  • [0021]
    FIG. 6 is a fragmentary side plan view of the ultrasonic probe of the present invention undergoing a transverse vibration.
  • [0022]
    FIG. 7 is a fragmentary perspective view of the ultrasonic probe of the present invention undergoing a transverse vibration along an active area of the ultrasonic probe and a torsional vibration along a section proximal to the active area of the ultrasonic probe.
  • [0023]
    FIG. 8 is a fragmentary side plan view of the ultrasonic probe of the present invention having a plurality of nodes and a plurality of anti-nodes along an active area of the ultrasonic probe.
  • [0024]
    FIG. 9 is a fragmentary perspective view of a portion of a longitudinal axis of an ultrasonic probe of the present invention comprising an approximately circular cross section at a proximal end of the ultrasonic probe and a radially asymmetric cross section at a distal end of the ultrasonic probe.
  • [0025]
    FIG. 10 is a side plan view of the ultrasonic probe of the present invention located within a sheath.
  • [0026]
    While the above-identified drawings set forth preferred embodiments of the present invention, other embodiments of the present invention are also contemplated, as noted in the discussion. This disclosure presents illustrative embodiments of the present invention by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of the present invention.
  • DETAILED DESCRIPTION
  • [0027]
    The present invention provides an apparatus and a method for using an ultrasonic medical device vibrating in a torsional mode and transverse mode to treat a biological material. The ultrasonic medical device comprises an ultrasonic probe, a transducer, a coupling engaging a proximal end of the ultrasonic probe to a distal end of the transducer and an ultrasonic energy source engaged to a proximal end of the transducer. The ultrasonic energy source produces an ultrasonic energy that is transmitted to the transducer, where the transducer creates a torsional vibration of the ultrasonic probe. The torsional vibration induces a transverse vibration along an active area of the ultrasonic probe, creating a plurality of nodes and a plurality of anti-nodes along the active area resulting in cavitation along the active area. The active area of the ultrasonic probe supports the torsional vibration and the transverse vibration.
  • [0028]
    The following terms and definitions are used herein:
  • [0029]
    “Ablate” as used herein refers to removing, clearing, destroying or taking away a biological material. “Ablation” as used herein refers to a removal, clearance, destruction, or taking away of the biological material.
  • [0030]
    “Node” as used herein refers to a region of a minimum energy emitted by an ultrasonic probe at or proximal to a specific location along a longitudinal axis of the ultrasonic probe.
  • [0031]
    “Anti-node” as used herein refers to a region of a maximum energy emitted by an ultrasonic probe at or proximal to a specific location along a longitudinal axis of the ultrasonic probe.
  • [0032]
    “Probe” as used herein refers to a device capable of propagating an energy emitted by the ultrasonic energy source along a longitudinal axis of the ultrasonic probe, resolving the energy into an effective cavitational energy at a specific resonance (defined by a plurality of nodes and a plurality of anti-nodes along an “active area” of the probe) and is capable of an acoustic impedance transformation of an ultrasound energy to a mechanical energy.
  • [0033]
    “Biological material” as used herein refers to a collection of a matter including, but not limited to, a group of similar cells, intravascular blood clots or thrombus, fibrin, calcified plaque, calcium deposits, occlusional deposits, atherosclerotic plaque, fatty deposits, adipose tissues, atherosclerotic cholesterol buildup, fibrous material buildup, arterial stenoses, minerals, high water content tissues, platelets, cellular debris, wastes and other occlusive materials.
  • [0034]
    “Vibration” as used herein refers to movement wherein portions of an object move alternately in opposite directions from a position of equilibrium. Vibration also refers to motion, oscillation and wave propagation.
  • [0035]
    An ultrasonic medical device capable of operating in a torsional mode and transverse mode is illustrated generally at 11 in FIG. 1. The ultrasonic medical device 11 includes an ultrasonic probe 15 which is coupled to an ultrasonic energy source or generator 99 for the production of an ultrasonic energy. A handle 88, comprising a proximal end 87 and a distal end 86, surrounds a transducer within the handle 88. The transducer, having a proximal end engaging the ultrasonic energy source 99 and a distal end coupled to a proximal end 31 of the ultrasonic probe 15, transmits the ultrasonic energy to the ultrasonic probe 15. A connector 93 and a connecting wire 98 engage the ultrasonic energy source 99 to the transducer. The ultrasonic probe 15 includes the proximal end 31, a distal end 24 that ends in a probe tip 9 and a longitudinal axis between the proximal end 31 and the distal end 24. In a preferred embodiment of the present invention shown in FIG. 1, a diameter of the ultrasonic probe decreases from a first defined interval 26 to a second defined interval 28 along the longitudinal axis of the ultrasonic probe 15 over a diameter transition 82. A coupling 33 that engages the proximal end 31 of the ultrasonic probe 15 to the transducer within the handle 88 is illustrated generally in FIG. 1. In a preferred embodiment of the present invention, the coupling is a quick attachment-detachment system. An ultrasonic medical device with a quick attachment-detachment system is described in the Assignee's co-pending patent applications U.S. Ser. No. 09/975,725; U.S. Ser. No. 10/268,487 and U.S. Ser. No. 10/268,843, and the entirety of all these applications are hereby incorporated herein by reference.
  • [0036]
    FIG. 2 shows an alternative embodiment of the ultrasonic probe 15 of the present invention. In the embodiment of the present invention shown in FIG. 2, the diameter of the ultrasonic probe 15 is approximately uniform from the proximal end 31 of the ultrasonic probe 15 to the distal end 24 of the ultrasonic probe 15.
  • [0037]
    In a preferred embodiment of the present invention, the ultrasonic probe 15 is a wire.
  • [0038]
    In a preferred embodiment of the present invention, a cross section of the ultrasonic probe is approximately circular from the proximal end 31 of the ultrasonic probe 15 to the distal end 24 of the ultrasonic probe 15. In an embodiment of the present invention, the ultrasonic probe 15 is elongated. In an embodiment of the present invention, the diameter of the ultrasonic probe 15 decreases at greater than two defined intervals. In an embodiment of the present invention, the diameter transitions 82 of the ultrasonic probe 15 are tapered to gradually change the diameter from the proximal end 31 to the distal end 24 along the longitudinal axis of the ultrasonic probe 15. In another embodiment of the present invention, the diameter transitions 82 of the ultrasonic probe 15 are stepwise to change the diameter from the proximal end 31 to the distal end 24 along the longitudinal axis of the ultrasonic probe 15. Those skilled in the art will recognize that there can be any number of defined intervals and diameter transitions, and that the diameter transitions can be of any shape known in the art and be within the spirit and scope of the present invention.
  • [0039]
    In an embodiment of the present invention, the gradual change of the diameter from the proximal end 31 to the distal end 24 occurs over the at least one diameter transitions 82, with each diameter transition 82 having an approximately equal length. In another embodiment of the present invention, the gradual change of the diameter from the proximal end 31 to the distal end 24 occurs over a plurality of diameter transitions 82 with each diameter transition 82 having a varying length. The diameter transition 82 refers to a section where the diameter varies from a first diameter to a second diameter.
  • [0040]
    The probe tip 9 can be any shape including, but not limited to, bent, a ball or larger shapes. In one embodiment of the present invention, the ultrasonic energy source 99 is a physical part of the ultrasonic medical device 11. In another embodiment of the present invention, the ultrasonic energy source 99 is not an integral part of the ultrasonic medical device 11. The ultrasonic probe 15 is used to treat a biological material and may be disposed of after use. In a preferred embodiment of the present invention, the ultrasonic probe 15 is for a single use and on a single patient. In a preferred embodiment of the present invention, the ultrasonic probe 15 is disposable. In another embodiment of the present invention, the ultrasonic probe 15 can be used multiple times.
  • [0041]
    The ultrasonic probe 15 has a stiffness that gives the ultrasonic probe 15 a flexibility allowing the ultrasonic probe 15 to be deflected and articulated when the ultrasonic medical device 11 is in motion. The ultrasonic probe 15 can be bent, flexed and deflected to reach the biological material at locations in the vasculature of the body that are difficult to reach. The ultrasonic probe 15 has a flexibility to support a torsional vibration and a transverse vibration.
  • [0042]
    In a preferred embodiment of the present invention, the ultrasonic probe 15 comprises a substantially uniform cross section from the proximal end 31 to the distal end 24. In a preferred embodiment of the present invention, a cross section of the ultrasonic probe 15 is approximately circular. In another embodiment of the present invention, a portion of the longitudinal axis of the ultrasonic probe 15 is radially asymmetric. In another embodiment of the present invention, the cross section of the ultrasonic probe 15 is spline shaped with a plurality of projections extending from an outer surface of the ultrasonic probe 15. In another embodiment of the present invention, the shape of the cross section of the ultrasonic probe 15 includes, but is not limited to, square, trapezoidal, elliptical, rectangular, oval, triangular, circular with a flat spot and similar cross sections. Those skilled in the art will recognize that other cross sectional geometries known in the art would be within the spirit and scope of the present invention.
  • [0043]
    In another embodiment of the present invention, the ultrasonic probe comprises a varying cross section from the proximal end 31 of the ultrasonic probe 15 to the distal end 24 of the ultrasonic probe 15. Various cross sectional shapes including, but not limited to square, trapezoidal, elliptical, spline shaped, rectangular, oval, triangular, circular with a flat spot and similar cross sections can be used to modify the active area.
  • [0044]
    In a preferred embodiment of the present invention, the ultrasonic probe 15 comprises titanium or a titanium alloy. In a preferred embodiment of the present invention, the ultrasonic probe 15 comprises titanium alloy Ti-6A1-4V. The elements comprising Ti-6A1-4V and the representative elemental weight percentages of Ti-6A1-4V are titanium (about 90%), aluminum (about 6%), vanadium (about 4%), iron (maximum about 0.25%) and oxygen (maximum about 0.2%). Titanium is a strong, flexible, low density, low radiopacity and easily fabricated metal that is used as a structural material. Titanium and its alloys have excellent corrosion resistance in many environments and have good elevated temperature properties. In another embodiment of the present invention, the ultrasonic probe 15 comprises stainless steel. In another embodiment of the present invention, the ultrasonic probe 15 comprises an alloy of stainless steel. In another embodiment of the present invention, the ultrasonic probe 15 comprises aluminum. In another embodiment of the present invention, the ultrasonic probe 15 comprises an alloy of aluminum. In another embodiment of the present invention, the ultrasonic probe 15 comprises a combination of titanium and stainless steel. Those skilled in the art will recognize that the ultrasonic probe can be comprised of many other materials known in the art and be within the spirit and scope of the present invention.
  • [0045]
    In a preferred embodiment of the present invention, the ultrasonic probe 15 has a small diameter. In an embodiment of the present invention, the diameter of the ultrasonic probe 15 gradually decreases from the proximal end 31 to the distal end 24. In an embodiment of the present invention, the diameter of the distal end 24 of the ultrasonic probe 15 is about 0.004 inches. In another embodiment of the present invention, the diameter of the distal end 24 of the ultrasonic probe 15 is about 0.015 inches. In other embodiments of the present invention, the diameter of the distal end 24 of the ultrasonic probe 15 varies between about 0.003 inches and about 0.025 inches. Those skilled in the art will recognize an ultrasonic probe 15 can have a diameter at the distal end 24 smaller than about 0.003 inches, larger than about 0.025 inches, and between about 0.003 inches and about 0.025 inches and be within the spirit and scope of the present invention.
  • [0046]
    In an embodiment of the present invention, the diameter of the proximal end 31 of the ultrasonic probe 15 is about 0.012 inches. In another embodiment of the present invention, the diameter of the proximal end 31 of the ultrasonic probe 15 is about 0.025 inches. In other embodiments of the present invention, the diameter of the proximal end 31 of the ultrasonic probe 15 varies between about 0.003 inches and about 0.025 inches. Those skilled in the art will recognize the ultrasonic probe 15 can have a diameter at the proximal end 31 smaller than about 0.003 inches, larger than about 0.025 inches, and between about 0.003 inches and about 0.025 inches and be within the spirit and scope of the present invention.
  • [0047]
    The length of the ultrasonic probe 15 of the present invention is chosen so as to be resonant in a torsional mode and a transverse mode. In an embodiment of the present invention, the ultrasonic probe 15 is between about 30 centimeters and about 300 centimeters in length. For the ultrasonic probe 15 to operate in the torsional mode and the transverse mode, the ultrasonic probe 15 should be detuned from the transducer, meaning that the length of the ultrasonic probe 15 should not be an integer multiple of one-half wavelength of the fundamental torsional resonance of the transducer. The ultrasonic probe 15 is detuned from the transducer when the resonant frequency of the ultrasonic probe 15 is different from the resonant frequency of the transducer. The section below entitled “Theory of Operation” provides details and equations for determining the length for the ultrasonic probe operating in the torsional mode and the transverse mode. For example, for an ultrasonic probe comprised of titanium operating at a frequency of 20 kHz, the length of the ultrasonic probe should not be an integer multiple of one-half wavelength (approximately 7.58 centimeters (about 3 inches)). Those skilled in the art will recognize an ultrasonic probe can have a length shorter than about 30 centimeters, a length longer than about 300 centimeters and a length between about 30 centimeters and about 300 centimeters and be within the spirit and scope of the present invention.
  • [0048]
    The handle 88 surrounds the transducer located between the proximal end 31 of the ultrasonic probe 15 and the connector 93. In a preferred embodiment of the present invention, the transducer includes, but is not limited to, a horn, an electrode, an insulator, a backnut, a washer, a piezo microphone, and a piezo drive. The transducer converts electrical energy provided by the ultrasonic energy source 99 to mechanical energy and sets the operating frequency of the ultrasonic medical device 11. By an appropriately oriented and driven cylindrical array of piezoelectric crystals of the transducer, the horn creates a torsional wave along at least a portion of the longitudinal axis of the ultrasonic probe 15, causing the ultrasonic probe 15 to vibrate in a torsional mode with a torsional vibration. The transducer crystals are vibrated in a direction approximately tangential to the cylindrical surface of the ultrasonic probe 15. U.S. Pat. No. 2,838,695 to Thurston describes how an appropriately oriented and driven cylindrical array of transducer crystals creates torsional waves, and the entirety of this patent is hereby incorporated herein by reference. The transducer transmits ultrasonic energy received from the ultrasonic energy source 99 to the ultrasonic probe 15, causing the ultrasonic probe 15 to vibrate in a torsional mode. The transducer is capable of engaging the ultrasonic probe 15 at the proximal end 31 with sufficient restraint to form an acoustical mass that can propagate the ultrasonic energy provided by the ultrasonic energy source 99.
  • [0049]
    The ultrasonic probe 15 is moved to a treatment site of the biological material and the ultrasonic probe 15 is placed in communication with the biological material. The ultrasonic probe 15 may be swept, twisted or rotated along the treatment site of the biological material. Those skilled in the art will recognize the ultrasonic probe can be placed in communication with the biological material in many other ways known in the art and be within the spirit and scope of the present invention.
  • [0050]
    The ultrasonic energy source 99 is activated to produce the ultrasonic energy that produces a torsional vibration of the ultrasonic probe 15. The ultrasonic energy source 99 provides the electrical power to the transducer at the resonant frequency of the transducer. The ultrasonic energy source 99 provides a low power electric signal of between about 2 watts to about 15 watts to the transducer that is located within the handle 88. Piezoelectric ceramic crystals inside the transducer create a torsional vibration that is converted into a standing torsional wave along the longitudinal axis of the ultrasonic probe 15. In a preferred embodiment of the present invention, the ultrasonic energy source 99 finds the resonant frequency of the transducer through a Phase Lock Loop (PLL) circuit.
  • [0051]
    The torsional wave is transmitted along the longitudinal axis of the ultrasonic probe 15. The torsional wave produces a component of force in a transverse direction relative to the longitudinal axis of the ultrasonic probe 15, thereby exciting a transverse wave along the longitudinal axis of the ultrasonic probe 15. As a result, the ultrasonic probe 15 undergoes both a torsional vibration and a transverse vibration.
  • [0052]
    The torsional vibration along the longitudinal axis of the ultrasonic probe 15 induces a transverse vibration along an active area of the ultrasonic probe 15. In a preferred embodiment of the present invention, the active area is at least a portion of the longitudinal axis of the ultrasonic probe 15. In an embodiment of the present invention, the active area is at the distal end 24 of the ultrasonic probe 15. Those skilled in the art will recognize the active area can be located anywhere along the longitudinal axis of the ultrasonic probe and the active area can have varying lengths and be within the spirit and scope of the present invention.
  • [0053]
    FIG. 3 shows a perspective view of the ultrasonic probe 15 of the present invention undergoing a torsional vibration and a transverse vibration along the active area of the ultrasonic probe 15. The torsional vibration is shown as the alternating clockwise and counterclockwise sets of arrows, with each set comprising five arrows in FIG. 3. The transverse vibration is shown with a wave-like motion in a repeating form where the vibration rises from the longitudinal axis to a maximum amplitude, descends back down to the longitudinal axis to a minimum amplitude, proceeds from the longitudinal axis to a maximum amplitude and returns to the longitudinal axis of the ultrasonic probe 15.
  • [0054]
    Depending upon physical properties (i.e. length, diameter, etc.) and material properties (i.e., yield strength, modulus, etc.) of the ultrasonic probe 15, the transverse vibration is excited by the torsional vibration. The active area of the ultrasonic probe 15 undergoes both the torsional vibration and the transverse vibration. By vibrating the ultrasonic probe 15 both torsionally and transversely, the ultrasonic probe 15 is operated in a torsional mode of vibration and a transverse mode of vibration. Coupling of the torsional mode of vibration and the transverse mode of vibration is possible because of common shear components for the elastic forces. The transverse vibration is induced when the frequency of the transducer is close to a transverse resonant frequency of the ultrasonic probe 15. The combination of the torsional mode of vibration and the transverse mode of vibration is possible because for each torsional mode of vibration, there are many close transverse modes of vibration.
  • [0055]
    The torsional wave motion along the longitudinal axis of the ultrasonic probe 15 creates a shear force gradient along the longitudinal axis of the ultrasonic probe 15. The shear force gradient generates a transverse motion when the frequency of the torsional motion is close to a transverse resonant frequency of the ultrasonic probe 15. The shear force is in the approximate same direction as the transverse motion. The magnitude of the shear force is proportional to the torsional or angular displacement. As shown in FIG. 3, the wavelength for the transverse mode of vibration is less than the wavelength for the torsional mode of vibration. In an embodiment of the present invention, two or more wavelengths for the transverse mode of vibration are produced for one wavelength for the torsional mode of vibration. In the embodiment of the present invention shown in FIG. 3, the transverse vibration wavelength is about one-fifth (⅕) of the torsional vibration wavelength.
  • [0056]
    By applying tension to the ultrasonic probe 15, the transverse and torsional vibrations are shifted in frequency. For example, bending the ultrasonic probe 15 causes the transverse and torsional vibration to shift in frequency. Bending the ultrasonic probe 15 causes a shift in frequency resulting from the changes in tension. In an embodiment of the present invention, the ultrasonic probe 15 is coupled to the transducer through an acoustic impedance mismatch so that the tuning of the ultrasonic probe 15 will not affect the drive frequency. The acoustic impedance mismatch can be achieved by maintaining a large difference between the moment of inertia of the transducer and the moment of inertia of the ultrasonic probe 15. The acoustic impedance mismatch can be created by a discontinuity at the transducer or created further down the longitudinal axis of the ultrasonic probe 15 by reducing the diameter in a stepwise manner toward the distal end 24 of the ultrasonic probe 15. An ultrasonic probe device having an impedance mismatch with rapid attachment and detachment means is described in Assignee's co-pending patent application U.S. Ser. No. 10/268,487, the entirety of which is hereby incorporated herein by reference.
  • [0057]
    FIG. 4 shows a fragmentary perspective view of the ultrasonic probe 15 of the present invention undergoing the torsional vibration. As discussed above, the alternating clockwise and counterclockwise arrows represent the torsional vibration, showing the rotational and counterrotational motion of the ultrasonic probe 15. FIG. 5A shows a fragmentary side plan view of the ultrasonic probe 15 of the present invention undergoing the torsional vibration while FIG. 5B shows a graph corresponding to the torsional vibration shown in FIG. 5A.
  • [0058]
    FIG. 6 shows the ultrasonic probe 15 undergoing the transverse vibration. To clearly describe the torsional vibration and the transverse vibration, the torsional vibration will be examined while discussing FIG. 4, FIG. 5A and FIG. 5B while the transverse vibration will be separately examined while discussing FIG. 6.
  • [0059]
    The torsional vibration of the ultrasonic probe 15 in FIG. 4 and FIG. 5A is shown as movement of the ultrasonic probe in alternating clockwise and counterclockwise directions along the longitudinal axis of the ultrasonic probe 15. The torsional vibration shown in FIG. 4 and FIG. 5A is a torsional oscillation whereby equally spaced points along the longitudinal axis of the ultrasonic probe 15 including the probe tip 9 vibrate back and forth in a short arc of the same amplitude in a plane perpendicular to the longitudinal axis of the ultrasonic probe 15. The vibration creates a plurality of torsional nodes 50 and a plurality of torsional antinodes 52 along an active area of the ultrasonic probe 15. A section proximal to each of the plurality of torsional nodes 50 and a section distal to each of the plurality of torsional nodes 50 are vibrated out of phase, with the proximal section vibrated in a clockwise direction and the distal section vibrated in a counterclockwise direction, or vice versa. The torsional vibration produces a rotation and counterrotation along the longitudinal axis of the ultrasonic probe 15. As shown in FIG. 5A and FIG. 5B, the torsional vibration is propagated in a forward direction and a reverse direction about a torsional node 50. Traveling along the longitudinal axis, at each torsional node 50, the direction of the rotation reverses and the amplitude increases until reaching a torsional anti-node 52 and subsequently decreases toward the next torsional node 50. An ultrasonic probe operating in a torsional mode for biological material ablation are described in the Assignee's co-pending patent application U.S. Ser. No. 10/774,985 filed Feb. 9, 2004, and the entirety of this application is hereby incorporated herein by reference.
  • [0060]
    FIG. 5A shows the alternating clockwise and counterclockwise motion about the torsional node 50 and shows an expansion and a compression of the ultrasonic probe 15 in the torsional mode. FIG. 5A shows the expansion of the ultrasonic probe 15 as the clockwise and counterclockwise motion of the ultrasonic probe 15 extends away from the torsional node 50. As the alternating clockwise and counterclockwise motion returns back to the torsional node 50, the ultrasonic probe 15 is compressed. The ultrasonic probe 15 will expand and compress about the plurality of torsional nodes 50 along an active area of the ultrasonic probe 15.
  • [0061]
    The transverse vibration of the ultrasonic probe 15 shown in FIG. 6 results in a portion of the longitudinal axis of the ultrasonic probe 15 vibrated in a direction not parallel to the longitudinal axis of the ultrasonic probe 15. The transverse vibration results in movement of the longitudinal axis of the ultrasonic probe 15 in a direction approximately perpendicular to the longitudinal axis of the ultrasonic probe 15. The transverse vibration creates a plurality of transverse nodes 60 and a plurality of transverse anti-nodes 62 along the active area of the ultrasonic probe 15. Transversely vibrating ultrasonic probes for biological material ablation are described in the Assignee's U.S. Pat. Nos. 6,551,337 and 6,652,547 and co-pending patent application U.S. Ser. No. 09/917,471, which further describe the design parameters for such an ultrasonic probe and its use in ultrasonic devices for an ablation, and the entirety of these patents and patent applications are hereby incorporated herein by reference.
  • [0062]
    As best shown in FIG. 3, the torsional vibration shown in FIG. 4 and the transverse vibration shown in FIG. 6 are combined at the active area of the ultrasonic probe 15 to produce the torsional vibration and transverse vibration shown in FIG. 3. The torsional vibration and the transverse vibration create a plurality of nodes 50, 60 and a plurality of antinodes 52, 62 along the active area of the ultrasonic probe 15. In the torsional mode of vibration and the transverse mode of vibration, the active area of the ultrasonic probe 15 is vibrated in a direction not parallel to the longitudinal axis of the ultrasonic probe 15 while equally spaced points along the longitudinal axis of the ultrasonic probe 15 in a proximal section vibrate back and forth in a short arc about the longitudinal axis of the ultrasonic probe 15. In a preferred embodiment of the present invention, the torsional vibration and the transverse vibration are superimposed over the active area of the ultrasonic probe 15 (FIG. 3).
  • [0063]
    In an alternative embodiment of the present invention shown in FIG. 7, the torsional vibration of the ultrasonic probe 15 creates the transverse vibration along an active area of the ultrasonic probe, where the active area undergoes the transverse vibration without the torsional vibration. The transverse vibration creates the plurality of transverse nodes 60 and the plurality of transverse anti-nodes 62 along the longitudinal axis of the ultrasonic probe 15. FIG. 7 shows the alternative embodiment wherein the torsional vibration and the transverse vibration are segregated over the longitudinal axis of the ultrasonic probe 15. In one embodiment, a segregation section of the ultrasonic probe 15 is between the torsional vibration and the transverse vibration. In another embodiment, there is a minor overlap of the torsional vibration and the transverse vibration over the active area of the ultrasonic probe 15. Those skilled in the art will recognize a length of the segregation section between the torsional vibration and the transverse vibration can vary and be within the spirit and scope of the present invention.
  • [0064]
    FIG. 8 shows a fragmentary perspective view of the ultrasonic probe 15 with the plurality of nodes 50, 60 and the plurality of anti-nodes 52, 62 for the torsional mode of vibration and the transverse mode of vibration along the active area of the ultrasonic probe 15 caused by the torsional vibration and the transverse vibration of the ultrasonic probe 15. FIG. 8 and FIG. 3 both show the pattern of the plurality of nodes 50, 60, and the plurality of antinodes 52, 62 for the torsional mode of vibration and the transverse mode of vibration are independently created for each mode of vibration. As a result, the pattern of the plurality of nodes 50, 60 and the plurality of anti-nodes 52, 62 has a different spacing for the torsional mode of vibration and the transverse mode of vibration. The plurality of nodes 50, 60 are areas of minimum energy and minimum vibration. The plurality of anti-nodes 52, 62, areas of maximum energy and maximum vibration, also occur at repeating intervals along the active area of the ultrasonic probe 15. The torsional vibration and the transverse vibration at the active area of the ultrasonic probe 15 create the plurality of nodes 50, 60 and the plurality of anti-nodes 52, 62 along the active area of the ultrasonic probe 15 resulting in cavitation in a medium surrounding the ultrasonic probe 15 that ablates the biological material.
  • [0065]
    The combined torsional motion and transverse motion of the ultrasonic probe 15 caused by the torsional vibration and the transverse vibration causes an interaction between the surface of the ultrasonic probe 15 and the medium surrounding the ultrasonic probe 15 to cause an acoustic wave in the medium surrounding the ultrasonic probe 15. In effect, acoustic energy is generated in the medium surrounding the ultrasonic probe 15. The motion caused by the torsional vibration and the transverse vibration causes cavitation in the medium surrounding the ultrasonic probe 15 over an active area of the ultrasonic probe 15.
  • [0066]
    Cavitation is a process in which small voids are formed in a surrounding fluid through the rapid motion of the ultrasonic probe 15 and the voids are subsequently forced to compress. The compression of the voids creates a wave of acoustic energy which acts to dissolve the matrix binding the biological material, while having no damaging effects on healthy tissue. The biological material is resolved into a particulate having a size on the order of red blood cells (approximately 5 microns in diameter). The size of the particulate is such that the particulate is easily discharged from the body through conventional methods or simply dissolves into the blood stream. A conventional method of discharging the particulate from the body includes transferring the particulate through the blood stream to the kidney where the particulate is excreted as bodily waste.
  • [0067]
    The torsional motion of the ultrasonic probe 15 is less than the transverse motion of the ultrasonic probe 15. Once the transverse motion is established on the ultrasonic probe 15, almost all additional energy goes into transverse motion and the amplitude of the torsional motion does not increase appreciably past this point. Cavitation is created primarily because of the transverse motion of the ultrasonic probe 15.
  • [0068]
    The number of nodes 50, 60 and the number of anti-nodes 52, 62 occurring along the active area of the ultrasonic probe 15 is modulated by changing the frequency of energy supplied by the ultrasonic energy source 99. The exact frequency, however, is not critical and the ultrasonic energy source 99 run at, for example, about 20 kHz is sufficient to create an effective number of biological material destroying anti-nodes 52, 62 along the longitudinal axis of the ultrasonic probe 15. The low frequency requirement of the present invention is a further advantage in that the low frequency requirement leads to less damage to healthy tissue. Those skilled in the art will recognize that changing the dimensions of the ultrasonic probe 15, including diameter, length and distance to the ultrasonic energy source 99, will affect the number and spacing of the nodes 50, 60 and the anti-nodes 52, 62 along the active area of the ultrasonic probe 15.
  • [0069]
    The present invention allows the use of ultrasonic energy to be applied to the biological material selectively, because the ultrasonic probe 15 conducts energy across a frequency range from about 10 kHz through about 100 kHz. The amount of ultrasonic energy to be applied to a particular treatment site is a function of the amplitude and frequency of vibration of the ultrasonic probe 15. In general, the amplitude or throw rate of energy is in the range of about 25 microns to about 250 microns, and the frequency in the range of about 10 kHz to about 100 kHz. In a preferred embodiment of the present invention, the frequency of ultrasonic energy is from about 20 kHz to about 35 kHz.
  • [0070]
    As discussed above, once the transverse motion of the ultrasonic probe 15 is established, almost all additional energy goes into transverse motion of the ultrasonic probe 15 and the amplitude of the torsional motion does not increase appreciably past this point. As such, in the preferred embodiment of the present invention, the torsional motion of the ultrasonic probe 15 is less than the transverse motion of the ultrasonic probe 15.
  • [0071]
    FIG. 9 shows a perspective view of another embodiment of the present invention where the cross section of the ultrasonic probe 15 varies from the proximal end 31 of the ultrasonic probe 15 to the distal end 24 of the ultrasonic probe 15. In the embodiment of the present invention shown in FIG. 9, the cross section of the ultrasonic probe varies from an approximately circular cross at the proximal end 31 of the ultrasonic probe 15 to a radially asymmetric cross section at the distal end 24 of the ultrasonic probe 15. In FIG. 9, the radially asymmetric cross section at the distal end 24 of the ultrasonic probe 15 is approximately rectangular. Other radially asymmetric cross sections at the distal end 24 of the ultrasonic probe 15 that can be used to create torsional motion that subsequently produces cavitation along a portion of the length of the longitudinal axis include, but are not limited to, square, trapezoidal, elliptical, star shaped, rectangular, oval, triangular, circular with a flat spot and similar cross sections. Those skilled in the art will recognize other radially asymmetric cross sections known in the art are within the spirit and scope of the present invention.
  • [0072]
    The torsional vibration and the transverse vibration of the ultrasonic probe 15 according to the present invention differ from an axial (or longitudinal) mode of vibration disclosed in the prior art. Rather than vibrating in an axial direction, the ultrasonic probe 15 of the present invention vibrates both torsionally and transversely along the active area of the ultrasonic probe 15. As a consequence of the torsional vibration and the transverse vibration of the ultrasonic probe 15, the biological material destroying effects of the ultrasonic medical device 11 are not limited to the tip of the ultrasonic probe 15. Rather, as a section of the longitudinal axis of the ultrasonic probe 15 is positioned in proximity to the biological material, the biological material is removed in all areas adjacent to the plurality of nodes 50, 60 and the plurality of anti-nodes 52, 62 that are produced by the torsional vibration and transverse vibration along the active area of the ultrasonic probe 15, typically in a region having a radius of up to about 6 mm around the ultrasonic probe 15. The torsional mode of vibration and transverse mode of vibration results in an ultrasonic energy transfer to the biological material with minimal loss of ultrasonic energy that could limit the effectiveness of the ultrasonic medical device 11. In addition to increasing the biological material destroying area of the ultrasonic probe 15, the probe tip 9 is able to ablate the biological material when the probe tip 9 encounters the biological material and the ultrasonic probe 15 is vibrated torsionally and transversely.
  • [0073]
    In one embodiment of the present invention, the ultrasonic probe 15 is swept along the treatment site of the biological material. In another embodiment of the present invention, the ultrasonic probe 15 is moved back and forth along the treatment site of the biological material. In another embodiment of the present invention, the ultrasonic probe 15 is twisted along the treatment site of the biological material. In another embodiment of the present invention, the ultrasonic probe 15 is rotated along the treatment site of the biological material. Those skilled in the art will recognize the ultrasonic probe can be place in communication with the biological material in many ways known in the art and be within the spirit and scope of the present invention.
  • [0074]
    Unlike the prior art longitudinal mode of operation where the biological material destroying effects are limited to the tip of the probe, an active area of the ultrasonic probe 15 operating in the torsional mode and transverse mode extends from the probe tip 9 and along a portion of a longitudinal axis of the ultrasonic probe 15. The section below entitled “Theory of Operation” discusses some differences between the longitudinal mode of operation used in the prior art and the torsional mode and transverse mode of operation used in the present invention. In the torsional mode and transverse mode of vibration, the biological material is removed in all areas adjacent to the plurality of nodes 50, 60 and the plurality of anti-nodes 52, 62 that are produced by the torsional vibration and transverse vibration along the active area of the ultrasonic probe 15. By treating a larger area of the treatment site of the biological material, the ultrasonic medical device 11 of the present invention allows for shorter medical procedures. By reducing the time of the medical procedure, a patient is not subjected to additional health risks associated with longer medical procedures.
  • [0075]
    FIG. 10 shows the ultrasonic probe 15 of the present invention extending from a distal end 34 of a sheath 36. As shown in FIG. 10, the ultrasonic probe 15 is placed within the sheath 36, which can provide an at least one irrigation channel 38 and an at least one aspiration channel 39. In an embodiment of the present invention, irrigation is provided between the ultrasonic probe 15 and the sheath 36. The ultrasonic probe 15 may be moved in an axial direction within the sheath 36 to move the distal end 24 of the ultrasonic probe 15 axially inwardly and outwardly relative to the distal end 34 of the sheath 36. By extending or retracting the ultrasonic probe 15 relative to the sheath 36, the amount of the ultrasonic probe 15 exposed is modified, thereby modifying the biological material destroying area of the ultrasonic probe 15.
  • [0076]
    In an embodiment of the present invention, the sheath 36 is comprised of polytetrafluoroethylene (PTFE). In another embodiment of the present invention, the sheath 36 is comprised of teflon tubing or similar fluoropolymer tubing. The sheath absorbs the ultrasonic energy emanating from the portions of the ultrasonic probe 15 located within the sheath 36, thereby allowing control over the amount of biological material affected by the ultrasonic probe 15. The sheath 36 is preferably comprised of a material which is resistant to heat from the ultrasonic energy, even though the irrigation fluid can act as a coolant for the sheath 36.
  • [0077]
    The present invention provides a method of treating a biological material in the body with the ultrasonic medical device 11. The ultrasonic probe 15 of the ultrasonic medical device 11 is moved to the treatment site of the biological material and placed in communication with the biological material. The ultrasonic energy source 99 of the ultrasonic medical device 11 engaged to the ultrasonic probe 15 is activated to produce the torsional vibration of the ultrasonic probe 15. The transducer engaging the ultrasonic energy source 99 at the proximal end of the transducer and the ultrasonic probe 15 at the distal end of the transducer creates the torsional vibration along the longitudinal axis of the ultrasonic probe 15. The torsional vibration of the ultrasonic probe 15 induces the transverse vibration in the active area of the ultrasonic probe, wherein the active area of the ultrasonic probe 15 supports the torsional vibration and the transverse vibration.
  • [0078]
    The present invention also provides a method of removing a biological material in the body. The ultrasonic probe 15 of the ultrasonic medical device 11 is moved in the body and placed in communication with the biological material. The ultrasonic energy source 99 of the ultrasonic medical device 11 produces an electric signal that drives the transducer of the ultrasonic medical device 11 to produce a torsional vibration of the ultrasonic probe 15. The torsional vibration of the ultrasonic probe 15 induces the transverse vibration along the longitudinal axis of the ultrasonic probe 15, creating a plurality of nodes 50, 60 and a plurality of anti-nodes 52, 62 along an active area of the ultrasonic probe 15.
  • Theory of Operation
  • [0079]
    The torsional mode of vibration and transverse mode of vibration of the present invention differs from longitudinal mode of vibration of the prior art. In the longitudinal vibration of the prior art, the frequencies of the individual modes depend on the modulus of elasticity E and the density ρ.
  • [0000]
    c l = E ρ
  • [0000]
    For the torsional waves, the expression is the same except the shear modulus, G, is used instead of the modulus of elasticity, E. The shear modulus, G, and the modulus of elasticity, E, are linked through Poisson's ratio υ:
  • [0000]
    G = E 2 ( 1 + υ )
  • [0000]
    and the corresponding torsional speed of propagation is:
  • [0000]
    c t = GK T ρ I
  • [0000]
    where KT is the torsional stiffness factor of the cross section and I is the moment of inertia of the cross section. For a circular cross section the ratio KT/I=1, while for radially asymmetric cross sections the ratio KT/I<1. Therefore, the speed of propagation will be slower for the torsional wave by a factor of:
  • [0000]
    c t c l = K T 2 ( 1 + υ ) I
  • [0080]
    For a symmetric cross section KT/I=1, and for a radially asymmetric cross section KT/I<1. For common metals, Poisson's ratio υ is on the order of 0.3, therefore the speed of propagation for a torsional wave will be approximately 62% or less of that for the longitudinal wave. A decrease in the speed of propagation implies a proportional decrease in the wavelength for a given frequency. Decreasing the wavelength greatly improves the devices ability to deliver energy through the tortuous paths and the tight bends of the vasculature.
  • [0081]
    The operating frequencies of the longitudinal and torsional modes are dependent on the properties of the ultrasonic probe. Selection of material properties depends primarily on acoustic loss, the choice of operating frequency and the desired amplitude of vibration. As discussed previously, with the ultrasonic probe comprised of titanium and operating at a frequency of about 20 kHz, the torsional wave speed for a circular cross section is as follows:
  • [0000]
    c t = E 2 ( 1 + v ) ρ = 1.1 10 11 Pa 2 ( 1 + 0.3 ) 4600 kg / m 3 = 3032 m / s
  • [0082]
    Using the torsional wave speed to solve for a condition of the length of the ultrasonic probe to operate in a torsional mode and a transverse mode gives:
  • [0000]
    L = λ 2 = c 2 f = 3032 m / s 2 ( 20 , 000 Hz ) = 0.0758 m = 7.58 cm 3 in .
  • [0083]
    Thus, for the ultrasonic probe to operate in a torsional mode and a transverse mode, the length of the ultrasonic probe should not be an integer multiple of 7.58 cm (about 3 inches) for this particular case. Those skilled in the art will recognize that changes to other material properties can influence the operation in the torsional mode and these changes are within the spirit and scope of the present invention.
  • [0084]
    The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode. The active area of the ultrasonic probe is vibrated in a direction not parallel to the longitudinal axis of the ultrasonic probe while equally spaced points along the active area are vibrated back and forth in a short arc along the active area of the ultrasonic probe. The present invention provides an ultrasonic medical device that is simple, user-friendly, time efficient, reliable and cost effective.
  • [0085]
    All patents, patent applications, and published references cited herein are hereby incorporated herein by reference in their entirety. While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2270922 *17 Oct 193927 Jan 1942Telefunken GmbhPiezoelectric crystal holder
US3241780 *5 Aug 196322 Mar 1966Indiana Steel & Wire Company IWire tensioning filament feeding apparatus
US3304449 *22 Aug 196314 Feb 1967Pohlman ReimarApparatus for producing sonic and ultrasonic oscillations
US3565062 *13 Jun 196823 Feb 1971Ultrasonic SystemsUltrasonic method and apparatus for removing cholesterol and other deposits from blood vessels and the like
US3861391 *20 Mar 197421 Jan 1975Blackstone CorpApparatus for disintegration of urinary calculi
US3939033 *16 Dec 197417 Feb 1976Branson Ultrasonics CorporationUltrasonic welding and cutting apparatus
US4069541 *23 Apr 197624 Jan 1978U.S. Floor Systems, Inc.Cleaning method and apparatus
US4136700 *14 Jun 197630 Jan 1979Cavitron CorporationNeurosonic aspirator
US4248232 *12 Sep 19783 Feb 1981Eckart EngelbrechtMethod of dissolving the bond between interconnected components
US4311147 *8 May 198019 Jan 1982Richard Wolf GmbhApparatus for contact-free disintegration of kidney stones or other calculi
US4315181 *22 Apr 19809 Feb 1982Branson Ultrasonics CorporationUltrasonic resonator (horn) with skewed slots
US4316465 *29 Nov 197923 Feb 1982Dotson Robert S JunOphthalmic handpiece with pneumatically operated cutter
US4368410 *14 Oct 198011 Jan 1983Dynawave CorporationUltrasound therapy device
US4425115 *21 Apr 197810 Jan 1984Wuchinich David GUltrasonic resonant vibrator
US4428748 *9 Apr 198031 Jan 1984Peyman Gholam ACombined ultrasonic emulsifier and mechanical cutter for surgery
US4493694 *25 May 198415 Jan 1985Cooper Lasersonics, Inc.Surgical pre-aspirator
US4498025 *20 Nov 19815 Feb 1985Seiko Instruments & Electronics Ltd.Tuning fork
US4571520 *7 Jun 198418 Feb 1986Matsushita Electric Industrial Co. Ltd.Ultrasonic probe having a backing member of microballoons in urethane rubber or thermosetting resin
US4572041 *10 May 198525 Feb 1986Rissmann Horst GTorque limiting wrench
US4634420 *31 Oct 19846 Jan 1987United Sonics IncorporatedApparatus and method for removing tissue mass from an organism
US4642509 *21 Feb 198610 Feb 1987Hitachi Maxell, Ltd.Ultrasonic motor using bending, longitudinal and torsional vibrations
US4643717 *16 Sep 198517 Feb 1987Site Microsurgical Systems, Inc.Aspiration fitting adaptor
US4718907 *20 Jun 198512 Jan 1988Atrium Medical CorporationVascular prosthesis having fluorinated coating with varying F/C ratio
US4794912 *17 Aug 19873 Jan 1989Welch Allyn, Inc.Borescope or endoscope with fluid dynamic muscle
US4892089 *23 Feb 19899 Jan 1990Duke UniversityMethod for comminuting kidney stones
US4904391 *9 Oct 198527 Feb 1990Freeman Richard BMethod and apparatus for removal of cells from bone marrow
US4986808 *20 Dec 198822 Jan 1991Valleylab, Inc.Magnetostrictive transducer
US4989583 *21 Oct 19885 Feb 1991Nestle S.A.Ultrasonic cutting tip assembly
US4989588 *27 Feb 19875 Feb 1991Olympus Optical Co., Ltd.Medical treatment device utilizing ultrasonic wave
US5176141 *2 Oct 19905 Jan 1993Du-Med B.V.Disposable intra-luminal ultrasonic instrument
US5176677 *17 Nov 19895 Jan 1993Sonokinetics GroupEndoscopic ultrasonic rotary electro-cauterizing aspirator
US5180363 *23 Dec 199119 Jan 1993Sumitomo Bakelite Company Company LimitedOperation device
US5285795 *12 Sep 199115 Feb 1994Surgical Dynamics, Inc.Percutaneous discectomy system having a bendable discectomy probe and a steerable cannula
US5287775 *18 Sep 199222 Feb 1994Moore Allen MTorque limiting drawing holder nut wrench
US5380273 *19 May 199310 Jan 1995Dubrul; Will R.Vibrating catheter
US5380274 *12 Oct 199310 Jan 1995Baxter International Inc.Ultrasound transmission member having improved longitudinal transmission properties
US5382228 *28 Sep 199317 Jan 1995Baxter International Inc.Method and device for connecting ultrasound transmission member (S) to an ultrasound generating device
US5385372 *8 Jan 199331 Jan 1995Utterberg; David S.Luer connector with integral closure
US5387190 *15 Apr 19947 Feb 1995Olympus Optical Co., Ltd.Probe break detector for an ultrasonic aspirator
US5387197 *25 Feb 19937 Feb 1995Ethicon, Inc.Trocar safety shield locking mechanism
US5388569 *5 Jan 199314 Feb 1995American Cyanamid CoPhacoemulsification probe circuit with switch drive
US5390678 *12 Oct 199321 Feb 1995Baxter International Inc.Method and device for measuring ultrasonic activity in an ultrasound delivery system
US5391144 *20 Jul 199321 Feb 1995Olympus Optical Co., Ltd.Ultrasonic treatment apparatus
US5484398 *17 Mar 199416 Jan 1996Valleylab Inc.Methods of making and using ultrasonic handpiece
US5492001 *18 Jan 199420 Feb 1996Kabushiki Kaisha Yutaka GikenMethod and apparatus for working burred portion of workpiece
US5590653 *9 Mar 19947 Jan 1997Kabushiki Kaisha ToshibaUltrasonic wave medical treatment apparatus suitable for use under guidance of magnetic resonance imaging
US5593394 *24 Jan 199514 Jan 1997Kanesaka; NozomuShaft for a catheter system
US5599326 *20 Dec 19944 Feb 1997Target Therapeutics, Inc.Catheter with multi-layer section
US5603445 *24 Feb 199418 Feb 1997Hill; William H.Ultrasonic wire bonder and transducer improvements
US5704787 *20 Oct 19956 Jan 1998San Diego Swiss Machining, Inc.Hardened ultrasonic dental surgical tips and process
US5707359 *14 Nov 199513 Jan 1998Bufalini; BrunoExpanding trocar assembly
US5709120 *23 Feb 199620 Jan 1998Shilling; Paul L.Straight line drawing device
US5713363 *24 Apr 19963 Feb 1998Mayo Foundation For Medical Education And ResearchUltrasound catheter and method for imaging and hemodynamic monitoring
US5713848 *7 Jun 19953 Feb 1998Dubrul; Will R.Vibrating catheter
US5715825 *10 Jun 199610 Feb 1998Boston Scientific CorporationAcoustic imaging catheter and the like
US5720300 *21 Feb 199524 Feb 1998C. R. Bard, Inc.High performance wires for use in medical devices and alloys therefor
US5720710 *11 Jul 199424 Feb 1998Ekos CorporationRemedial ultrasonic wave generating apparatus
US5861023 *16 Dec 199719 Jan 1999Pacesetter, Inc.Thrombus and tissue ingrowth inhibiting overlays for defibrillator shocking coil electrodes
US5868773 *7 Jun 19959 Feb 1999Endoscopic Concepts, Inc.Shielded trocar with safety locking mechanism
US5868778 *5 May 19979 Feb 1999Vascular Solutions, Inc.Vascular sealing apparatus and method
US6010476 *17 Oct 19974 Jan 2000Angiotrax, Inc.Apparatus for performing transmyocardial revascularization
US6010498 *6 Oct 19974 Jan 2000The Regents Of The University Of CaliforniaEndovascular electrolytically detachable wire and tip for the formation of thrombus in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas
US6017340 *27 Jan 199725 Jan 2000Wiltek Medical Inc.Pre-curved wire guided papillotome having a shape memory tip for controlled bending and orientation
US6017354 *15 Aug 199625 Jan 2000Stryker CorporationIntegrated system for powered surgical tools
US6017359 *17 Jun 199725 Jan 2000Vascular Solutions, Inc.Vascular sealing apparatus
US6019777 *21 Apr 19971 Feb 2000Advanced Cardiovascular Systems, Inc.Catheter and method for a stent delivery system
US6021694 *16 Oct 19988 Feb 2000Aseculap Ag & Co. KgSurgical torque wrench
US6022336 *6 Mar 19978 Feb 2000Percusurge, Inc.Catheter system for emboli containment
US6022369 *13 Feb 19988 Feb 2000Precision Vascular Systems, Inc.Wire device with detachable end
US6027515 *2 Mar 199922 Feb 2000Sound Surgical Technologies LlcPulsed ultrasonic device and method
US6032078 *22 Oct 199729 Feb 2000Urologix, Inc.Voltage controlled variable tuning antenna
US6190353 *11 Oct 199620 Feb 2001Transvascular, Inc.Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures
US6193683 *28 Jul 199927 Feb 2001AllerganClosed loop temperature controlled phacoemulsification system to prevent corneal burns
US6346091 *20 Oct 199912 Feb 2002Stephen C. JacobsenDetachable coil for aneurysm therapy
US6348039 *7 Apr 200019 Feb 2002Urologix, Inc.Rectal temperature sensing probe
US6503223 *18 Mar 19997 Jan 2003Nippon Zeon Co., Ltd.Balloon catheter
US6508781 *30 Dec 199921 Jan 2003Advanced Cardiovascular Systems, Inc.Ultrasonic ablation catheter transmission wire connector assembly
US6508782 *16 Aug 200021 Jan 2003Bacchus Vascular, Inc.Thrombolysis device
US6509348 *27 Oct 199921 Jan 2003Bristol-Myers Squibb CompanyCombination of an ADP-receptor blocking antiplatelet drug and a thromboxane A2 receptor antagonist and a method for inhibiting thrombus formation employing such combination
US6511492 *1 May 199828 Jan 2003Microvention, Inc.Embolectomy catheters and methods for treating stroke and other small vessel thromboembolic disorders
US6512957 *26 Jun 200028 Jan 2003Biotronik Mess-Und Therapiegeraete Gmbh & Co. Ingenieurburo BerlinCatheter having a guide sleeve for displacing a pre-bent guidewire
US6514210 *8 May 20014 Feb 2003Pentax CorporationForward viewing and radial scanning ultrasonic endoscope
US6522929 *9 May 200118 Feb 2003Fred P. SwingTreatment of peripheral vascular disease, leg cramps and injuries using needles and electrical stimulation
US6524251 *15 Feb 200125 Feb 2003Omnisonics Medical Technologies, Inc.Ultrasonic device for tissue ablation and sheath for use therewith
US6695782 *11 Oct 200124 Feb 2004Omnisonics Medical Technologies, Inc.Ultrasonic probe device with rapid attachment and detachment means
US6840952 *7 Dec 200111 Jan 2005Mark B. SakerTissue tract sealing device
US6849062 *23 Aug 20021 Feb 2005Medtronic Vascular, Inc.Catheter having a low-friction guidewire lumen and method of manufacture
US6855123 *2 Aug 200215 Feb 2005Flow Cardia, Inc.Therapeutic ultrasound system
US6855125 *31 May 200115 Feb 2005Conor Medsystems, Inc.Expandable medical device delivery system and method
US6984220 *11 Apr 200110 Jan 2006Wuchinich David GLongitudinal-torsional ultrasonic tissue dissection
US20020007130 *1 Sep 199817 Jan 2002Senorx, Inc.Methods and apparatus for securing medical instruments to desired locations in a patients body
US20020016565 *18 May 19997 Feb 2002Gholam-Reza Zadno-AziziCatheter system for emboli containment
US20030009125 *27 Jun 20029 Jan 2003Henry NitaUltrasonic devices and methods for ablating and removing obstructive matter from anatomical passageways and blood vessels
US20040019266 *29 Jul 200229 Jan 2004Omnisonics Medical Technologies, Inc.Apparatus and method for radiopaque coating for an ultrasonic medical device
US20040024393 *20 Jun 20035 Feb 2004Henry NitaTherapeutic ultrasound system
US20040024402 *2 Aug 20025 Feb 2004Henry NitaTherapeutic ultrasound system
US20040039311 *26 Aug 200226 Feb 2004Flowcardia, Inc.Ultrasound catheter for disrupting blood vessel obstructions
US20040039375 *20 May 200326 Feb 2004Olympus Optical Co., Ltd.Ultrasonic operating apparatus
US20050043629 *6 Oct 200424 Feb 2005Omnisonics Medical Technologies, Inc.Apparatus and method for an ultrasonic medical device having a probe with a small proximal end
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US86230401 Jul 20097 Jan 2014Alcon Research, Ltd.Phacoemulsification hook tip
US923302124 Oct 201312 Jan 2016Alcon Research, Ltd.Phacoemulsification hook tip
Classifications
U.S. Classification601/2
International ClassificationA61B17/32, A61B17/22, A61N7/00, A61H1/00, A61B17/20
Cooperative ClassificationA61B17/22012, A61B2017/320072, A61B2017/320084, A61B2017/22008, A61B2017/320088
European ClassificationA61B17/22B2
Legal Events
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1 Oct 2010ASAssignment
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Owner name: EMIGRANT BANK, N.A., NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OMNISONICS MEDICAL TECHNOLOGIES, INC.;REEL/FRAME:025091/0928
Effective date: 20091118
22 Dec 2010ASAssignment
Owner name: CYBERSONICS, INC., PENNSYLVANIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:EMIGRANT BANK, N.A.;REEL/FRAME:025779/0820
Effective date: 20101201
24 Feb 2011ASAssignment
Owner name: EMIGRANT BANK, N.A., NEW YORK
Free format text: SECURITY AGREEMENT;ASSIGNOR:CYBERSONICS, INC.;REEL/FRAME:025879/0635
Effective date: 20101201