An apparatus for lysing adipose tissue, the apparatus comprising a power source and a modulator assembly configured to supply modulated electrical power; an ultrasonic therapeutic transducer connected to the power source and modulator assembly and configured to convert the modulated electrical power to ultrasonic energy directed at a target volume in a region of a body containing adipose and non-adipose tissue, so as to selective generally lyse the adipose tissue and generally not lyse the non-adipose tissues; an ultrasonic imaging sub-system configured to identify changes in the target volume resulting from the ultrasonic energy; and a lipolysis control computer configured to control the power source and modulator assembly based on the changes identified by the ultrasonic imaging sub-system.

FIELD OF THE INVENTION

The present invention relates to lipolysis generally and more particularly to ultrasonic lipolysis.

BACKGROUND OF THE INVENTION

SUMMARY OF THE INVENTION

There is provided, in accordance with an embodiment, an apparatus for lysing adipose tissue, the apparatus comprising: a power source and modulator assembly configured to supply modulated electrical power; an ultrasonic therapeutic transducer connected to said power source and modulator assembly and configured to convert the modulated electrical power to ultrasonic energy directed at a target volume in a region of a body containing adipose and non-adipose tissue, so as to selectively generally lyse the adipose tissue and generally not lyse the non-adipose tissue; an ultrasonic imaging sub-system configured to identify changes in the target volume resulting from the ultrasonic energy; and a lipolysis control computer configured to control said power source and modulator assembly based on the changes identified by said ultrasonic imaging sub-system.

In some embodiments, said ultrasonic imaging sub-system comprises an ultrasonic imaging transducer and an ultrasonic reflection analyzer.

In some embodiments, the changes identified by said ultrasonic imaging sub-system comprise cavitation in the target volume.

In some embodiments, the changes identified by said ultrasonic imaging sub-system comprise lysis of adipose tissue in the target volume.

In some embodiments, said ultrasonic therapeutic transducer comprises a director configured to vary a focus of the ultrasonic energy directed towards the target volume.

In some embodiments, the varying of the focus comprises changing a volume of said target volume.

In some embodiments, the varying of the focus comprises changing a distance of said target volume from said ultrasonic therapeutic transducer.

There is further provided, in accordance with an embodiment, a method for selectively lysing adipose tissue, the method comprising: generating a time-varying electrical signal having a series of relatively high amplitude portions separated in time by a series of relatively low amplitude portions; converting the electrical signal to a corresponding ultrasonic signal; and directing the ultrasonic signal towards a target volume in a region of a body containing adipose and non-adipose tissue, thereby inducing selective cavitation in the adipose tissue while generally not lysing the non-adipose tissue in the target volume.

In some embodiments, the series of relatively high amplitude portions comprises: one or more initial portions having amplitude above a cavitation initiation threshold; and later portions having an amplitude above a cavitation maintenance threshold.

In some embodiments, the series of relatively low amplitude portions comprises portions having amplitude below the cavitation initiation and maintenance thresholds.

In some embodiments, the series of relatively high amplitude portions comprises between 25-500 relatively high amplitude portions.

In some embodiments, the generating of the time-varying electrical signal comprises generating the series of the relatively high amplitude portions and the series of relatively low amplitude portions at a duty cycle of between 1:5 and 1:20.

In some embodiments, the ultrasonic signal has a frequency in the range of 150-1000 KHz.

There is yet further provided, in accordance with an embodiment, an automatically-positionable adipose tissue lysis apparatus, comprising: an ultrasonic transducer secured to a three-dimensional positioning assembly, said ultrasonic transducer being configured to direct ultrasonic energy at a target volume in a region of a body containing adipose and non-adipose tissue, so as to selectively generally lyse the adipose tissue and generally not lyse the non-adipose tissue; a lipolysis control computer having a video camera connected thereto, said video camera being configured to externally image a portion of the body, and said lipolysis control computer being configured to detect indications on the imaged portion of the body; and a positioning control unit configured to control said three-dimensional positioning assembly so as to automatically position said ultrasonic transducer based on the detected indications.

In some embodiments, the apparatus further comprises a lipolysis control computer connected to said positioning control unit and configured to control the directing of the ultrasonic energy from said ultrasonic transducer based on the detected indications.

In some embodiments, the apparatus further comprises an ultrasonic imaging sub-system connected to said lipolysis control computer and configured to identify changes in the target volume resulting from the ultrasonic energy, wherein said lipolysis control computer is further configured to control the directing of the ultrasonic energy from said ultrasonic transducer based on the identified changes.

In some embodiments, the changes identified by said ultrasonic imaging sub-system comprise cavitation in the target volume.

In some embodiments, the changes identified by said ultrasonic imaging sub-system comprise lysis of adipose tissue in the target volume.

In some embodiments, the apparatus further comprises an ultrasonic imaging sub-system connected to said lipolysis control computer and configured to detect thicknesses of tissue layers in the region of the body, wherein said lipolysis control computer is further configured to control the directing of the ultrasonic energy from said ultrasonic transducer based on the detected thicknesses.

In some embodiments, said lipolysis control computer is further configured to control a focus of said ultrasonic transducer, so as to vary a distance of said target volume from said ultrasonic transducer.

DETAILED DESCRIPTION

Reference is now made toFIG. 1, which is a simplified pictorial illustration of the general structure and operation of ultrasonic lipolysis apparatus constructed and operative in accordance with a preferred embodiment of the present invention. As seen inFIG. 1, an ultrasonic energy generator and director, such as an ultrasonic transducer10, disposed outside a body, generates ultrasonic energy which, by suitable placement of the transducer10relative to the body, is directed to a target volume12inside the body and is operative to selectively generally lyse adipose tissue and generally not lyse non-adipose tissue in the target volume.

A preferred embodiment of ultrasonic energy generator and director useful in the present invention comprises an ultrasonic therapeutic transducer13including a curved phased array14of piezoelectric elements15, typically defining a portion of a sphere or of a cylinder, and having conductive coatings16on opposite surfaces thereof. The piezoelectric elements15may be of any suitable configuration, shape and distribution. An intermediate element18, formed of a material, such as polyurethane, which has acoustic impedance similar to that of soft mammalian tissue, generally fills the curvature defined by phased array14and defines a contact surface20for engagement with the body, typically via a suitable coupling gel (not shown). Contact surface20may be planar, but need not be.

Suitably modulated AC electrical power is supplied by conductors22to conductive coatings16to cause the piezoelectric elements15to provide a desired focused acoustic energy output.

In accordance with a preferred embodiment of the present invention an imaging ultrasonic transducer subassembly23is incorporated within transducer10and typically comprises a piezoelectric element24having conductive surfaces26associated with opposite surfaces thereof. Suitably modulated AC electrical power is supplied by conductors32to conductive surfaces26in order to cause the piezoelectric element24to provide an acoustic energy output. Conductors32, coupled to surfaces26, also provide an imaging output from imaging ultrasonic transducer subassembly23.

It is appreciated that any suitable commercially available ultrasonic transducer may be employed or alternatively, imaging ultrasonic transducer subassembly23may be eliminated.

It is further appreciated that various types of ultrasonic transducers10may be employed. For example, such transducers may include multiple piezoelectric elements, multilayered piezoelectric elements and piezoelectric elements of various shapes and sizes arranged in a phase array.

In a preferred embodiment of the present invention shown inFIG. 1, the ultrasonic energy generator and director are combined in transducer10. Alternatively, the functions of generating ultrasonic energy and focusing such energy may be provided by distinct devices.

In accordance with a preferred embodiment of the present invention, a skin temperature sensor34, such as an infrared sensor, may be mounted alongside imaging ultrasonic transducer subassembly23. Further in accordance with a preferred embodiment of the present invention a transducer temperature sensor36, such as a thermocouple, may also be mounted alongside imaging ultrasonic transducer subassembly23.

Ultrasonic transducer10preferably receives suitably modulated electrical power from a power source and modulator assembly40, forming part of a control subsystem42. Control subsystem42also typically includes a lipolysis control computer44, having associated therewith a camera46, such as a video camera, and a display48. A preferred embodiment of power source and modulator assembly40is illustrated inFIG. 2and described hereinbelow. Ultrasonic transducer10is preferably positioned automatically or semi-automatically as by an X-Y-Z positioning assembly49. Alternatively, ultrasonic transducer10may be positioned at desired positions by an operator.

In accordance with a preferred embodiment of the present invention, camera46is operative for imaging a portion of the body on which lipolysis is to be performed. A picture of the portion of the patient's body viewed by the camera is preferably displayed in real time on display48.

An operator may designate the outline of a region containing adipose tissue. In accordance with one embodiment of the present invention, designation of this region is effected by an operator marking the skin of a patient with an outline50, which outline is imaged by camera46and displayed by display48and is also employed by the lipolysis control computer44for controlling the application of ultrasonic energy to locations within the region. A computer calculated representation of the outline may also be displayed on display48, as designated by reference numeral52. Alternatively, the operator may make a virtual marking on the skin, such as by using a digitizer (not shown), which also may provide computer calculated outline representation52on display48.

In addition to the outline representation52, the functionality of the system of the present invention preferably also employs a plurality of markers54which are typically located outside the region containing adipose tissue, but may be located inside the region designated by outline50. Markers54are visually sensible markers, which are clearly seen by camera46, captured by camera46and displayed on display48. Markers54may be natural anatomic markers, such as distinct portions of the body or alternatively artificial markers such as colored stickers. These markers are preferably employed to assist the system in dealing with deformation of the region nominally defined by outline50due to movement and reorientation of the body. Preferably, the transducer10also bears a visible marker56which is also captured by camera46and displayed on display48.

Markers54and56are typically processed by computer44and may be displayed on display48as respective computed marker representations58and60on display48.

FIG. 1illustrates the transducer10being positioned on the body over a location within the region containing adipose tissue. Blocks designated by reference numerals62and64show typical portions of a region containing adipose tissue, respectively before and after lipolysis in accordance with a preferred embodiment of the invention. It is seen from a comparison of blocks62and64that, in accordance with a preferred embodiment of the present invention, within the region containing adipose tissue, the adipose tissue, designated by reference numeral66, is lysed, while non-adipose tissue, such as connective tissue, designated by reference numeral68, is not lysed.

Reference is nowFIG. 2, which is a simplified block diagram illustration of a preferred power source and modulator assembly40(FIG. 1), showing a pattern of variation of ultrasonic pressure over time in accordance with a preferred embodiment of the present invention. As seen inFIG. 2, the power source and modulator assembly40preferably comprises a signal generator100which provides a time varying signal which is modulated so as to have a series of relatively high amplitude portions102separated in time by a series of typically relatively low amplitude portions104. Each relatively high amplitude portion102preferably corresponds to a cavitation period and preferably has a decreasing amplitude over time.

Preferably the relationship between the time durations of portions102and portions104is such as to provide a duty cycle between 1:2 and 1:250, more preferably between 1:5 and 1:30 and most preferably between 1:10 and 1:20.

Preferably, the output of signal generator100has a frequency in a range of 50 KHz-1000 KHz, more preferably between 100 KHz-500 KHz and most preferably between 150 KHz-300 KHz.

The output of signal generator100is preferably provided to a suitable power amplifier106, which outputs via impedance matching circuitry108to an input of ultrasonic transducer10(FIG. 1), which converts the electrical signal received thereby to a corresponding ultrasonic energy output. As seen inFIG. 2, the ultrasonic energy output comprises a time varying signal which is modulated correspondingly to the output of signal generator100so as to having a series of relatively high amplitude portions112, corresponding to portions102, separated in time by a series of typically relatively low amplitude portions114, corresponding to portions104.

Each relatively high amplitude portion102preferably corresponds to a cavitation period and has an amplitude at a target volume12(FIG. 1) in the body which exceeds a cavitation maintaining threshold120and preferably has a decreasing amplitude over time. At least an initial pulse of each relatively high amplitude portion112has an amplitude at the target volume12, which also exceeds a cavitation initiation threshold122.

Relatively low amplitude portions114have an amplitude which lies below both thresholds120and122.

Preferably the relationship between the time durations of portions112and portions114is such as to provide a duty cycle between 1:2 and 1:250, more preferably between 1:5 and 1:30 and most preferably between 1:10 and 1:20.

Preferably, the ultrasonic energy output of ultrasonic transducer10has a frequency in a range of 50 KHz-1000 KHz, more preferably between 100 KHz-500 KHz and most preferably between 150 KHz-300 KHz.

Preferably, each high amplitude portion112is comprised of between 2 and 1000 sequential cycles at an amplitude above the cavitation maintaining threshold120, more preferably between 25 and 500 sequential cycles at an amplitude above the cavitation maintaining threshold120and most preferably between 100 and 300 sequential cycles at an amplitude above the cavitation maintaining threshold120.

Reference is now made toFIGS. 3A and 3B, which are simplified pictorial illustrations of the appearance of an operator interface display during normal operation and faulty operation respectively. As seen inFIG. 3A, during normal operation, display48typically shows a plurality of target volumes12(FIG. 1) within a calculated target region200, typically delimited by outline representation52(FIG. 1). Additionally, display48preferably provides one or more pre-programmed performance messages202and status messages203.

It is seen the various target volumes12are shown with different shading in order to indicate their treatment status. For example, unshaded target volumes, here designated by reference numerals204have already experienced lipolysis. A blackened target volume12, designated by reference numeral205is the target volume next in line for lipolysis. A partially shaded target volume206typically represents a target volume which has been insufficiently treated to achieve complete lipolysis, typically due to an insufficient treatment duration.

Other types of target volumes, such as those not to be treated due to insufficient presence of adipose tissue therein or for other reasons, may be designated by suitable colors or other designations, and are here indicated by reference numerals208and210.

Typical performance messages202may include “CAVITATION IN PROCESS” and “FAT LYSED IN THIS VOLUME”. Typical status messages203may include an indication of the power level, the operating frequency, the number of target volumes12within the calculated target region200and the number of target volumes12which remain to undergo lipolysis.

Display48also preferably includes an graphical cross sectional indication212derived from an ultrasonic image preferably provided by imaging ultrasonic transducer subassembly23(FIG. 1). Indication212preferably indicates various tissues in the body in cross section and shows the target volumes12in relation thereto. In accordance with a preferred embodiment of the present invention, indication212may also provide a visually sensible indication of cavitation within the target volume12.

Turning toFIG. 3B, it is seen that during abnormal operation, display48provides pre-programmed warning messages214.

Typical warning messages may include “BAD ACOUSTIC CONTACT”, “TEMPERATURE TOO HIGH”. The “TEMPERATURE TOO HIGH” message typically relates to the skin tissue, although it may alternatively or additionally relate to other tissue inside or outside of the target volume or in transducer10(FIG. 1).

Reference is now made toFIG. 4, which illustrates an ultrasonic lipolysis system constructed and operative in accordance with a preferred embodiment of the present invention. As described hereinabove with reference toFIG. 1and as seen inFIG. 4, the ultrasonic lipolysis system comprises a lipolysis control computer44which outputs to a display48. Lipolysis control computer44preferably receives inputs from video camera46(FIG. 1) and from a temperature measurement unit300, which receives temperature threshold settings as well as inputs from skin temperature sensor34(FIG. 1) and transducer temperature sensor36(FIG. 1). Temperature measurement unit300preferably compares the outputs of both sensors34and36with appropriate threshold settings and provides an indication to lipolysis control computer44of exceedance of either threshold.

Lipolysis control computer44also preferably receives an input from an acoustic contact monitoring unit302, which in turn preferably receives an input from a transducer electrical properties measurement unit304. Transducer electrical properties measurement unit304preferably monitors the output of power source and modulator assembly40(FIG. 1) to ultrasonic therapeutic transducer13.

An output of transducer electrical properties measurement unit304is preferably also supplied to a power meter306, which provides an output to the lipolysis control computer44and a feedback output to power source and modulator assembly40.

Lipolysis control computer44also preferably receives inputs from cavitation detection functionality308, tissue layer identification functionality310and lysed adipose tissue identification functionality312, all of which receive inputs from ultrasonic reflection analysis functionality314. Ultrasonic reflection analysis functionality314receives ultrasonic imaging inputs from an ultrasonic imaging subsystem316, which operates ultrasonic imaging transducer23(FIG. 1).

Lipolysis control computer44provides outputs to power source and modulator assembly40, for operating ultrasonic therapeutic transducer13, and to ultrasonic imaging subsystem316, for operating ultrasonic imaging transducer23. A positioning control unit318also receives an output from lipolysis control computer44for driving X-Y-Z positioning assembly49(FIG. 1) in order to correctly position transducer10, which includes ultrasonic therapeutic transducer13and ultrasonic imaging transducer23.

Reference is now made toFIGS. 5A,5B and5C, which are together a simplified flowchart illustrating operator steps in carrying out lipolysis in accordance with a preferred embodiment of the present invention. As seen inFIG. 4A, initially an operator preferably draws an outline50(FIG. 1) on a patient's body. Preferably, the operator also adheres stereotactic markers54(FIG. 1) to the patient's body and places transducer10, bearing marker56, at a desired location within outline50.

Camera46(FIG. 1) captures outline50and markers54and56. Preferably, outline50and markers54and56are displayed on display48in real time. The output of camera46is also preferably supplied to a memory associated with lipolysis control computer44(FIG. 1).

A computerized tracking functionality preferably embodied in lipolysis control computer44preferably employs the output of camera46for computing outline representation52, which may be displayed for the operator on display48. The computerized tracking functionality also preferably computes coordinates of target volumes for lipolysis treatment, as well as adding up the total volume of tissue sought to undergo lipolysis.

Preferably, the operator confirms the locations of markers54and56on display48and the computerized tracking functionality calculates corresponding marker representations58and60.

In accordance with a preferred embodiment of the present invention the computerized tracking functionality employs markers54and marker representations58for continuously maintaining registration of outline50with respect to outline representation52, and thus of target volumes12with respect to the patient's body, notwithstanding movements of the patients body during treatment, such as due to breathing or any other movements, such as the patient leaving and returning to the treatment location.

The computerized tracking functionality selects an initial target volume to be treated and positioning control unit318(FIG. 4), computes the required repositioning of transducer10. X-Y-Z positioning assembly49repositions transducer10to overlie the selected target volume.

Referring additionally toFIG. 5B, it is seen that following repositioning of transducer10, the lipolysis control computer44confirms accurate positioning of transducer10with respect to the selected target volume. The ultrasonic imaging subsystem316(FIG. 4) operates ultrasonic imaging transducer23, causing it to provide an ultrasonic reflection analysis functionality314for analysis.

Based on an output from ultrasonic reflection analysis functionality314, the thicknesses of the various tissue layers of the patient are determined. Upon receiving an indication of the tissue layer thicknesses, an operator may approve the selected target volume and activates the power source and modulator assembly40(FIG. 1).

Turning additionally toFIG. 5C, it is seen that the following functionalities take place:

Transducer electrical properties measurement unit304provides an output to acoustic contact monitoring unit302, which determines whether sufficient acoustic contact with the patient is present, preferably by analyzing the current and voltage at therapeutic transducer13.

Transducer electrical properties measurement unit304provides an output to power meter306, which computes the average electrical power received by the therapeutic transducer13. If the average electrical power received by the therapeutic transducer13exceeds a predetermined threshold, operation of the power source and modulator assembly40may be automatically terminated.

Skin temperature sensor34measures the current temperature of the skin at transducer10and supplies it to temperature measurement unit300, which compares the skin temperature to the threshold temperature. Similarly, transducer temperature sensor36measures the current temperature at transducer10and supplies it to temperature measurement unit300, which compares the transducer temperature to the threshold temperature. The outputs of temperature measurement unit300are supplied to lipolysis control computer44.

The ultrasonic imaging subsystem316operates ultrasonic imaging transducer23and receives an imaging output, which is analyzed by ultrasonic reflection analysis functionality314. The result of this analysis is employed for cavitation detection and a cavitation detection output is supplied to lipolysis control computer44.

Should any of the following four conditions occur, the power source and modulator assembly40automatically terminates operation of therapeutic transducer13. Should none of the following conditions occur, the automatic operation of power source and modulator assembly40continues:

1. Acoustic contact is insufficient.

2. Skin temperature exceeds threshold temperature level.

4. Cavitation is not detected.

Returning toFIG. 5B, it is noted that during automatic operation of power source and modulator assembly40, video camera46preferably records the target region and notes whether the transducer10remained stationary during the entire treatment duration of the selected target volume12. If so, and if none of the aforesaid four conditions took place, lipolysis control computer44confirms that the selected target volume was treated. The computerized tracking functionality of lipolysis control computer44then proposes a further target volume12to be treated.

If, however, the transducer10did not remain stationary for a sufficient duration, the selected target volume is designated by lipolysis control computer44as having been insufficiently treated.

It is appreciated that by using multiple transducers multiplicity of target volumes can be treated at various time patterns such as sequential time patterns or partially overlapping time patterns.

It is also appreciated that the multiplicity of target volumes may also overlap in space or partially overlap in space.

The computational tracking functionality is set forth in the Computer Program Listing Appendix of U.S. Pat. No. 7,347,855, which is incorporated herein by reference in its entirety.