Abstract:
A device for thermal ablation therapy having emitting means for emitting ultrasound energy capable of heating tissue and moving means for moving the emitting means between an undeployed position, in which the emitting means is in a first orientation which facilitates insertion of the device, and a deployed position, in which the emitting means is in a different second orientation that is selected to efficiently deliver ultrasound energy to the tissue to be ablated. The moving means includes one or more movable carriers and the emitting means is one or more piezoelectric transducers that are securely mounted on the carriers for conjoint movement therewith. A method for thermal ablation therapy using ultrasound energy involves positioning an ultrasound device in an undeployed position proximate to tissue to be heated; moving the ultrasound device from its undeployed position to a deployed position; and activating the ultrasound device to emit ultrasound energy for a predetermined period of time.

Description:
FIELD OF THE INVENTION 
     The present invention relates to devices having deployable ultrasound transducers for performing endometrial ablation. 
     BACKGROUND OF THE INVENTION 
     Menorrhagia is a common problem in women that is characterized by extended or irregular menstrual cycles or excessive amounts of bleeding during menstrual cycles. The endometrium is the uterine lining which is responsible for the bleeding that occurs during menstrual cycles, as well as dysfunctional uterine bleeding. Heating to at least superficially destroy the endometrium, also known as endometrial ablation, has been shown to reduce the aforesaid abnormal bleeding. In some cases ablating the endometrium results in cessation of the menstrual bleeding altogether, which may be preferable to the irregular cycles and excessive bleeding that otherwise occur. 
     There are many technologies on the market and in clinical trials which utilize a range of energy sources, but the goal for each is the same, i.e., endometrial tissue destruction by thermal cryo-coagulation. For example, Neuwirth, et al, “The Endometrial Ablator: A New Instrument”, Obst. &amp; Gyn., 1994, Vol. 83, No. 5, Part 1, 792-796, performed endometrial ablation using a dextrose-filled balloon device mounted at the end of a carrier catheter and including a heating element inside the balloon. This device also includes a system that monitors the pressure and temperature inside the balloon. Neuwirth, et al. determined that if the surface of the balloon-tissue interface is maintained at about 90° C. for 7-12 minutes, the depth of damage to the endometrium was about 4-10 millimeters. This depth of damage is believed to be clinically acceptable to the extent that such a procedure could be considered as an alternative to surgical procedures, such as hysterectomy. 
     High frequency, or radiofrequency (RF), energy has been used to ablate the endometrium as well as cryo-techniques. For example, Prior, et al., “Treatment of Mennorrhagia By Radiofrequency Heating”, Int. J. Hyperthermia, 1991 Vol. 7, No. 2, 213-220, achieved a significant reduction in dysfunctional uterine bleeding using a device that includes a probe having a high frequency RF energy source that is inserted directly into the patient&#39;s uterus through the vagina and cervix. The energy source is an RF system having an electrode on the probe and a belt placed around the patient that serves as the return electrode. This RF system is operated at 27.12 MHz at a power of 550 Watts for about 20 minutes and achieves a deeper penetration than the Neuwirth, et al. device, which is an advantage over the Neuwirth, et al. device. 
     A system marketed under the tradename THERMACHOICE®, by Ethicon, Inc. of Somerville, N.J., is currently used to perform endometrial ablation and includes a latex balloon filled with a heated dextrose and water solution. The balloon is attached to the distal end of a catheter carrier and the device often delivers satisfactory results. Some patients, however, present a need for deeper and broader endometrial penetration during ablation. 
     U.S. Pat. No. 5,620,479 discloses a device for thermal treatment having an array of tubular piezoelectric transducers disposed on a semi-flexible tubular carrier for delivering ultrasound energy directly to tissue to be ablated. The transducers are covered with a sealant coating and there is an outer covering over the sealant coating. This device also includes thermocouple sensors embedded in the sealant coating over each transducer for continuous monitoring of the tissue-applicator interface temperatures for feedback control of the power delivered to the transducers. 
     U.S. Pat. No. 5,733,315 also discloses a device for ablating tissue using ultrasound energy, but is adapted specifically for insertion into the rectum for treating the prostate. This device includes one or more ultrasound transducers disposed at least partly about a support tube, each ultrasound transducer having inactivated portions for reducing ultrasound energy directed to the rectal wall. The transducers of this device are also enclosed in a sealant. 
     U.S. Pat. No. 5,437,629 discloses an apparatus and method for recirculating heated fluid in the uterus to perform endometrial ablation, without using a balloon. U.S. Pat. No. 5,769,880 discloses an apparatus and method for performing tissue ablation, including endometrial ablation, using bipolar RF energy. This device includes an electrode-carrying member mounted to the distal end of a shaft and an array of electrodes mounted to the surface of the electrode carrying member. A vacuum is utilized to draw out vapors, which are created when the tissue is ablated. 
     The foregoing devices and techniques are all either too complex or provide less than optimal results. In addition, they all deliver energy in a general manner, without the ability to control or direct the application of energy in situ to the tissue to be treated. It is further noted that there are no devices specifically adapted for endometrial ablation that use therapeutic ultrasound. 
     The device of the present invention addresses the shortcomings of the existing apparatus and process for endometrial ablation by providing a device that delivers ultrasound energy to the endometrial tissue in a controlled and efficient manner by having deployable piezoelectric transducers mounted on movable carriers that are deployed after insertion into the uterus. 
     SUMMARY OF THE INVENTION 
     A device for thermal ablation therapy having emitting means for emitting ultrasound energy capable of heating tissue and moving means for moving the emitting means between an undeployed position, in which the emitting means is in a first orientation which facilitates insertion of the device, and a deployed position, in which the emitting means is in a different second orientation that is selected to efficiently deliver ultrasound energy to the tissue to be ablated. The emitting means is movable from the undeployed position to any one of an infinite number of orientations for efficiently delivering ultrasound energy to the tissue. The moving means is one or more movable carriers and the emitting means is one or more piezoelectric transducers that are securely mounted on the carriers for conjoint movement therewith. 
     The moving means includes a rod which has a distal end and a proximal end, and a hollow sleeve, which has a through passage. The rod is slideably received in the through passage and the distal end of the rod is connected to a carrier, whereby sliding movement of the rod moves the piezoelectric transducer or transducers mounted thereon between the undeployed and deployed positions. The piezoelectric transducer and the sleeve are linearly arranged relative to each other when the piezoelectric transducer is in its undeployed position. When the piezoelectric transducer is in its deployed position, the piezoelectric transducer and the sleeve are arranged relative to each other in a non-linear manner. In addition, moving means may also include a handle having a movable part that is connected to the proximal end of the rod for moving the piezoelectric transducer between its undeployed and deployed positions in response to movement of the movable part of the handle. 
     In one embodiment, a set of first transducers is mounted linearly on a first carrier and a set of second transducers is mounted linearly on a second carrier. When the first and second transducers are in their undeployed positions, the first transducers are arranged linearly relative to the sleeve and the second transducers are also arranged linearly relative to the sleeve. When the first and second transducers are in their deployed positions, the first transducers are arranged at an angle relative to the sleeve and the second transducers are arranged at an angle relative to the sleeve and relative to said second transducers 
     In another embodiment, a plurality of transducers are mounted linearly on a carrier. When the transducers are in their undeployed positions, they are arranged linearly relative to the sleeve and when the transducers are in their deployed positions, they are arranged perpendicularly relative to the sleeve. 
     In still another embodiment, a first carrier has a first transducer mounted thereon and a second carrier includes a second transducer mounted thereon and the first and second carriers are pivotable relative to one another such that the first and second transducers are movable between their undeployed and deployed positions. When the first and second transducers are in their undeployed positions the first and second transducers are both arranged linearly relative to the sleeve. When the first and second transducers are in their deployed positions, the first and second transducers are oriented substantially perpendicularly relative to the sleeve and the first and second transducers are arranged linearly relative to one another. 
     A method for thermal ablation therapy using ultrasound energy involves positioning an ultrasound device in an undeployed position in which said ultrasound device in is a first orientation which facilitates positioning of the device proximate to tissue to be heated; moving the ultrasound device from its undeployed position to a deployed position which is selected to efficiently deliver ultrasound energy to tissue to be heated; and activating the ultrasound device to emit ultrasound energy for a predetermined period of time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the following detailed description of a preferred embodiment of the present invention considered in conjunction with the accompanying drawings, in which: 
     FIG. 1A is a schematic perspective view of a cylindrical piezoelectric transducer used in connection with certain embodiments of the present invention; 
     FIG. 1B is a schematic top plan view of the cylindrical piezoelectric transducer of FIG. 1A showing the direction of ultrasound energy emission therefrom; 
     FIG. 1C is a schematic side elevational view of the cylindrical piezoelectric transducer of FIG. 1A showing the direction of ultrasound energy emission therefrom; 
     FIG. 2A is a schematic perspective view of a hemi-cylindrical piezoelectric transducer used in connection with certain embodiments of the present invention; 
     FIG. 2B is a schematic top plan view of the hemi-cylindrical piezoelectric transducer of FIG. 2A showing the direction of ultrasound energy emission therefrom; 
     FIG. 2C is a schematic side elevational view of the hemi-cylindrical piezoelectric transducer of FIG. 2A showing the direction of ultrasound energy emission therefrom; 
     FIG. 3 is a perspective view of a first embodiment of the device of the present invention, in an undeployed state; 
     FIG. 4 is a top plan view of the first embodiment of the device of FIG. 3; 
     FIG. 5 is a perspective view of the first embodiment of the device of FIG. 3, in a deployed state; 
     FIG. 6 is a schematic cut away view of the first embodiment of the device of FIG. 5, in a delpoyed state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers; 
     FIG. 7 is an exploded perspective view of the major components of the first embodiment of the device of FIG. 3; 
     FIG. 8 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the first embodiment of FIG. 3, with the device in the undeployed state; 
     FIG. 9 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the first embodiment of FIG. 5, with the device in the deployed state; 
     FIG. 10 is a perspective view of a second embodiment of the device of the present invention, in an undeployed state; 
     FIG. 11 is a top plan view of the second embodiment of the device of FIG. 10; 
     FIG. 12 is a perspective view of the second embodiment of the device of FIG. 10, in a deployed state; 
     FIG. 13 is a schematic cut away view of the second embodiment of the device of FIG. 12, in a deployed state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers; 
     FIG. 14 is an exploded perspective view of the major components of the second embodiment of the device of FIG. 10; 
     FIG. 15 is an enlarged perspective cut-away view of the connections between the carrier bar bearing the piezoelectric transducer and the actuator rods of the second embodiment of FIG. 12, with the device in the deployed state; 
     FIGS. 16A-16C are sequential perspective cut-away views of the piezoelectric transducer and the actuator rods of the second embodiment of FIG. 11, showing the progressive movement of the transducer and actuator rods from the undeployed state to the deployed state; 
     FIG. 17 is a perspective view of a third embodiment of the device of the present invention, in an undeployed and extended state; 
     FIG. 18 is a top plan view of the third embodiment of the device of FIG. 17; 
     FIG. 19 is a perspective view of the third embodiment of the device of FIG. 17, in a deployed and extended state; 
     FIG. 20 is a perspective view of the third embodiment of the device of FIG. 17, in a deployed and retracted state; 
     FIG. 21 is a schematic cut away view of the first embodiment of the device of FIG. 20, in a delpoyed and retracted state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers; 
     FIG. 22 is an exploded perspective view of the major components of the third embodiment of the device of FIG. 17; and 
     FIG. 23 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the third embodiment of FIG. 17, with the device in the deployed state. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The three embodiments of the device of the present invention that are described hereinafter each employ piezoelectric transducers for producing and emitting ultrasound energy to ablate the endometrium of patients experiencing dysfunctional uterine bleeding. The basic construction and operation of piezoelectric transducers are well known and understood to those having ordinary skill in the art. However, in order to facilitate the description of the device present invention, the following discussion provides a general description of piezoelectric transducers of two particular shapes, i.e., cylindrical and hemi-cylindrical, that are most suitable for use with the preferred embodiments of the present invention. Both of these piezoelectric transducers are made of ceramic material such as, PZT4, PZT8, or C5800, each of which is commercially available from ValpeyFischer Corp, Hopkinton, Mass. 
     With reference initially to FIGS. 1A-1C a cylindrical piezoelectric transducer  10  is shown schematically from an elevational perspective view (FIG.  1 A), from a top plan view (FIG. 1B) and from a front elevational view (FIG.  1 C). More particularly, the cylindrical transducer  10  has an inner surface  12  and an outer surface  14 . Both the inner and outer surfaces  12 ,  14  are coated with a conductive coating, such as gold, nickel, gold/chromium, etc., to provide electrical contact with the entire area of each surface  12 ,  14 , while also avoiding electrical contact therebetween. The conductive coatings may be formed by vapor deposition, or any other suitable method that is known and understood to persons having ordinary skill in the art. An electrically conductive wire  16  is connected at one end thereof to the inner surface  12  and another electrically conductive wire  18  is connected at one end thereof to the outer surface  14  of the cylindrical transducer  10 . Both wires  16 ,  18  are preferably a coaxial cable (not shown) and connected at their opposite ends to a source of electrical voltage, more particularly, an RF power source  20  (shown schematically only in FIG. 1A) so that a radiofrequency (RF) electrical voltage can be applied to the cylindrical transducer  10 . The RF power source  20  typically operates at about 1-12 MHz. In operation, as shown schematically by the arrows in FIGS. 1B and 1C, when an RF voltage is applied to the cylindrical transducer  10 , a collimated acoustical wave of ultrasound energy is emitted radially outwardly from the entire outer surface  14  of the cylindrical transducer  10 , in a direction perpendicular to the outer surface  14 . 
     With reference now to FIGS. 2A-2C, a hemi-cylindrical piezoelectric transducer  22  is shown schematically from an elevational perspective view (FIG.  2 A), from a top plan view (FIG. 2B) and from a front elevational view (FIG.  2 C). More particularly, the hemi-cylindrical piezoelectric transducer  22  has an inner surface  24  and an outer surface  26 , both of which are coated with a conductive coating, such as gold, nickel, gold/chromium, etc., to provide electrical contact with the entire area of each surface  24 ,  26 , while also avoiding electrical contact therebetween. In a manner similar to that described hereinabove in connection with the cylindrical transducer  10 , electrically conductive wires  28 ,  30 , which are preferably a coaxial cable (not shown), are connected to the inner surface  24  and the outer surface  26 , respectively, of the hemi-cylindrical transducer  22  and also to a source of electrical voltage, more particularly, an RF power source  32  (shown schematically only in FIG. 2A) so that a radiofrequency (RF) electrical current can be applied to the hemi-cylindrical transducer  10 . The RF power source  32  typically operates at about 1-12 MHz. In operation, as shown schematically by the arrows in FIGS. 2B and 2C, when an RF voltage is applied to the hemi-cylindrical transducer  22 , a collimated acoustical wave of ultrasound energy is emitted radially outwardly from the entire outer surface  26  of the hemi-cylindrical transducer  22 , in a direction perpendicular to the outer surface  26 . 
     When ultrasound energy is absorbed by tissue, it is converted into heat and, therefore, the tissue becomes heated. The RF power is supplied by the RF power sources  20 ,  32  at the resonant frequency of the transducers  10 ,  22 , respectively, which is proportional to the thickness of each transducer  10 ,  22  between the inner and outer surfaces  12 ,  24 ,  14 ,  26 , respectively, thereof. Typically, for use in connection with the present invention, the transducers  10 ,  22  should each be constructed having resonant frequencies ranging between about 4 to 12 MHz, preferably about 7 MHz. It is noted that the direction of ultrasound energy emissions from the transducers  10 ,  22  are easier to control than the direction of RF energy emissions from bipolar or monopolar RF devices known in the prior art. This is partly because the ultrasound energy emissions are collimated and partly because their direction of travel does not depend upon the placement of an antipolar electrode or ground plate, nor on tissue electrical properties that vary with tissue dessication that occurs during ablation. Since the transducers  10 ,  22  are directional, moving the transducer  10 ,  22  along a certain angle will also angle the ultrasonic acoustic field and redirect the tissue heating. 
     Since all three embodiments of the device of the present invention include one or more piezoelectric transducers of the two general types described hereinabove, and because the transducers are constructed and operated as described hereinabove, the transducers and their components shown in FIGS. 3-23 are labeled using variations of the reference numbers used in FIGS. 1A-1C and  2 A- 2 C. For example, where the embodiment being discussed includes one or more cylindrical piezoelectric transducers like that described hereinabove, they will be labeled using reference number “ 10 ” followed by a lower-case letter, for example,  10   a ,  10   b ,  10   c , etc. Where the embodiment being discussed includes one or more hemi-cylindrical piezoelectric transducers like that described hereinabove, they will be labeled using reference number “ 22 ” followed by a lower-case letter, for example  22   a ,  22   b ,  22   c , etc. In addition, where the terms “distal” and “proximal” are used hereinafter in connection with the device of the present invention or components thereof, these terms refer to positions that are relative to the user, or surgeon, operating the device. 
     With reference now to FIGS. 3-9, a first embodiment of a device  34  in accordance with the present invention is shown. More particularly, FIGS. 3 and 4 show the device  34  in an undeployed state in a perspective view and a top plan view, respectively. FIG. 5 shows a perspective view of the device  34  in a deployed state. The device  34  includes a handle  36  having a fixed arm  38  and a pivotable arm  40 . The pivotable arm  40  is pivotably attached to the fixed arm  38  such that the handle provides means for manual manipulation and operation of the device  34 , as will be described in further detail hereinafter. As seen in FIG. 7, the fixed and pivotable arms  38 ,  40  each include connecting means, such as connecting ears  42 ,  44  proximate to their distal ends, that cooperate in a manner known in the art to facilitate connecting the pivotable arm  40  to the fixed arm  38  in a pivotable manner. The fixed and pivotable arms  38 ,  40  of the first embodiment also each include a finger grip  46 ,  48  sized and shaped to receive the fingers of the surgeon therethrough for facilitating manual manipulation and operation of the device  34 . The fixed arm  38  also includes a stop post  50  to prevent the pivotable arm  40  from moving too closely toward the fixed arm  38 , thereby controlling the degree of deployment of the device  34 , as explained in further detail hereinafter. 
     With further reference to FIGS. 3,  4 ,  5  and  7 , the handle  36  also has a hollow shaft  52  that extends from the distal end of the fixed arm  38 . The hollow shaft  52  has a through passage  54  and may be formed integrally with the fixed arm  38  or it may be formed as a separate component and attached to the fixed arm  38  by conventional means, such as welding or gluing. A hollow sleeve  56  also having a through passage  58  is connected to, and extends from, the distal end of the hollow shaft  52 . The hollow sleeve  56  is sized and shaped to conform to the size and shape of the hollow shaft  52  such that their outer diameters are approximately equal and their through passages  54 ,  58 , respectively, align with one another. 
     The device  34  also includes six hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  that are aligned and grouped with one another at the distal end of the hollow sleeve  56  as shown in FIGS. 3-9. More particularly, as can be seen in FIGS. 5 and 7, three of the hemi-cylindrical transducers  22   a ,  22   b ,  22   c  are securely mounted on a first carrier bar  60  such that their outer surfaces  24   a ,  24   b ,  24   c  all face one direction, which is perpendicular to the length of the first carrier bar  60 . The other three hemi-cylindrical transducers  22   d ,  22   e ,  22   f  are securely mounted on a second carrier bar  62 , such that their outer surfaces  24   d ,  24   e ,  24   f  all face a direction perpendicular to the length of the second carrier bar  62  and opposite that of the three hemi-cylindrical transducers  22   a ,  22   b ,  22   c  mounted on the first carrier bar  60 . It is noted that, when the device  34  is in its undeployed state (see FIGS.  3  and  4 ), the six hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  are aligned and grouped with one another to form three pairs  22   a - 22   d ,  22   b - 22   e ,  22   c - 22   f  of transducers. 
     It is noted that, although not specifically shown in the figures, each of the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  has a pair of electrically conductive wires (not shown) that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the hemi-cylindrical transducer  22 . To protect the wires, which are preferably coaxial cables (not shown), and minimize interference with the manipulation and operation of the device  34  by the surgeon, the aforesaid wires (not shown) can be attached to the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f , and extended through the through passages  54 ,  58  of the hollow shaft  52  and hollow sleeve  56 , to the RF power source or sources. As such, each hemi-cylindrical transducer  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  may have a separate power control if a multi-channel RF power source is used (not shown, but known to those of ordinary skill in the art). In this way, the thermal field and heating of tissue can be varied and further controlled. 
     In the foregoing arrangement, during operation of the device  34 , ultrasound energy is emitted by the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  in a radially outward direction, thereby approximating the directional effect of three cylindrical transducers when the device  34  is in an undeployed state (as shown in FIGS.  3  and  4 ). Furthermore, when the device  34  is in its deployed state, the carrier bars  60 ,  62  and also, therefore, the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  mounted thereon, form a “V” shape (see FIGS.  5  and  6 ). When the device  34  is in its deployed state, the ultrasound energy is emitted by the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  in the direction shown by the arrows in FIG. 6 (which shows the device  34  in use, in its deployed state, after insertion into the vagina  100  and uterus  98  of a female patient). The method of operating the device  34  in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter. 
     With reference to FIGS. 5,  6  and  7 , in particular, the proximal ends of the first and second carrier bars  60 ,  62  each have an extended tongue  64 ,  66 , respectively, by which each of the first and second carrier bars  60 ,  62  is pivotably attached to the distal end of a corresponding actuator rod  68 ,  70 , respectively. More specifically, as seen most clearly in FIGS. 7,  8  and  9 , the extended tongue  64  of the first carrier bar  60  includes a first pivot hole  72  that is proximate to the first carrier bar  60  and a second pivot hole  74  that is remote from the first carrier bar  60  (in other words, proximate to the end of the extended tongue  64 ). The extended tongue  66  of the second carrier bar  62  includes a first pivot hole  76  that is proximate to the second carrier bar  62  and second pivot hole  78  that is remote from the second carrier bar  62  (in other words, proximate to the end of the extended tongue  66 ). 
     In addition, each of the actuator rods  68 ,  70  has a ninety-degree bend proximate its distal end, which forms a pivot hook  80 ,  82  on each actuator rod  68 ,  70 , respectively. The pivot hooks  80 ,  82  of the actuator rods  68 ,  70  are each sized and shaped to fit into the first pivot hole  72 ,  76  of a corresponding one of the first and second carrier bars  60 ,  62 , respectively (see FIGS. 7,  8  and  9 ). The hollow sleeve  56  has two pivot pins  84 ,  86  at its distal end that are each sized and shaped to be received through the second pivot hole  74 ,  78  of a corresponding one of the first and second carrier bars  60 ,  62 , respectively (see FIGS. 7,  8  and  9 ). 
     With continued reference to FIGS. 7,  8  and  9 , it is noted that the positions of each of the pivot pins  84 ,  86  of the hollow sleeve  56  are stationary relative to the hollow sleeve  56  and relative to the first and second carrier bars  60 ,  62 . Thus, when the pivot pins  84 ,  86  of the hollow sleeve  56  are received within the second pivot holes  74 ,  78  of the first and second carrier bars  60 ,  62 , respectively, they form the pivot point of each of the first and second carrier bars  60 ,  62  thereby allowing the first and second carrier bars  60 ,  62 , with the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  mounted thereon, to form the abovementioned “V” shape. As seen most clearly in FIGS. 8 and 9, when the pivot hooks  80 ,  82  of the actuator rods  68 ,  70  are received within the first pivot holes  72 ,  76  of the first and second carrier bars  60 ,  62 , respectively, the distal ends of the actuator rods  68 ,  70  extend together in between the pivot pins  84 ,  86  of the hollow sleeve  56 . The purpose of the foregoing arrangement of pivot holes  72 ,  74 ,  76 ,  78 , pivot hooks  80 ,  82  and pivot pins  84 ,  86  will become apparent hereinafter during discussion of the operation of the device  34 . 
     With reference now specifically to FIGS. 3,  4  and  7 , the actuator rods  68 ,  70  are slidingly received in the through passages  58 ,  54  of the hollow sleeve  56  and the hollow shaft  52 , respectively, and extend together from the first and second carrier bars  60 ,  62 , through the through passages  58 ,  54 , and out of the proximal end of the hollow shaft  52 . The proximal end of each actuator rod  68 ,  70  is affixed to the distal end  88  of the pivotable arm  40 . More particularly, the proximal end of each actuator rod  68 ,  70  is inserted through one of a pair of holes  90 ,  92  provided in the distal end  88  of the pivotable arm  40  (see FIG. 7) and the proximal end of each actuator rod  68 ,  70  includes an enlarged stop  94 ,  96 , respectively, thereon for retaining the proximal ends of the actuator rods  68 ,  70  through the holes  90 ,  92 . 
     With reference to the overall size and shape of the device  34 , it is noted that while the device  34  of the present invention may be adapted for ablation of tissue within cavities or lumens other than the uterus, the embodiments disclosed herein are intended for use in performing endometrial ablation and, therefore, they are sized and shaped to be inserted and operated within the uterus of a patient. More particularly, the sum of the lengths of the hollow shaft  52  and hollow sleeve  56  should be between about 15 and 50 centimeters (cm), preferably about 25 cm. Regarding the individual lengths of these components, the length of the hollow shaft  52  should be from about 5 to 15 cm, preferably about 10 cm, and the length of the hollow sleeve  56  should be from about 10 to 35 cm, preferably 15 cm. Moreover, the outer diameters of the hollow shaft  52  and the hollow sleeve  56  should be substantially the same as one another and, more specifically, from approximately 5 to 10 millimeters (mm), preferably about 5 mm. The diameter of the through passages  54 ,  58  of the hollow shaft  52  and the hollow sleeve  56 , respectively, should be large enough to slidingly receive therethrough both actuator rods  68 ,  70  and all of the wires (not shown) attached to the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f , more particularly, from about 3 mm to 8 mm, preferably about 3.5 mm. In addition, the lengths of the first and second carrier bars  60 ,  62  should be the same as one another and be between about 3 and 6 cm, preferably about 4 cm. 
     With regard to the size of the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f , it is noted that although they are shown in FIGS. 3-9 as being of the same size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the members of each pair of hemi-cylindrical transducers (for example,  22   a - 22   d ,  22   b - 22   e ,  22   c - 22   f  in FIG. 3) should be the same size as each other. In the present embodiment of the device  34 , each hemi-cylindrical transducer  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  is between about 1 and 3 cm long, preferably about 1.5 cm long. In addition, each hemi-cylindrical transducer  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  is about 5 to 10 millimeters (mm) wide at its greater width, such that the pairs of hemi-cylindrical transducers  22   a - 22   d ,  22   b - 22   e ,  22   c - 22   f  approximate the shape of three cylindrical transducers having an overall diameter of about 5 to 10 mm, preferably about 5 mm. 
     The method of using the device  34  to perform endometrial ablation will now be described. Initially, it is noted that the device  34  of the present invention may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid. The fluid is required to provide a means for the ultrasound energy emitted from the ultrasound transducers to travel to, and be absorbed by, the endometrial tissues to be treated. For purposes of the following discussion, the uterus will be prepared for surgery and filled with a suitable fluid, such as saline, in a manner that is well-known to those of ordinary skill in the art and consistent with currently accepted medical/surgical standards. 
     With reference now to FIG. 6, after the uterus has been prepared and filled with fluid, as described above, the device  34  in its undeployed state (see FIGS. 3 and 4) is inserted into the uterus  98  of a patient. More particularly, the device  34  is held by the finger grips  46 ,  48  of the handle  36  by the surgeon and the first and second carrier bars  60 ,  62  (with the undeployed hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  mounted thereon) and at least a portion of the hollow sleeve  56  are inserted through the vagina  100  and into the uterus  98 . The hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  are positioned approximately centrally within the uterus  98 , or at an otherwise appropriate position within the uterus as clinically determined by the surgeon. With reference now to FIG. 5, the device  34  is then deployed by squeezing the fixed and pivotable arms  38 ,  40  together such that the pivotable arm  40  moves toward the fixed arm  38  as far as the stop post  50 , which causes the distal end  88  of the pivotable arm  40  to move away from the fixed arm  38  and the hollow shaft  52  in the direction indicated by the arrow A in FIG.  5 . When the distal end  88  of the pivotable arm  40  moves away from the fixed arm  38 , the actuator rods  68 ,  70  are pulled through the through passages  54 ,  58  and the pivot hooks  80 ,  82  at the distal ends of the actuator rods  68 ,  70  are moved toward the hollow sleeve  56  in the direction indicated by the arrow B in FIGS. 5,  8  and  9 , which, in turn, causes the first and second carrier bars  60 ,  62  to move away from one another, as indicated by the arrows C in FIGS. 5 and 9, into a deployed “V” shape. The RF power source (not shown) is then turned on, which causes RF power to be delivered to the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  which causes them to emit ultrasound energy, as shown by the arrows in FIG. 6, which travels to the endometrial tissue where it is absorbed, resulting in heating and ablation of the tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes. 
     As shown in FIG. 6, the lateral walls  102 ,  104  of the uterus  98  and also, therefore, a portion of the endometrium  106 , are sloped. When the device  34  is in its deployed state, the outer surfaces  24   a ,  24   b ,  24   c ,  24   d ,  24   e ,  24   f  of the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  are substantially aligned with the sloping portion of the endometrium  106  such that the ultrasound energy emitted by the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  will contact the sloping portion of the endometrium  106  from a direction that is nearly perpendicular thereto, which maximizes the amount of heat energy that will be received by the endometrial tissue at this location. During in situ operation of the device  34 , the device  34  can be moved, for example back and forth or tilted, such that the carrier bars  60 ,  62  and the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  mounted thereon are also so moved within the uterus  98  of the patient. Such movement will direct at least a portion of the ultrasound energy from the hemi-cylindrical transducers  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  upward to heat and ablate the upper endometrial tissue. 
     With reference now to FIGS. 10-16C, a second embodiment of the device  108  in accordance with the present invention is shown. More particularly, FIGS. 10 and 11 show the device  108  in an undeployed state in a perspective view and a top plan view, respectively. FIG. 12 shows a perspective view of the device  108  in a deployed state. The device  108  includes a handle  110  having a fixed arm  112  and a pivotable arm  114 . The pivotable arm  114  is pivotably attached to the fixed arm  112  such that the handle  110  provides means for manual manipulation and operation of the device  108 , as will be described in further detail hereinafter. As seen in FIG. 14, the fixed and pivotable arms  112 ,  114  each include connecting means, such as connecting ears  116 ,  118  proximate to their distal ends, that cooperate in a manner known in the art to facilitate connecting the pivotable arm  114  to the fixed arm  112  in a pivotable manner. The fixed and pivotable arms  112 ,  114  of the first embodiment also each include a finger grip  120 ,  122  sized and shaped to receive the fingers of the surgeon therethrough for facilitating manual manipulation and operation of the device  108 . The fixed arm  112  also includes a stop post  124  to prevent the pivotable arm  114  from moving too closely toward the fixed arm  112 , thereby controlling the degree of deployment of the device  108 , as explained in further detail hereinafter. 
     With further reference to FIGS. 10,  11 ,  12  and  14 , the handle  110  also has a hollow shaft  126  that extends from the distal end of the fixed arm  112 . The hollow shaft  126  has a through passage  128  and may be formed integrally with the fixed arm  112  or it may be formed as a separate component and attached to the fixed arm  112  by conventional means, such as welding or gluing. A hollow sleeve  130  also having a through passage  132  is connected to, and extends from, the distal end of the hollow shaft  126 . The hollow sleeve  130  is sized and shaped to conform to the size and shape of the hollow shaft  126  such that their outer diameters are approximately equal and their through passages  128 ,  132 , respectively, align with one another. 
     The device  108  also includes a cylindrical transducer  10   a  positioned proximate to the distal end of the hollow sleeve  130 , as well as two incomplete cylindrical transducers  10   b ,  10   c  mounted upon a carrier  134  that is positioned proximate to the cylindrical transducer  10   a . Furthermore, the carrier  134  is pivotably attached, at a location intermediate its ends, to the distal end of a stationary bar  136  that has a hole  138  therethrough for such pivotable attachment (see FIGS.  14  and  15 ). The proximal end of the stationary bar  136  is attached to the distal end of the hollow sleeve  130  and the stationary bar  136  extends out of the hollow sleeve  130  and completely through the interior of the cylindrical transducer  10   a  (see FIGS.  15  and  16 A- 16 C). 
     With reference to FIGS. 12,  13  and  14 , in particular, the device  108  also includes an actuator rod  140  with a hole  142  at its distal end and an enlarged plug  144  at its proximate end. The actuator rod  140  is slidingly received within the through passages  132 ,  128  of the hollow sleeve  130  and the hollow shaft  126  and is pivotably attached at its distal end to the carrier  134 , at a position that is proximate to the position at which the stationary bar  136  is attached to the carrier  134  (see FIGS.  15  and  16 A- 16 C). Furthermore, the enlarged plug  144  of the actuator rod  140  is received within a recess  146  provided in the distal end  148  of the pivotable arm  114  of the handle  110 . 
     It is noted that, although not specifically shown in the figures, the cylindrical transducer  10   a  and the incomplete cylindrical transducers  10   b ,  10   c  each have a pair of electrically conductive wires (not shown), preferably as a coaxial cable (not shown), that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the cylindrical transducer  10 . To protect the wires and minimize interference with the manipulation and operation of the device  108  by the surgeon, the aforesaid wires (not shown) can be attached to the cylindrical transducer  10   a  and the incomplete cylindrical transducers  10   b ,  10   c  and extended through the through passages  128 ,  132  of the hollow shaft  126  and hollow sleeve  130 , to the RF power source (not shown). 
     In the foregoing arrangement, during operation of the device  108 , when RF power is supplied to the transducers  10   a ,  10   b ,  10   c , ultrasound energy is emitted by the cylindrical transducer  10   a  in a radially outward direction, as discussed hereinabove in connection with the typical cylindrical transducer  10 . Furthermore, when the device  108  is in its deployed state, the carrier  134  and also, therefore, the incomplete cylindrical transducers  10   b ,  10   c  mounted thereon, are oriented perpendicularly to the cylindrical transducer  10   a  (see FIGS. 12 and 15) and ultrasound energy is emitted by the incomplete cylindrical transducers  10   b ,  10   c  in the direction shown by the arrows in FIG. 13 (which shows the device  108  in use, in its deployed state, after insertion into the vagina  100 ′ and uterus  98 ′ of a female patient). The method of operating the device  108  in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter. 
     With reference now to FIGS.  15  and  16 A- 16 C, it is noted that the position of the stationary bar  136  which extends from the hollow sleeve  130  is stationary relative to the hollow sleeve  130  and relative to the cylindrical transducer  10   a . Thus, the connection between the carrier  134  and the distal end of the stationary bar  136  forms the pivot point of the carrier  134 . As shown in FIGS. 16A-16C, the carrier  134 , with the incomplete cylindrical transducers  10   b ,  10   c  mounted thereon, is pivotable between an undeployed position (shown in FIGS. 10,  11  and  16 A), wherein the incomplete cylindrical transducers  10   b ,  10   c  align longitudinally with the cylindrical transducer  10   a  and the hollow sleeve  130 , and a deployed position (shown in FIGS. 12 16 C), wherein the incomplete cylindrical transducers  10   b ,  10   c  are aligned perpendicularly to the cylindrical transducer  10   a  and the hollow sleeve  130 . More particularly, when the fixed and pivotable arms  112 ,  114  of the handle  110  are squeezed together, the pivotable arm  114  moves toward the fixed arm  112  as far as the stop post  124  which causes the distal end  148  of the pivotable arm  114  to move away from the fixed arm  112  and the hollow shaft  126 , in the direction indicated by the arrow D in FIG.  12 . When the distal end  148  of the pivotable arm  114  moves away from the fixed arm  112 , the actuator rod  140  is pulled through the through passages  128 ,  132  in the direction indicated by the arrow E in FIG. 12 and, as shown in the sequential cut away views of FIGS. 16A-16C, the actuator rod  140  pulls the carrier  134  from its undeployed position (FIG. 16A) to its deployed position (FIG.  16 C), which results in the repositioning of the incomplete cylindrical transducers  10   b ,  10   c  such that they are oriented perpendicularly to the cylindrical transducer  10   a.    
     With reference to the overall size and shape of the device  108 , the sum of the lengths of the hollow shaft  126  and hollow sleeve  130  should be between about 15 and 20 cm, preferably about 25 cm. Regarding the individual lengths of these components, the length of the hollow shaft  126  should be from about 5 to 15 cm, preferably about 10 cm, and the length of the hollow sleeve  130  should be from about 10 to 35 cm, preferably 15 cm. Moreover, the outer diameters of the hollow shaft  126  and the hollow sleeve  130  should be substantially the same as one another and, more specifically, from approximately 5 to 10 mm, preferably about 5 mm. The diameter of the through passages  128 ,  132  of the hollow shaft  126  and the hollow sleeve  130 , respectively, should be large enough to slidingly receive therethrough the actuator rod  140  (without interfering with the stationary bar  136 ) and all of the wires (not shown) attached to the cylindrical transducer  10   a  and the incomplete cylindrical transducers  10   b ,  10   c . More particularly, the diameter of the through passages  128 ,  132  should be from about 3 mm to 15 mm, preferably about 5 mm in diameter. In addition, the length of the carrier  134  should be between about 2 and 3 cm, preferably about 3 cm. 
     With regard to the size of the cylindrical transducer  10   a  and the incomplete cylindrical transducers  10   b ,  10   c , it is noted that, although they are shown in FIGS. 3-9 as being of the same general size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the two transducers  10   b ,  10   c  that are mounted onto the carrier  134  be of similar size and shape to one another. In the present embodiment of the device  108 , each of the transducers  10   a ,  10   b ,  10   c  is between about 1 and 3 cm long, preferably about 1.5 cm long and about 5 to 10 in diameter, preferably about 5 mm in diameter. 
     The method of operating the device  108  of the second embodiment to perform endometrial ablation will now be described. Initially, it is noted that, like the device  34  of the first embodiment discussed hereinabove, the device  108  of the second embodiment may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid. 
     With reference now to FIG. 13, after the uterus  98 ′ has been prepared and filled with fluid, as described hereinabove, the device  108  in its undeployed state (see FIGS. 10 and 11) is inserted into the uterus  98 ′ of a patient. More particularly, the device  108  is held by the finger grips  120 ,  122  of the handle  110  by the surgeon and the carrier  134  (with the cylindrical transducer  10   a  and undeployed incomplete cylindrical transducers  10   b ,  10   c  mounted thereon) and at least a portion of the hollow sleeve  130  are inserted through the vagina  100 ′ and into the uterus  98 ′. The transducers  10   a ,  10   b ,  10   c  are positioned approximately centrally within the uterus  98 ′, or at an otherwise appropriate position within the uterus as clinically determined by the surgeon. The device  108  is then deployed, as described above in connection with FIGS.  15  and  16 A- 16 C, by squeezing the fixed and pivotable arms  112 ,  114  together such that the carrier  134  is moved to its deployed position and the incomplete transducers  10   b ,  10   c  are reoriented to be perpendicular to the cylindrical transducer  10   a  and hollow sleeve  130 . The RF power source (not shown) is then turned on, which causes RF power to be delivered to the transducers  10   a ,  10   b ,  10   c , which causes them to emit ultrasound energy, as shown by the arrows in FIG. 13, that travels to the endometrium  106 ′ where it is absorbed, resulting in heating and ablation of the endometrial tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the transducers  10   a ,  10   b ,  10   c . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes. 
     As can be seen from viewing FIG. 13, the ultrasound energy emitted by the transducers  10   a ,  10   b ,  10   c  when the device  108  is in its deployed state achieves wider coverage of the endometrium  106 ′ than the ultrasound energy that would be emitted from a device having only longitudinally aligned transducers (such as, for example, the arrangement of the transducers  10   a ,  10   b ,  10   c  when the device  108  is in its undeployed state as in FIG.  10 ). More particularly, in its deployed state, the device  108  delivers ultrasound energy directly to the top wall  150 ′ of the uterus  98 ′, which would otherwise be nearly entirely neglected by existing devices having only longitudinally aligned transducers. As with the device  34  of the first embodiment, the device  108  of the second embodiment can be moved, for example back and forth or tilted, during in situ use such that the transducers  10   a ,  10   b ,  10   c  are also so moved within the uterus  98  of the patient. Such movement will allow the surgeon to have greater directional control of at least a portion of the ultrasound energy that is emitted from the transducers  10   a ,  10   b ,  10   c  toward the endometrial tissue. 
     With reference now to FIGS. 17-23, a third embodiment of the device  152  in accordance with the present invention is shown. More particularly, FIGS. 17 and 18 show the device  152  in an undeployed and extended state in a perspective view and a top plan view, respectively. FIG. 19 shows a perspective view of the device  152  in a deployed and extended state, while FIG. 20 shows a perspective view of the device  152  in a fully deployed and retracted state. 
     With reference in particular to FIGS. 17-20 and  22 , the device  152  includes a handle  154  with lateral walls  156 ,  158  and a bottom portion  160  that form a cavity  162  therebetween. The handle  154  includes a first pair of aligned holes  164  (only one of which is visible) through the lateral walls  156 ,  158  and a second pair of aligned holes  166  (only one of which is visible) through the lateral walls, for a purpose to be explained hereinafter. The handle  154  also includes a deploying lever  168  and a retraction trigger  170  that are sized and shaped to fit at least partly within the cavity  162 , as described hereinafter. 
     More particularly, with reference to FIG. 22, the retraction trigger  170  has a planar body  172  with a finger pad  174  and a post  176  extending therefrom and an elongate slot  178 . When the retraction trigger  170  is positioned within the cavity  162  of the handle  154 , a pivot hole  180  on the planar body  172  aligns with the first pair of holes  164  (only one of which is visible) and a pin  182  is inserted therethrough, thereby pivotably mounting the retraction trigger  170  within the cavity  162 . In addition, the elongate slot  178  on the planar body  172  aligns with the second pair of aligned holes  166  (only one of which is visible) and a bolt  167  is inserted therethrough, whereby the retraction trigger  170  is pivotable between a predetermined extended position (shown in FIGS. 17 and 19) and a predetermined retracted position (see FIG.  20 ). Furthermore, the post  176  and finger pad  174  extend out of the cavity  162  when the retraction trigger  170  is pivotably mounted within the cavity  160 , for purposes which will become apparent hereinafter. 
     With reference again to FIG. 22, the deploying lever  168  has a pair of leg extensions  184 ,  186  with holes  188 ,  190  for receiving therethrough a pin  192  which extends from the retraction trigger  170 , whereby the deploying lever  168  is pivotably mounted onto the retraction trigger  170 . As shown in FIGS.  17  and  19 - 21 , the deploying lever  168  also has a thumb peg  194  which extends out of the cavity  162  and with which the deploying lever  168  is movable between an undeployed position (see FIG. 17) and a deployed position (see FIG.  19 ), as will be described hereinafter. 
     With reference to FIGS. 17-20 and  22 , the handle  154  also includes a hollow shaft  196  extending therefrom and having a through passage  198 . The device  152  further includes a hollow sleeve  200  that is connected to and extends from the hollow shaft  196  of the handle  154 . The hollow sleeve  200  has a through passage  202  (see FIG. 22 only), as well as a proximal portion  204  and a distal portion  206  that is narrower than the proximal portion  204 . An actuator sleeve  208  is slideably received within the through passages  198 ,  202  of the hollow shaft  196  and the hollow sleeve  200 . The actuator sleeve  208  has a fork extension  210  at its proximal end that is sized and shaped to be moveably attached to the thumb peg  194  of the deploying lever  168  (see FIGS. 17,  19  and  20 ). The actuator sleeve  208  also has a pair of prongs  212 ,  214 , each with a hole  216 ,  218 , respectively, at its distal end, for a purpose which will be explained hereinafter. 
     With continued reference to FIGS. 17-20 and  22 , the actuator sleeve  208  has a bore  220  (shown in phantom in FIG. 22 only) therethrough within which a retraction rod  222  is slideably received. The proximal end of the retraction rod  222  is provided with a connector  224  having a hole  226  which is sized and shaped to receive the post  176  of the retraction trigger  170  therethrough, in a moveable manner (see FIGS.  17 - 20 ). The retraction rod  222  also has, at its distal end, a tab  228  with a hole  230  and a pin  232 , for a purpose which will be explained hereinafter. 
     The device  152  also includes a cylindrical transducer  10   d  that is securely received about the narrow distal portion  206  of the hollow sleeve  200 . In addition, a first hemi-cylindrical transducer  22   g  is mounted onto a first carrier bar  234 . The first carrier bar  234  has a tongue  236  at one end with a first hole  238  proximate to the first carrier bar  234  and a second hole  240  located remotely from the first carrier bar  234 . The second hole  240  of the first carrier bar  234  is aligned with the hole  230  on the tab  228  at the distal end of the retraction rod  222  and a plug  242  is inserted through both holes  230 ,  238 , thereby moveably attaching the first carrier bar  234  to the retraction rod  222  (see dotted lines in FIG.  22  and see FIG.  23 ). The first carrier bar  234  is moveably connected to the distal end of the actuator sleeve  208  by a first connector rod  244  having two hooked ends  246 ,  248 , as follows. As indicated by the dotted lines provided in FIG.  22  and shown in FIG. 23, one hooked end  246  of the first connector rod  244  is pivotably inserted into the hole  216  of one of the prongs  212  at the distal end of the actuator sleeve  208  and the other hooked end  248  is pivotably inserted into the first hole  238  on the tongue  236  of the first carrier bar  234 . 
     The device  152  also includes a second hemi-cylindrical transducer  22   g  mounted onto a second carrier bar  250 . The second bar carrier bar  250  has a tongue  252  at one end with a first hole  254  proximate to the second carrier bar  250  and a second hole  256  located remotely from the second carrier bar  250 . The pin  232  on the tab  228  at the distal end of the retraction rod  222  is moveably received within the second hole  256  of the second carrier bar  250 , thereby moveably attaching the second carrier bar  250  to the retraction rod  222  (see dotted lines in FIG.  22  and see FIG.  23 ). The second carrier bar  250  is moveably connected to the distal end of the actuator sleeve  208  by a second connector rod  258  having two hooked ends  260 ,  262 , as follows. As indicated by the dotted lines provided in FIG.  22  and shown in FIG. 23, one hooked end  260  of the second connector rod  258  is pivotably inserted into the hole  218  of the other prong  214  at the distal end of the actuator sleeve  208  and the other hooked end  262  of the second connector rod  258  is pivotably inserted into the first hole  254  on the tongue  252  of the second carrier bar  250 . 
     It is noted that, although not specifically shown in the figures, the cylindrical transducer  10   d  and the hemi-cylindrical transducers  22   g ,  22   h  each have a pair of electrically conductive wires (not shown), preferably as a coaxial cable (not shown), that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the cylindrical and hemi-cylindrical transducers  10 ,  22 . To protect the wires and minimize interference with the manipulation and operation of the device  152  by the surgeon, the aforesaid wires (not shown) can be attached to the cylindrical transducer  10   d  and the hemi-cylindrical transducers  22   g ,  22   h  and extended through the through passages  198 ,  202  of the hollow shaft  196  and hollow sleeve  200  (or through the bore  220  of the actuator sleeve  208 ), to the RF power source (not shown). 
     In the foregoing arrangement, during operation of the device  152 , when RF power is supplied to the transducers  10   d ,  22   g ,  22   h , ultrasound energy is emitted by the cylindrical transducer  10   d  in a radially outward direction, as discussed hereinabove in connection with the typical cylindrical transducer  10 . Furthermore, when the device  152  is in its deployed state (see FIGS.  19  and  20 ), the carrier bars  234 ,  250  and also, therefore, the hemi-cylindrical transducers  22   g ,  22   h  mounted thereon, are oriented perpendicularly to the cylindrical transducer  10   d  and ultrasound energy is emitted by the hemi-cylindrical transducers  22   g ,  22   h  in the direction shown by the arrows in FIG. 21 (which shows the device  152  in use, in its deployed state, after insertion into the vagina  100 ″ and uterus  98 ″ of a female patient). The method of operating the device  152  in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter. 
     With reference now to FIGS. 17,  19  and  20 , operation of the device to move the hemi-cylindrical transducers  22   g ,  22   h  from their undeployed positions to their deployed and retracted positions will now be explained. It is noted that the cylindrical transducer  10   d  is not deployable and, therefore, remains in a fixed position with respect to the hollow sleeve  200 . With reference in particular to FIG. 17, the device  152  is shown with the hemi-cylindrical transducers  22   g ,  22   h  in their undeployed and extended positions and, when they are in such positions, the retraction lever  170  of the handle  154  is positioned such that the finger pad  174  extends fully out of the cavity  162  and the post  176  is at a position nearest to the hollow shaft  196 . In addition, the deploying lever  168  is pivoted away from the retraction lever  170  such that the thumb peg  194  is pivoted to a position away from the post  176 . 
     When the thumb peg  194  is pressed (for example, by a surgeon&#39;s thumb) toward the post  176  and hollow shaft  196 , in the direction indicated by the arrow F in FIG. 19, the actuator sleeve  208  is moved slideably through the through passages  198 ,  202  of the hollow shaft  196  and the hollow sleeve  200 , respectively, in the direction indicated by the arrow G in FIG.  19 . The distal end of the actuator sleeve  208 , in turn, pushes the first and second connector rods  244 ,  258  also in the direction of the arrow G in FIG.  19 . The retractor rod  222  remains stationary and, as a result of the movement of the first and second connector rods  244 ,  258 , the first and second carrier bars  234 ,  250  (with the hemi-cylindrical transducers  22   g ,  22   h  mounted thereon) are pivotably moved (in the directions indicated by the arrows H in FIGS. 17 and 19) from their undeployed positions (see FIG. 17) to their deployed positions (see FIGS.  19  and  20 ), which is perpendicular to the cylindrical transducer  10   d  and the hollow sleeve  200 . 
     As shown in FIG. 19, when the first and second carrier bars  234 ,  250  (with the hemi-cylindrical transducers  22   g ,  22   h  mounted thereon) are pivotably moved to their deployed positions, the distance between the hemi-cylindrical transducers  22   g ,  22   h  and the cylindrical transducer  10   d  become significant. Thus, it is preferable to move, or retract, the hemi-cylindrical transducers  22   g ,  22   h  closer to the cylindrical transducer  10   d  and hollow sleeve  200  (i.e., in the direction indicated by the arrow J in FIG.  20 ). 
     Thus, when the finger pad  174  is pushed into the cavity  162  of the handle  154  (in the direction indicated by the arrow K in FIG.  20 ), the entire retraction lever  170  is pivoted backward, which moves the post  176  and the thumb peg  194  (with the actuator sleeve  208  connected thereto) backward away from the hollow shaft  196  (in the direction indicated by the arrow L in FIG.  20 ). The actuator sleeve  208  is moved slideably backward though the through passages  198 ,  202  of the hollow shaft  196  and the hollow sleeve  200 , respectively, in the direction indicated by the arrow J in FIG.  20 ). Similarly and simultaneously, the retraction rod  222  is also slideably moved in the direction indicated by the arrow J in FIG. 20, through the bore  220  of the actuator sleeve  208 , which pulls, or retracts, the first and second carrier bars  234 ,  250  (with the hemi-cylindrical transducers  22   g ,  22   h  mounted thereon), in their deployed positions, backward toward the cylindrical transducer  10   d  and hollow sleeve  200 , in the direction of the arrow J. After the foregoing procedure, the device  154  and hemi-cylindrical transducers  22   g ,  22   h  are in their deployed positions, which are shown in FIG.  20 . 
     With reference to the overall size and shape of the device  152 , the sum of the lengths of the hollow shaft  196  and hollow sleeve  200  should be between about 10 and 30 cm, preferably about 20 cm. Regarding the individual lengths of these components, the length of the hollow shaft  196  should be from about 5 to 10 cm, preferably about 10 cm, and the length of the hollow sleeve  200  should be from about 5 to 15 cm, preferably 10 cm. Moreover, the outer diameters of the hollow shaft  196  and the proximal portion  204  of the hollow sleeve  200  should be substantially the same as one another and, more specifically, from approximately 3 to 10 mm, preferably about 5 mm. The outer diameter of the narrow distal portion  206  of the hollow sleeve  200  should correspond to the inner diameter of the cylindrical transducer  10   d  such that the cylindrical transducer  10   d  is snugly received thereon. Furthermore, the length of the narrow distal portion  206  of the hollow sleeve  200  should be the same or slightly (i.e., about 2 to 5 mm) longer than the length of the cylindrical transducer  10   d , which is specified hereinafter. 
     The diameter of the through passages  198 ,  202  of the hollow shaft  196  and the hollow sleeve  200 , respectively, should be large enough to slidingly receive therethrough the actuator sleeve  208  all of the wires (not shown) attached to the cylindrical transducer  10   a  and the incomplete cylindrical transducers  10   b ,  10   c , more particularly, from about 3 mm to 10 mm, preferably about 4 mm. In addition, the length of the first and second carrier bars  234 ,  250  should, but do not have to be, approximately the same as one another, for example, between about 10 and 3 mm long each, preferably about 15 mm long each. 
     With regard to the size of the cylindrical transducer  10   d  and the hemi-cylindrical transducers  22   g ,  22   h , it is noted that, although they are shown in FIGS. 17-22 as being of the same general size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the two hemi-cylindrical transducers  22   g ,  22   h  be of similar size and shape to one another. In the present embodiment of the device  152 , each of the transducers  10   d ,  22   g ,  22   h  is between about 1 and 3 cm long, preferably about 1.5 cm long. Moreover, a suitable diameter for the cylindrical transducer  10   d  is about 5 to 10 mm in diameter, preferably about 5 mm in diameter. In addition, each hemi-cylindrical transducer  22   g ,  22   h  is about 5 to 10 millimeters (mm) wide at its greater width such that, when the hemi-cylindrical transducers  22   g ,  22   h  are in the undeployed state, they approximate the shape of a cylindrical transducer having an overall diameter of about 5 to 10 mm, preferably about 5 mm. 
     The method of operating the device  152  of the second embodiment to perform endometrial ablation will now be described. Initially, it is noted that, like the devices  34 ,  108  of the first and second embodiments discussed hereinabove, the device  152  of the second embodiment may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid. 
     With reference now to FIG. 21, after the uterus  98 ″ has been prepared and filled with fluid, as described hereinabove, the device  152  in its undeployed state (see FIGS. 10 and 11) is inserted into the uterus  98 ″ of a patient. More particularly, the device  152  is held by the handle  154  by the surgeon and the first and second carrier bars  234 ,  250  (with the undeployed hemi-cylindrical transducers  22   g ,  22   h  mounted thereon), the cylindrical transducer  10   d , and at least a portion of the hollow sleeve  200  are inserted through the vagina  100 ″ and into the uterus  98 ″. The transducers  10   d ,  22   g ,  22   h  are positioned approximately centrally within the uterus  98 ″, or at an otherwise appropriate position within the uterus  98 ″ as clinically determined by the surgeon. The hemi-cylindrical transducers  22   g ,  22   h  are then deployed and retracted, as described above in connection with FIGS. 17,  19  and  20 , by first pressing the thumb peg  194  in the direction indicated by the arrow F in FIG. 19 to deploy the hemi-cylindrical transducers  22   g ,  22   h  into a position that is perpendicular to the cylindrical transducer  10   d . Then the finger peg  174  is in the direction of the arrow K in FIG. 20 to retract the hemi-cylindrical transducers  22   g ,  22   h  into a position that is closer to the cylindrical transducer  10   d.    
     The RF power source (not shown) is then turned on, which causes RF power to be delivered to the transducers  10   d ,  22   g ,  22   h , which causes them to emit ultrasound energy, as shown by the arrows in FIG. 21, that travels to the endometrium  106 ″ where it is absorbed, resulting in heating and ablation of the endometrial tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the transducers  10   d ,  22   g ,  22   h . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes. 
     As can be seen from viewing FIG. 21, the ultrasound energy emitted by the transducers  10   a ,  10   b ,  10   c  when the device  152  is in its deployed state achieves wider coverage of the endometrium  106 ″ than the ultrasound energy that would be emitted from a device having only longitudinally aligned transducers (such as, for example, the arrangement of the transducers  10   d ,  22   g ,  22   h  when the device  152  is in its undeployed state as in FIG.  17 ). More particularly, in its deployed state, the device  154  delivers ultrasound energy directly to the top wall  150 ″ of the uterus  98 ″, which would otherwise be nearly entirely neglected by existing devices having only longitudinally aligned transducers. As with the devices  34 ,  108  of the first and second embodiments, the device  152  of the third embodiment can be moved, for example back and forth or tilted, during in situ use such that the transducers  10   d ,  22   g ,  22   h  are also so moved within the uterus  98 ″ of the patient. Such movement will allow the surgeon to have greater directional control of at least a portion of the ultrasound energy that is emitted from the transducers  10   d ,  22   g ,  22   h  toward the endometrial tissue. The RF source may have multiple (for example, three) individual channels such that the power level supplied to each of the transducers  10   d ,  22   g ,  22   h  can be individually controlled. The transducers  10   d ,  22   g ,  22   h  may also be “multiplexed” such that a single RF power source is sequentially switched among the transducers  10   d ,  22   g ,  22   h.    
     It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications, including but not limited to those discussed hereinabove, without departing from the spirit and scope of the present invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.