Ultrasonic surgical instrument with probe at angle to handpiece

Abstract

An ultrasonic surgical instrument includes a handpiece housing and an electromechanical transducer assembly disposed inside the handpiece housing, wherein the transducer assembly includes a front driver and the transducer assembly has a longitudinal axis. A probe is operably connected to the front driver at an acute angle to the longitudinal axis of the transducer assembly. A sheath surrounds the probe and is connected to the handpiece housing at a proximal end. The sheath is connected to the housing by a torsional quick release coupling. A septum seal inside the proximal end of the sheath blocks liquid irrigation agent in a cylindrical space between the sheath and the probe from permeating near a port that supplies irrigation agent to the space. The front driver is geometrically configured to enable the probe to be angularly connected to the handpiece near the node plane.

Description

Background of the Invention

[0002] The present invention relates to an ultrasonic tool or instrument for use in medical surgical procedures.

[0003] Ultrasonic tools have been increasingly used in surgical procedures. Ultrasonic ablation tools are recognized for their accuracy, reliability, and ease of use. Ultrasonic bone cutting blades can be designed to facilitate cutting of bones without damaging adjacent soft tissues. See U.S. Patent No. 8,343,178. Ultrasonic debriders remove necrotic or other damaged tissues without harming the underlying healthy tissue. Ultrasonic instruments such as debriders can have integrated tissue treatment modes, such as high energy current transmission for cauterization (see U.S. Patent No. 6,648,839) and low energy electrical energy transmission for pain suppression (U.S. Patent Application Publication No. 2008 / 0146921) or stimulation of tissue repair (U.S. Patent No. 8,025,672).

[0004] Ultrasonic instruments can combine a probe with a curved shaft to facilitate access to problematic locations. In some surgical procedures, it is advantageous to angle the operating head or end effector portion of the probe to one side of the shaft to further facilitate access to the desired surgical site. See U.S. Patent No. 10,398,463. Alternatively, the probe can be entirely straight and attached to the handpiece at an angle. See U.S. Patent Nos. 5,312,329 and 5,484,398.

[0005] While developing a new set of ultrasonic instruments in which a handpiece can be used with different probes that can have different end effectors and different surgical capabilities, the applicant encountered some surprising problems. Due to the rigid sheath defining an annular liquid flow path between the sheath and the probe, a user placing a hand on the sheath just distal to the handpiece occasionally experiences a burning or stinging sensation on the hand. It was ultimately discovered that experiencing this sensation is dependent on the compressive pressure applied to the sheath by the hand.

[0006] Another issue is designing the handpiece and the proximal end of the probe to facilitate removal of the probe and attachment of a different tool so that changes can be easily accomplished in the operating room. For example, one may wish to change from a bone cutting instrument to an abrasive or debridement instrument during spinal surgery.

[0007] Other issues include optimizing the efficiency of ultrasound energy transfer from the handpiece's transducer array to the probe, which is not a simple task given the angular relationship between the two instrument components.

[0008] Purpose of the Invention

[0009] It is an object of the present invention to provide an improved ultrasonic tool or instrument that is effectively used in minimally invasive surgical procedures.

[0010] It is another object of the present invention to provide an improved ultrasonic tool or instrument having a probe extending at an angle relative to a handpiece.

[0011] A more specific object of the present invention is to provide such a tool or instrument having a sheath surrounding the probe and fluid flow therebetween, wherein the risk of painful sensations when holding the sheath during surgery is reduced or eliminated.

[0012] It is another object of the present invention to provide such a tool or instrument wherein the probe is easily attached to and detached from the handpiece.

[0013] Another object of the present invention is to provide such a tool or instrument that is configured to effectively transfer ultrasonic mechanical vibration energy from the handpiece to the probe.

[0014] These and other objects of the present invention will be apparent from the description herein and the accompanying drawings.Although all objects of the present invention are achieved by one or more embodiments of the present invention, there is not necessarily any single embodiment that achieves all objects of the present invention. Summary of the invention

[0015] According to the present invention, an ultrasonic surgical instrument includes a handpiece housing and an electromechanical transducer assembly disposed inside the handpiece housing, wherein the transducer assembly includes a front driver and the transducer assembly has a longitudinal axis. The instrument also includes a probe, which is operably connected to the front driver at an acute angle to the longitudinal axis of the transducer assembly (and usually to the handpiece housing). The probe has a distal end, which is provided with an end effector such as a blade or a debridement surface. The sheath surrounds the probe and is connected to the handpiece housing at the proximal end, and the end effector extends distally from the distal tip of the sheath. The sheath is provided with an annular sealing member at the proximal end that engages the distal surface of the handpiece housing. The proximal end of the sheath and the distal end of the handpiece housing are provided with at least two first closing elements and the same number of second closing elements. The first closing element is provided on the distal surface of the handpiece housing or on the proximal end of the sheath, and the second closing element is provided on the proximal end of the sheath or on the distal surface of the handpiece housing. The first closure elements each take the form of a projection extending in a radial direction (inwardly from the outer member or outwardly from the inner member), while the second closure elements each take the form of an annular open channel or groove having one end that is tapered and defined by a cam surface.

[0016] Preferably, the annular sealing member is made of an elastically compressible material having a suitable surface friction coefficient. The first closing element and the second closing element are configured to frictionally lock the sheath to the handpiece housing by compressing the annular sealing member. The locking and unlocking of the sheath with the handpiece housing is achieved by twisting the sheath in opposite directions relative to the handpiece. Thus, the cam mechanism enables the sheath to be quickly coupled to the handpiece and also quickly detached.

[0017] Therefore, the handpiece housing is preferably secured to the sheath by only one locking mechanism, which includes the annular sealing member, the first closure element and the second closure element.

[0018] The projection may take the particular form of an annular rib extending in a plane transverse to the axis of the sheath.The cam surface is located distally along the annular open channel and faces the handpiece housing in a proximal direction.

[0019] An ultrasonic surgical instrument according to the present invention comprises a handpiece housing and an electromechanical transducer assembly disposed inside the handpiece housing, the transducer assembly comprising a front driver and the transducer assembly having a longitudinal axis. A probe is operably connected to the front driver at an acute angle to the longitudinal axis, the probe having a distal end provided with an end effector. A sheath surrounds the probe and is connected to the handpiece housing at a proximal end so that the end effector extends distally from the distal tip of the sheath. The sheath is provided with a port near the proximal end, the port being connectable to a pressurized liquid coolant source for allowing the pressurized liquid coolant to flow into the tubular space between the probe and the inner surface of the sheath. A diaphragm seal is disposed inside the proximal end of the sheath near the port, the diaphragm seal having an annular outer surface in liquid-tight contact with the inner surface of the sheath. The diaphragm is provided with an annular inwardly extending flange at the distal end, the flange circumferentially engaging the outer surface of the probe in a liquid-tight manner. The annular inwardly extending flange preferably engages the outer surface of the probe at a node of ultrasonic transmission.

[0020] The septum is preferably spaced apart from the probe as a whole, except at the annular inwardly extending flange.As described above, the septum seal eliminates occasional painful or distracting sensations when a user grasps the proximal portion of the sheath.

[0021] According to another feature of the invention, the septum is provided at the proximal end with an annular outwardly extending flange which is sandwiched between the proximal surface of the sheath and the distal surface of the handpiece housing.

[0022] According to another feature of the invention, the sheath has a body at the proximal end made of a rigid material, the sheath also comprising a distal portion made of a silicone polymer.

[0023] The ultrasonic surgical instrument according to the present invention comprises a handpiece housing and an electromechanical transducer assembly arranged inside the handpiece housing, the transducer assembly comprising a front driver, and further comprising a probe, the probe being operably connected to the front driver at an acute angle to the longitudinal axis, wherein the probe has a distal end provided with an end effector or an operating head. The front driver has an outwardly protruding annular flange, and a first cylindrical outer surface coaxial with the longitudinal axis of the transducer assembly is formed at the distal end. The front driver has a second cylindrical outer surface at the distal end on a side opposite to the first cylindrical outer surface, and the second cylindrical outer surface is coaxial with the longitudinal axis of the probe.

[0024] According to another feature of the invention, the front driver has two mutually parallel planar outer surfaces extending parallel to the longitudinal axis of the transducer assembly, each of the two mutually parallel planar outer surfaces being adjacent to the first cylindrical outer surface and the second cylindrical outer surface.

[0025] The handpiece housing preferably forms a cylindrical first inner surface at the distal end that is coaxial with the longitudinal axis of the transducer assembly and also forms a cylindrical second inner surface that is coaxial with the longitudinal axis of the probe.

[0026] According to the present invention, an ultrasonic surgical instrument includes a handpiece housing and an electromechanical transducer assembly disposed inside the handpiece housing, the transducer assembly including a front driver having an internal threaded receiver at the distal end. A tubular member extends through the transducer assembly to the proximal end of the internal threaded receiver. A probe having a longitudinal hole is operably connected to the front driver at an acute angle to the longitudinal axis of the transducer assembly, and the probe has a distal end provided with an end effector. The internal threaded receiver receives an external threaded connector at the proximal end of the probe and has a proximal surface disposed at an acute angle relative to the longitudinal axis of the transducer assembly. A sheath surrounds the probe and is connected to the handpiece housing at the proximal end, and the end effector extends distally from the distal tip of the sheath. The tubular member has an inner cavity, and the inner cavity has a uniform cross-section including at the distal end opening of the inner cavity. The hole of the probe has a proximal opening with a cross-section smaller than the cross-section of the tubular member. The hole of the probe is aligned with the distal end opening of the tubular member. The tubular member and the hole together define a continuous inner cavity, and the inner cavity does not have a shoulder facing the distal direction at the junction of the tubular member and the hole.

[0027] According to the present invention, a bracket for manually attaching an ultrasound probe to a handpiece at an acute angle relative to the axis of the handpiece comprises a frame and a support on the frame, the support defining an acute angle relative to the bottom side of the frame. The frame has a stopper at one end thereof, which can be engaged with the front end of the handpiece. The stopper has an opening that allows a user to access a front driver of a transducer assembly housed in the handpiece. Two wings extend from the frame in opposite directions at its bottom side so as to contact a flat surface on which the frame is placed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a side view of an ultrasonic surgical instrument according to the present invention.

[0029] Figure 2 is parallel to Figure 1 A longitudinal sectional view taken in the plane of the drawing.

[0030] Figure 3 is with Figure 2 A longitudinal cross-sectional view of the coplanar view showing the probe and the Figure 1 and Figure 2 The transducer array within the handpiece housing is shown.

[0031] Figure 4 yes Figure 3 Front, side, and top perspective views of the operating structure (ie, the probe and transducer array, and the proximal cap assembly of the handpiece housing) are shown.

[0032] Figure 5 yes Figure 3 A partial longitudinal cross-sectional view on an enlarged scale of section V showing the probe-transducer coupling.

[0033] Figure 6 is a longitudinal cross-sectional view of the front driver of the transducer array.

[0034] Figure 7 yes Figure 1 and Figure 2 Side view of the handpiece housing.

[0035] Figure 8 yes Figure 1 , Figure 2 and Figure 7 Front view of the handpiece housing.

[0036] Fig. 9 yes Figure 1 , Figure 2 , Figure 7 and Figure 8 Top, side and front perspective views of the handpiece housing.

[0037] Fig.10 yes Figure 2 A partial longitudinal cross-sectional view on an enlarged scale of section X showing the diaphragm seal and the jacket-housing connection.

[0038] Fig.11 So the probe (for example, Figure 3 , Figure 4 ) Manually attached to the handpiece housing for orientation retention Figure 1 and Figure 2 Side view of a holder for an ultrasonic instrument.

[0039] Fig.12 yes Figure 1 and Figure 2 A partially exploded perspective view of the top, front and side portions of an ultrasonic instrument of Fig.11 The bracket holds the handpiece and positions it for attaching the probe.

[0040] Fig.13 yes Figure 1 and Figure 2 Top, front, and side perspective views of an assembled ultrasonic instrument after the probe is attached to the handpiece housing.

[0041] Fig.14 yes Fig.13 Top, front and side perspective views of a bracket and instrument of the present invention, also showing a wrench for twisting the probe onto the handpiece or for loosening the probe for removal from the handpiece.

[0042] Fig.15 It is along Figure 1 A cross-sectional view taken along line XIII-XIII in FIG. DETAILED DESCRIPTION

[0043] like Figure 1 and Figure 2 As shown, the ultrasonic surgical instrument includes a handpiece housing 10 and an electromechanical transducer assembly 12 disposed inside the housing, wherein the transducer assembly includes a front driver 14 and has a longitudinal axis 16 ( Figure 3 and Figure 5 ). The instrument also includes a probe 18, which is typically made of a metal alloy and is operably connected to the front driver 14 at an acute angle (exemplarily 20°) to the longitudinal axis 16 of the transducer assembly 12. The transducer assembly 12 is preferably symmetrically positioned within the housing 10 so that the axis 16 also serves as the symmetric longitudinal axis of the housing. The probe 18 has a distal end (not separately labeled) provided with an end effector 20, such as a bone cutting blade (not shown) or a debridement head (shown). A sheath 22 surrounds the probe 18 except for the end effector or operating head 20 and is connected to the handpiece housing 10 at the proximal end. The end effector or operating head 20 extends distally from a distal tip 24 of the sheath 22.

[0044] The transducer assembly 12 has a structure well known in the art and is as follows: Figure 2 and Figure 3As shown, it basically includes a plurality of annular piezoelectric disks 26 and a thinner annular metal electrode 28, which is arranged in a linear array around the longitudinal axis 16 and sandwiched between the front driver 14 on the distal side and the rear driver 30 on the proximal side. The electrode 28 is connected to an ultrasonic electrical waveform generator (not shown), whereby the piezoelectric disk is alternately expanded and contracted parallel to the transducer axis 16 to generate an ultrasonic standing wave in the probe 18, thereby causing the end effector or operating head 20 to reciprocate at a predetermined ultrasonic frequency.

[0045] A tubular member 32 coaxial with the transducer axis 16 passes through the transducer assembly 12 and terminates at a proximal surface 34 of an internally threaded receiver 36 disposed on the distal end of the front driver 14 for receiving an externally threaded connector 38 at the proximal end of the probe 18. The proximal surface 34 is disposed at an acute probe-transducer angle (20°) relative to the transducer axis 16. The tubular member 32 serves as a liquid guide channel. In the case where the end effector 20 is a debridement head, the tubular member 32 guides a slurry of irrigation fluid and organic particles from the surgical site to a debris collector or trap (not shown) and a suction source (not shown). At the proximal end, the tubular member 32 is connected to and passes through an end cap assembly 40, and the tubular member carries a fitting 42 for connecting a hose (not shown) extending to the debris collector. The end cap assembly 40 carries an electrical connector 43 for connecting a cable (not shown) from an ultrasonic waveform generator (not shown).

[0046] like Figures 2 to 4 and Figure 6 As shown, the front driver 14 has an outwardly protruding annular flange 44 (with an O-ring seal 44') at the proximal end, and is formed with a first cylindrical outer surface 46 coaxial with the transducer axis 16 at its distal end. The front driver 14 is also formed with a second cylindrical outer surface 48 at the distal end on the side opposite to the cylindrical outer surface 44. The second cylindrical outer surface 48 is coaxial with the longitudinal axis 49 of the probe 18. The axis 16 and the axis 49 intersect each other at a probe-transducer angle of 20°. The front driver 14 has two mutually parallel planar outer surfaces or flat portions 50 and 52 extending parallel to the transducer axis 16, and the planar outer surfaces or flat portions are respectively adjacent to the cylindrical outer surfaces 46 and 48 along corresponding edges or intersection trajectories 54, 56, 58, 60 (see Figure 8 and Fig. 9 The front driver 14 also has three mutually adjacent faces or surfaces 62 ( Figure 4 ), one being planar and two being cylindrical arcs, extending between an annular flange 44 at the proximal end and an inclined cylindrical surface 48 at the distal end.

[0047] like Figure 6As shown, the handpiece housing 10 is formed at the distal end with a cylindrical first inner surface 64 coaxial with the transducer axis 16 and a cylindrical second inner surface 66 coaxial with the probe axis 49. These surfaces 64 and 66 are closely juxtaposed with the front driver outer surfaces 46 and 48, respectively, and are parallel to each other.

[0048] Regarding the connection of the sheath 22 to the handpiece housing 10, the sheath is provided with an annular sealing member 96 ( Fig.10 ), the annular sealing member engages the distal end surface 70 ( Figure 8 and Fig. 9 As described below, when liquid irrigation is supplied to the space 88 between the sheath 22 and the probe 18, the sealing member 96 may be implemented as an annular outwardly extending flange of the diaphragm seal 92.

[0049] The sheath 22 is provided at the proximal end with a pair of closing or locking elements in the form of two inwardly and radially projecting arcuate flanges or ribs 72 and 74 ( Fig.10 ), the arcuate flange or rib extending in a plane transverse to the axis of the sheath (typically but not necessarily the probe axis 49). At the same time, the handpiece housing 10 is formed at its distal end with a pair of cooperating closure or locking elements in the form of two annular open channels or grooves 76, 78 (see Figure 6 ), the annular open channel or groove each has a tapered end and is defined by a corresponding cam surface 80. The cam surface 80 is located distally along the corresponding annular open channel 76 and faces the handpiece housing 10 in the proximal direction.

[0050] At least two sets of cooperating closure elements 72, 74 and 76, 78 are provided on the sheath 22 and the handpiece housing 10, although three or more sets may be provided. The annular sealing member 96 is made of an elastically compressible material, such as silicone rubber having a suitable surface friction coefficient. The closure elements 72, 74, 76 are mutually configured to frictionally lock the sheath 22 to the handpiece housing 10 by compressing the annular sealing member 96. The locking and unlocking of the sheath 22 relative to the handpiece housing 10 is achieved by twisting the sheath in opposite angular directions (clockwise, counterclockwise) relative to the handpiece. Therefore, the cam mechanism including the flanges 72 and 74 and the corresponding cam surface 80 can not only achieve compression-enhanced friction locking, but also achieve quick coupling of the sheath 22 with the handpiece 10, and quick disconnection. Therefore, the handpiece housing 10 can be fixed to the sheath 22 by a single locking mechanism consisting of the annular sealing member 96, the first closure elements 72 and 74 and the second closure elements 78, 80. In the absence of a liquid irrigation being delivered between the sheath 22 and the probe 18, the sealing member may have a leaf-like form in the form of a clover leaf, or may have a simple circular geometry.

[0051] like Figure 1 and Figure 2 As shown, the sheath 22 has two parts, a proximally located body 82 made of a rigid polymer material and a tapered distal portion 84 made of a flexible or elastic material (such as a silicone polymer). The sheath 22 is provided with a port or fitting 86 near the proximal end, which can be connected to a pressurized liquid coolant source (not shown) for allowing the coolant to flow into the tubular space 88 between the probe 18 and the inner surface 90 of the sheath. Figure 2 and Fig.10 As shown, a diaphragm seal 92 is disposed within the proximal end of the sheath 22, proximate the port or fitting 86. The diaphragm seal 92 has an annular outer surface 93 disposed along the inner surface 90 of the sheath 22, and is provided at the distal end with an annular inwardly extending flange 94 that circumferentially engages an outer surface (not separately labeled) of the probe 18 in a fluid-tight seal.

[0052] The septum seal 92 has an annular geometry that conforms to the geometry of the sheath inner surface 90 at the proximal end of the sheath. The septum seal 92 is preferably spaced apart from the probe 18 throughout except at an annular inwardly extending flange 94. As described above, the septum seal 92 is used to eliminate the occasional painful or distracting sensation that occurs when a user grasps the proximal portion of the sheath. The septum seal 92 is also formed with an annular outwardly extending flange at the proximal end that serves as a sealing member 96 that clamps between the proximal surface of the sheath (not separately labeled in the drawings) and the distal surface 70 (not separately labeled in the drawings) of the handpiece housing 10. Figure 6 and Figures 8 to 10 )between.

[0053] As described above, tubular member 32 extends through transducer assembly 12 to proximal end surface 34 of threaded receiver 36. Tubular member 32 has lumen 100 having a uniform cross-section at distal end opening 102 including in the plane of receiver end surface 34. Probe 18 has longitudinal bore or passage 98 having proximal end opening 104 having a cross-section smaller than distal end opening 102 or the cross-section of tubular member 32. Probe bore 98 is aligned with distal end opening 102 of tubular member 32. Lumen 100 and bore or passage 98 together define a continuous passageway having no shoulder facing in the distal direction at the junction of tubular member 32 and probe bore 98.

[0054] like Figures 11 to 14As shown, a bracket 106 for manually attaching a probe 18 to a handpiece housing 10 at an acute angle (e.g., 20°) relative to a transducer or handpiece axis 16 includes a rectangular prism-shaped container or frame 108 having an open upper side 110 and a support 112 (such as a surface or crossbar) inside the frame that holds the handpiece housing at an acute angle relative to a bottom 114 of the frame. The container or frame 108 is placed on a horizontal surface, such as a tabletop (not shown), with the bottom 114 in contact with the horizontal surface. The container or frame 108 is provided with a stabilizing rod or bar 118 that extends outwardly from the container on opposite sides of the container. The stabilizing rod 118 is located in the plane of the bracket bottom 114 with its underside (not separately listed).

[0055] When attaching the probe 18 to the handpiece housing 10, the user manually screws the connector 38 of the probe into the receiver 36. This step can be performed after placing the handpiece housing 10 into the container or frame 108, but is preferably performed before. The frame 108 has a wall 116 at one end that serves as a stop that can engage the front or distal end of the handpiece housing 10. The wall or stop 116 has a slot 122 that receives the distal portion of the front driver 14, which protrudes to the exterior of the housing 10 (see also FIG. 1 ). Figure 8 and Fig. 9 ). The slot 122 allows the user to access the front driver 14. To tighten the probe 18 to the front driver 14 and thus to the housing 10, the torque wrench 120 is pivoted about the probe axis 49 ( Fig.14 ), while pressing the housing 10 and bracket 108 against a horizontal tabletop. Stabilizing rod 118 assists in applying torque. Wrench 120 is of the type with a torque detector that automatically prevents further rotation of the wrench when a pre-selected torque amount is reached.

[0056] The ultrasonic surgical instrument according to the present invention provides safe and effective removal of hard tissue (such as bone) in minimally invasive surgery under microscopic or annular magnification, wherein the operating end of the instrument is inserted through a tubular retractor or cannula having an inner diameter as small as 18 mm and a probe length as high as 80 mm. The instrument can be used with other types of retractors.

[0057] The ultrasonic surgical instrument according to the present invention can have an outer diameter of less than 10 mm in the tissue access area, with an instrument working length of up to 165 mm. The angled design (20°) provides a direct line of sight to the distal end of the instrument compatible with a microscope setup (microscope focal length is approximately 300 mm)

[0058] The ultrasonic surgical instrument according to the present invention preferably has a combined handpiece and probe length suitable for full wave (two half waves) operation at a frequency of about 23 KHz, wherein the angled transition is located at about 1 / 4 wavelength from the proximal end of the handpiece. Thus, the resonator assembly can be composed of a 1 / 4 wave handpiece and a 3 / 4 wave probe, wherein the probe is connected near the first nodal plane.

[0059] The present invention contemplates a viable ultrasonic handpiece-probe assembly in which the probe is connected to the handpiece at an acute angle proximate to the nodal plane. In contrast, the prior art (see U.S. Pat. No. 5,222,937) teaches that the angled connection must be located at the anti-node (ring). If the handpiece is not angled, the angled feature must be present along with the probe length, or an angled adapter must be provided. As described in U.S. Pat. No. 5,222,937, the connection at the ring (i.e., anti-node) is necessary to avoid breakage of the "threaded connection portion". It should be noted that the amplitude of motion of the present instrument is within the same range as the prior art (100-300 μm) and the assembly will not break.

[0060] like Fig.15 As shown, the sheath 22 is provided with at least one circular array of circumferentially spaced protrusions or bumps 124 along the inner surface 90, which extend inwardly from the surface 90 to the probe 18 to ensure that the sheath and the probe are separated or spaced from each other while allowing irrigation fluid to flow in the distal direction from the port or fitting 86 to the distal sheath tip 24. The array of circumferentially spaced protrusions 124 is positioned proximate to the second nodal plane of the transducer-probe ultrasonic resonator.

[0061] Although the present invention has been described in terms of specific embodiments and applications, those skilled in the art may generate additional embodiments and modifications based on this teaching without departing from the spirit of the claimed invention or exceeding the scope of the claimed invention. Therefore, it should be understood that the drawings and descriptions herein are provided as examples to aid in understanding the present invention and should not be interpreted as limiting the scope of the present invention.

Claims

1. An ultrasonic surgical instrument, comprising: Handpiece housing; an electromechanical transducer assembly disposed within the handpiece housing, the transducer assembly including a front driver, the transducer assembly having a longitudinal axis; a probe operably connected to the front driver at an acute angle to the longitudinal axis, the probe having a distal end provided with an end effector; a sheath surrounding the probe and connected at a proximal end to the handpiece housing, the end effector extending distally from a distal tip of the sheath, the sheath being provided at a proximal end with an annular sealing member engaging a distal surface of the handpiece housing; as well as At least two first closing elements and an equal number of second closing elements, wherein the at least two first closing elements are arranged on one of the distal surface of the handpiece housing and the proximal end of the sheath, and the second closing elements are arranged on the other of the distal surface of the handpiece housing and the proximal end of the sheath, the at least two first closing elements are each in the form of a protrusion extending in a radial direction, and the second closing elements are each in the form of an annular open channel having a tapered end defined by a cam surface.

2. The ultrasonic surgical instrument of claim 1 , wherein the annular sealing member is made of an elastically compressible material, and the at least two first closing elements and the second closing element are configured to frictionally lock the sheath to the handpiece housing by compressing the annular sealing member.

3. The ultrasonic surgical instrument of claim 2, wherein the handpiece housing is secured to the sheath by only one locking mechanism, the only one locking mechanism comprising the annular sealing member, the at least two first closure elements, and the second closure element.

4. The ultrasonic surgical instrument of claim 1, wherein the protrusion is an annular rib extending in a plane transverse to the axis of the sheath.

5. The ultrasonic surgical instrument of claim 1, wherein the cam surface is located distally along the annular open channel and faces the handpiece housing in a proximal direction.

6. The ultrasonic surgical instrument of claim 1, wherein the probe is connected to the front driver proximate a nodal plane.

7. An ultrasonic surgical instrument, comprising: Handpiece housing; an electromechanical transducer assembly disposed within the handpiece housing, the transducer assembly including a front driver, the transducer assembly having a longitudinal axis; a probe operably connected to the front driver at an acute angle to the longitudinal axis, the probe having a distal end provided with an end effector; a sheath surrounding the probe and connected to the handpiece housing at a proximal end, the end effector extending distally from a distal tip of the sheath, the sheath being provided with a port near the proximal end, the port being connectable to a source of pressurized liquid coolant for flowing the pressurized liquid coolant into a tubular space between the probe and an inner surface of the sheath; as well as A diaphragm seal is disposed within the proximal end of the sheath adjacent the port, the diaphragm seal having an annular outer surface in fluid-tight contact with the inner surface of the sheath, the diaphragm being provided at a distal end with an annular inwardly extending flange that circumferentially engages the outer surface of the probe in a fluid-tight seal.

8. The ultrasonic surgical instrument of claim 7, wherein the diaphragm is provided at a proximal end with an annular outwardly extending flange, the flange being sandwiched between a proximal surface of the sheath and a distal surface of the handpiece housing.

9. The ultrasonic surgical instrument of claim 7 wherein said diaphragm is spaced apart from said probe except at said annular inwardly extending flange.

10. The ultrasonic surgical instrument of claim 7, wherein the sheath has a body at a proximal end made of a rigid material, the sheath further comprising a distal portion made of a silicone polymer.

11. The ultrasonic surgical instrument of claim 7, wherein the front driver has two mutually parallel planar outer surfaces extending parallel to the longitudinal axis of the transducer assembly, each of the two mutually parallel planar outer surfaces being adjacent to the first cylindrical outer surface and the second cylindrical outer surface.

12. The ultrasonic surgical instrument of claim 7, wherein the handpiece housing is formed at a distal end with a cylindrical first inner surface coaxial with the longitudinal axis of the transducer assembly, and is also formed with a cylindrical second inner surface coaxial with the longitudinal axis of the probe.

13. The ultrasonic surgical instrument of claim 7, wherein the probe is connected to the front driver proximate a nodal plane.

14. An ultrasonic surgical instrument, comprising: Handpiece housing; an electromechanical transducer assembly disposed within the handpiece housing, the transducer assembly including a front driver having an internally threaded receiver at a distal end, the transducer assembly having a longitudinal axis; a tubular member connected to a proximal side of the transducer assembly, the tubular member and the front driver defining an internal lumen of uniform cross-section extending axially to a proximal end of the internally threaded receiver; a probe operably connected to the front driver at an acute angle to the longitudinal axis, the probe having a distal end provided with an end effector, the probe having a longitudinal bore, the internally threaded receiver receiving an externally threaded proximal connector of the probe, the internally threaded receiver having a proximal surface disposed at the acute angle relative to the longitudinal axis; and The lumen and the aperture together define a flow channel having no distally facing shoulder at a junction of the lumen and the aperture.

15. The ultrasonic surgical instrument of claim 14, further comprising a sheath surrounding the probe and connected to the handpiece housing at a proximal end, the end effector extending distally from a distal tip of the sheath.

16. The ultrasonic surgical instrument of claim 1, wherein the probe is connected to the front driver proximate a nodal plane.

17. A bracket for manually attaching an ultrasound probe to a handpiece at an acute angle relative to the axis of the handpiece, the bracket comprising: frame; a support on the frame, the support defining the acute angle relative to a bottom side of the frame, the frame having a stop at one end of the frame, the stop engageable with a front end of the handpiece, the stop having an opening to allow a user to access a front driver of a transducer assembly housed within the handpiece; as well as At least one elongated rod or bar extending from the frame at the bottom side of the frame in opposite directions so as to contact a planar surface upon which the frame is placed.

18. An ultrasonic surgical instrument, comprising: a handpiece housing a transducer assembly including a front driver; an ultrasound probe connected at a proximal end to the front driver; as well as a sheath surrounding the probe and connected at a proximal end to the handpiece, The sheath 22 is provided along an inner surface with at least one array of circumferentially spaced projections or nubs extending inwardly from the inner surface to the probe, thereby spacing the sheath and probe from each other.

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