Patent Description:
The ultrasonic mechanical vibrations, when transmitted to biological tissue at suitable energy levels and using a suitable end-effector, may effectively and efficiently cut, dissect, and/or coagulate tissue in an accurate and precise manner. Thus, ultrasonic surgical instruments can minimize patient trauma during surgical procedures by facilitating substantially simultaneous cutting of tissue and hemostatic coagulation. Accordingly, ultrasonic surgical instruments are used by clinicians to perform various surgical procedures, including open (invasive), laparoscopic, endoscopic, and robotic-assisted surgical procedures.

Although ultrasonic surgical instruments have gained wide acceptance among surgeons and other clinicians, some areas of improvement still remain. For example, ultrasonic surgical instruments that facilitate increased surgical site access, visibility, and manipulability would be advantageous. Additionally, ultrasonic surgical instruments with decreased manufacturing costs would be advantageous.

<CIT> discloses an ultrasonic clamp coagulator assembly that is configured to permit selective cutting, coagulation, and fine dissection required in fine and delicate surgical procedures. The assembly includes a clamping mechanism, including a clamp arm pivotally-mounted at the distal portion of the instrument using a ball-bearing assembly, which is specifically configured to create a desired level of tissue clamping forces.

<CIT> discloses an ultrasonic blade comprising a folded portion.

The present invention provides an ultrasonic surgical instrument, as defined in claim <NUM>. Further optional features of the invention are defined in the dependent claims.

This specification generally relates to ultrasonic surgical instruments. Described herein are ultrasonic surgical instruments having offset blade configurations, which provide for increased surgical site access and visibility to surgeons. Further described herein are ultrasonic surgical instruments having blades that may be fabricated from sheet metal stock, which decreases manufacturing cost. Further described herein are ultrasonic surgical blades and end-effectors configured for use with ultrasonic surgical instruments, and related assemblies and systems.

Described herein is an ultrasonic surgical instrument comprising an ultrasonic transducer having a central transducer axis, an acoustic horn acoustically coupled to the ultrasonic transducer, and an ultrasonic transmission waveguide acoustically coupled to the acoustic horn. The ultrasonic transmission waveguide comprises a curved portion and a linear portion. An ultrasonic surgical blade is acoustically coupled to the ultrasonic transmission waveguide. The linear portion of the ultrasonic transmission waveguide and the ultrasonic surgical blade are angularly off-set from the central transducer axis.

Further described herein is an ultrasonic surgical instrument comprising an ultrasonic transducer, an acoustic horn acoustically coupled to the ultrasonic transducer, and an ultrasonic transmission waveguide acoustically coupled to the acoustic horn. The ultrasonic transmission waveguide has a central waveguide axis. An ultrasonic surgical blade is acoustically coupled to the ultrasonic transmission waveguide through a compound curvature component. The compound curvature component transversely off-sets the ultrasonic surgical blade from the central waveguide axis.

Various features and characteristics of the invention described in this specification may be better understood by reference to the accompanying figures, in which:.

The reader will appreciate the foregoing features and characteristics, as well as others, upon considering the following detailed description of the invention according to this specification.

In this specification, including the claims, spatial terms (e.g., front, rear, back, top, bottom, upper, lower, vertical, horizontal, above, below, over, under, and the like), used to describe the relative orientation, location, or positioning of components, are used for clarity and convenience and are not to be construed as limited to any absolute frame of reference. Additionally, the terms "proximal" and "distal" (and grammatical variants such as "proximally" and "distally") are used in this specification with reference to a surgeon or other operator holding the handle portion of a surgical instrument comprising the feature or characteristic described as "proximal" or "distal," wherein the term "proximal" refers to the portion closest to the operator and the term "distal" refers to the portion located away from the operator. Also, where materials of construction are described for certain components is this specification, the components are not necessarily limited to the materials of construction so described, and other materials of construction may be used to implement the invention in practice.

Ultrasonic surgical instruments generally comprise an ultrasonic transducer acoustically coupled to an ultrasonic surgical blade through an ultrasonic transmission waveguide. In prior ultrasonic surgical instruments, the ultrasonic transducer, the ultrasonic transmission waveguide, and the ultrasonic surgical blade are co-axially aligned along a common longitudinal axis. Examples of such ultrasonic surgical instruments are described, for example, in the following documents.

The ultrasonic surgical instruments described in this specification comprise angularly and/or transversely (linearly) off-set ultrasonic surgical blades. Referring to <FIG>, which are not in accordance with the present invention, an ultrasonic surgical instrument <NUM> has tissue clamping functionality and an angled scissor grip configuration. The ultrasonic surgical instrument <NUM> comprises a handle assembly <NUM>, a shaft assembly <NUM> connected to the handle assembly <NUM>, and an end-effector <NUM> connected to the shaft assembly <NUM>. The handle assembly <NUM> comprises a handle body <NUM> comprising a finger grip ring <NUM> integrally formed on the rear distal surface of the handle body <NUM> at the bottom end of the handle body <NUM>. The shaft assembly <NUM> comprises a lower shaft member <NUM> that is integrally formed with the handle body <NUM> and a reciprocating upper shaft member <NUM> located above the lower shaft member <NUM>. Although the lower shaft member <NUM> is shown integrally formed with the handle body <NUM>, it is understood that the lower shaft member <NUM> can be otherwise fixedly attached (e.g., welded, fastened, and the like) to the handle body <NUM>, and that the lower shaft member <NUM> and the handle body <NUM> are not necessarily required to be formed from a contiguous piece of material.

The end-effector <NUM> comprises an ultrasonic surgical blade <NUM> (see <FIG>), a blade housing <NUM>, and a clamp arm <NUM>. The blade housing <NUM> of the end-effector <NUM> surrounds the non-tissue-engaging surfaces of the ultrasonic surgical blade <NUM>, but the tissue-engaging surfaces <NUM> of the ultrasonic surgical blade <NUM> remain exposed for the cutting and coagulation of tissue during operation. The blade housing <NUM> of the end-effector <NUM> is connected to the lower shaft member <NUM> of the shaft assembly <NUM> using a suitable attachment (e.g., a fastener such as a pin, rivet, or screw). Referring to <FIG>, the end-effector <NUM> is shown with the blade housing <NUM> removed for ease of illustration. The clamp arm <NUM> is pivotably coupled to the lower shaft member <NUM> of the shaft assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 41a in the clamp arm <NUM> and a pin aperture 41b in the distal end of the lower shaft member <NUM> - see <FIG> and <FIG>). The clamp arm <NUM> is also pivotably coupled to the reciprocating upper shaft member <NUM> of the shaft assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 43a in the clamp arm <NUM> and a pin aperture 43b in the distal end of the reciprocating upper shaft member <NUM> - see <FIG> and <FIG>).

As described in more detail below, longitudinal translation of the reciprocating upper shaft member <NUM> causes pivoting actuation of the clamp arm <NUM> toward and away from the ultrasonic surgical blade <NUM> at the end-effector <NUM>. In the open position, as shown in <FIG> and <FIG>, wherein the clamp arm <NUM> is pivoted away from the ultrasonic surgical blade <NUM>, the end-effector <NUM> can be positioned in a surgical site so that tissue is located between a tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> and a tissue-engaging surface <NUM> of the clamp arm <NUM>. In the closed position, as shown in <FIG> and <FIG>, tissue is mechanically clamped between the respective tissue-engaging surfaces <NUM> and <NUM> of the ultrasonic surgical blade <NUM> and the clamp arm <NUM>, and ultrasonic activation of the blade <NUM> can cause cutting and/or coagulation of the clamped tissue.

Referring to <FIG> and <FIG>, the ultrasonic surgical blade <NUM> is acoustically coupled to an ultrasonic transmission waveguide <NUM>. The ultrasonic transmission waveguide <NUM> is in turn acoustically coupled to an acoustic horn <NUM>, which is in turn acoustically coupled to an ultrasonic transducer <NUM>. The ultrasonic transmission waveguide <NUM> comprises a linear portion <NUM> located within the shaft assembly <NUM> between the lower shaft member <NUM> and the reciprocating upper shaft member <NUM>. The ultrasonic transmission waveguide <NUM> further comprises a curved portion <NUM> acoustically coupled between the linear portion <NUM> and the acoustic horn <NUM>. Referring to <FIG> and <FIG>, the curved portion <NUM> of the ultrasonic transmission waveguide <NUM>, the acoustic horn <NUM>, and the ultrasonic transducer <NUM> are located within the handle body <NUM> of the handle assembly <NUM>. The ultrasonic transducer <NUM> is electrically coupled to a generator <NUM> (see <FIG> and <FIG>) via a cable <NUM>.

During operation, the ultrasonic transducer <NUM> receives electrical power from the generator <NUM> and converts the electrical power into ultrasonic vibrations using at least one, and typically a stack of, for example, four to eight ceramic piezoelectric elements with a motion null point located at some point along the stack such as at the proximal rear end of the stack, for example. The generator <NUM> may include a power source and control module that is configured to provide an electrical power profile to the ultrasonic transducer <NUM> that is configured for the generation of ultrasonic vibrations through the transducer <NUM>. By way of example only, the generator <NUM> may comprise a GEN <NUM> available from Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. The generator <NUM> may be constructed as described in <CIT>. It is understood that at least some of the functionality of the generator <NUM> may be integrated into the handle assembly <NUM>; for example, the handle assembly <NUM> may include a battery or other on-board power source such that cable <NUM> is omitted.

The functionality provided by the generator <NUM> may also be provided as described in <CIT> (Method for Improving the Start Up of an Ultrasonic System Under Zero Load Conditions); <CIT> (Method for Detecting a Loose Blade in a Handle Connected to an Ultrasonic Surgical System); <CIT> (Method for Driving an Ultrasonic System to Improve Acquisition of Blade Resonance Frequency at Startup); <CIT> (Method for Detecting Blade Breakage Using Rate and/or Impedance Information); <CIT> (Method for Detecting Presence of a Blade in an Ultrasonic System); <CIT> (Output Displacement Control Using Phase Margin in an Ultrasonic Surgical Handle); <CIT> (Method for Detecting Transverse Vibrations in an Ultrasonic Handle); <CIT> (Apparatus and Method for Altering Generator Functions in an Ultrasonic Surgical System); <CIT> (Detection Circuitry for Surgical Handpiece System); <CIT> (Method for Calculating Transducer Capacitance to Determine Transducer Temperature); <CIT> (Method for Driving an Ultrasonic System to Improve Acquisition of Blade Resonance Frequency at Startup); and <CIT> (Apparatus and Method for Alerting Generator Function in an Ultrasonic Surgical System).

Referring again to <FIG>, the handle assembly <NUM> further comprises a clamp actuation member <NUM> comprising a finger grip ring <NUM> integrally formed on the front proximal surface of the clamp actuation member <NUM> at the bottom end of the clamp actuation member <NUM>. Referring to <FIG> and <FIG>, the clamp actuation member <NUM> further comprises levering projections <NUM> extending from the top end of the clamp actuation member <NUM>. The clamp actuation member <NUM> is pivotably coupled to the handle body <NUM> of the handle assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 21a in the clamp actuation member <NUM> and a pin aperture 21b in the handle assembly <NUM>). The levering projections <NUM> of the clamp actuation member <NUM> are pivotably coupled to the reciprocating upper shaft member <NUM> of the shaft assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 31a in the levering projections <NUM> and a pin aperture 31b in the reciprocating upper shaft member <NUM>).

As described above, the handle assembly <NUM> comprises a scissor grip configuration. It is understood, however, that a handle assembly can be structured in other configurations including, but not necessarily limited to, a pistol grip configuration as described below in connection with <FIG>. In the illustrated scissor grip configuration, the pivoting of the clamp actuation member <NUM> toward and away from the handle body <NUM> (for example, by a surgeon's or other operator's hand with their thumb located through the finger grip ring <NUM> and their middle finger located through the finger grip ring <NUM> - see <FIG>) longitudinally translates the reciprocating upper shaft member <NUM> distally and proximally, respectively, which in turn pivots the clamp arm <NUM> toward and away from the ultrasonic surgical blade <NUM>, respectively, which closes and opens the clamping action of the end-effector <NUM>. The reciprocating upper shaft member <NUM> translates distally and proximally relative to the lower shaft member <NUM>, and over the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>, during closing and opening action of the ultrasonic surgical instrument <NUM>.

Referring again to <FIG> and <FIG>, the handle assembly <NUM> comprises a biasing member <NUM>. The biasing member <NUM> is illustrated in the form of a U-shaped spring clip, but it is understood that other biasing member configurations may be used. The biasing member <NUM> is located between the handle body <NUM> and the clamp actuation member <NUM>. Referring to <FIG>, <FIG>, <FIG>, and <FIG>, the biasing member <NUM> is seated within a recess <NUM> in the front proximal surface of the handle body <NUM> and a recess <NUM> in the rear distal surface of the clamp actuation member <NUM>. The biasing member <NUM> biases the clamp actuation member <NUM> away from the handle body <NUM>, which biases the reciprocating upper shaft member <NUM> proximally away from the end-effector <NUM>, which biases the clamp arm <NUM> away from the ultrasonic surgical blade <NUM>, thereby biasing the end-effector into an open position.

When a surgeon or other operator pivots the clamp actuation member <NUM> proximally about the joint <NUM>, against the biasing force provided by the biasing member <NUM>, and toward the handle body <NUM> (as indicated by arrow <NUM> in <FIG>), the levering projections <NUM> pivot distally and transmit the distal motion to the reciprocating upper shaft member <NUM> through the joint <NUM>. The distal motion of the reciprocating upper shaft member <NUM> transmits through the joint <NUM> to the clamp arm <NUM>. The distal motion transmitted through the joint <NUM> causes the clamp arm <NUM> to pivot about the joint <NUM> toward the ultrasonic surgical blade <NUM>, thereby closing the end-effector <NUM>.

To open the end-effector <NUM>, a surgeon or other operator releases the force provided by their hand against the biasing force provided by the biasing member <NUM>. The biasing member <NUM> then pivots the clamp actuation member <NUM> distally about the joint <NUM> away from the handle body <NUM> (as indicated by arrow <NUM> in <FIG>), and the levering projections <NUM> pivot proximally and transmit the proximal motion to the reciprocating upper shaft member <NUM> through the joint <NUM>. The proximal motion of the reciprocating upper shaft member <NUM> transmits through the joint <NUM> to the clamp arm <NUM>. The proximal motion transmitted through the joint <NUM> causes the clamp arm <NUM> to pivot about the joint <NUM> away from the ultrasonic surgical blade <NUM>, thereby opening the end-effector <NUM>.

The ultrasonic surgical instrument <NUM> comprises an acoustic system <NUM>. Referring to <FIG>, the acoustic system <NUM> comprises the ultrasonic transducer <NUM>, the acoustic horn <NUM>, the ultrasonic transmission waveguide <NUM>, and the ultrasonic surgical blade <NUM>. As described above, the ultrasonic surgical blade <NUM> is acoustically coupled to the acoustic horn <NUM> and the ultrasonic transducer <NUM> through the ultrasonic transmission waveguide <NUM>, which comprises a linear portion <NUM> located within the shaft assembly <NUM> and a curved portion <NUM> located within the handle assembly <NUM>.

The orientation of the ultrasonic transducer <NUM> within the handle assembly <NUM> defines a central (linear) transducer axis <NUM>, and the orientation of the linear portion <NUM> of the ultrasonic transmission waveguide <NUM> within the shaft assembly <NUM> defines a central (linear) waveguide/shaft axis <NUM>. The central transducer axis <NUM> and the central waveguide/shaft axis <NUM> intersect and form an angle θ that angularly off-sets the ultrasonic surgical blade <NUM> from the central transducer axis <NUM>. The angular off-set of the ultrasonic surgical blade <NUM> (and the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>) from the central transducer axis <NUM> is provided by the curved portion <NUM> of the ultrasonic transmission waveguide <NUM>, which acoustically couples the linear portion <NUM> to the horn <NUM>. The off-set angle θ may range, for example, from <NUM>-degrees to <NUM>-degrees, or any sub-range subsumed therein, such as, for example, from <NUM>-degrees to <NUM>-degrees. An off-set angle θ of approximately <NUM>-degrees may provide an optimal balance of human factors and ergonomics for a surgeon or other operator of the ultrasonic surgical instrument <NUM> and effectiveness and efficiency of acoustic transmission through the curved portion <NUM> of the ultrasonic transmission waveguide <NUM>.

The components of the acoustic system <NUM> may be configured to ultrasonically vibrate at the same resonant frequency. When the ultrasonic transducer <NUM> is energized, a standing wave is established in the ultrasonic transmission waveguide <NUM> defining nodes and antinodes, where the nodes represent regions of minimal or no displacement and the antinodes represent regions of maximum displacement. The nodes and antinodes occur periodically based on the driving frequency of approximately <NUM> kilohertz, for example, and the structure and materials of construction of the acoustic horn <NUM>, the ultrasonic transmission waveguide <NUM>, and the ultrasonic surgical blade <NUM>. The nodes and antinodes are located at one quarter wavelength apart.

The ultrasonic transducer <NUM>, the acoustic horn <NUM>, the ultrasonic transmission waveguide <NUM>, and the ultrasonic surgical blade <NUM> may be tuned such that the resulting length of each such element is one-half wavelength or a multiple thereof. The back and forth vibrating motion provided by the ultrasonic transducer <NUM> is amplified as the diameter of the acoustic horn <NUM> decreases closer to the ultrasonic transmission waveguide <NUM>. The acoustic horn <NUM> and the ultrasonic transmission waveguide <NUM> may be shaped and dimensioned to amplify the motion of the ultrasonic surgical blade <NUM> and provide ultrasonic vibration in resonance with the rest of the acoustic system <NUM>, which produces the maximum vibratory motion of the distal end of the acoustic horn <NUM> where it transitions to the ultrasonic transmission waveguide <NUM>. For example, vibratory motion from <NUM> to <NUM> microns peak-to-peak at the piezoelectric elements of the ultrasonic transducer <NUM> may be amplified by the horn <NUM> into movement in the ultrasonic surgical blade <NUM> of about <NUM> to <NUM> microns peak-to-peak.

The ultrasonic vibrations that are generated by the ultrasonic transducer <NUM> and amplified by the horn <NUM> are transmitted along the ultrasonic transmission waveguide <NUM>, through the handle assembly <NUM> and the shaft assembly <NUM>, and reach the ultrasonic surgical blade <NUM> in the end-effector <NUM>. The ultrasonic transmission waveguide <NUM> is secured within and acoustically isolated from the handle assembly <NUM> and the shaft assembly <NUM> using, for example, attachments and/or isolation spacers (not shown). The attachments and/or isolation spacers used to secure and isolate the ultrasonic transmission waveguide <NUM> within the handle assembly <NUM> and the shaft assembly <NUM> are located at position(s) along the length of the waveguide <NUM> corresponding to a node (no vibratory motion) associated with resonant ultrasonic vibrations transmitted through the ultrasonic transmission waveguide <NUM>.

As described above, when the ultrasonic surgical blade <NUM> is in an activated state (i.e., vibrating ultrasonically), the ultrasonic surgical blade <NUM> is operable to effectively cut through and seal tissue, particularly when the tissue is being clamped between the clamp arm <NUM> and the ultrasonic surgical blade <NUM>. It is understood that the waveguide <NUM>, like the horn <NUM>, may be configured to amplify ultrasonic mechanical vibrations transmitted through the waveguide <NUM>, and may include features operable to control the gain of the vibrations along the waveguide <NUM> and/or features to tune the waveguide <NUM> to the resonant frequency of the acoustic system <NUM>.

In one example, the distal end of the ultrasonic surgical blade <NUM> is located at a position corresponding to an anti-node associated with resonant ultrasonic vibrations communicated through the ultrasonic transmission waveguide <NUM>, in order to tune the acoustic system <NUM> to a preferred resonant frequency f<NUM> when the acoustic system <NUM> is not loaded by tissue. When the ultrasonic transducer <NUM> is energized, the distal end of the ultrasonic surgical blade <NUM> is configured to move longitudinally along the central waveguide/shaft axis <NUM> (see <FIG>) in the range of, for example, approximately <NUM> to <NUM> microns peak-to-peak, and in some instances in the range of about <NUM> to about <NUM> microns at a predetermined vibratory frequency f<NUM> of, for example, <NUM>. When the ultrasonic transducer <NUM> is activated, the piezoelectric-mechanical vibrations are transmitted through the acoustic horn <NUM> and the ultrasonic transmission waveguide <NUM> to reach the ultrasonic surgical blade <NUM>, thereby providing vibration of the ultrasonic surgical blade <NUM> at the resonant ultrasonic frequency.

In another example, the distal end of the ultrasonic surgical blade <NUM> is located at a position corresponding to a node associated with resonant ultrasonic vibrations communicated through the waveguide <NUM>. When the ultrasonic transducer <NUM> is energized, the distal end of the ultrasonic surgical blade <NUM> does not move longitudinally, but a region of the tissue-engaging surface <NUM> corresponds to an antinode, and that portion of the ultrasonic surgical blade <NUM> moves along the central waveguide/shaft axis <NUM> (see <FIG>) in the range of, for example, approximately <NUM> to <NUM> microns peak-to-peak, and in some instances in the range of about <NUM> to about <NUM> microns at a predetermined vibratory frequency f<NUM> of, for example, <NUM>. When the ultrasonic transducer <NUM> is activated, the piezoelectric-mechanical vibrations are transmitted through the acoustic horn <NUM> and the ultrasonic transmission waveguide <NUM> to reach the ultrasonic surgical blade <NUM>, thereby providing vibration of the ultrasonic surgical blade <NUM> at the resonant ultrasonic frequency.

Thus, when tissue is clamped between the ultrasonic surgical blade <NUM> and the clamp arm <NUM>, the ultrasonic vibration of the ultrasonic surgical blade <NUM> may simultaneously sever the tissue and denature the proteins in the adjacent cells and intercellular matrix of the tissue, thereby providing a coagulative effect with relatively little thermal spread. In some examples, an alternating electrical current (e.g., at radio frequencies (RF)), may also be provided through the ultrasonic surgical blade <NUM> and/or through electrode(s) (not shown) located on the tissue-engaging surfaces <NUM> of the clamp arm <NUM> to provide cauterization and additional tissue sealing functionality.

In various examples, a foot pedal or other switching device (not shown) operably connected to the generator <NUM> may be employed to control the application of electrical power from the generator <NUM> to the ultrasonic transducer <NUM>. When power is applied to the ultrasonic transducer <NUM> by operation of a foot pedal or other switch arrangement, the acoustic system <NUM> may, for example, cause the ultrasonic surgical blade <NUM> to vibrate longitudinally along the central waveguide/shaft axis <NUM> (see <FIG> and <FIG>) at approximately <NUM>, and the amount of longitudinal movement will vary proportionately with the amount of driving power (electrical current) applied, which may be adjustably selected by a surgeon or other operator of the ultrasonic surgical instrument <NUM>.

When relatively high power is applied, the ultrasonic surgical blade <NUM> may be configured to move longitudinally in the range of about <NUM> to <NUM> microns at the ultrasonic vibrational rate. Such ultrasonic vibration of the blade <NUM> will generate heat as the blade contacts tissue, i.e., the acceleration of the ultrasonic surgical blade <NUM> through the tissue converts the mechanical energy of the moving ultrasonic surgical blade <NUM> to thermal energy in the localized tissue-contact area. This localized heat creates a narrow zone of coagulation, which will reduce or eliminate bleeding in small blood vessels, such as blood vessels less than one millimeter in diameter. The cutting efficiency of the ultrasonic surgical blade <NUM>, as well as the degree of hemostasis, will vary with the level of driving power applied, the cutting rate or force applied by the surgeon to the blade <NUM> through the clamp arm <NUM>, and the properties of the tissue type and the vascularity of the tissue.

Referring to <FIG>, which are not in accordance with the present invention, a prototype ultrasonic surgical instrument is shown comprising the features shown in <FIG> and described above. The prototype ultrasonic surgical instrument is shown in <FIG> and <FIG> in an open position with the clamp arm pivoted away from the ultrasonic surgical blade, the reciprocating upper shaft member translated proximally, and the clamp actuation member pivoted away from the handle body (compare with <FIG>). The prototype ultrasonic surgical instrument is shown in <FIG> in a closed position with the clamp arm pivoted toward the ultrasonic surgical blade, the reciprocating upper shaft member translated distally, and the clamp actuation member pivoted toward the handle body (compare with <FIG>).

The ultrasonic surgical instrument <NUM> shown in <FIG> (and the prototype shown in <FIG>) may facilitate improved surgical technique and execution in procedures where the surgical area is too small for the effective use of conventional scissor clamp ultrasonic devices. The angled scissor grip configuration of the ultrasonic surgical instrument <NUM> (provided by the angular off-set of the ultrasonic surgical blade <NUM> from the central transducer axis <NUM> of the ultrasonic transducer <NUM>) moves the ultrasonic transducer <NUM> out of longitudinal alignment with the blade, which increases surgical site access, visibility, and manipulability because the shaft assembly <NUM> extends away from the operator's hand when grasping the handle assembly <NUM>. In this manner, a surgeon or other operator can readily see the end-effector <NUM> without any obscuring or impairment of their line-of-sight by the location of the ultrasonic transducer <NUM> or by the location of their hand when grasping the instrument <NUM>.

As shown in <FIG>, which is not in accordance with the present invention, the ultrasonic surgical blade <NUM> is aligned with the central waveguide/shaft axis <NUM>. In some examples, it would be advantageous for an ultrasonic surgical blade to off-set transversely from the central waveguide/shaft axis <NUM>. Referring to <FIG>, which is not in accordance with the present invention, an ultrasonic surgical blade <NUM> is shown transversely (linearly) off-set from the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>. The ultrasonic surgical blade <NUM> has a central blade axis <NUM> that is parallel to the central waveguide/shaft axis <NUM>. The tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> is parallel to the central blade axis <NUM>, the central waveguide/shaft axis <NUM>, and the lower surface (indicated by the line <NUM>) of the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>.

The ultrasonic surgical blade <NUM> is coupled to the linear portion <NUM> of the ultrasonic transmission waveguide <NUM> through a compound curvature component <NUM>. As used herein, the term "compound curvature component" means a transitional component of an acoustic system located between a distal ultrasonic surgical blade and a proximal ultrasonic transmission waveguide or other proximal component of an acoustic system (e.g., the distal end of an acoustic horn) comprising at least two bends along the length of the component. Still referring to <FIG>, the compound curvature component <NUM> comprises a distal curved portion <NUM> and a proximal curved portion <NUM>. The distal curved portion <NUM> of the compound curvature component <NUM> is coupled to the ultrasonic surgical blade <NUM>. The proximal curved portion <NUM> of the compound curvature component <NUM> is coupled to the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>. Although the curved portions <NUM> and <NUM> are shown as smooth curves or bends in the material forming the compound curvature component <NUM>, it is understood that any one or more of the at least two bends along the length of a compound curvature component can be shaped such that the compound curvature component comprises a J-shape. The shape of a compound curvature component can be generally defined using a spline function.

Still referring to <FIG>, and as described above, the compound curvature component <NUM> transversely (linearly) off-sets the ultrasonic surgical blade <NUM> from the linear portion <NUM> of the ultrasonic transmission waveguide <NUM>. The central blade axis <NUM> is transversely off-set from the central waveguide/shaft axis <NUM> by a linear distance Δ. As a result, the tissue-engaging surface <NUM> of the ultrasonic surgical blade is transversely off-set from the lower surface <NUM> of the linear portion <NUM> of the ultrasonic transmission waveguide <NUM> by a linear distance δ. The ultrasonic surgical blade <NUM> is therefore located off-axis relative to the ultrasonic transmission waveguide <NUM> (linearly off-axis relative to the linear portion <NUM>, and angularly off-axis relative to the curved portion <NUM> - see <FIG>). The compound curvature component <NUM> may be connected to the linear portion <NUM> at a location that is distal to the most distal node in the ultrasonic transmission waveguide <NUM>.

As illustrated in <FIG>, which is not in accordance with the present invention, the transversely (linearly) off-set ultrasonic surgical blade <NUM> and the compound curvature component <NUM> can be incorporated in place of the ultrasonic surgical blade <NUM> in the ultrasonic surgical instrument <NUM> shown in <FIG>. The end-effector <NUM>' comprises the ultrasonic surgical blade <NUM> and the clamp arm <NUM> (for ease of illustration, an optional blade housing that surrounds the non-tissue-engaging surfaces of the ultrasonic surgical blade <NUM>, but that exposes the tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> for the cutting and coagulation of tissue during operation, is omitted from <FIG>). As described above, the clamp arm <NUM> is pivotably coupled to the lower shaft member <NUM> of the shaft assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 41a in the clamp arm <NUM> and a pin aperture 41b in the distal end of the lower shaft member <NUM>). The clamp arm <NUM> is also pivotably coupled to the reciprocating upper shaft member <NUM> of the shaft assembly <NUM> through a pivotable joint <NUM> (e.g., a cylindrical pin located within a pin aperture 43a in the clamp arm <NUM> and a pin aperture 43b in the distal end of the reciprocating upper shaft member <NUM>). The clamp arm <NUM> actuates in the manner described above.

Still referring to <FIG>, the tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> is transversely off-set from the lower surface (indicated by line <NUM>) of the lower shaft member <NUM> of the shaft assembly <NUM> by a linear distance (d). The ultrasonic surgical blade <NUM> is transversely off-set away from the central waveguide/shaft axis <NUM> and the clamp arm <NUM>, while the tissue-engaging surface <NUM> remains parallel to the waveguide/shaft axis <NUM>. In this manner, the ultrasonic surgical blade <NUM> is effectively stepped-down away from the clamp arm <NUM>, which may improve surgical site visibility and ergonomics for a surgeon or other operator. The transverse off-set of the ultrasonic surgical blade <NUM> away from the waveguide/shaft axis <NUM> and the clamp arm <NUM> also allows for the optional use of a thicker clamp pad <NUM> (with tissue-engaging surface <NUM>') than can be accommodated in an ultrasonic surgical instrument with an ultrasonic surgical blade that is not transversely off-set away from the clamp arm <NUM> (see, e.g., <FIG>).

As described above, the examples of the ultrasonic surgical instrument <NUM> illustrated in <FIG> comprise a scissor grip configuration. Although scissor grip configurations often provide excellent manual control of end-effector operation and haptic feedback from manipulated tissue, the ultrasonic surgical instruments described in this specification can be implemented using alternative configurations such as, for example, a pistol grip configuration. For example, <FIG>, which is not in accordance with the present invention, illustrates an ultrasonic surgical instrument <NUM> comprising a handle assembly <NUM>, a shaft assembly <NUM>, and an end-effector <NUM>. As described, for example, in <CIT>, the shaft assembly <NUM> can comprise an outer sheath, an inner tube slidably disposed within the outer sheath, and a waveguide disposed within the inner tube. Longitudinal translation of the inner tube causes actuation of a clamp arm <NUM> at an end-effector <NUM>. Still referring to <FIG>, the handle assembly <NUM> comprises a body <NUM> including a pistol grip <NUM> and a pair of buttons <NUM>. The handle assembly <NUM> also includes a trigger <NUM> that is pivotable toward and away from the pistol grip <NUM>.

Still referring to <FIG>, an ultrasonic transducer assembly <NUM> extends proximally from the body <NUM> of the handle assembly <NUM>. It is understood, however, that the ultrasonic transducer assembly <NUM> can be located within the pistol grip <NUM>, for example, in a manner analogous to the location of the ultrasonic transducer <NUM> within the handle body <NUM> of the handle assembly <NUM> of the ultrasonic surgical instrument <NUM> described above in connection with <FIG>. In such examples, the ultrasonic transducer assembly <NUM> is structured and configured as part of an acoustic system analogous to the acoustic system <NUM> shown in <FIG>, wherein the central axis of an ultrasonic surgical blade <NUM> and the central axis of the shaft assembly <NUM> are both angularly off-set from the central transducer axis of the ultrasonic transducer assembly <NUM> located within the pistol grip <NUM>. The transducer assembly <NUM> is coupled to a generator <NUM> via a cable <NUM> and may operate and comprise the features and characteristics described above.

The end-effector <NUM> comprises an ultrasonic surgical blade <NUM> and a clamp arm <NUM>. The end-effector <NUM> may comprise features and characteristics described above in connection with end-effectors <NUM> and <NUM>' (see, e.g., <FIG> and <FIG>). An operator may activate buttons <NUM> to selectively activate the ultrasonic transducer assembly <NUM> to activate the ultrasonic surgical blade <NUM>. In the illustrated example, the ultrasonic surgical instrument <NUM> is activated by two buttons <NUM> - one for activating the ultrasonic surgical blade <NUM> at a lower power and another for activating the ultrasonic surgical blade <NUM> at a higher power. However, it is understood that any other operable number of buttons, alternative activation devices, and/or selectable power levels may be implemented. For instance, a foot pedal may be provided to selectively activate the ultrasonic transducer assembly <NUM>.

The buttons <NUM> are located such that an operator may readily fully operate the ultrasonic surgical instrument <NUM> with a single hand. For instance, the operator may position their thumb about the pistol grip <NUM>, position their middle, ring, and/or little finger(s) about the trigger <NUM>, and manipulate the buttons <NUM> using their index finger. In operation, pivoting the trigger <NUM> toward the pistol grip <NUM> causes the clamp arm <NUM> to pivot toward the ultrasonic surgical blade <NUM>, thereby closing the end-effector <NUM>. Conversely, pivoting the trigger <NUM> away from the pistol grip <NUM> causes the clamp arm <NUM> to pivot away from the ultrasonic surgical blade <NUM>, thereby opening the end-effector <NUM>.

The example ultrasonic surgical instruments described above (<NUM>/<NUM>) comprise either a scissor grip or a pistol grip configuration to actuate an end-effector (<NUM>/<NUM>'/<NUM>) comprising a clamp arm (<NUM>/<NUM>) and an ultrasonic surgical blade (<NUM>/<NUM>/<NUM>) that is off-set angularly and/or linearly to provide an off-axis configuration (relative to the central transducer axis and/or the central waveguide/shaft axis). However, off-set ultrasonic surgical blade may be advantageous in ultrasonic surgical instruments comprising end-effectors having unencumbered ultrasonic surgical blades without clamping functionality.

Referring to <FIG>, which is not in accordance with the present invention, an ultrasonic surgical instrument <NUM> comprises a handle assembly <NUM>, a shaft assembly <NUM>, and a surgical end-effector <NUM>. The handle assembly <NUM> comprises a first shroud 208a and a second shroud 208b, an activation button assembly <NUM>, and a nose cone <NUM>. The activation button assembly <NUM> comprises a plurality of activation buttons 210a-210d distributed about the handle assembly <NUM>. The shaft assembly <NUM> comprises an outer sheath <NUM>. The end-effector <NUM> comprises an ultrasonic surgical blade <NUM> connected to an ultrasonic transmission waveguide <NUM> through a compound curvature component <NUM>. The ultrasonic surgical blade <NUM> is transversely (linearly) off-set from the ultrasonic transmission waveguide <NUM> and the shaft assembly <NUM> (including the outer sheath <NUM>). The ultrasonic transmission waveguide <NUM> is isolated from the outer sheath <NUM> with multiple isolation spacers <NUM>, which can be overmolded over the ultrasonic transmission waveguide <NUM>.

The handle assembly <NUM> also comprises an ultrasonic transducer (not shown) located within the handle assembly <NUM> and acoustically coupled to the ultrasonic transmission waveguide <NUM>, which in turn is acoustically coupled to the ultrasonic surgical blade <NUM> through the compound curvature component <NUM>. The handle assembly <NUM> is electrically connected to an ultrasonic energy generator (not shown), which can be activated by one of the plurality of activation buttons 210a-210d, for example the activation button 210a. Depressing the activation button 210a activates the ultrasonic generator and delivers electrical energy to the ultrasonic transducer located in the handle assembly <NUM>. The ultrasonic transducer in the handle assembly <NUM> converts the electrical energy to ultrasonic vibratory motion, which is acoustically coupled to the ultrasonic transmission waveguide <NUM>, the compound curvature component <NUM>, and the ultrasonic surgical blade <NUM>. The ultrasonic surgical blade <NUM> vibrates, for example, at a frequency of approximately <NUM> kilohertz and a peak-to-peak displacement of <NUM> to <NUM> microns, as described above.

<FIG>, which is not in accordance with the present invention, shows the ultrasonic surgical instrument <NUM> shown in <FIG> with the outer sheath <NUM> removed to reveal the underlying ultrasonic transmission waveguide <NUM>. The isolation spacers <NUM> are located over the ultrasonic transmission waveguide <NUM> to acoustically isolate the outer sheath <NUM> from the ultrasonic transmission waveguide <NUM>. Accordingly, the plurality of isolation spacers <NUM> are located on respective nodes along the ultrasonic transmission waveguide <NUM> to minimize the vibrations acoustically coupled to the outer sheath <NUM>. In one example, the isolation spacers <NUM> may be overmolded over the ultrasonic transmission waveguide <NUM>.

Referring to <FIG>, which is not in accordance with the present invention, the ultrasonic surgical blade <NUM> is transversely (linearly) off-set from the ultrasonic transmission waveguide <NUM>. The ultrasonic surgical blade <NUM> is coupled to the ultrasonic transmission waveguide <NUM> through a compound curvature component <NUM>. The compound curvature component <NUM> comprises a distal curved portion <NUM> and a proximal curved portion <NUM>. The distal curved portion <NUM> of the compound curvature component <NUM> is coupled to the ultrasonic surgical blade <NUM>. The proximal curved portion <NUM> of the compound curvature component <NUM> is coupled to the ultrasonic transmission waveguide <NUM>. Although the curved portions <NUM> and <NUM> are shown as smooth curves or bends in the material forming the compound curvature component <NUM>, it is understood that any one or more of the at least two bends along the length of a compound curvature component can be shaped such that the compound curvature component comprises a J-shape. The shape of a compound curvature component can be generally defined using a spline function. The compound curvature component <NUM> may be coupled to the ultrasonic transmission waveguide <NUM> at a location that is distal to the most distal node in the ultrasonic transmission waveguide <NUM>.

Still referring to <FIG>, the compound curvature component <NUM> transversely off-sets the ultrasonic surgical blade <NUM> from the ultrasonic transmission waveguide <NUM>. The ultrasonic surgical blade <NUM> defines a central blade axis <NUM> that is parallel to the central waveguide/shaft axis <NUM>. The tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> is parallel to the central blade axis <NUM>, the central waveguide/shaft axis <NUM>, and the outer surface (indicated by the line <NUM>) of the outer sheath <NUM>. The central blade axis <NUM> is transversely off-set from the central waveguide/shaft axis <NUM> by a linear distance Δ. As a result, the tissue-engaging surface <NUM> is transversely off-set from the outer surface <NUM> of the ultrasonic transmission waveguide <NUM> by a linear distance δ. The ultrasonic surgical blade <NUM> is therefore located off-axis relative to the ultrasonic transmission waveguide <NUM> and the outer sheath <NUM>.

The ultrasonic surgical blade <NUM> comprises a tissue-engaging surface <NUM> facing inwardly toward the central waveguide/shaft axis <NUM>. Alternatively, or additionally, the ultrasonic surgical blade <NUM> may optionally comprise a tissue-engaging surface <NUM>' facing outwardly away from the central waveguide/shaft axis <NUM>. Because the ultrasonic surgical instrument <NUM> comprises an unencumbered ultrasonic surgical blade <NUM>, and the end-effector <NUM> does not comprise clamping functionality, the presence of two or more tissue-engaging surfaces <NUM> and <NUM>' on the ultrasonic surgical blade <NUM> may increase the functionality of the ultrasonic surgical instrument <NUM> during surgical operations.

The transverse off-set of the ultrasonic surgical blade <NUM> from the ultrasonic transmission waveguide <NUM> through the compound curvature component <NUM> increases the effective transverse size of the end-effector <NUM>. Referring to <FIG>, the effective transverse size (y) of the end-effector <NUM> may be larger than the inside diameter (di) of the outer sheath <NUM>. The relative size difference between the inside diameter (di) of the outer sheath <NUM> and the effective transverse size (y) of the end-effector <NUM> may create mechanical interference that prevents the positioning of the ultrasonic transmission waveguide <NUM> within the lumen <NUM> of the outer sheath <NUM> because the inside diameter (di) is too small to accommodate the effective transverse size (y). As a result, the assembly and manufacture of ultrasonic surgical instruments, such as instruments <NUM> and <NUM> that comprise a transversely off-set ultrasonic surgical blade connected to an ultrasonic transmission waveguide located within an outer sheath, may be problematic, particularly where the ultrasonic transmission waveguide, the distally-coupled compound curvature component, and proximally-coupled components (e.g., an acoustic horn having an effective transverse size greater than di) are formed from a single piece of material (e.g., machined from metal or alloy rod or bar stock).

Additionally, in surgical applications where the surgical sites are relatively small and/or awkwardly located (e.g., transcranial, ear-nose-throat, or neck surgeries), it is advantageous to minimize the cross-sectional size of the ultrasonic transmission waveguide and the outer sheath, which further increases the size difference between the inner diameter of the outer sheath and the effective transverse size of an end-effector. Examples of slotted sheath assemblies are described below which address the assembly and manufacturing issues created by size differences between the inner diameter of an outer sheath and the effective transverse size of an end-effector comprising a transversely off-set ultrasonic surgical blade. Slotted sheath assemblies, examples of which are illustrated in <FIG>, may be used with end-effectors comprising a transversely off-set ultrasonic surgical blade, such as end-effector <NUM>, in ultrasonic surgical instruments having unencumbered ultrasonic surgical blades without clamping functionality, or in ultrasonic surgical instruments with clamping functionality and comprising, for example, either a scissor grip or a pistol grip configuration, such as the ultrasonic surgical instruments described above (<NUM>/<NUM>/<NUM>).

Referring to <FIG>, which are not in accordance with the present invention, an acoustic system comprises an ultrasonic transducer <NUM>, an ultrasonic transmission waveguide <NUM> acoustically coupled to the ultrasonic transducer <NUM>, and an ultrasonic surgical blade <NUM> acoustically coupled to and transversely off-set from the ultrasonic transmission waveguide <NUM> through a compound curvature component <NUM>. The proximally-coupled ultrasonic transducer <NUM> and the distally-coupled compound curvature component <NUM> prevent the ultrasonic transmission waveguide <NUM> and overmolded isolation spacers 218a from being inserted into a circumferentially closed sheath, as described above (see <FIG>).

Still referring to <FIG>, a sheath 214a comprises an open slot <NUM> extending longitudinally along the proximal-distal length of the sheath 214a. The slot <NUM> comprises longitudinal edges <NUM> and <NUM>. The sheath 214a may be made of compliant material having elastic properties (e.g., a thermoplastic material such as polytetrafluoroethylene (TEFLON) or a metallic material such as aluminum or stainless steel, for example) that permit the width of the slot <NUM> to be increased so that the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a can be inserted into the lumen 217a of the sheath 214a, as indicated by the arrow <NUM>, without the need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217a of the sheath 214a. A sealing member 215a is then inserted into the slot <NUM> of the sheath 214a to bridge the slot <NUM>, circumferentially close the sheath 214a, and seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217a of the sheath 214a.

The sealing member 215a comprises closed slots <NUM> and <NUM> in the longitudinal edges of the sealing member 215a and extending along the proximal-distal length of the sealing member 215a. When the sealing member 215a is inserted into the slot open <NUM> of the sheath 214a, the longitudinal edges <NUM> and <NUM> of the open slot <NUM> are secured within the closed slots <NUM> and <NUM> in the longitudinal edges of the sealing member 215a, as shown in <FIG>. The mutual engagement of the edges <NUM> and <NUM> and the slots <NUM> and <NUM> secure the sealing member 215a in place within the slot <NUM>, thereby bridging the slot <NUM>, circumferentially closing the sheath 214a, and sealing the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217a of the sheath 214a. In some examples, the sealing member 215a may be made of an elastomer material (e.g., a silicone rubber material). In some examples, both the sealing member 215a and the isolation spacers 218a may be made of an elastomer material (e.g., a silicone rubber material).

Referring to <FIG>, which are not in accordance with the present invention, an alternative example is shown in which the isolation spacers 218b and the sealing member 215b are overmolded on the ultrasonic transmission waveguide <NUM> as a single, integral component. The ultrasonic transmission waveguide <NUM>, the isolation spacers 218b, and the sealing member 215b are simultaneously inserted into the sheath 214a as a single assembly, as indicated by the arrow <NUM>, without a need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217a of the sheath 214a. When the sealing member 215b is inserted into the slot <NUM> of the sheath 214a, the longitudinal edges <NUM> and <NUM> of the slot <NUM> are secured within the slots <NUM> and <NUM> in the longitudinal edges of the sealing member 215b, as shown in <FIG>. The mutual engagement of the edges <NUM> and <NUM> and the slots <NUM> and <NUM> secure the sealing member 215b in place within the slot <NUM>, thereby bridging the slot <NUM>, circumferentially closing the sheath 214a, and sealing the ultrasonic transmission waveguide <NUM> and the isolation spacers 218b within the lumen 217a of the sheath 214a.

Referring to <FIG>, which are not in accordance with the present invention, an alternative example is shown in which a shrinkable tube <NUM> is provided instead of a sealing member 215a/215b. The ultrasonic transmission waveguide <NUM> and the isolation spacers 218a are inserted through the slot <NUM> and into the lumen 217a of the sheath 214a, as indicated by the arrow <NUM>, without a need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217a of the sheath 214a. The shrinkable tube <NUM> is then positioned over the outer circumference of the sheath 214a and shrunk to circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217a of the sheath 214a. Although not shown in <FIG>, it is understood that the shrinking of the tube <NUM> may impart sufficient to circumferential force to the sheath 214a to circumferentially deform the sheath 214a and bring the longitudinal edges <NUM> and <NUM> of the slot <NUM> into contact with each other, thereby eliminating the slot <NUM> and circumferentially closing the sheath 214a. The shrinkable tube <NUM> may be made of a heat-shrinkable material such as a crosslinked polyolefin (e.g., heat-shrinkable polyethylene, polypropylene, or poly(ethylene-propylene) copolymers).

Referring to <FIG>, which is not in accordance with the present invention, an alternative example of a slotted sheath (214b) is shown, which may be used in place of the slotted sheath 214a in the examples illustrated in <FIG>. The sheath 214b comprises an open slot <NUM>' extending longitudinally along a portion of the proximal-distal length of the sheath 214a. The sheath 214b comprises a fully-closed circumferential portion <NUM> at the distal end of the sheath 214b. Therefore, the slot <NUM>' and the longitudinal edges <NUM>' and <NUM>' of the slot <NUM>' only extend along a proximal portion of the total length of the sheath 214b. The fully-closed circumferential portion <NUM> may provided increased hoop strength to the sheath 214b.

Referring to <FIG>, which are not in accordance with the present invention, the ultrasonic surgical blade <NUM>, the compound curvature component <NUM>, the ultrasonic transmission waveguide <NUM>, and the isolation spacers 218a can be inserted through the slot <NUM>' into the lumen 217b of the sheath 214b, as indicated by the arrow <NUM>'. The ultrasonic surgical blade <NUM> and the compound curvature component <NUM> are inserted through the fully-closed circumferential portion <NUM>. A sealing member 215a/215b (not shown, but see <FIG>) is then inserted into the slot <NUM>' of the sheath 214b to bridge the slot <NUM>', circumferentially close the sheath 214b, and seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217b of the sheath 214b. Alternatively, shrinkable tube <NUM> (not shown) is then positioned over the outer circumference of the sheath 214b and shrunk to circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217b of the sheath 214b.

Referring to <FIG>, which are not in accordance with the present invention, a sheath 214c comprises an open slot <NUM> extending longitudinally along the proximal-distal length of the sheath 214c. The slot <NUM> comprises crimped edges <NUM> and <NUM> along the length of the slot <NUM>. The ultrasonic transmission waveguide <NUM> and the isolation spacers 218a are inserted into the lumen 217C of the sheath 214C, as indicated by the arrow <NUM>, without a need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217c of the sheath 214c. The circumference of the sheath 214c is then compressed until the crimped edges <NUM> and <NUM> meet and interlock to form a crimpled edge seam <NUM>, as shown in <FIG>, which closes the slot <NUM>. A shrinkable tube <NUM> is then positioned over the outer circumference of the sheath 214c and shrunk to circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217c of the sheath 214c.

Referring to <FIG>, which are not in accordance with the present invention, the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a are inserted through the slot <NUM> and into the lumen 217a of the sheath 214a, as indicated by the arrows <NUM>, without a need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217a of the sheath 214a. The circumference of the sheath 214a is then compressed until the edges <NUM> and <NUM> of the slot <NUM> meet and form a seam <NUM>, thereby closing the slot <NUM>. The slot <NUM> may be permanently closed, for example, by laser welding the seam <NUM>, ultrasonic welding the seam <NUM>, applying adhesive to the seam <NUM>, or otherwise bonding together the edges <NUM> and <NUM> of the slot <NUM> to form a bonded seam <NUM>, which seals the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217a of the sheath 214a. Alternatively, or additionally, a shrinkable tube (not shown) is positioned over the outer circumference of the sheath 214a and shrunk to circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217a of the sheath 214a.

Referring to <FIG>, which are not in accordance with the present invention, a sheath 214d comprises an open slot <NUM> extending longitudinally along the entire proximal-distal length of the sheath 214d. The sheath 214d also comprises reduced outside diameter portions <NUM> located on the proximal and distal ends of the sheath 214d. The ultrasonic transmission waveguide <NUM> and the isolation spacers 218a are inserted through the slot <NUM> and into the lumen 217d of the sheath 214d, as indicated by the arrow <NUM>, without a need to insert either the ultrasonic transducer <NUM> or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217d of the sheath 214d. The circumference of the sheath 214d is then compressed until the longitudinal edges of the slot <NUM> meet and form a seam <NUM>, thereby closing the slot <NUM>. End caps <NUM> are then press fit onto the proximal and distal ends of the sheath 214d, as indicated by arrows <NUM>, wherein the reduced outside diameter portions <NUM> of the sheath 214d are inserted into the lumens <NUM> of the end caps <NUM>.

The press fitting of the end caps <NUM> over the reduced outside diameter portions <NUM> of the sheath 214d close the slot <NUM>, which seals the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217d of the sheath 214d. Optionally, the seam <NUM> may be laser welded, ultrasonic welded, bonded with an adhesive, or otherwise bonded. Alternatively, or additionally, a shrinkable tube (not shown) is positioned over the outer circumference of the sheath 214d and shrunk to further circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217d of the sheath 214d.

Referring to <FIG>, which are not in accordance with the present invention, a sheath 214d comprises an open slot <NUM> extending longitudinally along the entire proximal-distal length of the sheath 214d. The sheath 214d also comprises reduced outside diameter portions <NUM> located on the proximal and distal ends of the sheath 214d. The ultrasonic transmission waveguide <NUM> and the isolation spacers 218a are inserted through the slot <NUM> and into the lumen 217d of the sheath 214d, as indicated by the arrow <NUM>, without a need to insert either an ultrasonic transducer or the compound curvature component <NUM> and the ultrasonic surgical blade <NUM> through the lumen 217d of the sheath 214d. The circumference of the sheath 214d is then compressed until the longitudinal edges of the slot <NUM> meet and form a seam <NUM>, thereby closing the slot <NUM>. A distal end cap <NUM> and a proximal end cap <NUM> are then press fit onto the distal and proximal ends, respectively, of the sheath 214d, as indicated by arrows <NUM>, wherein the reduced outside diameter portions <NUM> of the sheath 214d are inserted into the lumens <NUM> of the end caps <NUM> and <NUM>.

The press fitting of the end caps <NUM> and <NUM> over the reduced outside diameter portions <NUM> of the sheath 214d close the slot <NUM>, which seals the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217d of the sheath 214d. Optionally, the seam <NUM> may be laser welded, ultrasonic welded, bonded with an adhesive, or otherwise bonded. Alternatively, or additionally, a shrinkable tube (not shown) is positioned over the outer circumference of the sheath 214d and shrunk to further circumferentially seal the ultrasonic transmission waveguide <NUM> and the isolation spacers 218a within the lumen 217d of the sheath 214d.

The proximal end cap <NUM> may comprise external threads (not shown) located on the outer circumference surface of the end cap <NUM>. A second sheath <NUM> has an inside diameter that is larger than the outside diameter of the sheath 214d and the proximal end cap <NUM>. The second sheath <NUM> may comprise internal threads (not shown) located on the inner circumferential surface of the second sheath. The external threads on the proximal end cap <NUM> and the internal threads on the second sheath <NUM> mutually engage to attach the second sheath <NUM> to the sheath 214d. This allows multiple sheath segments to be joined together using an end cap as a coupler, where the diameter of the most distal sheath segment can be minimized relative to the more proximal sheath segment(s). In examples comprising a shrinkable tube (not shown), the shrunk tube may extend over both of the sheath segments 214d and <NUM>, including the threaded joint between the second sheath <NUM> and the proximal end cap <NUM>.

In connection with the examples described above, certain components of the acoustic systems (ultrasonic surgical blades, compound curvature components, ultrasonic transmission waveguides (including separate linear and curved regions), acoustic horns, and the like) are illustrated in the drawings as a single, contiguous piece of material (see, e.g., <FIG>, <FIG>, <FIG>, and <FIG>, and <FIG>). In such examples, the acoustic couplings between each component (or portions thereof) is provided by the contiguous material of the integrally formed components (and portions thereof). It is understood, however, that each component (or portion thereof) may be produced separately and acoustically coupled together in an operable manner, for example, using operable fastening mechanisms (e.g., threaded couplings) or metallurgical bonding techniques (e.g., welding).

Ultrasonic surgical blades and the associated acoustic components (e.g., ultrasonic transmission waveguides, acoustic horns, and the like) may be produced by forming and/or machining round bar or rod stock of a suitable metallic material such as titanium or titanium alloy, for example, to form an at least partially integral acoustic system. In some examples, it may be advantageous to produce ultrasonic surgical blades and integral acoustic components from a single piece of sheet metal stock that can be cut and formed instead of machined like bar or rod stock, and thus decrease manufacturing costs.

Referring to <FIG>, an ultrasonic surgical instrument <NUM> is shown having a scissor grip configuration. The ultrasonic surgical instrument <NUM> comprises a transducer/waveguide housing <NUM> and a clamp actuation member <NUM>. The transducer/waveguide housing <NUM> and the clamp actuation member <NUM> are pivotably connected through a pivotable joint <NUM>. The ultrasonic surgical instrument <NUM> comprises finger grip rings <NUM> and <NUM> integrally formed on the transducer/waveguide housing <NUM> and the clamp actuation member <NUM>, respectively, at the proximal end <NUM> of the ultrasonic surgical instrument <NUM>. The transducer/waveguide housing <NUM> comprises a transducer portion <NUM> within which an ultrasonic transducer <NUM> is housed (see <FIG>). The ultrasonic transducer <NUM> is coupled to a generator <NUM> via a cable <NUM> and may operate and comprise the features and characteristics described above.

Referring to <FIG> and <FIG>, the transducer/waveguide housing <NUM> and the clamp actuation member <NUM> extend proximally from the pivotable joint <NUM>. The ultrasonic surgical instrument <NUM> comprises an end-effector <NUM> extending distally from the pivotable joint <NUM> at the distal end <NUM> of the ultrasonic surgical instrument <NUM>. The end-effector <NUM> comprises an ultrasonic surgical blade <NUM> and a clamp arm <NUM>. The clamp arm <NUM> is integrally formed with the clamp actuation member <NUM> and extends distally from the pivotable joint <NUM>. The clamp arm <NUM> comprises an optional clamp pad <NUM> which provides a tissue-engaging surface on the clamp arm <NUM>.

Referring again to <FIG> and <FIG>, the ultrasonic surgical blade <NUM> according to the present invention comprises a body portion <NUM>, a bent portion <NUM>, and a folded portion <NUM>. A gap <NUM> is located between the body portion <NUM> and the folded portion <NUM>. In some examples, the gap <NUM> may contain an isolation spacer or other filler material (e.g., an elastomeric material such as silicone rubber) that maintains separation of the body portion <NUM> and the folded portion <NUM> and prevents contact during ultrasonic vibratory activation of the ultrasonic surgical blade <NUM>. The ultrasonic surgical blade <NUM> comprises a tissue-engaging surface <NUM> which is located on the bent portion <NUM>.

Referring to <FIG>, <FIG>, <FIG>, the ultrasonic surgical instrument <NUM> comprises an acoustic system <NUM> comprising the ultrasonic surgical blade <NUM>, an ultrasonic transmission waveguide <NUM>, and a transduction shaft <NUM>. As shown in <FIG>, the acoustic system <NUM> is formed from a single, contiguous piece of material (e.g., a single piece of sheet metal stock that is cut and formed to produce the ultrasonic surgical blade <NUM>, the ultrasonic transmission waveguide <NUM>, and the transduction shaft <NUM>). Thus, the ultrasonic surgical blade <NUM>, the ultrasonic transmission waveguide <NUM>, and the transduction shaft <NUM> are integrally formed from the single, contiguous piece of material (e.g., a single piece of sheet metal stock).

Referring to <FIG> and <FIG>, and as described above, the ultrasonic surgical blade <NUM> comprises a body portion <NUM>, a bent portion <NUM>, a folded portion <NUM>, a gap <NUM> located between the body portion <NUM> and the folded portion <NUM> (optionally containing an isolation spacer or other filler material that maintains separation of the body portion <NUM> and the folded portion <NUM> and prevents contact during ultrasonic vibratory activation of the ultrasonic surgical blade <NUM>), and a tissue-engaging surface <NUM> located on the bent portion <NUM>. As shown in <FIG>, the ultrasonic surgical blade <NUM> comprises a U-shaped cross-section transverse to a central transducer/waveguide axis <NUM> (see <FIG>) in accordance with the present invention.

Referring to <FIG>, and <FIG>, the ultrasonic transmission waveguide <NUM> comprises a top portion <NUM> and a bottom portion <NUM>. The top portion <NUM> and the bottom portion <NUM> are separated by an inward bend <NUM> and an outward bend <NUM>, which coincide with the central transducer/waveguide axis <NUM>. The inward bend <NUM> forms an inwardly bent side <NUM> of the ultrasonic transmission waveguide <NUM>. The outward bend <NUM> forms an outwardly bent side <NUM> of the ultrasonic transmission waveguide <NUM>. As shown in <FIG>, the ultrasonic transmission waveguide <NUM> comprises a V-shaped cross-section transverse to the central transducer/waveguide axis <NUM>.

Referring to <FIG>, the transduction shaft <NUM> is acoustically coupled to the ultrasonic transmission waveguide <NUM> through a T-shaped region formed where the top portion <NUM> and the bottom portion <NUM> begin to transversely extend from the central (longitudinal) transducer/waveguide axis <NUM> (and also from the inward and outward bends <NUM> and <NUM>). As show in <FIG>, the T-shaped transition region is formed by the intersection of the transduction shaft <NUM> with the top and bottom proximal edges <NUM> and <NUM> of the top and bottom portions <NUM> and <NUM> of the ultrasonic transmission waveguide <NUM>. The transduction shaft <NUM> also comprises a proximal bore <NUM> through the thickness of the transduction shaft <NUM>.

Referring again to <FIG>, the transduction shaft <NUM> and the ultrasonic transmission waveguide <NUM> of the acoustic system <NUM> are located within the transducer/waveguide housing <NUM>, and the ultrasonic surgical blade extends outside the transducer/waveguide housing <NUM>, distally from the pivotable joint <NUM>. Referring again to <FIG> and <FIG>, the transduction shaft <NUM> of the acoustic system <NUM> is located through an aperture that extends the length of the ultrasonic transducer <NUM>. The ultrasonic transducer <NUM> is clamped between the top and bottom proximal edges <NUM> and <NUM> of the ultrasonic transmission waveguide <NUM> and a cam lock <NUM> extending through the proximal bore <NUM> in the transduction shaft <NUM>.

Referring to <FIG> and <FIG>, the top and bottom proximal edges <NUM> and <NUM> of the ultrasonic transmission waveguide <NUM> engage the distal end surface <NUM> of the ultrasonic transducer <NUM>. The cam lock <NUM> engages the proximal end surface <NUM> of the ultrasonic transducer <NUM>. The rotation of the cam lock <NUM> (for example, using a hex wrench in the hex-shaped blind bore <NUM>) forces the transduction shaft <NUM> proximally, as indicated by arrow <NUM>, which tensions the transduction shaft <NUM> and secures the top and bottom proximal edges <NUM> and <NUM> of the ultrasonic transmission waveguide <NUM> against the distal end surface <NUM> of the ultrasonic transducer <NUM>, thereby acoustically coupling the ultrasonic transmission waveguide <NUM> to the ultrasonic transducer <NUM>.

As shown in <FIG>, the width of the ultrasonic transmission waveguide <NUM> perpendicular to the central transducer/waveguide axis <NUM> decreases from a maximum at the top and bottom proximal edges <NUM> and <NUM> to a minimum at the distal transition region with the ultrasonic surgical blade <NUM>. The ultrasonic transmission waveguide <NUM> thus has a tapered width that decreases from a maximum at the acoustic coupling with the ultrasonic transducer <NUM> to a minimum at the transition to the ultrasonic surgical blade <NUM> (see <FIG> and <FIG>). This longitudinal taper allows the ultrasonic transmission waveguide <NUM> to also function as an acoustic horn that focuses and amplifies the ultrasonic vibrations produced by the ultrasonic transducer <NUM> to the ultrasonic surgical blade <NUM>. Referring to <FIG>, the tissue-engaging surface <NUM> of the ultrasonic surgical blade <NUM> is transversely off-set from the central transducer/waveguide axis <NUM> by a linear distance Δ.

In various examples, a foot pedal or other switching device (not shown) operably connected to the generator <NUM> may be employed to control the application of electrical power from the generator <NUM> to the ultrasonic transducer <NUM>. When power is applied to the ultrasonic transducer <NUM> by operation of a foot pedal or other switch arrangement, the acoustic system <NUM> may, for example, cause the ultrasonic surgical blade <NUM> to vibrate longitudinally along the central waveguide/shaft axis <NUM> (see <FIG>) at approximately <NUM>, and the amount of longitudinal movement will vary proportionately with the amount of driving power (electrical current) applied, which may be adjustably selected by a surgeon or other operator of the ultrasonic surgical instrument <NUM>.

The ultrasonic transducer <NUM> transmits ultrasonic vibrations to the acoustically coupled ultrasonic transmission waveguide <NUM> through the T-shaped region where the top and bottom proximal edges <NUM> and <NUM> of the top and bottom portions <NUM> and <NUM> of the ultrasonic transmission waveguide <NUM> are secured against the distal end surface <NUM> of the ultrasonic transducer <NUM>. The ultrasonic vibrations are then transmitted and focused through the ultrasonic transmission waveguide <NUM> to the ultrasonic surgical blade <NUM>. A surgeon or other operator can pivot the ultrasonic surgical blade <NUM> and the clamp arm <NUM> toward and away from each other by pivoting the transducer/waveguide housing <NUM> and the clamp actuation member <NUM> toward and away from each other using the finger grip rings <NUM> and <NUM>.

The instruments, devices, assemblies, and systems described in this specification can be configured for disposal after a single use, or they can be configured for reuse one or more times. In either case, however, the instruments, devices, assemblies, and systems can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the instruments, devices, assemblies, and systems, followed by cleaning or replacement of particular pieces, and subsequent reassembly. For example, an instrument or device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the instrument or device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of an instrument or device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the invention(s) described in this specification.

By way of example only, the instruments described in this specification may be processed before use in a surgical procedure. First, a new or used instrument may be obtained and when necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill or otherwise inactivate bacteria, viruses, or other microorganisms or pathogenic material on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device also may be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide treatment, plasma peroxide treatment, or steam treatment.

The ultrasonic surgical instruments described in this specification may be used for performing laparoscopic and minimally invasive surgical procedures. However, the reader will appreciate that the instruments can be used in numerous surgical procedures and applications including, for example, in connection with open or otherwise invasive surgical procedures. The reader will further appreciate that the instruments may be inserted into a patient's body in any way, such as through a natural orifice (e.g., ear, nose, mouth, or rectum), through an incision or puncture hole formed in tissue, and the like. The end-effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device (e.g., a trocar) that has a working channel through which the end-effector and an elongated shaft of a surgical instrument can be advanced. Additionally, it is understood that the ultrasonic surgical instruments described in this specification may be implemented in medical surgical procedures on humans or in veterinary surgical procedures on animals.

The extent of the protection conferred shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims. Various features and characteristics of the invention(s) are described in this specification and illustrated in the drawings to provide an understanding of the structure, function, operation, and/or manufacture of the disclosed instruments, devices, assemblies, systems, and methods. It is understood that the various features and characteristics of the inventions(s) described in this specification and illustrated in the drawings can be combined in any suitable manner, regardless of whether such features and characteristics are expressly described or illustrated in combination in this specification.

The invention(s) described in this specification can comprise, consist of, or consist essentially of the various features and characteristics described in this specification. The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. Thus, an instrument, device, assembly, system, or method, and the like, that "comprises," "has," "includes," or "contains" one or more features and/or characteristics possesses those one or more features and/or characteristics, but is not limited to possessing only those one or more features and/or characteristics. Likewise, an element of an instrument, device, assembly, system, or method, and the like, that "comprises," "has," "includes," or "contains" one or more features and/or characteristics possesses those one or more features and/or characteristics, but is not limited to possessing only those one or more features and/or characteristics, and may possess additional features and/or characteristics.

Claim 1:
An ultrasonic surgical instrument (<NUM>) comprising:
an ultrasonic transducer (<NUM>);
an ultrasonic transmission waveguide (<NUM>) acoustically coupled to the ultrasonic transducer (<NUM>); and
an ultrasonic surgical blade (<NUM>) integrally formed with the ultrasonic transmission waveguide (<NUM>), wherein the ultrasonic transmission waveguide (<NUM>) has a tapered width that decreases from a maximum at the acoustic coupling with the ultrasonic transducer (<NUM>) to a minimum at a transition to the ultrasonic surgical blade (<NUM>), wherein the ultrasonic surgical blade (<NUM>) comprises:
a body portion (<NUM>) acoustically coupled to the ultrasonic transmission waveguide (<NUM>);
a bent portion (<NUM>) forming a tissue-engaging surface; and
a folded portion (<NUM>) forming a gap (<NUM>) between the body portion (<NUM>) and the folded portion (<NUM>), wherein the ultrasonic surgical blade (<NUM>) comprises a U-shaped cross-section transverse to a central waveguide axis (<NUM>).