Patent ID: 12185965

DETAILED DESCRIPTION

The present disclosure is not limited to the particular embodiments described herein. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting beyond the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs.

Although embodiments of the present disclosure are described with reference to ultrasonic endoscopic medical devices, e.g., which include distally actuated end effectors configured to cut/resect mucosal tissue of the gastrointestinal (GI) tract using ultrasonic transverse rotation, it should be appreciated that such ultrasonic endoscopic medical devices may include a variety of end effectors (e.g., scissors, graspers, biopsy needles, etc.) configured to manipulate mucosal and non-mucosal tissues in a variety of body lumens, body passageways, organs and the like.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used herein, specify the presence of stated features, regions, steps elements and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and/or groups thereof.

As used herein, the term “distal” refers to the end farthest away from the medical professional or physician when introducing a device into a patient, while the term “proximal” refers to the end closest to the medical professional or physician when introducing a device into a patient.

An obstacle to the development of endoscopic medical devices with ultrasonic end effectors is the generation and translation of motion along the length of the endoscopic medical device, which typically includes a flexible elongate member, to a distal end effector. Translating the motion along the length of the endoscopic medical device without generating excessive heat adds further complexity to the obstacle. Laparoscopic medical devices used for open surgical procedures (e.g., non-endoscopic devices) are sufficiently large to include a transducer in a handle that is rigidly connected to a distal amplification horn and/or the distal end effector to support the translation of linear actuation to impart ultrasonic motion in the distal end effector. However, in current endoscopic medical devices, the translation of linear motion to a distal amplification horn is challenging due to flexibility and sizes of the current endoscopic medical devices. In various embodiments, the present disclosure relates generally to flexible endoscopic medical devices which may use distally actuated axial displacement to impart in-plane ultrasonic reciprocation (e.g., ultrasonic transverse rotation, etc.) to an end effector without the need for a distal amplification horn. As described herein, the low temperature frictional heat induced by such ultrasonic transverse rotation may allow the end effector to cut and coagulate tissue with high precision (e.g., along the desired tissue margins) without damaging/destroying tissue architecture (e.g., of the target tissue and/or the surrounding tissues). In various embodiments, an end effector of the present disclosure may include a variety of cutting surfaces and/or profiles, including, by way of non-limiting example, a sharpened edge, a serrated edge, a semi-sharpened edge, a dulled edge, a curved edge, a scalloped edge and combinations thereof.

Referring toFIGS.1A-1F, in one embodiment, an ultrasonic medical device100of the present disclosure may include a collar112attached to a distal end of a flexible elongate sheath110(e.g., catheter, etc.). An end effector114(e.g., blade, etc.) may be pivotally attached to the collar112such that a cutting edge114bof the end effector114may extend beyond a distal end of the collar112. A transducer116(e.g., one or more piezoelectric stacks/disks) may be housed within a distal portion of the flexible elongate sheath110. A motion block118may be housed within the distal portion of the flexible elongate sheath110and between the transducer116and the end effector114. An arm118a(e.g., distal arm) of the motion block118may be configured to move along (e.g., slide along) a curved surface114aof the end effector114. In various embodiments, the curved surface114amay be disposed along one side of a proximal portion of the end effector114and may extend into the distal portion of the flexible elongate sheath110. A compression spring120(e.g., pre-load device, etc.) may be disposed between the motion block118and a proximal end of the end effector114. For example, the compression spring120may be disposed adjacent to (e.g., alongside) the arm118aof the motion block118within a space between a distal end of the motion block118and a proximal end of the end effector114. As discussed below, the compression spring120may move from a substantially non-compressed (e.g., relaxed) configuration to a compressed configuration as the end effector114moves/pivots away from a first position (see e.g.,FIG.1D) to a second position (see e.g.,FIG.1C). In some embodiments, the first position may comprise a home or resting position.

In one embodiment, the collar112may be attached to the flexible elongate sheath110by a sling122. For example, a proximal portion of the sling122may be housed within the distal portion of the flexible elongate sheath110and a distal portion of the sling122may be housed within the collar112. The end effector114may be pivotally attached to the collar112by a pin or lever arm124extending through opposite sides of the collar112and sling122and through a proximal portion of the end effector114. In various embodiments, the transducer116, motion block118and compression spring120may be housed within the proximal portion of the sling122, e.g., within the distal portion of the flexible elongate sheath110. One or more leads126(e.g., flexible control wire(s), flexible signal wire(s), etc.) may extend along a length of the flexible elongate sheath110(e.g., along an inner or outer surface of the flexible elongate sheath). A proximal end of the lead(s)126may be connected to (e.g., conductively or electrically connected to) an external energy source (e.g., a RF generator, not shown) and a distal end of the lead(s)126may be conductively connected to the transducer116.

In one embodiment, the transducer116(e.g., when energized by the external energy source) may be configured to translate (e.g., impart) linear motion (e.g., linear displacement, linear movement, etc.) to the motion block118relative to a longitudinal axis of the flexible elongate sheath110. The arm118aof the motion block118may be configured to move along the curved surface114aof the end effector114to translate (e.g., impart) a side-to-side reciprocating movement (e.g., displacement in-plane) to the end effector114, e.g., as the end effector114pivots around the pin124. The combined interactions of the transducer116, the motion block118, the end effector114and the compression spring120may translate axial displacement of the motion block118by the transducer116to side-to-side reciprocation in-plane of the end effector114. As discussed below, the interaction between the arm118aof the motion block118and the curved surface114aof the end effector114may provide angular displacement through varying radial lengths (X1inFIG.1B) to amplify in-plane displacement of the distal end of the end effector114, e.g., to provide ultrasonic in-plane reciprocal movement. One embodiment for the end effector is a cutting blade. When the blade is reciprocating side-to-side and the device is advanced to contact tissue, the target tissue will be cut.

In various embodiments, the combined interaction of the transducer116and motion block118may be configured to move/pivot the end effector114from a first position (e.g., home or resting position) to a second position and the compression spring120may be configured to move/pivot the end effector114from the second position to the first position. For example, the linear displacement of the motion block118imparted by the transducer116may urge the arm118ato slide along the curved surface114aalong one side of the end effector114to pivot the end effector114away from the first position about the pin124. As the end effector114pivots away from the first position, a distance/space between the motion block118and end effector114within which the compression spring120is disposed may be decreased, e.g., as the side of the end effector114opposite the curved surface114aextends into the space within which the compression spring120is housed. The compression spring120may move from a substantially non-compressed configuration to a compressed configuration as the end effector114pivots further away from the first position (see e.g.,FIG.1C). The transducer116may then be de-energized and the force exerted by the compression spring120against the proximal end of the end effector114may move/return the end effector114from the second position to the first position about the pin124(see e.g.,FIG.1D). As discussed below, the continued/repeated back-and-forth in-plane reciprocation of the end effector114resulting from the combined/opposing forces of the compression spring120and transducer116may generate/provide high frequency oscillation (e.g., 40-60 kHz) of the distal end of the end effector114.

Referring toFIGS.2A-2C, in one embodiment, an ultrasonic medical device200of the present disclosure may include a sling222disposed within a distal portion of a flexible elongate sheath210(e.g., catheter, etc.). The sling222may include a reflow element223extending beyond a distal end of the flexible elongate sheath210. In various embodiments, the reflow element223may include an outer surface configured to promote attachment of the sheath210to the sling222. For example, the outer surface of reflow element223may include bumps and/or ridges to increase surface area and friction for combining the sheath210to the sling222. In such examples, the sheath210may be placed over reflow element223and then shrunk around the sling222(e.g., via heat shrinking) to attach the sheath210to the sling222. An end effector214(e.g., blade, etc.) may be pivotally attached to the reflow element223such that a cutting edge214bof the end effector214may extend beyond a distal end of the sling222. A transducer216(e.g., one or more piezoelectric stacks/disks) may be housed within the sling222, e.g., within the portion of the sling222disposed within the distal portion of the flexible elongate sheath210. A motion block218may be housed within the distal portion of the flexible elongate sheath210and between the transducer216and the end effector214. An arm218a(e.g., distal arm) of the motion block218may be configured to move along (e.g., slide along) a curved surface214aof the end effector214. In various embodiments, the curved surface214amay be disposed along one side of a proximal portion of the end effector214and may extend into the distal portion of the flexible elongate sheath210. The end effector214may be pivotally attached to the reflow element223of the sling222by a pin or lever arm224extending through opposite sides of the reflow element223and through a proximal portion of the end effector214. A torsion spring220(e.g., pre-load device, etc.) may be disposed around an outer surface of the pin224within the reflow element223. As discussed below, the torsion spring220may move from a substantially non-compressed (e.g., relaxed) configuration to a compressed configuration around the pin224as the arm218aof the motion block218moves/pivots the end effector214away from first position (e.g., a home or resting position) to a second position.

In various embodiments, the transducer216and motion block218may be housed within the proximal portion of the sling222, e.g., within the distal portion of the flexible elongate sheath210. One or more leads226(e.g., flexible control wire(s), flexible signal wire(s), etc.) may extend along a length of the flexible elongate sheath210(e.g., along an inner or outer surface of the flexible elongate sheath). A proximal end of the lead(s)226may be connected to (e.g., conductively or electrically connected to) an external energy source (e.g., a RF generator, not shown) and a distal end of the lead(s)226may be conductively connected to the transducer216.

In one embodiment, the transducer216(e.g., when energized by the external energy source) may be configured to translate (e.g., impart) linear motion (e.g., linear displacement, linear movement, etc.) to the motion block218relative to a longitudinal axis of the flexible elongate sheath210. The arm218aof the motion block218may be configured to move along the curved surface214aof the end effector214to translate (e.g., impart) in-plane reciprocating movement (e.g., in-plane movement, etc.) to the end effector214, e.g., as the pin224pivots/rotates within the reflow element223. The combined interactions of the transducer216, the motion block218, the end effector214, the pin224and the torsion spring220may translate axial displacement of the motion block by the transducer to in-plane reciprocation of the end effector214. As discussed below, the interaction between the arm218aof the motion block218and the curved surface214aof the end effector214may provide angular displacement through varying radial lengths to amplify side-to-side in-plane displacement of the distal end of the end effector214, e.g., to provide ultrasonic in-plane reciprocal movement.

In various embodiments, the combined interaction of the transducer216and motion block218may be configured to move/pivot the end effector214from a first position (e.g., a home or resting position) to a second position, and the torsion spring220may be configured to move/pivot the end effector214from the second position to the first position. For example, the linear displacement of the motion block218imparted by the transducer216may urge the arm218ato slide along the curved surface214aalong one side of the end effector214to pivot the end effector214away from the first position about the pin224. As the end effector214pivots away from the first position, the torsion spring220may move from a substantially non-compressed configuration to a compressed configuration around the pin224. The transducer216may then be de-energized and the torsion spring220may return to the non-compressed configuration about the pin224to move/return the end effector214from the second position to the first position about the pin224. As discussed below, the continued/repeated back-and-forth in-plane reciprocation of the end effector214resulting from the combined/opposing forces of the torsion spring220and transducer216may generate/provide high frequency oscillation (40-60 kHz) of the distal end of the end effector214.

In various embodiments, the angular displacement through varying radial lengths provided by the combined interaction of the arm118a,218aof the motion block118,218and the curved surface114a,214aof the end effector114,214may eliminate the need for an amplification horn by converting the relatively small linear motion/displacement of the motion block118,218to a significantly larger in-plane rotational displacement of the distal end of the end effector114,214of the ultrasonic medical devices100,200. Referring to Table 1, in-plane rotational displacement at a distal end of an end effector (Blade Displacement) with a known length (Blade Length) may be calculated based on the linear displacement (Transducer Displacement) and degree of rotation (Rad) of the end effector using the formulas L=RX2(e.g., displacement) and D=2R Cos(X1/2) (e.g., rotation). An exemplary illustration of the geometric relationships of the parameters for these formulas is provided inFIG.1Band/orFIG.1F.

TABLE 1True-scale blade length and blade displacement resultsTransducerBladeBladeDisplacementRotationLengthDisplacement(um)(Rad)(mm)(um)100.006848100.0061272200.011888

Referring first to rotation, a transducer which imparts 20.0 μm (e.g., 0.02 mm) of linear displacement (D) and 1.0 mm of rotational movement (X1), e.g., pivoting of the end effector around (or along with) the pin, may provide 0.011 rad (e.g., 0.5 degrees of rotation) as follows:
D=2RCos(X1/2)
0.02 mm=2RCos(1.0 mm/2)
R=0.011 rad

Referring to displacement, an end effector with a length (X2) of 8.00 mm rotating about a proximal end thereof at 0.0111 rad may impart 88.0 μm of transverse displacement (L) to the distal end of the end effector as follows:
L=RX2
L=(0.011 rad)(8.0 mm)
L=88.0 μm

In various embodiments, the angular displacement through varying radial lengths may provide approximately 0.01 inches of in-plane ultrasonic reciprocation to an end effector at a frequency of approximately 40-60 kHz.

In one embodiment, an ultrasonic medical device300of the present disclosure may use distally actuated axial displacement to impart rotational (e.g., rotary) ultrasonic reciprocation (e.g., ultrasonic rotational movement, etc.) to an end effector without the need for a distal amplification horn. Referring toFIGS.3A-3B, in one embodiment, an ultrasonic medical device300of the present disclosure may include a tubular end effector312disposed within a distal portion of a flexible elongate sheath310(e.g., catheter, etc.). A functional characteristic or shape314(e.g., blade, etc.) may be attached to or integrally formed with a distal end of the tubular end effector312such that a cutting edge314bof the end effector314may extend beyond a distal end of the flexible elongate sheath310. A transducer316(e.g., one or more piezoelectric stacks/disks) may be housed within the distal portion of the flexible elongate sheath310and proximal to the tubular end effector312. An actuator rod318may be disposed within the distal portion of the flexible elongate sheath310and between the transducer316and the tubular end effector312. A proximal end of the actuator rod318may abut or contact a distal end of the transducer316. A distal end of the actuator rod318may include a hooked arm or peg318aconfigured to move along (e.g., slide along) a curved slot312aformed within a proximal portion of the tubular end effector312. In various embodiments, the curved slot312amay be formed within one side of the tubular end effector312. In another embodiment, the curved slot may be formed within two or more sides of the tubular end effector312, e.g., to provide additional rotational stability to the end effector. A compression spring320(e.g., pre-load device, etc.) may be disposed between a distal end of the transducer316and a proximal surface of an inner wall310aof the flexible elongate sheath310. As discussed below, the compression spring320may move from a substantially non-compressed (e.g., relaxed) configuration to a compressed configuration as the tubular end effector312moves/pivots from a first position (e.g., a home or resting position) to a second position.

One or more leads (not shown) may extend along a length of the flexible elongate sheath310(e.g., along an inner or outer surface of the flexible elongate sheath). A proximal end of the lead(s) may be connected to (e.g., conductively or electrically connected to) an external energy source (e.g., a RF generator, not shown) and a distal end of the lead(s) may be conductively connected to the transducer316.

Referring toFIGS.4A-4D, in one embodiment, the transducer316(e.g., when energized by the external energy source) may be configured to translate (e.g., impart) linear motion (e.g., linear displacement, linear movement, etc.) to the actuator rod318relative to a longitudinal axis of the flexible elongate sheath310. The hooked arm318aof the actuator rod318may be configured to move along (e.g., ride within) the curved slot312aof the tubular end effector312to translate (e.g., impart) rotational reciprocation (e.g., rotary/rotational movement) to the end effector314, e.g., as the peg318aof the actuator rod318moves back and forth within/along the curved slot312aof the tubular end effector312. The combined interactions of the transducer316, the actuator rod318, the tubular end effector312and compression spring320may translate axial displacement of the actuator rod by the transducer to rotational reciprocation of the end effector314. As discussed above, the interaction between the peg318aof the actuator rod318and the curved slot312aof the tubular end effector312may provide angular displacement through varying radial lengths to amplify rotational displacement of the distal end of the end effector314, e.g., to provide ultrasonic rotational movement of the distal end of the end effector314.

In various embodiments, the combined interaction of the transducer316and actuator rod318may be configured to move/pivot the tubular end effector312from a first position (e.g., home or resting position) to a second position and the compression spring320may be configured to move/pivot the end effector314from the second position to the first position. For example, the linear displacement of the actuator rod318imparted by the transducer316may urge the arm318ato advance forward (i.e. distally to the flexible sheath310) and cause peg318ato slide along the curved slot312aalong one side of the tubular end effector312to pivot the tubular end effector312away from the first position. As the tubular end effector312pivots away from the first position, a distance/space between the transducer316and the wall within the flexible shaft310within which the compression spring320is disposed may be decreased. The compression spring320may move from a substantially non-compressed configuration to a compressed configuration as the actuator rod318advances and the tubular end effector312pivots further away from the first position. The transducer316may then be de-energized and the force exerted by the compression spring320against the proximal surface of the inner wall310aof the flexible elongate sheath310may move/return the tubular end effector312to the first position. As discussed above, the continued/repeated back-and-forth rotary reciprocation of the end effector314resulting from the combined/opposing forces of the compression spring320and transducer316may generate/provide high frequency oscillation (e.g., 40-60 kHz) of the distal end of the end effector314.

Referring toFIG.5, in one embodiment, a transducer116,216,316of the present disclosure may include multiple piezoelectric stacks/disks a-d housed within the distal portion of a flexible elongate sheath110,210,310of the present disclosure and configured to be actuated in parallel. In various embodiments, one or more leads126a-126d,226a-226d(e.g., flexible control wire(s), flexible signal wire(s), etc.) may extend along a length of the flexible elongate sheath110,210,310(e.g., along an inner or outer surface of the flexible elongate sheath). A proximal end of each lead(s)126,226may be connected to (e.g., conductively or electrically connected to) an external energy source (e.g., a RF generator, not shown) and a distal end of each the lead(s)126,226may be conductively connected to a different one of the piezoelectric stacks/disks a-d

In various embodiments, a distal end of an end effector114,214,314of the present disclosure may include a substantially flat/planar cutting edge114b,214b(e.g., as depicted in the ultrasonic medical devices100,200of the present disclosure) or a curved/scalloped cutting edge314b(e.g., as depicted in the ultrasonic medical device300of the present disclosure). In various additional embodiments, the end effectors114,214,314of the present disclosure may be configured to be retracted (e.g., shielded, etc.) within a distal portion of the elongate flexible sheath110,210,310, e.g., for passage through a working channel of endoscope and/or advancement into a body lumen.

All of the devices and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and methods of this disclosure have been described in terms of preferred embodiments, it may be apparent to those of skill in the art that variations can be applied to the devices and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.