Patent Description:
Tumor resection and other tissue treatment is often performed by medical devices (e.g., endoscopic devices) by delivering radio frequency (RF) energy to destroy tissue. For malignant tumor resection, it may be desirable to preserve tissue architecture to confirm accurate diagnosis and to confirm complete removal and treatment of the tissue. Since tissue architecture may be destroyed during RF energy delivery, there may be a delayed or incomplete medical confirmation of a successful tissue resection. For example, the destroyed tissue architecture may delay or inhibit proper biopsy and classification of the treated tissue. Additionally, RF energy delivery devices may cause postoperative complications and tissue artifact as a result of, for example, delayed tissue effects. Therefore, a need exists for a fast, accurate, and precise method of resection with minimal collateral tissue damage.

<CIT> discloses an apparatus for ablating undesirable deposits along the inner blood vessel wall of human and animals, the apparatus comprising: a blood extracting and pressurizing unit for extracting source blood from a supply blood vessel and pressurizing the extracted source blood; and a blood delivering and injecting unit, in communicative connection with said blood extracting and pressurizing unit, for delivering and forcefully injecting the pressurized source blood into a blood vessel under treatment, wherein the direction of blood flow is designated as Z-direction of a Cartesian coordinate system, thereby, besides inducing a concomitant blood circulation from said supply blood vessel through said blood vessel under treatment, the apparatus ablates said undesirable deposits from a portion of said blood vessel under treatment in proximity to said blood delivering and injecting unit.

<CIT> discloses a system including an elongate member comprising a distal end, a proximal end, and at least one fluid delivery lumen extending therebetween; and at least one fluid delivery aperture disposed on a distal portion of the elongate member, wherein the at least one fluid delivery aperture is in fluid communication with the fluid delivery lumen.

<CIT> discloses a lithotomic apparatus which includes a probe for insertion into a body cavity. A distal tip is fixed to the distal end of the probe and has nozzles. Each nozzle has a rear end communicating with a feed passage defined in the probe and a front end opening to the distal end face of the distal tip. A high-pressure fluid supplied from a source is fed to the feed passage of the probe and pulsatively ejected from the nozzles toward a calculus in the body cavity by a drive mechanism.

The claimed invention comprises a medical device as defined by the appended independent claim <NUM>. Further embodiments of the claimed invention are described in the appended dependent claims.

The claimed medical device comprises a body that has a proximal end with a proximal opening. The body defines a channel from the proximal opening to a distal opening configured to emit a fluid jet along a longitudinal axis of the body. The body further includes a distal wall having an inner surface extending in a direction transverse to the longitudinal axis and facing the distal opening to receive the fluid jet. The body defines a space between the distal wall surface and the distal opening. The distal wall includes a protrusion configured to engage tissue, wherein the protrusion provides a solid surface for the fluid jet to impact. The distal opening is configured to emit the fluid jet at a pressure to pierce the tissue and the pressure is at or below <NUM> bar [<NUM> pounds per square inch], and the solid surface provided by the protrusion is convex or concave relative to the flow of the fluid jet.

In some example embodiments, the distal opening may have a diameter of approximately <NUM> millimeter or less. The proximal opening may have a diameter that is larger than a diameter of the distal opening. The channel may taper in a cross-sectional size from the proximal opening to the distal opening, and the protrusion may comprise one or more pointed tips to engage the tissue.

The body may further comprise a valve and a spring, the valve being fixedly coupled and disposed proximal to the spring and positioned between the proximal opening and the distal opening of the tubular member. The body may be electrically conductive to deliver radio frequency (RF) energy to the tissue. The RF energy delivered to the body may be conductive to the distal wall surface. The body may comprise a bottom surface disposed along the longitudinal axis between the distal opening and the distal wall surface to define a region to engage tissue. The medical device may also comprise a flexible tube coupled to the proximal end of the body. The flexible tube may have a channel to deliver fluid to the body. The flexible tube may include an electrically conductive tube, wire, cable, or braid for delivery of radio frequency (RF) energy to the body.

It may be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, which is defined by the appended set of claims. As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "exemplary" is used in the sense of "example," rather than "ideal. " As used herein, the term "proximal" means a direction closer to an operator, and the term "distal" means a direction further from an operator. Although endoscopy is referenced herein, such reference should not be construed as limiting the possible applications of the disclosed tools. For example, the disclosed tools may be used in procedures such as bronchoscopy, ureteroscopey, colonoscopey, or other procedures within the body.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of the present disclosure and together with the description, serve to explain the principles of the disclosure.

Tissue dissection, and specifically tissue/tumor resection and removal, may benefit from a medical device that implements a fast, accurate, and precise method of resection with minimal collateral tissue damage. Such medical devices may be more effective and advantageous than medical devices that deliver only radio frequency (RF) energy to perform tissue resection, for example, by preserving tissue architecture for confirmation of medical diagnosis and for effective tissue treatment. In some embodiments, fluid may be delivered to perform tissue dissection techniques (e.g., submucosal dissection). Fluid powered systems may be configured to dissect or resect tissue effectively with high precision and low heat. Additionally, fluid powered resection systems may be combined with RF or other energy delivery technologies to provide coagulation and hemostatic function during tissue resection. In one example, fluid powered tissue resection techniques may lead to reduced blood loss during a surgical procedure, and the low temperature helps preserve tissue and vessel architecture. Resection depth can also be controlled with varying fluid pressure applications. Therefore, aspects of the present disclosure and invention are directed to medical devices with fluid powered tissue resection systems.

Reference is now made to <FIG> depicts an example medical device <NUM>. The medical device <NUM> may be, for example, an endoscopic medical device, such as a catheter, used to perform tissue resection methods (e.g., submucosal tissue dissection). The medical device <NUM> has a tubular member <NUM> with a proximal end (not shown) and a distal end <NUM>. The tubular member <NUM> may be any known or contemplated tubular member <NUM> used for medical procedures, such as endoscopy, and may be, for example, a flexible tubular member with one or more channels or lumens disposed therein and extending between the proximal and distal ends <NUM> of the tubular member <NUM> for medical operation. In one example, the tubular member <NUM> is a catheter, which may be solid, slotted, braided, injection molded, or reflown. As shown in <FIG> and <FIG>, at least a distal portion of tubular member <NUM> is slotted to, for example, add flexibility to the tubular member <NUM>. The slotted portion may extend to an unslotted portion at distal end <NUM>, which couples to a body <NUM> to be described. In one example, the tubular member may be an extruded device. The medical device <NUM> also has a handle (not shown) connected to the proximal end of the tubular member <NUM>. An operator may use the handle to perform operations of the medical device <NUM>, including those described by the examples herein. The handle may be any known or contemplated handle used for medical procedures, and may include suitable ports and plugs for fluid and/or energy delivery. Additionally, the medical device <NUM> has a fluid delivery mechanism (not shown) located at the proximal end of the tubular member <NUM>. The fluid delivery mechanism may or may not be part of the handle, and enables fluid to flow from the proximal end of the tubular member <NUM>, via one or more internal channel or lumens, to the distal end <NUM> and ultimately to a body <NUM> to perform the fluid powered tissue resection techniques described herein. In one example, the fluid delivery mechanism may include a fluid source that is disposed at the proximal end of the tubular member <NUM>, for example within the handle. In another example, the fluid delivery mechanism may be a mechanism to drive fluid through the tubular member <NUM> (e.g., a pump) from a remote fluid source.

The medical device <NUM> also includes a body <NUM> disposed on the distal end <NUM> of the tubular member <NUM>. The body <NUM> has a proximal end <NUM> and a distal end <NUM>. In one example, the proximal end <NUM> of the body <NUM> is configured to interface with/engage the distal end <NUM> of the tubular member <NUM>. For example, the body <NUM> may plug into a mating component at the distal end <NUM> of the tubular member <NUM>. It should be appreciated that any internal working channels and/or lumens may be aligned in the body <NUM> and the tubular member <NUM>. In other examples, the body <NUM> may be integrally formed with and permanently fixed to the tubular member <NUM> (e.g., by being bonded or otherwise adhered or affixed to the tubular member <NUM>). The body <NUM> has a proximal opening (not shown in <FIG>) and a distal opening <NUM>.

<FIG> also shows a tissue boundary <NUM>. The tissue boundary <NUM> may be any tissue layer within the human body. <FIG> also shows a target tissue at reference numeral <NUM>. In one example, the target tissue <NUM> may be a tumor located within a gastrointestinal (GI) endothelium, though it should be appreciated that this may be any tissue in the human body. The techniques described herein enable treatment of the target tissue <NUM>, for example, by providing a fluid powered tissue resection method. <FIG> shows the distal end <NUM> of the body <NUM> embedded below the tissue boundary <NUM>. Reference numeral <NUM> shows a direction at which fluid may be delivered at a sufficiently high pressure to pierce the tissue boundary <NUM> and a tissue region <NUM> where treatment is being applied. Ultimately, the medical device <NUM> is used to resect the target tissue <NUM>. These systems and methods are described in more detail herein.

Reference is now made to <FIG>, which shows the body <NUM> at the distal end <NUM> of the tubular member <NUM> according to one example embodiment. As stated above, the body <NUM> is configured to interface with the tubular member <NUM>, e.g., by plugging into an opening (not shown in <FIG>) at the distal end <NUM> of the tubular member <NUM>. The body <NUM> has a proximal opening (not shown in <FIG>) and the distal opening <NUM> shown in <FIG>. An interim fluid channel (not shown in <FIG>) is formed in the body <NUM> between the proximal opening of the body <NUM> and the distal opening <NUM> of the body <NUM>, as described herein. It should be appreciated that, in one example, the interim fluid channel aligns with at least one channel or lumen of the tubular member <NUM> (e.g., catheter). <FIG> shows a fluid jet <NUM> that is emitted along an axis (e.g., a longitudinal axis) from the distal opening <NUM> of the body <NUM>. <FIG> also shows a direction of fluid flow along the axis, at reference numeral <NUM>. The proximal opening of the body <NUM> is configured to interface with, and receive fluid from, a fluid delivery device (e.g., the fluid delivery mechanism described in connection with <FIG>) that is internal and/or external to the medical device <NUM>. The distal opening <NUM> of the body <NUM> is configured to emit fluid delivered from the fluid delivery device. An interim fluid channel (not shown in <FIG>) is formed in the body <NUM> between the proximal opening of the body <NUM> and the distal opening <NUM> of the body <NUM>, as described herein. In one example, the fluid delivery device may be a fluid lumen or channel disposed within the tubular member <NUM> of the medical device <NUM>, such that fluid (e.g., water or a saline solution) is delivered from a source at the proximal end of the medical device <NUM> to the proximal opening of the body <NUM> for egress through the distal opening <NUM> of the body <NUM>. In this example, the body <NUM> is configured to deliver the fluid jet <NUM> as the fluid is emitted from the fluid delivery device.

The fluid jet <NUM> may be a fluid jet of water, saline, or other liquid that is delivered at a fluid pressure sufficient for tissue resection. For example, the fluid jet <NUM> may be emitted through the distal opening <NUM> of the body <NUM> at a fluid pressure of up to <NUM> atmospheric bars ("bars"), or approximately up to <NUM> pounds per square inch ("psi"). In one embodiment, the fluid jet <NUM> is emitted at a fluid pressure of <NUM> bar [<NUM> psi] or less when the diameter of the distal opening <NUM> of the body <NUM> is <NUM> millimeters ("mm"). It should be appreciated that the proper fluid pressure may vary depending on system and device parameters, including but not limited to the tissue type, the fluid used for the fluid jet <NUM>, the diameter of the distal opening <NUM> of the body <NUM>, etc. In one example, the diameter of the distal opening <NUM> varies based on the channels of the tubular member <NUM> and the desired size of the intended area of tissue impact of the fluid jet <NUM>. For example, a fluid pressure of between about <NUM>-<NUM> bars may be used for tissue resection, with, e.g., relatively lower pressures providing cleaner and more precise tissue piercings or perforations to minimize risk. In one example, when the distal opening <NUM> has a diameter of about <NUM> [<NUM> inches], less than about <NUM> bar [<NUM> psi] of fluid pressure may be sufficient to pierce tissue (e.g., muscle tissue, diseased tissue, or other types of tissue to be treated by the medical device <NUM>), and when the distal opening <NUM> has a diameter of about <NUM> [<NUM> inches], less than about <NUM> bar [<NUM> psi] of fluid pressure may be sufficient to pierce tissue. Higher fluid pressures may be desirable for tissue resection of mucosal and/or submucosal layers as opposed to fluid pressures for muscle tissue since the mucosal and submucosal layers of the GI tract may be tougher than muscle. In one example, fluid pressure of about <NUM> bar [<NUM> psi] may pierce mucosal and/or submucosal tissue. The fluid pressure may also vary based on the type of distal opening <NUM> (e.g., the internal shape and the geometry of the distal opening <NUM>). In one example, the distal opening <NUM> may be chamfered to disperse pressure, or conical/tapered inward (tapered from a proximal to distal direction) to focus the stream of fluid (e.g., fluid jet <NUM>).

<FIG> also shows an outer surface of a distal wall <NUM>. The distal wall <NUM> extends in a direction transverse to a longitudinal axis along which the fluid jet <NUM> is emitted. Referring to <FIG>, which shows a view of the body <NUM> according to an example embodiment, an inner, proximally-facing surface of the distal wall <NUM> is shown at reference numeral 220a. The inner surface 220a faces the distal opening <NUM> of the body <NUM>. When fluid is delivered through the body <NUM>, the fluid jet <NUM> is emitted from the distal opening <NUM> of the body <NUM> and the fluid jet <NUM> is received at the inner surface 220a of the distal wall <NUM>. <FIG> also shows the distal wall <NUM> having a protrusion <NUM> at a top end of the distal wall <NUM> and extending in the direction transverse to the longitudinal axis at which the fluid jet <NUM> is emitted. The protrusion <NUM> may be a relatively sharp tip of the distal wall <NUM> that points in a radially outward direction. The protrusion <NUM> is configured to engage tissue (e.g., to pierce the tissue surface and/or be placed on the tissue surface). For example, the protrusion <NUM> engages the tissue boundary <NUM>, described in connection with <FIG>, to guide or affix the body <NUM> to a region proximate a tissue of interest (e.g., the target tissue <NUM>) for ultimate performance of the fluid powered tissue resection methods described herein. In one example, the protrusion <NUM> is a hook or a hook-like feature that is configured to engage and affix to tissue. The protrusion <NUM> may comprise one or more tips or prongs.

As the fluid jet <NUM> is emitted at a sufficiently high fluid pressure to resect tissue, there is a desire to minimize or mitigate unintended tissue perforation. In one example, unmitigated fluid flow without a barrier to block the fluid jet <NUM> could quickly perforate organs/tissue not intended for tissue treatment. The protrusion <NUM> may prevent or limit unintended tissue perforation by blocking fluid flow past the tissue that is acquired by the protrusion <NUM>. The protrusion <NUM> provides a solid surface (e.g., the inner surface 220a of the distal wall <NUM>) for the fluid jet <NUM> to impact, which may dissipate the force of the fluid jet <NUM>. As the fluid jet <NUM> impacts the solid surface, the fluid may "splash back. " In order to mitigate or prevent unintended tissue perforation from the fluid splash back, the fluid splash back may be at a sufficiently low energy not to cause any damage to the surrounding healthy tissue (and, e.g., to avoid obscuring a camera view of operation). Thus, the protrusion <NUM> may be shaped to minimize the fluid energy of the splash back as the fluid jet <NUM> impacts the protrusion <NUM>. According to the claimed invention, the solid surface (e.g., the inner surface <NUM>(a) of the distal wall <NUM>) is convex or concave relative to the flow of the fluid jet <NUM>. In general, the profiles of the distal wall <NUM> and the protrusion <NUM> may be optimized in terms of distance from the distal opening <NUM>, shape, material, and thickness in order to direct the splash back safely. Referring back to <FIG>, this dissipation is shown at reference numeral <NUM>, as fluid dissipates along the edges and sides of the body <NUM> and the distal wall <NUM> and causes minimal or no unintended tissue perforation.

<FIG> also shows a bed region ("bed") <NUM> of the body <NUM>. The bed <NUM> in one example is a surface disposed along the longitudinal axis between the distal opening <NUM> of the body <NUM> and the distal wall <NUM> of the body <NUM>. The bed <NUM> may define a space in the body <NUM> for receiving tissue between the distal opening <NUM> and the distal wall <NUM>. In one example, the bed <NUM> is a surface that connects the inner surface 220a of the distal wall <NUM> to a side of the body <NUM> with the distal opening <NUM> of the body <NUM>. The bed <NUM> may be used during a medical procedure to remove a resected tissue from a patient's body. For example, after the target tissue <NUM> is treated with the fluid-powered resection methods, the body <NUM> may be maneuvered such that the target tissue <NUM> is placed on the bed <NUM> and removed from the patient's body as the medical device <NUM> is removed. To assist in capturing the resected tissue and retaining it during retraction of the medical device <NUM> from the patient, the surface of bed <NUM> may be treated with a tacky coating or otherwise treated so that the resected tissue adheres to the surface of the bed <NUM>.

Reference is now made to <FIG>, which shows a cross-sectional view of the medical device <NUM>. <FIG> shows the cross-sectional view of the body <NUM> and a distal end of the tubular member <NUM> of the medical device <NUM>. <FIG> shows an interim fluid channel <NUM> in the body <NUM> and a primary fluid channel <NUM> in the tubular member <NUM>. As described in connection with <FIG>, the interim fluid channel <NUM> is formed between a proximal opening in the body <NUM> and the distal opening <NUM> of the body <NUM>. In <FIG>, fluid in the primary fluid channel <NUM> flows to the interim fluid channel <NUM>, as shown by arrows <NUM>, via the proximal opening of the body <NUM> (not shown in <FIG>). In other words, the proximal opening of the body <NUM> interfaces with a distal opening of the primary fluid channel <NUM> such that fluid may flow between the primary fluid channel <NUM> and the interim fluid channel <NUM>. The interim fluid channel <NUM> tapers from a proximal end to the distal end. In other words, the cross-sectional area and/or the diameter of the interim fluid channel <NUM> decreases from its proximal end to its distal end. As a result, as fluid flows through the interim fluid channel <NUM> in the distal direction (shown at arrow <NUM>), fluid pressure increases. Thus, the fluid flows at a higher pressure toward the distal end of the interim fluid channel <NUM> when compared to the fluid flow at the proximal end of the interim fluid channel <NUM> and when compared to the fluid flow in the primary fluid channel <NUM>. As a result, as the fluid jet <NUM> egresses from the interim fluid channel <NUM> at the distal opening <NUM> of the body <NUM>, the fluid jet <NUM> is emitted at a higher fluid pressure relative to the fluid pressure of the primary fluid channel <NUM>. In this example, the distal opening <NUM> of the body <NUM> operates as a nozzle to emit the fluid jet <NUM> at a high relative fluid pressure. As described herein, the fluid pressure of the fluid jet <NUM> is sufficiently high to perform tissue resection operations. Splash back is limited, as shown by the water dissipation at reference <NUM>.

Reference is now made to <FIG>, which show a cross-sectional view of another embodiment a medical device <NUM>'. <FIG> shows a tubular member <NUM>, a distal end structure <NUM>, and a body <NUM>. The tubular member <NUM> may have the structure and functions of the tubular member <NUM>, and the body <NUM> may have the structure and functions of the body <NUM>. The distal end structure <NUM> may have the structure and functions of the distal end <NUM>. The distal end structure <NUM> further includes a valve <NUM>, and a spring <NUM>. In the example depicted in <FIG>, fluid may be delivered to a distal end of the medical device <NUM>'. At the distal end, after the fluid has traveled through the tubular member <NUM> to an interim fluid channel, shown at <NUM>, the interim fluid channel <NUM> holds the fluid as the interim fluid channel <NUM> narrows.

The valve <NUM> is located in a distal portion of the interim fluid channel <NUM>, distal to a narrowing <NUM> of the interim fluid channel <NUM>. The narrowing <NUM> has a smaller diameter and/or cross-sectional area relative to portions of channel <NUM> distal to and proximal to the narrowing <NUM>. The valve <NUM> is not fixed to the interim fluid channel <NUM> and is therefore able to translate longitudinally within channel <NUM>, e.g., along a direction shown by arrow <NUM>. The spring <NUM> also is located in the distal portion of the interim fluid channel <NUM>, distal to the valve <NUM>. The spring <NUM> is affixed to the valve <NUM> at a proximal end of the spring <NUM>.

The spring <NUM> and the valve <NUM> are positioned between a proximal opening of the interim fluid channel <NUM>, shown at reference <NUM>, and a proximal end of the body <NUM>. In one example, the body <NUM> is bonded to the distal end structure <NUM> such that the spring <NUM> is affixed to a surface of the body <NUM> at a distal end of the spring <NUM>. In one example, the spring <NUM> is a coil spring that is compressible upon application of pressure (e.g., upon application of fluid pressure along the direction <NUM> on the valve <NUM>). In one example, the valve <NUM> is a one-way valve that allows fluid to egress from the interim fluid channel <NUM> in a single direction.

Reference is now made to <FIG> shows a closed state configuration of the valve <NUM>. In <FIG>, arrows 470a-470c represent fluid flowing into the interim fluid channel <NUM>. The fluid pressure increases at arrow 470c as the interim fluid channel <NUM> narrows toward the valve <NUM>. In <FIG>, the valve is closed, and thus fluid does not egress from the interim fluid channel <NUM>. <FIG> shows an open state configuration of the valve <NUM>. In <FIG>, once the fluid reaches sufficient pressure (e.g., a threshold pressure), the proximal force exerted by the spring <NUM> on the valve <NUM> is overcome, and the pressure forces the valve <NUM> in a distal direction toward the spring <NUM> (e.g., along direction <NUM>), thus compressing the spring <NUM> in the distal direction. Once the distal motion begins, a shape of the valve <NUM> may result in a greater area of the valve <NUM> exposed to fluid flow, forcing it to open quickly. Thus, when the spring <NUM> is in the compressed state (e.g., when the valve <NUM> and the spring <NUM> have moved in a distal direction beyond a threshold distance resulting from the threshold pressure), fluid may be able to flow around the valve, as shown in arrows 472a-472d, into an egress channel, shown at reference <NUM>. Egress channel <NUM> may extend from the proximal opening <NUM> to the distal end structure <NUM>, such that fluid may flow towards the body <NUM> e.g., in the direction of arrows 472a-472d. The fluid leaves the egress channel <NUM> and flows toward the protrusion (e.g., protrusion <NUM>). As fluid pressure in the interim fluid channel <NUM> decreases (e.g., when the fluid supplied to the device <NUM>' is decreased), the proximal pressure of the spring <NUM> on the valve <NUM> may be greater than the fluid pressure exerted on the valve <NUM>, and the valve <NUM> may recede (e.g., travel in a proximal direction) to the closed state shown in <FIG>.

In one example, the fluid is emitted from the interim fluid channel <NUM> at a constant or relatively constant pressure. Thus, the mechanism described in <FIG> enables fluid to be emitted from the egress channel <NUM> at a constant or near constant pressure, which avoids a scenario where the fluid pressure gradually builds up during fluid egress from the interim fluid channel <NUM> and the distal opening <NUM>. In some examples, it is advantageous for fluid to be emitted from the egress channel <NUM> at a substantially constant pressure to avoid unintended tissue damage during pressure build up or suboptimal tissue resection.

Reference is now made to <FIG> shows a cross-sectional view of yet another embodiment of a medical device at <NUM>. In general, the device <NUM> is configured for fluid powered tissue dissection and RF energy delivery to tissue. <FIG> shows the cross-sectional view of tubular member <NUM> and body <NUM>. The tubular member <NUM> and the body <NUM> can have any of the structure and functions of tubular member <NUM>, <NUM> and the body <NUM>, <NUM>, respectively. The medical device <NUM> is advantageous for endoscopic procedures to provide coagulative functions with RF delivery in addition to the tissue resection functions performed by the fluid powered system. The body <NUM> may be bonded or otherwise affixed to the tubular member <NUM>. The body <NUM> is made of metal or other electrically conductive material. The body <NUM> is configured to conduct RF energy. For example, RF energy may be delivered to the body <NUM> via a conductive tube, wire, cable, or braid of the medical device <NUM>. A conductive tube is shown at reference numeral <NUM> in the expanded view of the junction between the body <NUM> and the tubular member <NUM>. The conductive tube <NUM> may be surrounded by insulating material, shown at reference numerals <NUM> (an inner insulation) and <NUM> (an outer insulation). Thus, the conductive tube <NUM> forms an electrical conduit to carry the RF energy to the body <NUM> and ultimately to distal wall <NUM> to coagulate tissue during a medical operation. The RF active components of the body <NUM> therefore includes the distal wall <NUM>. Thus, in one example, the distal wall <NUM> may operate as the point of contact to the tissue to deliver RF energy for coagulation.

Reference is now made to <FIG>, which shows an example flow chart <NUM> depicting operations for performing the fluid-powered tissue resection techniques, described herein. At operation <NUM>, a resection device is placed proximate a tissue of interest. The resection device may be any of the medical devices <NUM>, <NUM>', <NUM> described herein. At operation <NUM>, the tissue of interest is engaged with a protrusion of the resection device to hold the resection device in a position at the tissue of interest. At operation <NUM>, fluid is emitted from a distal opening of the resection device towards a distal wall surface of the resection device along a longitudinal axis. The fluid resects the tissue of interest.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.

It should be understood that one or more of the aspects of any of the medical devices described herein may be used in combination with any other medical device known in the art, such as medical imaging systems or other scopes such as colonoscopes, bronchoscopes, ureteroscopes, duodenoscopes, etc., or other types of imagers.

It also should also be understood that one or more aspects of any of the medical devices described herein may be used for resection, cutting, or otherwise dissecting tissue in any part of the human body. For example, any of the medical devices described herein may be used in medical procedures where removal and/or detection of tissue is needed.

Claim 1:
A medical device (<NUM>) comprising:
a body (<NUM>) having a proximal end (<NUM>) with a proximal opening, the body defining a channel from the proximal opening to a distal opening (<NUM>) configured to emit a fluid jet (<NUM>) along a longitudinal axis of the body;
the body further including a distal wall (<NUM>) having an inner surface (220a) extending in a direction transverse to the longitudinal axis and facing the distal opening to receive the fluid jet, the body defining a space between the distal wall surface and the distal opening, the distal wall including a protrusion (<NUM>) configured to engage tissue, wherein the protrusion provides a solid surface for the fluid jet to impact;
wherein
the distal opening is configured to emit the fluid jet at a pressure to pierce the tissue and characterized in that the pressure is at or below <NUM> bar (<NUM> pounds per square inch), and
the solid surface provided by the protrusion is convex or concave relative to the flow of the fluid jet.