Ultrasound endoscope with conformal sheath and methods of assembly therof

Abstract

An endoscopic system is provided for ultrasound applications that involve the use of a protective sheath. A channel is provided on or within the elongate body of the endoscope, the channel being in flow communication with an ultrasound transducer supported by the elongate body, with the channel configured to provide flow relief for an acoustic coupling medium contacting the ultrasound transducer during insertion of the elongate body into a form-fitting sheath.

Description

ULTRASOUND ENDOSCOPE WITH CONFORMAL SHEATH AND METHODS OFASSEMBLY THEREOFCROSS-REFERENCE TO RELATED APPLICATIONThis application claims priority to U.S. Provisional Patent Application No. 63 / 524,166, titled “ULTRASOUND ENDOSCOPE WITH CONFORMAL SHEATH AND METHODS OF ASSEMBLY THEREOF” and filed on June 29, 2023, the entire contents of which is incorporated herein by reference.BACKGROUND

[0001] The present disclosure relates to endoscopic devices for use in ultrasound procedures.

[0002] Safety standards may require the use of sterile sheaths for semi-critical (device contacts mucous membranes) and critical (device contacts sterile tissue) medical procedures. The use of sheaths is encouraged to limit cross contamination for all ultrasound procedures.

[0003] For endoscopic applications, it can be important to employ a sheath that closely fits the shape of the device near the working end. Off-the-shelf sheaths are baggy on endoscopic devices and the excess material adds prohibitive size to devices carefully designed to fit into tight spaces. A loose sheath is also more likely to interfere with the procedure and be inadvertently ripped or cut.SUMMARY

[0004] An endoscopic system is provided for ultrasound applications that involve the use of a protective sheath. A channel is provided on or within the elongate body of the endoscope, the channel being in flow communication with an ultrasound transducer supported by the elongate body, with the channel configured to provide flow relief for an acoustic coupling medium contacting the ultrasound transducer during insertion of the elongate body into a form-fitting sheath.

[0005] Accordingly, in a first aspect, there is provided an ultrasound endoscopic system comprising: an ultrasound endoscope comprising: an elongate body; and an ultrasound imaging transducer supported by the elongate body at a location that is remote from a proximal end of the elongate body; anda sheath configured to be fitted over the elongate body such that the sheath conforms to an outer surface of the elongate body and encloses a distal end of the elongate body; the elongate body comprising an elongate channel configured such that when the elongate body is fully inserted into the sheath, a distal end of the elongate channel is in flow communication with the ultrasound imaging transducer within the sheath; the elongate channel thereby providing a flow relief conduit for collecting excess acoustic coupling medium during insertion of the elongate body into the sheath.

[0006] In some example implementations of the system, at least a portion of the elongate channel is defined by an elongate recessed region within the outer surface of the elongate body and wherein the elongate channel is enclosed by the sheath to form the flow relief conduit when the elongate body is fully inserted into the sheath.

[0007] The elongate recessed region may be defined within the outer surface of the elongate channel such that the elongate recessed region transitions to the outer surface through a curved transition.

[0008] In some example implementations of the system, at least a portion of the elongate channel is defined by a groove residing within the outer surface of the elongate body and wherein the elongate channel is enclosed by the sheath to form the flow relief conduit when the elongate body is fully inserted into the sheath.

[0009] In some example implementations of the system, at least a portion of the elongate channel is defined by a pair of elongate ridges extending from the outer surface of the elongate body, and wherein the elongate channel is enclosed by the sheath to form the flow relief conduit when the elongate body is fully inserted into the sheath.

[0010] In some example implementations of the system, at least a portion of the elongate channel forms a lumen within the elongate body.

[0011] In some example implementations of the system, the elongate channel is tapered such that a cross-sectional area of the elongate channel decreases from a distal end of the elongate channel towards a proximal end of the elongate channel.

[0012] In some example implementations of the system, at least a distal portion of the sheath is formed from an elastic material having a cross-sectional shape that is expanded upon fitting of the sheath over the elongate body. A proximal portion of the sheath may be formed from an inelastic material.

[0013] In some example implementations of the system, at least a distal portion of the sheath is formed from an inelastic material having shape that is configured to conformally fit over the elongate body.

[0014] In some example implementations of the system, the ultrasound endoscope further comprises a handle portion, wherein the elongate body extends from the handle portion, and wherein the sheath is configured to enclose the handle portion.

[0015] In some example implementations of the system, the elongate body comprises at least one additional elongate channel configured to form an additional flow relief conduit when the elongate body is fully inserted into the sheath.

[0016] In some example implementations of the system, the ultrasound imaging transducer is an ultrasound array.

[0017] In some example implementations of the system, the ultrasound imaging transducer is configured as a side-looking ultrasound transducer.

[0018] In some example implementations of the system, the ultrasound imaging transducer is a forward-looking ultrasound transducer.

[0019] In some example implementations of the system, the elongate body is fully inserted into the sheath; acoustic coupling medium resides between the ultrasound imaging transducer and an inner surface of the sheath; and excess acoustic coupling medium resides within at least a distal region of the elongate channel, the elongate channel thereby accommodating the excess acoustic coupling medium. The elongate channel may be partially filled with the excess acoustic coupling medium. At least the acoustic coupling medium residing between the ultrasound imaging transducer and the inner surface of the sheath may be absent of air bubbles.

[0020] In another aspect, there is provided a method of applying a sheath to an ultrasound endoscope, the method comprising: providing ultrasound endoscopic system as described above; applying a volume of acoustic coupling medium within a distal region of the sheath; and inserting the elongate body into the sheath such that a first portion of the acoustic coupling medium resides between the ultrasound imaging transducer and an inner surface of the sheath, and such that a second portion of the acoustic coupling medium is collected within at least a distal region of the elongate channel.

[0021] In some example implementations of the method, the acoustic coupling medium is an acoustic coupling gel.

[0022] In some example implementations of the method, the volume of the acoustic coupling medium applied within the distal region of the sheath is less than a volume of the elongate channel.

[0023] In another aspect, there is provided a method of applying a sheath to an ultrasound endoscope, the method comprising:providing ultrasound endoscopic system as described above; applying a volume of acoustic coupling medium to the ultrasound imaging transducer; inserting the elongate body into the sheath such that a first portion of the acoustic coupling medium resides between the ultrasound imaging transducer and an inner surface of the sheath, and such that a second portion of the acoustic coupling medium is collected within at least a distal region of the elongate channel.

[0024] In some example implementations of the method, the acoustic coupling medium is an acoustic coupling gel.

[0025] In some example implementations of the method, the volume of the acoustic coupling medium applied to the ultrasound imaging transducer is less than a volume of the elongate channel.

[0026] A further understanding of the functional and advantageous aspects of the disclosure can be realized by reference to the following detailed description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Embodiments are described with reference to the accompanying drawings. In the drawings, like reference numbers can indicate identical or functionally similar elements. The drawing in which an element first appears is generally indicated by the left-most digit in the corresponding reference number.

[0028] FIGS. 1A and 1 B show an elongate body of an ultrasound endoscope partially inserted into a conformal sheath, prior to flow of excess acoustic coupling medium into a channel defined in the elongate body.

[0029] FIGS. 2A and 2B show an elongate body of an ultrasound endoscope fully inserted into a conformal sheath, with excess acoustic coupling medium residing in a channel defined in the elongate body.

[0030] FIGS. 3A and 3B show cross-sectional views of example configurations of the elongate body, with differently shaped channel features.

[0031] FIGS. 4A and 4B are flow charts illustrating example methods of fitting a conformal sheath over an elongate body of an ultrasound endoscope while accommodating excess acoustic coupling medium within a flow relief conduit.

[0032] FIG. 5 shows an example elongate body of an ultrasound endoscope, the example elongate body including a channel for accommodating excess acoustic coupling medium during insertion of the elongate body within a conformal sheath.

[0033] FIGS. 6A and 6B show examples of different configurations of an elongate body of an ultrasound endoscope, the example elongate body including a first pair of channels foraccommodating excess acoustic coupling medium during insertion of the elongate body within a conformal sheath and a second pair of channels for mounting printed circuit boards.

[0034] FIG. 7 shows an example of a distal region of an elongate body of an ultrasound endoscope, the distal region including a channel in flow communication with an ultrasound transducer.

[0035] FIGS. 8A and 8B show detail view of an example elongate body of an ultrasound endoscope, the elongate body having a tapered recessed elongate channel.DETAILED DESCRIPTION

[0036] Various embodiments and aspects of the disclosure will be described with reference to details discussed below. The following description and drawings are illustrative of the disclosure and are not to be construed as limiting the disclosure. Numerous specific details are described to provide a thorough understanding of various embodiments of the present disclosure. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present disclosure.

[0037] As used herein, the terms “comprises” and “comprising” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in the specification and claims, the terms “comprises” and “comprising” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps, or components.

[0038] As used herein, the term “exemplary” means “serving as an example, instance, or illustration,” and should not be construed as preferred or advantageous over other configurations disclosed herein.

[0039] As used herein, the terms “about” and “approximately” are meant to cover variations that may exist in the upper and lower limits of the ranges of values, such as variations in properties, parameters, and dimensions. Unless otherwise specified, the terms “about” and “approximately” mean plus or minus 25 percent or less.

[0040] It is to be understood that unless otherwise specified, any specified range or group is as a shorthand way of referring to each and every member of a range or group individually, as well as each and every possible sub-range or sub-group encompassed therein and similarly with respect to any sub-ranges or sub-groups therein. Unless otherwise specified, the present disclosure relates to and explicitly incorporates each and every specific member and combination of sub-ranges or sub-groups.

[0041] As used herein, the term "on the order of', when used in conjunction with a quantity or parameter, refers to a range spanning approximately one tenth to ten times the stated quantity or parameter.

[0042] As described above, in the case of ultrasound endoscopic devices, a sheath that conformally fits to the shape of an endoscope is desirable in order to facilitate the insertion of the endoscope into the body and to avoid the tearing of the sheath during use. While such a closely fitting sheath is advantageous, when the present inventors attempted to use such a sheath, challenges were encountered during insertion of the endoscope into the sheath.

[0043] These challenges arose from the need to provide an acoustic coupling medium, such as acoustic coupling gel or a saline solution, between the ultrasound transducer and the sheath. The presence of the acoustic coupling medium is important to ensure the unimpeded transmission and reception of acoustic energy despite the presence of the sheath adjacent to the ultrasound transducer. Indeed, if acoustic coupling medium is not present in the space between the ultrasound transducer and the internal surface of sheath, the presence of air leads to acoustic losses and signal artifacts due to the high acoustic impedance contrast at the air / sheath interface and the air / transducer interface.

[0044] The inventors encountered technical challenges when attempting to fit a conformal sheath over the elongate body of the endoscope while also ensuring the presence of acoustic coupling medium within the sheath in the region proximal to the ultrasound transducer. The inventors had obtained a custom, conformal sheath with a cross-sectional shape corresponding to the cross-sectional shape of the elongate body of the endoscope. However, when attempting to insert the elongate body of the endoscope into the sheath, with a distal region of the sheath pre-loaded with acoustic coupling gel, air became trapped between the sheath and the elongate body of the endoscope. Moreover, the acoustic coupling gel was compressed and formed a bulge in the distal region of the sheath that prevented the endoscope from being fully inserted to the distal tip of the sheath.

[0045] The present inventors thus sought a solution that would permit the fitting of a conformal sheath over the elongate body of an ultrasound endoscope while also accommodating the inclusion of an acoustic coupling medium between the ultrasound transducer and the inner surface of the sheath. It was found that the inclusion of a channel, defined in the elongate body of the endoscope, and in flow communication with the ultrasound transducer, could function as a flow relief conduit for collecting excess acoustic coupling medium during insertion of the elongate body into the sheath.

[0046] Accordingly, in various example embodiments of the present disclosure, an ultrasound endoscopic system is provided that includes an ultrasound endoscope, having an elongate body supporting an ultrasound transducer remote from a proximal end of the elongate body, and also includes a sheath configured be fitted over the elongate body such that said sheath conforms to an outer surface of the elongate body and encloses a distal end of the elongate body. An elongate channel is provided within the elongate body. Theelongate channel is defined such that when the elongate body is fully inserted into the sheath, a distal end of the elongate channel is in flow communication with the ultrasound imaging transducer within the sheath, thereby providing a flow relief conduit for collecting excess acoustic coupling medium during insertion of the elongate body into the sheath.

[0047] An example implementation of such a system is illustrated in FIGS. 1A and 1 B, which shows an example endoscopic system that includes an ultrasound endoscope 100 having elongate body 110 that is configured for insertion into a subject (e.g. a bodily lumen or cavity), with an ultrasound transducer (not shown) residing at the distal end 140 of the elongate body 110. The ultrasound endoscope 100 also includes a handle portion 115 from which the elongate body 110 extends. While not shown in the figure, conductive paths are provided along or within the elongate body to deliver signals to and from the ultrasound transducer and to and from proximal ultrasound drive and / or beamforming circuitry.

[0048] In FIG. 1A, the ultrasound endoscope 100 is shown with the elongate body 110 partially inserted into a sheath 130, which encloses the distal end 140 of the elongate body 110. As can be seen in the figure, the sheath 130 conforms in shape to the outer surface of the elongate body 110 within the distal insertable region of the elongate body 110. In other words, the cross-sectional shape of the sheath corresponds to the cross-sectional shape of the elongate body 110. The distal end of the sheath is shown at 150.

[0049] The elongate body 110 includes a channel 120, which is shown in the present example implementation as an elongate recessed region that is recessed from the outer surface of the elongate body 110. When the sheath 130 extends over the elongate body 110, the inner surface of the sheath 130 and the channel 120 together form a flow relief conduit having distal end that is in flow communication with the ultrasound transducer, within the sheath 130.

[0050] As can be seen in FIG. 1A, and in the detailed view of the distal region shown in FIG. 1B, a volume of acoustic coupling medium 160 resides within the distal region of the sheath 130. The elongate body 110 is shown partially inserted along direction 170, such that the distal end of the elongate body 110 does not yet contact the acoustic coupling medium 160.

[0051] As the elongate body 110 is further inserted into the sheath and the distal end 140 of the elongate body 110 contacts and applies a compressive force to the acoustic coupling medium 160, excess acoustic coupling medium flows into the flow relief conduit defined by the channel 120 and the inner surface of the sheath 130. The flow relief conduit therefore accommodates the excess acoustic coupling medium and avoids the bulging of acoustic coupling medium near the ultrasound transducer and the entrapment of air bubbles.

[0052] FIGS. 2A and 2B show the elongate body 110 fully inserted into the sheath 130. A small volume of acoustic coupling medium 162 (smaller than the volume initially dispensed into the sheath) remains between the distal end of the elongate body 110 and the distal end 150 of the sheath 130, thereby facilitating acoustic coupling between the ultrasound transducer and the sheath 130. Excess acoustic coupling medium 164 now resides within the flow relief conduit between the channel 120 and the inner surface of the sheath 130. As can be seen in FIG. 2B, the elongate body 110 has been fully inserted into the sheath 130 without generating substantial bulging of the excess acoustic coupling medium and without the generation of air bubbles in the region proximal to the ultrasound transducer.Accordingly, the present example embodiment solves the aforementioned problems in the art by incorporating a channel into the elongate body of the endoscope that provides, when the elongate body is inserted into the sheath, a flow relief conduit that allows air and excess acoustic coupling material to escape from the distal region of the sheath.

[0053] It will be understood that the example embodiments shown in the figures are not intended to be limiting and may be modified without departing from the intended scope of the present disclosure. For example, many different configurations of relief channels, disposed along or within the elongated body, may be employed to facilitate the insertion of the elongate body into the sheath and, therefore, facilitate controlled acoustic coupling between the transducer elements and the sheath.

[0054] For example, FIGS. 3A and 3B illustrate two different example shapes of channels that can be defined in the outer surface of the elongate body 110. FIG. 3A shows an example similar to that shown in FIGS. 1A, 1 B, 2A and 2B, in which the channel 120 is formed as an elongate recessed region. While the sheath 130 conforms in shape to the outer (outermost) surface of the elongate body 110, the channel 120, together with inner surface of the sheath 130, defines a flow relief conduit 125. FIG. 3B illustrates an alternative example configuration in which the channels are defined as partial cylindrical grooves 122 extending inwardly from the outer surface of the elongate body 110.

[0055] The shape of the channel is not limited to the configurations shown in the figures. In another example embodiment, the channel has a square cross-sectional shape. In some example implementations, such as the example implementation shown in FIG. 3A, a smooth and curved transition exists between the channel and outermost surface of the endoscope body. In some example implementations, a pair of raised ridges, extending outwardly from the surface of the elongate body, may be employed to form a channel.

[0056] One or more channels may be provided to form one or more flow relief conduits for accommodating the flow of excess acoustic coupling medium. In some exampleembodiments, a pair of channels are defined within the outer surface of the elongate body on opposing sides of the elongate body.

[0057] In some example embodiments, at least one channel extends along a full length of the insertable elongate body of the ultrasound endoscope. In other example embodiments, at least one channel extends from the distal region, in flow communication with the ultrasound transducer, to an intermediate location along the length of the elongate body of the ultrasound endoscope. In some example implementations, the elongate channel is tapered such that a cross-sectional area of the elongate channel decreases from a distal end of the elongate channel towards a proximal end of the elongate channel.

[0058] In some example embodiments, the sheath is configured to conformally fit to the elongate body over a first region and the sheath is also configured to have a cross-sectional shape that is larger than that of the elongate body over a second region of the elongate body, with the second region being proximal to the first region. In such an embodiment, the channel need only extend, from a first end in which the channel is in flow communication with the ultrasound transducer, to a second end that resides within the second region, to facilitate air-venting of the channel when the elongate body is inserted into the sheath.

[0059] While some example embodiments employ a channel defined within an outer surface of the elongate body of the ultrasound endoscope, other example embodiments may employ a channel that forms an internal lumen within the elongate body. For example, a channel may be provided in the center of the endoscope with the ultrasound element(s) arranged to provide direct access from the channel to the front face of the device. In some example embodiments, a first portion of a channel may be externally defined within the outer surface of the elongate body, while a second portion of the channel may reside within the elongate body, provided that a distal end of the channel is in flow communication with the ultrasound transducer when the elongate body is inserted into the sheath.

[0060] It will be understood that the sheath can be fitted onto the elongate body, with the inclusion of acoustic coupling medium, according to several example methods. FIGS. 4A and 4B provide flow charts illustrating two non-limiting example methods. The method illustrated in FIG. 4A is similar to that illustrated in FIGS. 1 A, 1 B, 2A and 2B, in which a volume of acoustic coupling medium is initially dispensed into the distal end of the sheath, as shown at step 200 (e.g. using a dispensing device such as a pipette or syringe), and the elongate body is initially inserted into the sheath such that the distal end of the elongate body is brought into contact with the acoustic coupling medium residing in the distal region of the sheath, as shown at step 210. The elongate body is then further inserted into the sheath, such that a first portion of acoustic coupling medium resides between ultrasound transducer and sheath, and a second portion of acoustic coupling medium is collected within theelongate channel, as shown at step 220, with the elongate channel thereby providing flow relief for excess acoustic coupling medium residing within the sheath. Steps 210 and 220 may be performed serially or in a continuous motion. In some example implementations, the volume of acoustic coupling medium applied (within the sheath or on the ultrasound transducer) may be less than a volume of the elongate channel (or a total volume of a plurality of ultrasound channels) to ensure that the one or more channels can accommodate excess acoustic coupling medium during insertion of the elongate body into the sheath.

[0061] FIG. 4B illustrates an alternative workflow in which a volume of acoustic coupling medium is initially dispensed onto the elongate body at a location corresponding to the ultrasound transducer, with the acoustic coupling medium contacting an outer surface of the ultrasound transducer (as shown at step 300), after which the elongate body, with the acoustic coupling medium thereon, is inserted into the sheath, such that a first portion of acoustic coupling medium resides between ultrasound transducer and sheath, and a second portion of acoustic coupling medium is collected within the elongate channel, as shown at step 310, with the elongate channel thereby providing flow relief for excess acoustic coupling medium residing within the sheath. While FIGS. 4A and 4B illustrate example methods of assembly that involve insertion of the elongate body into the sheath, it will be understood that other example methods of assembly may involve the fitting of a rolled-up (or partially rolled-up) sheath over the elongate body.

[0062] While the figures illustrate specific and non-limiting example shapes and configurations of an ultrasound endoscope, it will be understood that the ultrasound endoscope may take on many different shapes and configurations. For example, the elongated portion may be straight, angled in a manner that is beneficial for access or may be flexible or otherwise adjustable, e.g. to facilitate functional operation for a given application.

[0063] The acoustic coupling medium can be any flowable medium liquid or gel that is acoustically conductive. Non-limiting examples of acoustic coupling media include ultrasound gel and saline.

[0064] The sheath may be provided in sterile or non-sterile form. The sheath may be made from a wide variety of materials. In some example implementations, the sheath is formed from an inelastic material having shape that is configured to conformally fit over the elongate body, at least over a distal insertable portion of the elongate body. Non-limiting examples of suitable inelastic materials include, but are not limited to, polyethylene. In other example embodiments, at least a distal insertable portion of the sheath may be formed from an elastic material (e.g. elastomeric material) having a cross-sectional shape that is expanded upon fitting of the sheath over the elongate body. Non-limiting examples ofsuitable elastic materials for forming at least a portion of the sheath include polyurethane and polyethylene vinyl acetate (PEVA).

[0065] In some example embodiments, a composite sheath may be formed from elastic and inelastic materials. For example, a distal insertable region of the sheath may be formed from an elastic material, and one or more proximal regions, such as a region including the endoscope handle and / or cabling system may be formed from an inelastic material.

[0066] While some of the embodiments illustrated herein refer to an ultrasound transducer located on the distal end of the elongate body, it will be understood that the location and configuration of the ultrasound transducer may take on many different forms. For example, an ultrasound transducer may be supported by the elongate body in a forward looking or side looking configuration. Moreover, the ultrasound transducer need not reside at the distal end of the elongate body, and may instead reside at a distal region offset from the distal end and oriented for side or forward-looking operation. The ultrasound transducer may be a single element transducer or may be formed from multiple ultrasound elements, e.g. as a phased array transducer. The elongate body may include a prescribed recessed region adjacent to the ultrasound transducer to accommodate a prescribed (pre-defined) volume of acoustic coupling medium adjacent to the ultrasound transducer when the elongate body is fully inserted into the sheath, with the sheath conformally fitting at least the distal region of the elongate body and excess acoustic coupling medium residing within one or more relief conduits formed, at least in part, by one or more flow channels defined within the elongate body of the endoscope.

[0067] While the example embodiments described above pertain to an ultrasound endoscope having an ultrasound transducer, it will be understood that the present example devices and methods may be adapted to endoscopic devices that employ other modalities that benefit from an internal coupling medium to support transduction when a conformal sheath is employed, such as, but not limited to, optical and photoacoustic endoscopic devices, and / or endoscopic devices that employ multiple imaging modalities.EXAMPLES

[0068] The following examples are presented to enable those skilled in the art to understand and to practice embodiments of the present disclosure. They should not be considered as a limitation on the scope of the disclosure, but merely as being illustrative and representative thereof.

[0069] FIG. 5 illustrates a non-limiting example embodiment of an elongate body 420 of an ultrasound endoscope that includes coupling relief channels 430 and a distal ultrasound transducer 410. The figure also shows a base structure 450 of the elongate body 420 thatincludes locking wings 440. The base structure also shows the proximal ends of interconnect printed circuit boards 450 that extend along the elongate body and are connected to the ultrasound transducer 410 during fabrication. The shape of this endoscope is shown as an example only and should not be interpreted as features limiting the present disclosure.

[0070] FIG. 6A shows an example of an elongate body that is absent of the printed circuit boards. As can be seen in the figure, the elongate body includes a first pair of elongate lateral channels 530 and 540 that accommodate the printed circuit boards and a second pair of elongate lateral channels that are configured to form flow relief channels for excess acoustic coupling medium during the fitting of the sheath. FIG. 6B illustrates an alternative example implementation in which the channels 512 and 522 are formed as smooth elongate recessed features within the elongate body.

[0071] FIG. 7 shows a distal region of an example elongate body 420 of an ultrasound endoscope. The distal region includes a channel 430 in flow communication with an ultrasound transducer 410. The figure also shows the distal region of a printed circuit board 450 and an acoustic lens 440 formed over the ultrasound transducer. Raised features 460 and 470 define an inner region, residing above the ultrasound transducer 410 and acoustic lens 440, that is capable of housing a small volume of acoustic coupling medium when a conformal sheath is fitted over the elongate body 420.

[0072] FIGS. 8A and 8B show detail view of an example elongate body 420 of an ultrasound endoscope, the elongate body including two segments with elongate recessed channel features 432 and 434 formed therein, where the channel features are tapered such that they reduce in depth from a distal region toward a proximal region.

[0073] The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

Claims

AMENDED CLAIMS received by the International Bureau on 25 October 2024 (25.10.2024)CLAIMS1. An ultrasound endoscopic system comprising: an ultrasound endoscope comprising: an elongate body; and an ultrasound imaging transducer supported by said elongate body at a location that is remote from a proximal end of said elongate body; and a sheath configured to be fitted over said elongate body such that said sheath conforms to an outer surface of said elongate body and encloses a distal end of said elongate body; said elongate body comprising an elongate channel configured such that when said elongate body is fully inserted into said sheath, a distal end of said elongate channel is in flow communication with said ultrasound imaging transducer within said sheath; said elongate channel thereby providing a flow relief conduit for collecting excess acoustic coupling medium during insertion of said elongate body into said sheath.

2. The ultrasound endoscopic system according to claim 1 wherein at least a portion of said elongate channel is defined by an elongate recessed region within said outer surface of said elongate body and wherein said elongate channel is enclosed by said sheath to form said flow relief conduit when said elongate body is fully inserted into said sheath.

3. The ultrasound endoscopic system according to claim 2 wherein said elongate recessed region is defined within said outer surface of said elongate channel such that said elongate recessed region transitions to said outer surface through a curved transition.

4. The ultrasound endoscopic system according to claim 1 wherein at least a portion of said elongate channel is defined by a groove residing within said outer surface of said elongate body and wherein said elongate channel is enclosed by said sheath to form said flow relief conduit when said elongate body is fully inserted into said sheath.

5. The ultrasound endoscopic system according to claim 1 wherein at least a portion of said elongate channel is defined by a pair of elongate ridges extending from said outer surface of said elongate body, and wherein said elongate channel is enclosed by said sheath to form said flow relief conduit when said elongate body is fully inserted into said sheath.

6. The ultrasound endoscopic system according to claim 1 wherein at least a portion of said elongate channel forms a lumen within said elongate body.17AMENDED SHEET (ARTICLE 19)7. The ultrasound endoscopic system according to any one of claims 1 to 6 wherein said elongate channel is tapered such that a cross-sectional area of said elongate channel decreases from a distal end of said elongate channel towards a proximal end of said elongate channel.

8. The ultrasound endoscopic system according to any one of claims 1 to 7 wherein at least a distal portion of said sheath is formed from an elastic material having a cross-sectional shape that is expanded upon fitting of said sheath over said elongate body.

9. The ultrasound endoscopic system according to claim 8 wherein a proximal portion of said sheath is formed from an inelastic material.

10. The ultrasound endoscopic system according to any one of claims 1 to 7 wherein at least a distal portion of said sheath is formed from an inelastic material having shape that is configured to conformally fit over the elongate body.11 . The ultrasound endoscopic system according to any one of claims 1 to 10 wherein said ultrasound endoscope further comprises a handle portion, wherein said elongate body extends from said handle portion, and wherein said sheath is configured to enclose said handle portion.

12. The ultrasound endoscopic system according to any one of claims 1 to 11 wherein said elongate body comprises at least one additional elongate channel configured to form an additional flow relief conduit when said elongate body is fully inserted into said sheath.

13. The ultrasound endoscopic system according to any one of claims 1 to 12 wherein said ultrasound imaging transducer is an ultrasound array.

14. The ultrasound endoscopic system according to any one of claims 1 to 12 wherein said ultrasound imaging transducer is configured as a side-looking ultrasound transducer.

15. The ultrasound endoscopic system according to any one of claims 1 to 12 wherein said ultrasound imaging transducer is a forward-looking ultrasound transducer.

16. The ultrasound endoscopic system according to any one of claims 1 to 15 wherein: said elongate body is fully inserted into said sheath;18AMENDED SHEET (ARTICLE 19)acoustic coupling medium resides between said ultrasound imaging transducer and an inner surface of said sheath; and excess acoustic coupling medium resides within at least a distal region of said elongate channel, said elongate channel thereby accommodating the excess acoustic coupling medium.

17. The ultrasound endoscopic system according to claim 16 wherein the elongate channel is partially filed with the excess acoustic coupling medium.

18. The ultrasound endoscopic system according to claim 16 wherein at least the acoustic coupling medium residing between said ultrasound imaging transducer and said inner surface of said sheath is absent of air bubbles.

19. A method of applying a sheath to an ultrasound endoscope, said method comprising: providing ultrasound endoscopic system according to any one of claims 1 to 15; applying a volume of acoustic coupling medium within a distal region of the sheath; and inserting said elongate body into said sheath such that a first portion of the acoustic coupling medium resides between the ultrasound imaging transducer and an inner surface of the sheath, and such that a second portion of the acoustic coupling medium is collected within at least a distal region of said elongate channel.

20. The method according to claim 19 wherein the acoustic coupling medium is an acoustic coupling gel.21 . The method according to claim 19 or 20 wherein the volume of the acoustic coupling medium applied within the distal region of the sheath is less than a volume of the elongate channel.

22. A method of applying a sheath to an ultrasound endoscope, said method comprising: providing ultrasound endoscopic system according to any one of claims 1 to 15; applying a volume of acoustic coupling medium to said ultrasound imaging transducer; inserting said elongate body into the sheath such that a first portion of the acoustic coupling medium resides between the ultrasound imaging transducer and an inner surface of the sheath, and such that a second portion of the acoustic coupling medium is collected within at least a distal region of said elongate channel.19AMENDED SHEET (ARTICLE 19)23. The method according to claim 22 wherein the acoustic coupling medium is an acoustic coupling gel.

24. The method according to claim 22 or 23 wherein the volume of the acoustic coupling medium applied to the ultrasound imaging transducer is less than a volume of the elongate channel.20AMENDED SHEET (ARTICLE 19)

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