Telescopic catheter

Abstract

Telescopic catheters for selectively moving components of a medical device system are disclosed. An exemplary telescoping catheter may include a proximal hub adjacent a proximal end of the catheter, a drive cable, and a telescoping section extending from the proximal end adjacent the proximal hub to a distal end. The telescoping section may include an intermediate sheath, an outer sheath, an inner sheath, and a sealing member; an intermediate sheath having a proximal end coupled to the proximal hub and extending distally to a distal end; an outer sheath disposed on the intermediate sheath, the outer sheath having a proximal end and a distal end; an inner sheath disposed within the intermediate sheath, the inner sheath having a proximal end and a distal end; the sealing member is disposed between the outer surfaces of the intermediate sheath and the inner sheath. The intermediate sheath may be configured to be longitudinally displaced relative to the inner sheath and the outer sheath.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 324,686, filed on March 29, 2022, the entire disclosure of which is incorporated by reference. Technical Field

[0002] The present disclosure relates to medical imaging, and systems and methods for medical imaging. More particularly, the present disclosure relates to systems and methods for vascular imaging including telescoping sections. Background Art

[0003] A wide variety of medical imaging systems and methods have been developed for medical use, for example, for imaging vascular anatomy. Some of these systems and methods include intravascular imaging modalities. These systems and methods include various configurations and may be operated or used according to any of a variety of methods. Each of the known vascular imaging systems and methods has certain advantages and disadvantages. Therefore, there is a continuing need to provide alternative systems and methods for vascular imaging and assessment. Summary of the invention

[0004] The present disclosure provides an alternative telescopic catheter. In a first example, the telescopic catheter may include a proximal hub, a drive cable, and a telescopic section, the proximal hub being adjacent to the proximal end of the telescopic catheter, the telescopic section extending from the proximal end adjacent to the proximal hub to the distal end. The telescopic section may include an intermediate sheath, an outer sheath, an inner sheath, and a sealing member; the intermediate sheath having a proximal end coupled to the proximal hub and extending distally to the distal end; the outer sheath being disposed on the intermediate sheath, the outer sheath having a proximal end and a distal end; the inner sheath being disposed within the intermediate sheath, the inner sheath having a proximal end and a distal end; the sealing member being disposed between the outer surfaces of the intermediate sheath and the inner sheath. The intermediate sheath may be configured to be longitudinally displaced relative to the inner sheath and the outer sheath.

[0005] Alternatively or in addition to any of the above examples, in another example, the sealing member can be configured to form a fluid tight seal between the inner jacket and the intermediate jacket.

[0006] Alternatively or in addition to any of the above examples, in another example, the intermediate sheath can have a constant outer diameter from its proximal end to its distal end.

[0007] Alternatively or in addition to any of the above examples, in another example, the sealing member may include an O-ring.

[0008] Alternatively or in addition to any of the above examples, in another example, the outer sheath and the inner sheath can be secured to one another.

[0009] Alternatively or in addition to any of the above examples, in another example, the intermediate sheath can define a lumen configured to generally surround the inner sheath when the intermediate sheath is in the distally advanced configuration and surround a portion of the drive cable when the intermediate sheath is in the proximally displaced configuration.

[0010] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include an outer jacket disposed over the drive cable.

[0011] Alternatively or in addition to any of the above examples, in another example, the outer jacket can include a first layer and a second layer.

[0012] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include a housing coupled to the proximal end of the outer sheath.

[0013] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include a retainer sleeve secured to an outer surface of the intermediate sheath.

[0014] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include a retainer plug extending distally from the sealing member.

[0015] Alternatively or in addition to any of the above examples, in another example, a proximal strain relief can be coupled to the proximal hub and can be configured to mechanically engage a proximal portion of the housing to limit proximal movement of the intermediate sheath.

[0016] Alternatively or in addition to any of the above examples, in another example, the retainer sleeve can be configured to mechanically engage a portion of the housing to limit proximal movement of the intermediate sheath.

[0017] Alternatively or in addition to any of the above examples, in another example, the outer diameter of the retainer plug can be the same as the outer diameter of the intermediate sheath.

[0018] Alternatively or in addition to any of the above examples, in another example, the retainer sleeve can be disposed over and in contact with the distal end region of the intermediate sheath, the seal member, and the proximal end region of the retainer plug.

[0019] In another example, a telescoping catheter may include a drive cable and a telescoping section that extends longitudinally along the telescoping catheter and has a distal end. The telescoping section may include an inner sheath, an outer sheath, an intermediate sheath, and a sealing member; the inner sheath is coupled to the distal end of the telescoping section and defines a first lumen for accommodating the drive cable; the outer sheath is coupled to the distal end of the telescoping section and defines a second lumen, wherein the outer sheath and the inner sheath may be fixed to each other and the outer sheath generally surrounds the inner sheath; the intermediate sheath has a proximal end and extends distally to the distal end; the sealing member is positioned adjacent to the distal end of the intermediate sheath and is configured to provide a fluid-tight seal between the intermediate sheath and the inner sheath. The intermediate sheath may be configured to slide between the inner sheath and the outer sheath for telescoping the telescoping catheter.

[0020] Alternatively or in addition to any of the above examples, in another example, the intermediate sheath may define a third lumen configured to generally surround the inner sheath when the intermediate sheath is in a distally advanced form and surround a portion of the drive cable when the intermediate sheath is in a proximally displaced form.

[0021] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include a retainer sleeve secured to an outer surface of the intermediate sheath.

[0022] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include a retainer plug extending distally from the sealing member.

[0023] Alternatively or in addition to any of the above examples, in another example, the intermediate sheath can have a constant outer diameter from the proximal end to the distal end.

[0024] Alternatively or in addition to any of the above examples, in another example, the outer diameter of the retainer plug can be the same as the outer diameter of the intermediate sheath.

[0025] Alternatively or in addition to any of the above examples, in another example, the retainer sleeve can be disposed over and in contact with the distal end region of the intermediate sheath, the seal member, and the proximal end region of the retainer plug.

[0026] Alternatively or in addition to any of the above examples, in another example, the sealing member may include an O-ring.

[0027] Alternatively or in addition to any of the above examples, in another example, the telescoping catheter may further include an outer jacket disposed over the drive cable.

[0028] Alternatively or in addition to any of the above examples, in another example, the outer jacket can include a first layer and a second layer.

[0029] In another example, a telescoping catheter may include a proximal hub adjacent to a proximal end of the telescoping catheter, a drive cable, and a telescoping section, the proximal hub being adjacent to a proximal end of the telescoping catheter, the telescoping section extending from a proximal end adjacent to the proximal hub to a distal end. The telescoping section may include a distal hub, an intermediate sheath assembly, an outer sheath, and an inner sheath; the distal hub is positioned adjacent to a distal end of the telescoping section; the outer sheath is disposed on the intermediate sheath, the outer sheath having a proximal end and a distal end, the distal end being fixedly coupled to the distal hub; the inner sheath is disposed within the intermediate sheath, the inner sheath having a proximal end and a distal end, the distal end being fixedly coupled to the distal hub. The intermediate sheath assembly may include an intermediate sheath, a retainer plug, a sealing member, and a retainer sleeve; the intermediate sheath has a proximal end connected to the proximal hub and extends distally to a distal end; the retainer plug has a proximal end and a distal end, the retainer plug and the intermediate sheath extend in line; the sealing member is located between the distal end of the intermediate sheath and the proximal end of the retainer plug; the retainer sleeve is disposed on and in contact with the distal end region of the intermediate sheath, the sealing member, and the proximal end region of the retainer plug. The intermediate sheath assembly may be configured to be longitudinally displaced relative to the inner sheath and the outer sheath.

[0030] Alternatively or in addition to any of the above examples, in another example, the retainer sleeve can be configured to mechanically engage a portion of a housing coupled to a proximal end of the outer sheath to limit proximal movement of the intermediate sheath.

[0031] Alternatively or in addition to any of the above examples, in another example, the intermediate sheath assembly can define a third lumen configured to generally surround the inner sheath when the telescoping catheter is in a fully retracted configuration and surround a portion of the drive cable when the telescoping catheter is in a fully extended configuration.

[0032] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present disclosure may be more fully understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which:

[0034] Figure 1 is a side view of an example medical device;

[0035] Figure 2 is a side view of another exemplary medical device;

[0036] Figure 3 In the retracted state Figure 2 A three-dimensional image of a medical device;

[0037] Figure 4 In extended form Figure 2 A three-dimensional image of a medical device;

[0038] Figure 5 For along Figure 3 The line 5-5 is intercepted Figure 2 a cross-sectional view of a portion of a medical device;

[0039] Figure 6 For along Figure 3 The line 6-6 is intercepted Figure 2 a cross-sectional view of a portion of a medical device; and

[0040] Figure 7 For along Figure 4 The line 7-7 is intercepted Figure 2 A cross-sectional view of a portion of a medical device.

[0041] Although the present disclosure may be modified into various modifications and alternatives, the details thereof have been shown in the drawings by way of example and will be described in detail. However, it should be understood that it is not intended to limit the present invention to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents and alternative forms that fall within the spirit and scope of the present disclosure. DETAILED DESCRIPTION

[0042] With respect to the following defined terms, these definitions shall apply, unless a different definition is given in the claims or elsewhere in this specification.

[0043] All numerical values ​​are assumed to be modified by the term "about" herein, whether or not explicitly indicated. The term "about" generally refers to an index range that one skilled in the art considers to be equivalent to the stated value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant figure.

[0044] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0045] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0046] It should be noted that references in the specification to "one embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiments may include one or more particular features, structures, and / or characteristics. However, such statements do not necessarily mean that all embodiments include the particular features, structures, or characteristics. Furthermore, when particular features, structures, or characteristics are described in conjunction with one embodiment, it should be understood that such features, structures, or characteristics may also be used in conjunction with other embodiments, whether or not explicitly described, unless explicitly indicated to the contrary.

[0047] The following detailed description should be read with reference to the drawings, in which similar elements in different drawings are labeled the same. The drawings, which are not necessarily drawn to scale, illustrate illustrative embodiments and are not intended to limit the scope of the invention.

[0048] In the medical field, catheters are often used to diagnose and treat various diseases in patients, such as, but not limited to, blood vessel blockage or obstruction. For example, a catheter is introduced into a patient's blood vessel by making an incision on the patient's blood vessel and inserting the catheter into the patient's blood vessel. Then, a catheter operator (such as a doctor) manipulates the catheter through the patient's blood vessel until the catheter is properly positioned to diagnose or treat the disease. Because the manipulation of the catheter in the patient's body can sometimes be a difficult task, requiring a high degree of caution and time-consuming to change the position of the catheter, a type of catheter known as a telescopic catheter is often used to perform these diagnoses and treatments. Disclosed herein is a telescopic catheter having reduced telescopic movement forces and reduced bubble formation.

[0049] Figure 11 is a side view of an example medical device 10. In at least some cases, the medical device 10 takes the form of an imaging medical device. For example, the medical device 10 may be an intravascular ultrasound (IVUS) device, which can be used to image a blood vessel. The structure / form of the medical device 10 can be changed. In some cases, the medical device 10 may include an elongated shaft 12 having a proximal end region 14 and a distal end region 16. A proximal hub or connector 18 may be coupled to or otherwise disposed adjacent to the proximal end region 14. A top member 20 may be coupled to or otherwise disposed adjacent to the distal end region 16. The top member 20 may include a guidewire lumen 30 having a guidewire outlet 32, a non-invasive distal end 34, one or more radiopaque markers 36, and / or other features. In some embodiments, the top member 20 may extend to the proximal end region 14 of the elongated shaft 12 at a non-parallel angle. An imaging assembly 22 may be disposed within the lumen of the shaft 12. Generally speaking, an imaging assembly may be used to capture / generate images of a blood vessel. In some cases, the medical device may include devices and / or features similar to those disclosed in U.S. Patent Application Publication No. US2012 / 0059241 and U.S. Patent Application Publication No. US2017 / 0164925, the entire disclosures of which are incorporated herein by reference. In at least some cases, the medical device 10 may be similar to and / or include features similar to OPTICROSS TM Features of the Imaging Catheter (available from BOSTON SCIENTIFIC, Marlborough, MA).

[0050] Imaging assembly 22 may include a drive cable or shaft 24, a housing 26, and an imaging member or transducer 28, which is coupled to drive cable 24 and / or housing 26. In at least some cases, transducer 28 includes an ultrasonic transducer. Other transducers are also contemplated. Transducer 28 may be rotatable and / or axially translatable relative to shaft 12. For example, drive cable 24 may rotate and / or translate to rotate and / or translate transducer 28 (and housing 26).

[0051] Although Figure 1 It is not explicitly shown, but the medical device 10 may include a telescoping section configured to allow a medical device operator to move the drive shaft 24 including the imaging assembly 22 proximally and distally within the catheter without moving the entire catheter within the patient. This allows the catheter operator to easily change the position of the imaging assembly or other medical device within the patient. For example, the telescoping section may be actuated to change the position of the imaging assembly 22 within the elongated shaft 12. Disclosed herein are medical devices that reduce the telescopic movement force required when actuating the telescoping portion.

[0052] In addition, when utilizing the medical device 10, it may be desirable to prepare and / or flush the shaft 12. To flush the medical device 10, a fluid may be infused at a flush port at or on the hub 18. The fluid may exit the medical device at a vent (not shown) adjacent to the distal end of the housing 26. In some cases, the flushing process may result in the formation of bubbles within the shaft 12. It may be desirable to flush the medical device 10 in a manner that reduces bubble formation and / or removes / destroys any bubbles that are formed, as bubbles may reflect / destroy the signal (e.g., ultrasound signal) of the transducer 28, thereby disrupting the image. Although flushing is generally effective in removing bubbles, some bubbles may still be trapped within the shaft 12. Disclosed herein are medical devices that are designed to help reduce the formation of bubbles within the medical device.

[0053] Figure 2 A side view of another exemplary medical device is shown, such as, but not limited to, a telescoping catheter 100. The catheter 100 extends from a proximal end region 102 to a distal end region 104. A proximal hub 106 may be attached adjacent to the proximal end region 102. The proximal hub 106 may include a check valve and a flush port 108. To flush the catheter 100, a fluid may be injected at the flush port 108. The catheter 100 may also include a telescoping section 110 extending from a proximal end region 113 to a distal end region 115 and located between the proximal end region 102 and the distal end region 104 of the catheter 100. An elongated shaft 112 extends distally from the distal end region 115 of the telescoping section 110. The elongated shaft 112 may include a tip member 114 adjacent to the distal end region 104 of the catheter 100. The tip member 114 may be similar in form and function to a telescoping section 110 with respect to the distal end region 104 of the catheter 100. Figure 1 The tip member 20 is described. For example, the tip member 114 can include a guidewire lumen having a guidewire exit port, an atraumatic distal end, one or more radiopaque markers, and / or other features.

[0054] Imaging assembly 116 (see e.g. Figure 3) is movably positioned within the lumen of the elongated shaft 112. The imaging assembly 116 may include a drive cable or shaft 120, a housing 122, and an imaging member or transducer 118, which is coupled to the drive cable 120 and / or the housing 122. It is contemplated that the imaging assembly 116 may include or be replaced by another medical device, such as, but not limited to, a cutting head or other device. The particular device selected for the drive cable 120 may be selected based on the desired function of the catheter 100. The drive cable 120 may extend proximally from the imaging member 118 through the telescoping section 110 to the proximal hub 106. The proximal hub 106 may include components that are suitable for connecting the drive cable 120 to a power source and / or other electronic connections. In some cases, the proximal end of the drive cable 120 may be attached to the proximal hub 106. Although not explicitly shown, the drive cable 120 may include a single layer of outer jacket or coating or two layers of outer jacket or coating as desired. If so configured, the outer jacket may extend the full length of the drive cable 120 or extend less than the full length of the drive cable 120 .

[0055] The telescoping section 110 may include a first or intermediate sheath 124, a second or outer sheath 126, and a third or inner sheath 128. Typically, the outer sheath 126 may be disposed over the intermediate sheath 124, and the intermediate sheath 124 may be disposed over the inner sheath 128. The intermediate sheath 124 may be axially and / or rotationally displaceable relative to the outer sheath 126 and the inner sheath 128 such that movement of the proximal hub 106 translates into movement of the intermediate sheath 124 and the drive cable 120. The distal hub 138 may be positioned adjacent to the distal end region 115 of the telescoping section 110. The distal hub 138 may include a distal strain relief 139 configured to be coupled to the elongated shaft 112. Additionally, the distal ends of the outer sheath 126 and the inner sheath 128 may each be securely secured to the distal hub 138.

[0056] The intermediate sheath 124 extends distally from a proximal end region 130 to a distal end 134, the proximal end region 130 being coupled to a proximal strain relief 132, and the distal end 134 extending within the outer sheath 126. The intermediate sheath 124 can have a constant diameter from the proximal end region 130 to the distal end 134, but this is not required. The proximal strain relief 132 is coupled to the proximal hub 106. The intermediate sheath 124 is movable relative to the inner sheath 128 and the outer sheath 126, such that the distal end 134 of the intermediate sheath 124 is movable between the distal hub 138 and the housing 142. The intermediate sheath 124 defines a lumen 136 (see, e.g., Figures 5 to 7 ), the lumen 136 extends from the proximal end region 130 to its distal end 134. The lumen 136 can receive and / or accommodate a portion of the drive shaft 120 and / or the inner sheath 128.

[0057] The outer sheath 126 extends distally from a proximal end region 140 coupled to a housing or receptacle 142 to a distal end 144 attached to a distal hub 138 (see, e.g., Figure 5 The outer sheath 126 defines a lumen 146 (see, e.g., Figures 5 to 7 ), the lumen 146 extends from the proximal end region 140 to the distal end 144. The lumen 146 can receive or accommodate a portion of the inner sheath 128 and / or the intermediate sheath 124.

[0058] The inner sheath 128 extends distally from the proximal end region to a distal end 148 that is attached to the distal hub 138 (see, e.g., Figure 5 Inner sheath 128 defines lumen 150 (see, e.g., Figures 5 to 7 ), the lumen 150 extends from the proximal end region to the distal end 148. The lumen 150 can receive or accommodate a portion of the drive shaft 120. For example, the inner sheath 128 can be configured to support the drive shaft 120 when the intermediate sheath 124 is in a proximally displaced configuration (see, e.g., Figure 4 ). In some embodiments, the proximal end region of the inner sheath 128 can be positioned adjacent to the proximal end region 140 of the outer sheath 126. In other embodiments, the proximal end region of the inner sheath 128 can be distal from the proximal end region 140 of the outer sheath 126.

[0059] Figure 3 Shows Figure 2 1 is a perspective view of a telescoping catheter with the proximal hub 106 and the intermediate sheath 124 (and therefore the drive shaft 120) in the most distal position. This configuration can be considered fully retracted because the catheter 100 is at its shortest length. Figure 3 In the figure, the elongated shaft 112 is not shown to more clearly illustrate the structure of the imaging assembly 116. Figure 3 In the embodiment of the present invention, the intermediate sheath 124 has been advanced distally within the lumen 146 of the outer sheath 126. Distal movement of the intermediate sheath 124 can be limited by a mechanical stop formed between the proximal strain relief 132 and the housing 142. When the proximal hub 106 and the intermediate sheath 124 are in the distal-most position, a majority of the length of the lumen 136 of the intermediate sheath 124 can surround the inner sheath 128.

[0060] Figure 4 Shows Figure 2 1 is a perspective view of the proximal portion of the telescoping catheter of FIG. 1 , wherein the proximal hub 106 and the intermediate sheath 124 (and thus the drive shaft 120) are near the most proximal position. This configuration can be considered fully extended because the catheter 100 has a maximum length. Figure 4In the embodiment of the present invention, the intermediate sheath 124 has been displaced proximally within the lumen 146 of the outer sheath 126. The proximal movement of the intermediate sheath 124 can be limited by a mechanical stop formed between a distal end region of the intermediate sheath 124 and mating features on the housing 142. When the proximal hub 106 and the intermediate sheath 124 are in the proximal-most position, a majority of the length of the lumen 136 of the intermediate sheath 124 can surround the drive cable 120.

[0061] Although Figure 3 and Figure 4 The approximate limits of movement of the telescoping section 110 are shown, but the proximal hub 106 and the intermediate sheath 124 can be located anywhere therebetween. Since the drive cable 120 is coupled to the proximal hub 106, proximal and distal movement is transferred to the drive cable 120 and the imaging assembly 116 to allow the imaging assembly to move without moving the entire catheter 100. It is also contemplated that rotational movement of the proximal hub 106 will also be transferred to the drive cable 120 and the imaging assembly 116 to allow the imaging assembly 116 to rotate within the elongated shaft 112.

[0062] Figure 5 For along Figure 3 5-5 of the telescoping section 110 when the proximal hub 106 and the intermediate sheath 124 are in the most distal configuration. The drive shaft 120, the inner sheath 128, the intermediate sheath 124, and the outer sheath 126 are coaxially arranged. In this configuration, the distal end 134 of the intermediate sheath 124 is adjacent to or near the distal ends 144, 148 of the outer sheath 126 and the inner sheath 128. The telescoping section 110 also includes a sealing member 152, which is located between the outer surfaces of the intermediate sheath 124 and the inner sheath 128 proximal to the distal end 134 of the intermediate sheath 124. The sealing member 152 can be a flexible and / or deformable component that is configured to provide a fluid-tight seal between the intermediate sheath 124 and the inner sheath 128. In some cases, the sealing member 152 can be a silicone O-ring. However, other sealing member shapes and / or materials can be envisioned. The size and shape of the sealing member 152 can be set to restrict the fluid path when the telescopic catheter 100 is flushed. For example, when the fluid is introduced via the port 108, the fluid can fill the lumen 136 of the intermediate sheath 124 and the lumen 150 of the inner sheath 128. However, the sealing member 152 prevents the fluid from leaving the lumen 136 of the intermediate sheath 124, and therefore prevents the fluid from entering the lumen 146 of the outer sheath 126, thereby providing a simpler flow path. In addition, the fluid is allowed to pass through the lumen 150 of the inner sheath 128 toward the distal side, through the distal hub 138, and travel into the elongated shaft 112. It can also be envisioned that the positioning of the sealing member 152 between the intermediate sheath 124 and the inner sheath 128 can reduce the telescopic movement force of the catheter 100.

[0063] In some embodiments, the intermediate sheath 124 may be part of the intermediate sheath assembly 154. The intermediate sheath assembly 154 may include the intermediate sheath 124, the retainer plug 156, the retainer sleeve 158 and the sealing member 152. The retainer plug 156 may extend colinearly with the intermediate sheath 124. For example, the retainer plug 156 may have an inner diameter and an outer diameter that are similar in size to the inner diameter and outer diameter of the intermediate sheath 124, but this is not necessary. In some embodiments, the sealing member 152 may be located between the distal end 134 of the intermediate sheath 124 and the proximal end 160 of the retainer plug 156. However, this is not necessary. As required, the sealing member 152 may be located in other positions and / or forms. For example, the sealing member 152 may be configured to extend between the inner surface of the intermediate sheath 124 and / or the retainer plug 156 and the outer surface of the inner sheath 128. It is conceivable that the intermediate sheath 124 and the retainer plug 156 may be formed as separate components and then attached. In other embodiments, the intermediate sheath 124 and the retainer plug 156 may form a single unitary structure. For example, the intermediate sheath 124 and the retainer plug 156 may be molded as a single component on the sealing member 152, or may be molded with a recess configured to receive the sealing member 152. These are just some examples.

[0064] Retainer sleeve 158 may be located on an outer surface of intermediate sheath 124, retainer plug 156, and / or seal member 152, and may extend from proximal end 164 to distal end 166. Proximal end 164 of retainer sleeve 158 may be positioned proximal to distal end 134 of intermediate sheath 124, and distal end 166 of retainer sleeve 158 may be positioned distal to proximal end 160 of retainer plug 156, such that retainer sleeve 158 extends over the distal end region of intermediate sheath 124, seal member 152, and proximal end region of retainer plug 156. It is contemplated that retainer sleeve 158 may be heat shrunk, molded, or adhered to intermediate sheath 124, seal member 152, and retainer plug 156. In some embodiments, retainer sleeve 158 may secure intermediate sheath 124, seal member 152, and retainer plug 156 to one another. Additionally or alternatively, intermediate sheath 124, sealing member 152, and retainer plug 156 may be secured using an adhesive, or may be formed as a unitary structure by molding or overmolding. Retainer sleeve 158 may have an inner diameter and an outer diameter, the inner diameter being substantially the same as the outer diameter of intermediate sheath 124 and / or retainer plug 156, and the outer diameter being smaller than the inner diameter of outer sheath 126, such that retainer sleeve 158 does not frictionally engage the inner surface of outer sheath 126.

[0065] Figure 6 For along Figure 36-6 of the proximal end region 113 of the telescoping section 110 when the proximal hub 106 and the intermediate sheath 124 are in the most distal configuration. The proximal end region 140 of the outer sheath 126 is fixed within the lumen 168 of the housing 142. The proximal end region 170 of the inner sheath 128 may not be attached to other components. In some embodiments, the housing 142 may include an anchor seal plug 172 located at or near its proximal end 174. The proximal end 176 of the anchor seal plug 172 may be configured to provide a mechanical stop with the proximal strain relief 132 to limit further distal movement 184 of the proximal hub 106 and the intermediate sheath 124. For example, when the proximal hub 106 and the intermediate sheath 124 are in the most distal configuration, the distal end of the proximal strain relief 132 contacts the proximal end 176 of the anchor seal plug 172.

[0066] As described above, the drive cable 120 may include an outer jacket or coating. The outer jacket may be formed of a first layer 121 and a second layer 123. However, in some embodiments, less than two layers (e.g., one or zero layers) may be provided, or more than two layers (e.g., three or more layers) may be provided, as desired.

[0067] Figure 7 For along Figure 4 A cross-sectional view of the intermediate region of the telescoping section 110 taken along line 7-7 when the proximal hub 106 and the intermediate sheath 124 are proximal to the most proximal configuration. Figure 4 and Figure 7 , the proximal hub 106 and the intermediate sheath 124 have been moved in the proximal direction 182 from Figure 3 , Figure 5 and Figure 6 The proximal hub 106 and the intermediate sheath 124 are actuated in the illustrated embodiment. In the illustrated embodiment, the proximal hub 106 and the intermediate sheath 124 have been displaced proximally until the proximal end 134 of the intermediate sheath 124 is disposed within the housing 142. The housing 142 may include an annular protrusion 178 extending radially inward from the inner surface of the housing 142. The annular protrusion may define a distal wall 180. It is contemplated that the protrusion 178 may define an opening having a diameter substantially the same as the outer diameter of the intermediate sheath 124. Since the retainer sleeve 158 has an outer diameter greater than that of the intermediate sheath 124, further proximal displacement 182 of the proximal hub 106 and the intermediate sheath 124 causes the proximal end 164 of the retainer sleeve 158 to abut the distal wall 180 of the protrusion 178. This mechanical engagement limits proximal movement 182 of the proximal hub 106 and the intermediate sheath 124 , and also prevents the intermediate sheath 124 from disengaging from the inner sheath 128 and the outer sheath 126 .

[0068] It should be understood that the present disclosure is in many respects illustrative only. Changes may be made in detail without exceeding the scope of the present disclosure, particularly with respect to the arrangement of shapes, sizes, and steps. To an appropriate degree, this may include the use of any one of the features of an example embodiment being used in other embodiments. Of course, the scope of the present invention is defined in the language of the appended claims.

Claims

1. A telescopic catheter, comprising: a proximal hub adjacent a proximal end of the telescoping catheter; Drive cable; a telescoping section extending from a proximal end adjacent to the proximal hub to a distal end, the telescoping section comprising: an intermediate sheath having a proximal end coupled to the proximal hub and extending distally to a distal end; an outer sheath disposed on the intermediate sheath, the outer sheath having a proximal end and a distal end; an inner sheath disposed within the intermediate sheath, the inner sheath having a proximal end and a distal end; and a sealing member disposed between the intermediate sheath and an outer surface of the inner sheath; Wherein, the intermediate sheath is configured to be longitudinally displaced relative to the inner sheath and the outer sheath.

2. The telescopic catheter according to claim 1, wherein: The sealing member is configured to form a fluid tight seal between the inner jacket and the intermediate jacket.

3. The telescopic catheter according to any one of claims 1 to 2, wherein: The intermediate sheath has a constant outer diameter from its proximal end to its distal end.

4. The telescopic catheter according to any one of claims 1 to 3, wherein: The sealing member includes an O-ring.

5. The telescopic catheter according to any one of claims 1 to 4, wherein: The outer sheath and the inner sheath are secured to each other.

6. The telescopic catheter according to any one of claims 1 to 5, wherein: The intermediate sheath defines a lumen configured to generally surround the inner sheath when the intermediate sheath is in the distally advanced configuration and to surround a portion of the drive cable when the intermediate sheath is in the proximally displaced configuration.

7. The telescopic catheter according to any one of claims 1 to 6, further comprising an outer jacket disposed on the drive cable.

8. The telescopic catheter according to claim 7, wherein: The outer jacket includes a first layer and a second layer.

9. The telescoping catheter of any one of claims 1 to 8, further comprising a housing coupled to the proximal end of the outer sheath.

10. The telescoping catheter of any one of claims 1 to 9, further comprising a retainer sleeve secured to an outer surface of the intermediate sheath.

11. The telescoping catheter of any one of claims 1 to 10, further comprising a retainer plug extending distally from the sealing member.

12. The telescopic catheter according to claim 9, wherein: A proximal strain relief is coupled to the proximal hub and is configured to mechanically engage a proximal portion of the housing to limit proximal movement of the intermediate sheath.

13. The telescopic catheter according to claim 10, wherein: The retainer sleeve is configured to mechanically engage a portion of the housing to limit proximal movement of the intermediate sheath.

14. The telescopic catheter according to claim 11, wherein: The retainer plug has an outer diameter that is the same as the outer diameter of the intermediate sheath.

15. The telescopic catheter according to claim 11, wherein: The retainer sleeve is disposed over and in contact with a distal end region of the intermediate sheath, the sealing member, and a proximal end region of the retainer plug.

Images