Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
DEVICE FOR DELIVERING AND DEPLOYING A STENT

2. APPLICANT:
Meril Corporation (I) Private Limited, an Indian company of the address Survey No. 135/139, Muktanand Marg, Bilakhia House, Pardi, Vapi, Valsad-396191 Gujarat, India.

The following specification particularly describes the invention and the manner in which it is to be performed:


FIELD OF INVENTION
[1] The present disclosure relates to a medical device. More particularly, the present disclosure relates to a device for delivering and deploying a stent.
BACKGROUND OF INVENTION
[2] The human body includes a network of blood vessels such as arteries, veins, etc. through which blood is pumped around the body. Peripheral vascular disease is the reduced blood circulation to a body part due to a blocked blood vessel. Blockage of blood vessels occurs due to the deposition of fats and cholesterol. This buildup is called plaque. The plaque results in narrowing of a blood vessel. Hence, passage of blood is blocked in a blood vessel, reducing blood flow and oxygen to vital organs. The plaque can also burst, leading to a blood clot. The plaque can cause chest pain or shortness of breath. The reduced blood flow can also lead to pain, numbness, or serious infection in different body parts. The peripheral vascular disease can also lead to a heart attack/stroke.
[3] Implanting a stent in a blocked portion of a vessel is one of the most common treatments. A delivery system is used to deliver a stent at a target location inside a patient’s body. In a typical procedure for implanting a self-expandable stent, a catheter is used to deliver a stent at a target location. An outer sheath of the catheter is then retracted to deploy the stent at the target location.
[4] In the existing delivery systems (or devices) the outer sheath of the catheter is retracted or advanced using mechanical actuators that are operated manually by an operating physician to deploy the stent. However, such manual procedures are tedious and laborious, and may cause hand fatigue to the surgeon. Further, the conventional systems do not provide any guidance with respect to, for example, how much a switch needs to be pressed, or how many times a roller needs to be rotated or how far a lever should be pulled to deploy the stent. Therefore, the conventional systems depend a lot on the skill and subjective judgement of the operating physician. This imposes high requirements on the operating physician and raises a considerable amount of risk in terms of faulty operations and inaccuracy of the operation, which may lead to deterioration in surgical performance, especially in case the stent is not deployed at the target site correctly. Moreover, the operating physician is unaware of how much the stent is deployed and hence, cannot properly plan the further deployment. This may result in insufficient stent deployment. Such instances may cause blood loss, enhanced trauma, infection and an overall sub-optimal outcome, which may prove fatal for the patient.
[5] Thus, there arises a need for a device that overcomes the problems associated with the conventional devices.
SUMMARY OF INVENTION
[6] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[7] The present disclosure relates to a device for deploying a stent. In an embodiment, the device includes a motor, a rotating member, a translating member, a catheter, a first control element and a control unit. The motor includes a shaft. The rotating member is rotatably coupled to the shaft and is configured to rotate in response to the rotation of the shaft of the motor. The translating member is coupled to the rotating member and is configured to move longitudinally in response to the rotation of the rotating member. The catheter includes an outer sheath coupled to the translating member and an inner lumen disposed within the outer sheath. The outer sheath is configured to move longitudinally in response to the longitudinal movement of the translating member. The first control element is capable of receiving a first actuation input. The control unit is coupled to the first control element and the motor. The control unit is configured to: detect the first actuation input received by the first control element; and in response to detecting the first actuation input, cause the motor to rotate in a first pre-defined direction to move the translating member in a proximal direction by a pre-defined distance, thereby deploying a stent, mounted on the inner lumen, by the pre-defined distance.
BRIEF DESCRIPTION OF DRAWINGS
[8] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentality disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[9] Fig. 1a depicts a perspective view of a proximal portion of a device 100 for delivering and deploying a stent, according to an embodiment of the present disclosure.
[10] Fig. 1b depicts an exploded view of the device 100, according to an embodiment of the present disclosure.
[11] Fig. 1c depicts a sectional view of the proximal portion of the device 100, according to an embodiment of the present disclosure.
[12] Fig. 2 depicts a perspective view of a handle 101, according to an embodiment of the present disclosure.
[13] Fig. 2a depicts a coupling of an inner lumen 111 of a catheter 110 with the handle 101, according to an embodiment of the present disclosure.
[14] Fig. 3 depicts a perspective view of a motor 120, according to an embodiment of the present disclosure.
[15] Fig. 3a depicts a perspective view of a first motor lock 201, according to an embodiment of the present disclosure.
[16] Fig. 4a depicts a perspective view of a rotating member 130, according to an embodiment of the present disclosure.
[17] Fig. 4b depicts a side cross-sectional view of the rotating member 130, according to an embodiment of the present disclosure.
[18] Fig. 5 depicts a perspective view of a translating member 140, according to an embodiment of the present disclosure.
[19] Fig. 5a depicts a coupling between the translating member 140 and an outer sheath 110c of the catheter 110, according to an embodiment of the present disclosure.
[20] Fig. 6 depicts a perspective view of a wire guide 170a, according to an embodiment of the present disclosure.
[21] Fig. 7 depicts a perspective view of a configuration showing coupling of a wire 150 with the rotating member 130, the translating member 140 and a plurality of wire guides 170a – 170e, according to an embodiment of the present disclosure.
[22] Fig. 8 depicts a perspective view of a locking member 160, according to an embodiment of the present disclosure.
[23] Fig. 9 depicts a method 900 of deploying a stent 10 using the device 100, according to an embodiment of the present disclosure.
[24] Fig. 9a depicts various components of the device 100 when the stent 10 is in an undeployed state, according to an embodiment of the present disclosure.
[25] Fig. 9b depicts various components of the device 100 when the stent 10 is in a partially deployed state, according to an embodiment of the present disclosure.
[26] Fig. 9c depicts various components of the device 100 when the stent 10 is in a fully deployed state, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[27] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[28] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[29] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[30] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[31] The present disclosure relates to a device for delivering and deploying a stent. The device may be used to deploy various types of stents, such as, without limitation, coronary stents, intravascular stents, airway stents, peripheral stents and the like. The present disclosure aims to make the delivery and deployment process of the stent at the target site highly precise and controllable. The device enables the medical practitioner to deploy the stent up to the exact length the medical practitioner wants to deploy. The device may be operated with the help of one or more control elements (e.g., buttons). In an embodiment, the device includes a first control element for deploying the stent. Various components of the device are designed such that when the first control element is actuated once, the stent is deployed precisely by a pre-defined length. Since a single actuation of the first control element exactly deploys the pre-defined length of the stent, the proposed device does not rely on subjectivity or skills of a user and eliminates manual errors as encountered with conventional stent delivery devices. Consequently, the device increases the ease of use, and enhances overall predictability and accuracy of the stent deployment process. The pre-defined length may be configurable. This gives more control to the user in deploying the stent based upon requirements. Further, the device may display the amount of stent deployed (either in terms of the actual length deployed or as a percentage of the total length of the stent). This knowledge, not offered by any conventional devices, enables the medical practitioner to plan further deployment of the stent in a better and more informed manner. Thus, the present disclosure provides higher precision, extra control over the stent deployment procedures and eliminates human error, thereby improving overall outcome for a patient.
[32] Now, referring to figures, Figs. 1a-1c depict a device 100 for deploying a stent, according to an embodiment of the present disclosure. In an embodiment, the device 100 ensures delivery and deployment of the stent at a target site within a patient’s vessel with high accuracy and precision. In an embodiment, the stent is a self-expanding stent. The device 100 has a proximal end 100a and a distal end 100b.
[33] The device 100 includes a handle 101, a catheter 110, a motor 120, a rotating member 130, a translating member 140, a wire 150, a plurality of wire guides, and a plurality of control elements 180. In an embodiment, the plurality of control elements 180 includes a first control element 181a, a second control element 181b and a third control element 181c. The device 100 further includes a control unit (not shown).
[34] Fig. 2 depicts an exemplary handle 101. The handle 101 is provided at the proximal end 100a of the device 100. The handle 101 encloses a space and houses various components of the device 100. The handle 101 allows the medical practitioner to hold and operate the device 100. The handle 101 may be made of a material including, without limitation, Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), High-density Polyethylene (HDPE), etc. In an exemplary embodiment, the handle 101 is made of Acrylonitrile Butadiene Styrene (ABS). The handle 101 is designed to have an ergonomic shape for the comfort of the medical practitioner. The handle 101 may include a first portion 101a disposed towards a proximal end of the handle 101 and a second portion 101b disposed towards a distal end of the handle 101. In an embodiment, the first portion 101a is generally cuboidal, though the first portion 101a may have any other shape. In an embodiment, the second portion 101b is generally cylindrical, though the second portion 101b may have any other shape. Further, the handle 101 may have a left section 101c and a right section 101d (shown in Fig. 1a), which when coupled together form the handle 101 having the first portion 101a and the second portion 101b. The left section 101c and the right section 101d may be coupled using, for example, a snap-fit mechanism, fasteners, etc. For example, the handle 101 may be provided with a plurality of protrusions 210 in the interior of the left section 101c and a corresponding plurality of grooves (not shown) in the interior of the right section 101d forming a snap-fit lock, or vice versa. In an embodiment, the protrusions 210 have a hook-like shape, though they may have any other shape.
[35] The catheter 110 has a proximal end and a distal end, defining a length therebetween. The catheter 110 includes an outer sheath 110c and an inner lumen 111 (shown in Fig. 2a) disposed within the outer sheath 110c. The catheter 110 has a tubular structure and may include at least a first lumen (not shown) extending for the entire length of the catheter 110. The first lumen provides a passage for the inner lumen 111. The inner lumen 111 is configured to provide a passage for a guidewire (not shown). The catheter 110 may further include additional lumens, for example, the catheter 110 may include one additional lumen (not shown) for a pusher tube to push the stent (not shown). The outer sheath 110c is coupled to the translating member 140 as explained later. The inner lumen 111 is fixedly coupled to the handle 101 such that the inner lumen 111 remains in a fixed position and does not move. In an embodiment, a holder 109 (shown in Fig. 2) is provided in the handle 101. The holder 109 is tubular. A proximal portion of the inner lumen 111 of the catheter 110 is disposed within the holder 109 (as shown in Fig. 2a). The holder 109 is coupled with the proximal portion of the inner lumen 111 using, for example, adhesive bonding. A stent to be deployed is disposed at a distal end 110b of the catheter 110 such that, in an undeployed state, the stent completely resides within the outer sheath 110c. The stent is mounted on the inner lumen 111 in a crimped state. The outer sheath 110c applies a constraining force on the stent. When the outer sheath 110c retracts in the proximal direction, a portion of the stent is exposed. In the absence of the constraining force on the stent by the outer sheath 110c, the exposed portion of the stent radially expands and is deployed. Upon retracting the outer sheath 110c for the entire length of the stent, the stent fully expands and is considered to be fully deployed. Similarly, when the outer sheath 110c advances in the distal direction and covers a portion of the stent. Since the outer sheath 110c applies constraining force on the said portion of the stent, the said portion of the stent radially contracts. In an embodiment, the catheter 110 may be a rapid exchange catheter and includes a rapid exchange port (not shown). The rapid exchange port provides a passage to insert a guidewire during the operation of the device 100.
[36] The dimensions of the outer sheath 110c and the inner lumen 111 of the catheter 110 may be chosen based upon requirements of the surgical procedure. In an embodiment, the length of the outer sheath 110c may range between 1000 mm and 4000 mm and the outer diameter of the outer sheath 110c may range between 1.2 mm and 5 mm. In an example implementation, the length and the outer diameter of the outer sheath 110c are 1800 mm and 2 mm, respectively. The length of the inner lumen 111 of the catheter 110 may range between 900 mm and 3900 mm and the outer diameter of the inner lumen 111 may range between 0.9 mm and 4.9 mm. In an example implementation, the length and the outer diameter of the inner lumen 111 are 1750 mm and 1.8 mm, respectively. The outer sheath 110c may be made of a biocompatible material, such as, without limitation, thermoplastic elastomer (e.g., Pebax), Polyetheretherketone (PEEK), Polyurethane (PU), etc. and the inner lumen 111 may be made of a biocompatible material, such as without limitation, thermoplastic elastomer (e.g., Pebax), PEEK, Polyurethane (PU), etc. In an example implementation, the outer sheath 110c and the inner lumen 111 are made of Pebax and PEEK, respectively. The second portion 101b of the handle 101 may be provided with a cut-out 103 (shown in Fig. 2) at the distal end of the handle 101 to provide a passage for the catheter 110 to extend into the handle 101. The proximal end of the catheter 110 is disposed within the second portion 101b.
[37] The device 100 enables the medical practitioner to retract (or advance) the outer sheath 110c by a precise distance to deploy (or retrieve) the stent in an accurate and controlled manner. In an embodiment, the motor 120, the rotating member 130, the translating member 140, the wire 150, and the wire guides may form a driving assembly configured to retract or advance the outer sheath 110c for deploying or retracting the stent. The outer sheath 110c is coupled to the driving assembly as explained later. Various components of the driving assembly are designed carefully and work in sync to achieve the precise deployment of the stent.
[38] Fig. 3 depicts an exemplary motor 120. The motor 120 may be disposed inside the first portion 101a of the handle 101 (as shown in Fig. 1c). In an embodiment, the motor 120 has a casing 120a and an extension 120b. The casing 120a is rectangular, though the casing 120a may have any other shape. The motor 120 is capable of rotating in both clockwise and anti-clockwise directions. The rotation of the motor 120 causes the outer sheath 110c of the catheter 110 to advance or retract depending upon the rotational direction of the motor 120. The motor 120 includes a shaft 121. In an embodiment, the motor 120 is a DC gear motor, and includes a gear box (not shown). The gear box (or the gearbox) is disposed within the extension 120b. The extension 120b acts as a casing for the gear box. The gear box is coupled to the output of the motor 120 and is configured to drive the shaft 121, i.e., transfer the rotational motion of the motor 120 to the shaft 121. The gear box includes two or more gears and has a pre-defined gear ratio. In an embodiment, the gear box is a step-down gearbox (i.e., the pre-defined gear ratio is less than one) and is configured to reduce the rotational speed and increase the output torque of the shaft 121. The two or more gears designed and coupled such that for each rotation of the motor 120, the shaft 121 completes a partial rotation. In an embodiment, the shaft 121 rotates in the same rotational direction as the motor 120.
[39] In an embodiment, the shaft 121 is coupled to the gear box such that the shaft 121 is perpendicular to the longitudinal axis of the motor 120. In this case, the motor 120 and the gear box form a worm gear mechanism. The shaft 121 may be coupled to the gearbox using any technique known in the art, such as, a locking screw, a key and slotted shaft, etc. The shaft 121 has a pre-defined shape such as, without limitation, oval, or semi-circular, D-shaped, etc. In an exemplary embodiment, the shaft 121 is D-shaped. The dimensions of the shaft 121 are chosen based upon requirements. The shaft 121 is used to drive the rotating member 130.
[40] The motor 120 further includes a first input terminal 125a and a second input terminal 125b. The first input terminal 125a and the second input terminal 125b receive a power signal each. Depending the polarity of the power signals received by the first input terminal 125a and the second input terminal 125b, the motor 120 rotates in the clockwise or in the anticlockwise direction. In an embodiment, the motor 120 rotates in the clockwise direction when a positive power signal and a negative power signal is provided at the first input terminal 125a and the second input terminal 125b, respectively, and the motor 120 rotates in the anti-clockwise direction when a negative power signal and a positive power signal is provided at the first input terminal 125a and the second input terminal 125b, respectively. According to an embodiment, the motor 120 runs at a pre-set speed and is not changed during the operation of the device 100. This facilitates a controlled, precise and predictable deployment (and retrieval) of the stent. The pre-set speed may be chosen based upon procedural requirements. In an embodiment, the pre-set speed ranges between 5 RPM and 20 RPM. In an example implementation, the pre-set speed is 8 RPM. In an embodiment, an encoder (not shown) is coupled to the motor 120 using any coupling technique known in the art. The encoder is configured to detect an angular position of the motor 120 and provide a corresponding signal to the control unit. The encoder may be a rotary encoder, an incremental encoder, an absolute encoder, an optical encoder, etc. The encoder may be capable indicating an absolute and/or incremental angular position. In an example implementation, the encoder is a rotary encoder and indicates the absolute angular position.
[41] Optionally, a first motor lock 201 and a second motor lock 203 are provided within the handle 101. The first motor lock 201 and the second motor lock 203 are configured to lock the motor 120 at a given position within the handle 101 and prevent any displacement of the motor 120. Fig. 3a depicts a perspective view of the first motor lock 201. The first motor lock 201 has a rectangular body, though the first motor lock 201 may have a body of any shape. A hole 201a is provided on the first motor lock 201. A protrusion 201b is provided at one end of the first motor lock 201. The protrusion 201b fits within a corresponding slot 205 (shown in Fig. 2) provided in the handle 101 to attach the first motor lock 201 with the handle 101. The second motor lock 203 (shown in Fig. 2) has a rectangular body, though the second motor lock 203 may have a body of any shape. The second motor lock 203 is aligned perpendicular to the first motor lock 201. A hole 203a is provided on top of the second motor lock 203. The holes 201a and 203a are aligned. A fastener (not shown) is inserted into the holes 201a and 203b, thereby coupling the first motor lock 201 and the second motor lock 203 together and locking the motor 120 in place.
[42] Fig. 4a depicts an exemplary rotating member 130 and Fig. 4b depicts a side cross-sectional view of the rotating member 130, according to an embodiment. The rotating member 130 is rotatably coupled to the shaft 121 of the motor 120. The rotating member 130 is configured to rotate in response to the rotation of the shaft 121 of the motor 120. The rotating member 130 may rotate in the same direction and by the same angle as that of the shaft 121. In an embodiment, in response to the motor 120 rotating by a pre-defined number of rotations, the shaft 121 and the rotating member 130 are configured to rotate by a pre-defined angle. The pre-defined angle depends upon the pre-defined number of rotations of the motor 120 and the pre-defined gear ratio of the gearbox. The pre-defined gear ratio may be chosen based upon requirements. For example, the pre-defined gear ratio may be 1/72, 1/236, 1/302, 1/603, 1/798, 1/1030, and the like. In an example implementation, the pre-defined gear ratio is 1/72 such that the shaft 121 and the rotating member 130 rotate by about 5 degrees for each rotation of the motor 120.
[43] In an embodiment, the rotating member 130 includes a central rod 131 and a flange 133 provided on each side of the central rod 131, thereby defining a groove 135. The groove 135 is configured to receive the wire 150. In an embodiment, the central rod 131 is cylindrical, though the central rod 131 may have any other suitable shape. The flanges 133 have a pre-defined shape, such as, without limitation, slotted, semi-circular, etc. In an exemplary embodiment, the flanges 133 are in the form of circular discs designed to form the groove 135 having a rectangular shape. It should be understood that the groove 135 may have any other shape, for example, U-shaped, V-shaped, etc., and the flanges 133 may be designed accordingly.
[44] In an embodiment, the rotating member 130 includes a first cavity 139c provided centrally and extending along the longitudinal axis of the rotating member 130 for at least a partial length of the rotating member 130. As shown, in an embodiment, the first cavity 139c extends through the central rod 131 and the flanges 133 for the entire length of the rotating member 130. The first cavity 139c is configured to receive the shaft 121 and is coupled with the shaft 121 using any coupling technique known in the art, such as, a locking screw, a screw and nut, a key-slot, etc. The first cavity 139c may have a pre-defined shape, such as, circular, D-shaped, etc. In an embodiment, the first cavity 139c is circular. Further, a pair of second cavities 137 may be provided on an outer surface of the central rod 131. The pair of second cavities 137 are situated diametrically opposite to each other. The pair of second cavities 137 extend from the outer surface of the central rod 131 to the first cavity 139c and are perpendicular to the longitudinal axis of the central rod 131. The pair of second cavities 137 are provided to prevent the wire 150 from slipping.
[45] Optionally, the rotating member 130 includes an extended portion 139 extending from one of the flanges 133 as shown in Fig. 4a and Fig. 4b. The extended portion 139 includes a third cavity 139b provided centrally and extending axially along the length of the extended portion 139. The third cavity 139b is co-axial and contiguous with the first cavity 139c of the rotating member 130 and is configured to receive the shaft 121. The third cavity 139b may have a pre-defined shape, such as, circular, D-shaped, etc. In the depicted embodiment, the third cavity 139b is circular. The extended portion 139 helps in locking the rotating member 130 with the shaft 121. For example, a hole 139a is provided on the outer surface of the extended portion 139 of the rotating member 130. The hole 139a extends to the third cavity 139b. The hole 139a of the rotating member 130 is configured to receive a fastener to lock the shaft 121 of the motor 120 with the rotating member 130. For example, once the fastener is inserted into and coupled with the hole 139a of the rotating member 130, a bottom face of the fastener mates with a top surface of the shaft 121. The locking of the rotating member 130 with the shaft 121 prevents any loosening between the two and ensures that the rotating member 130 and the shaft 121 rotate in sync. In an example implementation, the fastener may be a screw and accordingly, the hole 139a is provided with internal threads that engage with threads provided on the fastener.
[46] The rotating member 130 is disposed proximal to the translating member 140. Fig. 5 depicts an exemplary translating member 140. The translating member 140 may be disposed within the second portion 101b of the handle 101 as depicted in Fig. 1b and is slidable along the longitudinal axis of the second portion 101b. The translating member 140 is coupled to the rotating member 130 such that the translating member 140 is configured to move longitudinally in response to the rotation of the rotating member 130. The direction of longitudinal movement of the translating member 140 depends upon the rotational direction of the rotating member 130 and the distance travelled by the translating member 140 depends upon the angle by which the rotating member 130 rotates. In an embodiment, the translating member 140 is configured to move longitudinally (or linearly) in a proximal direction in response to motor 120 and the rotating member 130 rotating in a first pre-defined direction and in a distal direction in response to the motor 120 and the rotating member 130 rotating in a second pre-defined direction. Further, the translating member 140 is coupled to outer sheath 110c of the catheter 110 such that the outer sheath 110c is configured to move longitudinally in response to the longitudinal movement of the translating member 140. The translating member 140 and the outer sheath 110c move in the same direction and by the same distance.
[47] The translating member 140 has a proximal end 140a and a distal end 140b. The translating member 140 has a pre-defined shape, such as, without limitation, oval, slotted, square, rectangular, etc. In an exemplary embodiment, the translating member 140 is cylindrical in shape. In an embodiment, the translating member 140 includes a first aperture 141a, a second aperture 141b and a third aperture 141c. The first aperture 141a, the second aperture 141b and the third aperture 141c extend along the length of the translating member 140. The first aperture 141a is configured to receive a proximal portion of the outer sheath 110c of the catheter 110 and the proximal end of the outer sheath 110c is disposed within the first aperture 141a (as shown in Fig. 5a). The proximal portion of the outer sheath 110c is coupled to the first aperture 141a using, for example, adhesive bonding. The cross-sectional shape and diameter of the first aperture 141a corresponds to the cross-sectional shape and the outer diameter of the catheter 110. The second aperture 141b and the third aperture 141c are configured to provide a passage to the wire 150. The second aperture 141b and the third aperture 141c may have a pre-defined cross-sectional shape, such as, without limitation, square, semi-circular, etc. In an exemplary embodiment, the second aperture 141b and the third aperture 141c are circular. In an embodiment, the second aperture 141b is provided below the first aperture 141a and is adjacent to the first aperture 141a. This helps in balancing the force for smooth sliding of the translating member 140. The first aperture 141a and the third aperture 141c may be provided above and below the second aperture 141b, respectively. Further, the first aperture 141a, the second aperture 141b and the third aperture 141c are aligned vertically. Such an alignment ensures that the longitudinal axis of the section of the wire 150 when passing through the translating member 140, the longitudinal axis of the translating member 140 and the longitudinal axis of the outer sheath 110c are aligned with each other, resulting in a smooth and accurate movement of the translating member 140 and the outer sheath 110c.
[48] The translating member 140 may further include a fourth aperture 141d extending for the length of the translating member 140. The fourth aperture 141d helps in coupling the wire 150 with the translating member 140 as explained later. Each of a proximal and a distal end of the fourth aperture 141d is configured to receive a locking member 160 (depicted in Figs. 1b and 7). The fourth aperture 141d may be situated adjacent to the second aperture 141b and may be in horizontal alignment with the second aperture 141b. Such an alignment ensures that the wire 150 is tightly locked and maintains tension evenly. It should be appreciated that the positions of the first aperture 141a, the second aperture 141b, the third aperture 141c and the fourth aperture 141d depicted herein are merely exemplary and the said apertures may be situated at any other positions based upon requirements. Though the fourth aperture 141d is shown as a single, through hole, in another embodiment, the fourth aperture 141d may include two axially-aligned, blind apertures, with one of these apertures provided on each of a proximal and a distal face of the translating member 140 and configured to receive a locking member 160.
[49] In an embodiment, the translating member 140 is coupled to the rotating member 130 with the help of the wire 150 facilitating the longitudinal movement of the translating member 140. The wire 150 may be made of a material, such as, without limitation, stainless steel, braided stainless steel wire, etc. In an example implementation, the wire 150 is made of stainless steel. The wire 150 may have a pre-defined cross-sectional shape, such as, circular, rectangular, etc. In an embodiment, the wire 150 has a circular cross-section.
[50] The plurality of wire guides may be disposed within the handle 101 to support the wire 150 and assist in the movement of the wire 150. In an embodiment, the plurality of wire guides includes at least one first wire guide and at least one second wire guide. The at least one first wire guide is disposed distal to the translating member 140, for example, at the distal end of the handle 101. The at least one second wire guide is disposed proximal to the translating member 140 between the rotating member 130 and the translating member 140. In an example implementation, the at least one first wire guide includes two wire guides 170d – 170e and the at least one second wire guide includes three wire guides 170a – 170c. These numbers should not be considered as limiting and, the at least one first wire guide and the at least one second wire guide may have any other numbers of the wire guides based upon requirements. The wire guides 170a – 170e are coupled with the handle 101 via respective holes 101e disposed on the handle 101 (as shown in Fig. 2). The wire guides 170a – 170e may be placed at appropriate locations such that sufficient tension is maintained in the wire 150 throughout the operation of the device 100. Fig. 6 illustrates an exemplary wire guide 170a. In an embodiment, the wire guide 170a has a cylindrical shape, though the wire guide 170a may have any other suitable shape. An annular groove 171 (hereinafter, the groove 171) is provided on an outer surface of the wire guide 170a at a pre-defined location along the length of the wire guide 170a. A portion of the wire 150 is disposed within the groove 171. The wire guide 170a may be made of a material, such as, without limitation, stainless steel, glass fiber, etc. In an example implementation, the wire guide 170a is made of stainless steel. The wire guides 170b – 170e may have a similar structure and are, therefore, not described in detail for the sake of brevity. In an embodiment, the wire guides 170a – 170e are made of the same materials and have the same dimensions (e.g., length and diameter). It should be understood though that one or more of the wire guides 170a – 170e may be made of different materials and may have different dimensions. Further, though the depicted embodiment shows five wire guides 170a – 170e, the device 100 may have less than five or more than five wire guides.
[51] An exemplary configuration of the wire 150, the rotating member 130, the translating member 140 and the wire guides 170a – 170e (as shown in Fig. 7) is now explained below. A person skilled in art will appreciate that other configurations are also possible and are within the scope of the present disclosure.
[52] In an embodiment, a first end (not shown) of the wire 150 is coupled to the translating member 140 at the distal end 140b of the translating member 140. In an embodiment, the first end of the wire 150 is coupled to the translating member 140 using one locking member 160 (as explained later). The wire 150 passes through the second aperture 141b in a proximal direction. The wire 150 is wrapped around the at least one second wire guide. For example, the wire 150 is placed in the groove 171 of the wire guide 170a from the bottom of the wire guide 170a and in the groove 171 of the wire guide 170b from the top of the wire guide 170b. The wire guide 170a and the wire guide 170b may be aligned along the same horizontal axis. Further, the wire 150 is wrapped around the rotating member 130 such that a portion of the wire 150 is disposed within the groove 135 of the rotating member 130. The wire 150 is then placed in the groove 171 of the wire guide 170c from top of the wire guide 170c. The wire 150 passes through the third aperture 141c of the translating member 140 and extends towards the distal end of the handle 101. The wire guides 170a, 170c may be aligned along the same vertical axis. In addition, the wire guides 170a, 170c may be aligned with the second aperture 141b and the third aperture 141c, respectively, of the translating member 140. Such an alignment of the wire guides 170a, 170c, the second aperture 141b and the third aperture 141c ensures that a portion of the wire 150 between them is substantially horizontal, facilitating accurate movement of the translating member 140 along the longitudinal axis of the device 100. Further, the wire 150 is wrapped around the at least one first wire guide. For example, the wire 150 loops around the wire guides 170d and 170e placed at the distal end of the handle 101. The wire guides 170d and 170e are vertically aligned. This ensures that a top and a bottom section of the wire 150 remains axially aligned and parallel, facilitating an accurate movement of the translating member 140. The wire 150 then extends through the second aperture 141b and the second end of the wire 150 is coupled to the translating member 140 at the proximal end 140a of the translating member 140. Thus, the wire 150 forms a loop. In an embodiment, the second end of the wire 150 is coupled to the translating member using one locking member 160 as explained later. It should be appreciated the positions of the wire guides 170a – 170e shown herein are merely exemplary and the wire guides 170a – 170e may be positioned at any other locations without deviating from the scope of the present disclosure.
[53] Such a coupling of the wire 150 with the translating member 140 and the rotating member 130 ensures that in response to the rotation of the rotating member 130, a pulling force is generated at either the first end or the second end of the wire 150, causing the translating member 140 to move longitudinally. The distance by which the translating member 140 moves depends upon the angle by which the rotating member 130 rotates and the diameter of the rotating member 130. In an embodiment, the pre-defined gear ratio and the diameter of the rotating member 130 are designed such that for each rotation of the rotating member 130 by the pre-defined angle, the translating member 140 is configured to move by a pre-defined distance. For example, in response to the rotating member 130 rotating by the pre-defined angle in the first pre-defined direction, the first end of the wire 150 is pulled from the proximal side. This causes the translating member 140 to move in the proximal direction by the pre-defined distance and the outer sheath 110c is retracted by the pre-defined distance. Similarly, in response to the rotating member 130 rotating by the pre-defined angle in the second pre-defined direction, the second end of the wire 150 is pulled from the distal side, causing the translating member 140 to move in the distal direction by the pre-defined distance and the outer sheath 110c is advanced by the pre-defined distance. In an embodiment, the first pre-defined direction is anti-clockwise and the second pre-defined direction is clockwise. In another embodiment, the first pre-defined direction is clockwise and the second pre-defined direction is anti-clockwise. The wire guides 170a – 170e maintain tension in the wire 150 and minimize backlash, ensuring smooth and precise movements of the rotating member 130 and the translating member 140 during the operation of the device 100.
[54] According to an embodiment, the device 100 includes two locking members 160 configured to lock the wire 150 with the translating member 140, eliminating the risk of displacement/de-coupling of the wire 150 from the translating member 140. One locking member 160 is provided at each of the proximal end 140a and the distal end 140b of the translating member 140. In an embodiment, the locking member 160 may include a fastener, such as, a locking screw, countersunk screw, flat head screw, an indented hex screw, etc. Fig. 8 depicts an exemplary locking member 160. The locking member 160 includes a head 161 and a shank 163 extending from the head 161. In an embodiment, the head 161 and the shank 163 are cylindrical. The shank 163 configured to reside within the fourth aperture 141d of the translating member 140. The diameter of the shank 163 corresponds to the diameter of the fourth aperture 141d. The diameter of the head 161 may be larger than the diameter of the shank 163. The shank 163 may have a smooth, partially threaded or fully threaded outer surface. Correspondingly, the inner surface of the fourth aperture 141d may be smooth, partially threaded or fully threaded. The shank 163 may be coupled with the fourth aperture 141d using a technique, such as, without limitation, press-fit, tapered fit, threaded coupling, etc. In an embodiment, the shank 163 includes threads 163a configured to engage with corresponding threads (not shown) provided on the inner surface of the fourth aperture 141d. A top surface of the head 161 may include a groove (not shown) which helps in holding and manipulating the locking member 160 using, for example, a screw driver. According to an embodiment, the first end of the wire 150 is coupled with the locking member 160 provided at the distal end of the fourth aperture 141d is explained below. The threads 163a of the locking member 160 are engaged with the threads of the fourth aperture 141d and the locking member 160 is rotated to partially insert the shank 163 into the fourth aperture 141d. The first end of the wire 150 is wrapped around the shank 163. The locking member 160 is then tightened such that when the locking member 160 is coupled with the fourth aperture 141d the wire 150 is disposed between a distal face (not shown) of the translating member 140 and a face 161a of the head 161 of the locking member 160, thereby locking the wire 150 securely. The second end of the wire 150 is similarly coupled with another locking member 160 provided at the proximal end of the fourth aperture 141d, such that the wire 150 is disposed between a proximal face (not shown) of the translating member 140 and the face 161a of the head 161 of the other locking member 160.
[55] It should be understood that the coupling of the rotating member 130 and the translating member 140 using the wire 150 is merely exemplary and should not be considered as limiting. The rotating member 130 and the translating member 140 may be coupled using any other manner such that the translating member 140 moves longitudinally in response to the rotation of the rotating member 130 as described herein.
[56] In an embodiment, the first control element 181a, the second control element 181b, the third control element 181c and the control unit form a control assembly. The control assembly enables the medical practitioner to control the operation of the device 100 for deploying and/or retrieving the stent precisely and in a controlled manner. The first control element 181a and the second control element 181b help the medical practitioner to deploy and retrieve the stent, respectively.
[57] The first control element 181a, the second control element 181b and the third control element 181c are capable of receiving a first actuation input, a second actuation input and a third actuation input, respectively, which may be provided by the medical practitioner. In an embodiment, the first control element 181a, the second control element 181b and the third control element 181c are push buttons. Accordingly, the first, second and third actuation inputs are pressing of the respective button.
[58] In an embodiment, the plurality of control elements 180 are provided in the handle 101. For example, the plurality of control elements 180 are disposed within respective cut-outs 105 (shown in Fig. 2) provided on a top side of the first portion 101a of the handle 101. In an embodiment, the plurality of control elements 180 are made of the same material and have the same dimensions. In another embodiment, the plurality of control elements 180 may be made of different materials and may have different dimensions.
[59] The control unit is coupled to the first control element 181a, the second control element 181b and the third control element 181c. Further, the control unit is coupled to the motor 120. A first power output and a second power output of the control unit are coupled to the first input terminal 125a and the second input terminal 125b, respectively, of the motor 120 via respective cables (not shown). The control unit is configured to control the number of rotations and the rotational direction of the motor 120 by adjusting the duration and polarity of power signals provided at the first power output and the second power unit. Further, the control unit is coupled to the encoder.
[60] The control unit is configured to detect the first actuation input (e.g., pressing of) received by the first control element 181a. Further, in response to detecting the first actuation input received by the first control element 181a, the control unit is configured to cause the motor 120 to rotate in the first pre-defined direction to move the translating member 140 in the proximal direction by the pre-defined distance, thereby deploying the stent by the pre-defined distance. In an embodiment, in response to detecting the first actuation input, the control unit is configured to cause the motor 120 to rotate by the pre-defined number of rotations in the first pre-defined direction. For example, the control unit provides a positive power signal at the first power output and a negative power signal at the second power output. The rotation of the motor 120 in the first pre-defined direction, causes the shaft 121 and the rotating member 130 to rotate in the first pre-defined direction. This causes the translating member 140 and the outer sheath 110c to move in the proximal direction. The control unit is configured receive a first signal from the encoder of the motor 120. The first input signal indicates the angular position of the motor 120. The encoder may send the first input signal to the control unit at a pre-set time interval (depending upon the rotational speed of the motor 120) or upon reaching a specific angular position (e.g., upon completing one rotation). The control unit is configured to determine whether the motor 120 has completed the pre-defined number of rotations in the first pre-defined direction based upon the first signal. In response to determining that the motor 120 has completed the pre-defined number of rotations in the first pre-defined direction, the control unit is configured to cause the motor 120 to stop rotating, for example, by disconnecting power signals provided to the motor 120. As explained earlier, due to the rotation of the motor 120 by the pre-defined number of rotations in the first pre-defined direction, the shaft 121 and the rotating member 130 rotate by the pre-defined angle in the first pre-defined direction, and the translating member 140 and the outer sheath 110c move in the proximal direction by the pre-defined distance. This causes the pre-defined distance (interchangeably referred to as predefined length) of the stent to be deployed. The control unit may be configured to keep the power signals disconnected from the motor 120 until the first control element 181a is actuated again.
[61] Similarly, the control unit is configured to detect the second actuation input (e.g., pressing of) received by the second control element 181b. Further, in response to detecting the second actuation input received by the second control element 181b, the control unit is configured to cause the motor 120 to rotate in the second pre-defined direction to move the translating member 140 in the distal direction by the pre-defined distance, thereby retrieving the stent by the pre-defined distance. In an embodiment, in response to detecting the second actuation input, the control unit is configured to cause the motor 120 to rotate by the pre-defined number of rotations in the second pre-defined direction. For example, the control unit provides a negative power signal at the first power output and a positive power signal at the second power output. The rotation of the motor 120 in the second pre-defined direction, causes the shaft 121 and the rotating member 130 to rotate in the second pre-defined direction. This causes the translating member 140 and the outer sheath 110c to move in the distal direction by the pre-defined distance. The control unit is configured receive a second signal from the encoder. The second signal indicates the angular position of the motor 120. The encoder may send the second signal to the control unit at a pre-set time interval (depending upon the rotational speed of the motor 120) or upon reaching a specific angular position (e.g., upon completing one rotation). The control unit is configured to determine whether the motor 120 has completed the pre-defined number of rotations in the second pre-defined direction based upon the second signal. In response to determining that the motor 120 has completed the pre-defined number of rotations in the second pre-defined direction, the control unit is configured to cause the motor 120 to stop rotating, for example, by disconnecting the power signals from the motor 120. As explained earlier, due to the rotation of the motor 120 by the pre-defined number of rotations in the second pre-defined direction, the shaft 121 and the rotating member 130 rotate by the pre-defined angle in the second pre-defined direction, and the translating member 140 and the outer sheath 110c move in the distal direction by the pre-defined distance. This causes the pre-defined length of the stent to be retrieved. The control unit may be configured to keep the power signals disconnected from the motor 120 until the second control element 181b is actuated again.
[62] Thus, when the first control element 181a is pressed once, the stent is deployed by the pre-defined length and when the second control element 181b is pressed once, the stent is retrieved by the pre-defined length. By stopping the motor 120 automatically upon completing the pre-defined number of rotations, the device 100 minimizes manual intervention, eliminates human errors and enhances accuracy in delivery/retrieval of the stent. The pre-defined length (and the pre-defined distance) depends upon the pre-defined number of rotations of the motor 120, the pre-defined gear ratio and the diameter of the rotating member 130. The pre-defined distance may be chosen based upon requirements, and the pre-defined number of rotations of the motor 120, the pre-defined gear ratio and the diameter of the rotating member 130 may be designed accordingly. In an example implementation, the pre-defined distance is 1 mm. In this case, the pre-defined number of rotations of the motor 120 may be equal to two, the pre-defined gear ratio may be 1/72 and the diameter of the rotating member 130 may be equal to 10 mm, which results in the pre-defined angle of 10 degrees. It is possible that the pre-defined number of rotations of the motor 120, the pre-defined gear ratio and the diameter of the rotating member 130 may be designed to have other values to achieve the pre-defined distance of 1 mm. Further, it should be appreciated that the values of various parameters (including the pre-defined distance, the pre-defined number of rotations, the pre-defined gear ratio, the diameter of the rotating member 130) disclosed herein are merely exemplary, and any other values of the parameters may be selected based upon requirements.
[63] In an embodiment, the values of the pre-defined distance and the corresponding pre-defined number of rotations of the motor 120 may be pre-set, e.g., pre-stored in the control unit, and the medical practitioner may not be able to change these values. In another embodiment, the value of the pre-defined distance may be configurable by the medical practitioner with the help of the third control element 181c.
[64] According to an embodiment, the medical practitioner may actuate (e.g., press) the third control element 181c. The control unit is configured to detect the third actuation input (e.g., pressing of) received by the third control element 181c. In response to detecting the third actuation input, the control unit is configured to determine an updated value of the pre-defined distance and determine an updated value of the pre-defined number of rotations based upon the updated value of the pre-defined distance. The control unit may determine the updated value of the pre-defined distance in any number of ways. In an embodiment, the control unit may increase or decrease a current value of the pre-defined distance by a fixed distance (say, by 0.5 mm or 1 mm) when the third control element 181c is actuated each time. In another embodiment, the control unit may update the pre-defined distance by multiplying the current value of the pre-defined distance by a fixed ratio (for example, 0.5, 1.1, 2, etc.). In yet another embodiment, the control unit may update the pre-defined distance based upon a look-up table accessible to the control unit, where the control unit selects a successive value of the pre-defined distance in the loop-up table for every actuation of the third control element 181c. Further, in an embodiment, upon activating the third control element 181c a specific number of times (say, four times or five times), the control unit may reset the pre-defined distance to a default value. In an example implementation, when the third control element 181c is actuated once, twice and thrice, the pre-defined distance may be set to 1 mm, 2 mm, and 3 mm, respectively, and when the third control element 181c is actuated the fourth time, the pre-defined distance may be reset to 1 mm.
[65] According to an embodiment, the control unit may determine the updated value of pre-defined number of rotations using a look-up table, which may include a mapping of various pre-defined distances and corresponding values of the pre-defined number of rotations. In another embodiment, the control unit may calculate the updated value of the pre-defined number of rotations using the values of the updated pre-defined distance, the pre-defined gear ratio and the diameter of the rotating member 130. It should be appreciated that the pre-defined distance and the pre-defined number of rotations may be updated in any other manner without deviating from the scope of the present disclosure. The third control element 181c may be optional.
[66] In an embodiment, the device 100 may include a display 190 (depicted in Fig. 1c) configured to display a value corresponding to how much the stent has been deployed or retrieved. The control unit may be configured to provide the said value to the display 190 and cause the display 190 to display the said value. In other words, the device 100 provides accurate information to the medical practitioner about the progress of deployment/retrieval of the stent so that the medical practitioner may plan further deployment/retrieval accordingly. In an embodiment, the value may be equal to a percentage of the stent deployed/retrieved. The control unit may calculate the percentage based upon the length of the stent deployed/retrieved and the total length of the stent. The control unit may determine the length of the stent deployed/retrieved based upon the number of times the first control element 181a/second control element 181b are pressed and the pre-defined distance. Alternately, or in addition, the value may be equal to the length of the stent deployed/retrieved. In an embodiment, the display 190 may, alternately or in addition, display the pre-defined distance corresponding to each actuation of the third control element 181c. This helps the medical practitioner in selecting a desired value of the pre-defined distance. The display 190 may also display the pre-defined distance during the operation of the device 100 so that the medical practitioner knows how much length of the stent is exposed/retrieved for each press of the first control element 181a and the second control element 181b. The control unit provides such information to the display 190. The display 190 is provided on the handle 101. For example, the display 190 may be disposed within a corresponding cut-out 107 (shown in Fig. 2) provided on the top side of the first portion 101a of the handle 101. The display 190 may be an LED display, an LCD display, and the like. In an example implementation, the display 190 is an LED display.
[67] In an embodiment, the control unit may include a computing device and a memory. The computing device may be configured to execute instructions corresponding to various functions of the control unit. The computing device may include a microcontroller, a microprocessor, an application specific integrated circuit and the like. The memory is readable by the computing device and may store the said instructions. The memory may also store various data such as, the values of the parameters described herein (e.g., the pre-defined gear ratio, the pre-defined distance, the pre-defined angle, the diameter of the rotating member 130, etc.), the look-up tables, the length of the stent to be deployed and so on. The memory may include a non-volatile memory, such as, a read only memory, a flash memory, and the like. The memory may be embedded in the computing device.
[68] The device 100 may further include a power unit for providing power supply to the control unit, the motor 120, the display 190 and/or the control elements 180. The power unit is electrically coupled to the control unit, the motor 120, the display 190 and the control elements 180. In an embodiment, the power unit may include one or more DC batteries. The power unit may also include an AC/DC converter, which enables the device 100 to be operated by an AC power supply. Optionally, the power unit may include at least one voltage regulator to provide a regulated power supply to the control unit, the motor 120, the display 190 and the control elements 180.
[69] Fig. 9 depicts a flowchart of a method 900 for deploying a stent 10 using the device 100. In the depicted embodiment, the stent 10 is a self-expanding stent. The length of the stent 10 may be chosen based upon the needs of a patient. At step 901, the stent 10 is assembled with the catheter 110. In an example implementation, an inner tube 11 having a support element 12 (depicted in Figs. 9b – 9c) coupled at a distal end of the inner tube 11 may be provided. The inner tube 11 supports the stent 10 and the support element 12 facilitates easier insertion and navigation of the catheter 110 and reduces trauma to the patient’s vasculature throughout the procedure. The stent 10 may be crimped towards the distal end of the inner tube 11 proximal to the support element 12 using any crimping technique/device known in the art. The stent 10 is in the undeployed state at the moment. The inner tube 11 with the stent 10 crimped on it, is inserted into the outer sheath 110c of the catheter 110 so that the stent 10 is disposed towards the distal end of the catheter 110.
[70] At step 903, the catheter 110 is inserted into a patient’s vasculature at a desired location, e.g., a coronary artery, a peripheral artery, a carotid artery or the like, and navigated through the patient’s vasculature to a target site. The catheter 110 may be navigated to the target site over a guidewire inserted through the rapid exchange port of the catheter 110.
[71] Optionally, at step 905, the pre-defined distance may be set by the medical practitioner by actuating the third control element 181c. The pre-defined distance is set in a similar manner as explained earlier. The medical practitioner may press the third control element 181c multiple times until a desired pre-defined distance is set.
[72] At step 905, the first control element 181a is actuated one or more times to deploy the stent 10. As explained earlier, when the first control element 181a is actuated once, the motor 120 rotates by the pre-defined number of times (e.g., twice in the depicted embodiment) in the first pre-defined direction (e.g., in the anticlockwise direction in the depicted embodiment), and the rotating member 130 also rotates by the pre-defined angle (e.g., by 10 degrees in the depicted embodiment). This causes the translating member 140 and the outer sheath 110c to move in the proximal direction by the pre-defined distance (in the depicted embodiment, by 1 mm). As a result, the pre-defined length (e.g., 1 mm in this case) of the stent 10 is exposed and radially expands. Fig. 9a depicts the stent 10 deployed by the pre-defined length. Depending upon the length of the stent 10 and the pre-defined distance, the medical practitioner may need to actuate the first control element 181a multiple times until the stent 10 is deployed completely. Fig. 9b shows the stent 10 in a partially deployed state (i.e., when a partial length of the stent 10 is deployed) and Fig. 9c shows the stent 10 in a fully deployed state.
[73] It may happen that the stent 10 may not be delivered accurately at the target site or may have migrated. In these scenarios, the medical practitioner may want to retrieve the stent 10 so that the medical practitioner may re-adjust the position the stent 10. In such a situation, the medical practitioner may actuate the second control element 181b. As explained earlier, upon actuating the second control element 181b once, the outer sheath 110c advances by the pre-defined distance and the pre-defined length of the stent 10 is crimped due to the constraining force applied by the outer sheath 110c of the catheter 110. The medical practitioner may need to actuate the second control element 181b multiple times depending upon the pre-defined distance and an amount of length of the stent 10 that the medical practitioner wants to retract. The medical practitioner may then adjust the position of the stent 10 as needed. In an embodiment, the device 100 may be capable of retrieving the stent 10 at any stage up to 90% deployment of the stent 10. The aforesaid step of actuating the first control element 181a and the second control element 181b may be repeated until the stent 10 is fully deployed as desired.
[74] At step 907, upon successful deployment of the stent 10, the catheter 110 is withdrawn from the patient’s vasculature.
[75] The present disclosure offers several advantages over conventional stent delivery devices. The proposed device deploys (or retrieves) a stent by an exact amount of length each time a deployment button is pressed. Consequently, human errors (and variability) associated with conventional stent delivery devices are eliminated and the stent delivery process is more precise, consistent and repeatable. Further, the proposed device allows, with the help of the third control element, the medical practitioner to modify the length of the stent deployed (or retrieved) for each press of the button, thereby providing more control to the medical practitioner. Displaying the percentage (or exact length) of how much the stent has been deployed (or retrieved) arms the medical practitioner with extra knowledge, which helps the medical practitioner to plan further deployment of the stent and reduces the risk of insufficient stent deployment. In addition, the device enables the medical practitioner to retrieve the stent if the stent is not deployed correctly. Thus, the proposed device enhances precision and controllability of the stent deployment procedure, and increases the success rate of the stent deployment procedure, thereby improving the patient outcome.
[76] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM
1. A device (100) for deploying a stent, the device (100) comprising:
a. a motor (120) comprising a shaft (121);
b. a rotating member (130) rotatably coupled to the shaft (121) and configured to rotate in response to the rotation of the shaft (121) of the motor (120);
c. a translating member (140) coupled to the rotating member (130) and configured to move longitudinally in response to the rotation of the rotating member (130);
d. a catheter (110) comprising an outer sheath (110c) coupled to the translating member (140) and an inner lumen (111) disposed within the outer sheath (110c), the outer sheath (110c) is configured to move longitudinally in response to the longitudinal movement of the translating member (140);
e. a first control element (181a) capable of receiving a first actuation input; and
f. a control unit coupled to the first control element (181a) and the motor (120), the control unit configured to:
i. detect the first actuation input received by the first control element (181a); and
ii. in response to detecting the first actuation input, cause the motor (120) to rotate in a first pre-defined direction to move the translating member (140) in a proximal direction by a pre-defined distance, thereby deploying a stent, mounted on the inner lumen (111), by the pre-defined distance.
2. The device (100) as claimed in claim 1, wherein in response to detecting the first actuation input, the control unit is configured to cause the motor (120) to rotate by a pre-defined number of rotations in the first pre-defined direction, wherein in response to the motor (120) rotating by the pre-defined number of rotations in the first pre-defined direction, the translating member (140) and the outer sheath (110c) move linearly in a proximal direction by the pre-defined distance.
3. The device (100) as claimed in claim 2, wherein the control unit is configured to:
a. receive a first signal indicating an angular position of the motor (120) from an encoder coupled to the motor (120) and the control unit;
b. determine whether the motor (120) has completed the pre-defined number of rotations in the first pre-defined direction based upon the first signal; and
c. in response to determining that the motor (120) has completed the pre-defined number of rotations in the first pre-defined direction, cause the motor (120) to stop.
4. The device (100) as claimed in claim 2, wherein the device (100) comprises a third control element (181c) coupled to the control unit and capable of receiving a third actuation input, wherein the control unit is configured to:
a. detect the third actuation input received by the third control element (181c);
b. in response to detecting the third actuation input, determine an updated value of the pre-defined distance; and
c. determine an updated value of the pre-defined number of rotations based upon the updated value of the pre-defined distance.
5. The device (100) as claimed in claim 2, wherein a value of the pre-defined number of rotations is pre-set.
6. The device (100) as claimed in claim 2, wherein the shaft (121) and the rotating member (130) are configured to rotate by a pre-defined angle in the first pre-defined direction in response to the motor (120) rotating by the pre-defined number of rotations in the first pre-defined direction.
7. The device (100) as claimed in claim 1, where the motor (120) comprises a gear box coupled to the shaft (121) and configured to drive the shaft (121), the gear box has a pre-defined gear ratio.
8. The device (100) as claimed in claim 7, wherein the pre-defined gear ratio of the gear box is less than one.
9. The device (100) as claimed in claim 7, wherein the shaft (121) is coupled to the gear box such that shaft (121) is perpendicular to a longitudinal axis of the motor (120).
10. The device (100) as claimed in claim 1, wherein the rotating member (130) comprises a first cavity (139c) configured to receive the shaft (121).
11. The device (100) as claimed in claim 1, wherein the translating member (140) comprises a first aperture (141a) configured to receive a proximal portion of the outer sheath (110c).
12. The device (100) as claimed in claim 1, wherein the translating member (140) is coupled to the rotating member (130) using a wire (150) wrapped around the rotating member (130) disposed proximal to the translating member (140), the wire (150) comprising a first end coupled to the translating member (140) at a distal end (140b) of the translating member (140) and a second end coupled to the translating member (140) at a proximal end (140a) of the translating member (140), wherein the wire (150) passes through a third aperture (141c) of the translating member (140) and is wrapped around at least one first wire guide (170d, 170e) disposed distal to the translating member (140).
13. The device (100) as claimed in claim 12, wherein the rotating member (130) comprises:
a. a central rod (131); and
b. a flange (133) provided on each side of the central rod (131), defining a groove (135) configured to receive the wire (150).
14. The device (100) as claimed in claim 12, wherein the wire (150) is wrapped around at least one second wire guide (170a, 170b, 170c) disposed between the rotating member (130) and the translating member (140), each of the at least one first wire guide (170d, 170e) and the at least one second wire guide (170a, 170b, 170c) comprise an annular groove (171) configured to receive the wire (150).
15. The device (100) as claimed in claim 12, wherein the first end and the second end of the wire (150) are coupled to the translating member (140) using a locking member (160) each, wherein the locking member (160) comprises a head (161) and a shank (163) configured to reside within a fourth aperture (141d) of the translating member (140), wherein when the locking member (160) is coupled to the fourth aperture (141d), the wire (150) is disposed between a proximal face or a distal face of the translating member (140) and a face (161a) of the head (161) of the locking member (160).
16. The device (100) as claimed in claim 1, wherein the device (100) comprises a second control element (181b) coupled to the control unit and capable of receiving a second actuation input; wherein the control unit is configured to:
a. detect the second actuation input received by the second control element (181b); and
b. in response to detecting the second actuation input, cause the motor (120) to rotate in a second pre-defined direction to move the translating member (140) by the pre-defined distance in a distal direction, thereby retrieving the stent by the pre-defined distance.
17. The device (100) as claimed in claim 16, wherein in response to detecting the second actuation input, the control unit is configured to cause the motor (120) to rotate by a pre-defined number of rotations in the second pre-defined direction, wherein in response to the motor (120) rotating by the pre-defined number of rotations in the second pre-defined direction, the translating member (140) and the outer sheath (110c) move linearly in a distal direction by the pre-defined distance.
18. The device (100) as claimed in claim 17, wherein the control unit is configured to:
a. receive a second signal indicating an angular position of the motor (120) from an encoder coupled to the motor (120) and the control unit;
b. determine whether the motor (120) has completed the pre-defined number of rotations in the second pre-defined direction based upon the second signal; and
c. in response to determining that the motor (120) has completed the pre-defined number of rotations in the second pre-defined direction, causing the motor (120) to stop.
19. The device (100) as claimed in claim 1, wherein the device (100) comprises a display (190) configured to display at least one of: a percentage of the stent deployed, a length of the stent deployed or the pre-defined distance.