Patent Application
20160000443
Endoscopic medical devices such as, for example, hemostatic clipping devices, comprise a clip coupled via a flexible shaft member to a handle member which remains outside of patient's body while the flexible shaft and the clip are inserted to a target site (e.g., through an endoscope or other insertion device passed into a body lumen via a natural body orifice). The flexible shaft member may be formed, for example, as a coil of wire or other flexible structure to facilitate insertion of the clip into the body via along tortuous paths. When the clip has reached a target site, physicians may wish to rotate the clip to a desired orientation by rotating the handle or the proximal end of the flexible shaft. These flexible members may, at times, inefficiently transmit torque applied at the proximal end of the flexible member to the clip at the distal end making it difficult for the physician to orient the clip as desired. To enhance the transmission of torque along the flexible member some devices have included a braided member over an outer surface of the coil of the flexible member.
According to aspect 1, the present disclosure is directed to a medical device, comprising a flexible shaft extending along a longitudinal axis from a distal end to a proximal end, the shaft including a first reduced cross-sectional area portion extending along a distal portion of a length thereof and a braid applied overlappingly over a portion of the reduced cross-sectional area portion of the shaft, a first layer of the braid applied proximally over the shaft from a braid distal end to a first braid end point distal of a proximal end of the first reduced cross-sectional area portion, a second layer of the braid applied distally over the first layer from the first braid end point to a second end point proximal of the braid distal end, and a third layer applied proximally over the second layer proximally beyond the proximal end of the reduced cross-sectional area to a third braid end point along the shaft.
The device of aspect 1, wherein a distal braid termination is formed by cutting away a portion of the first layer extending distally beyond a distal edge of the second layer of the braid.
The device of aspect 2, wherein a braid angle of the first layer is less than 90 degrees and, more particularly, is between 50 and 60 degrees, and is selected to be sufficiently low so that the portions of the first layer extending distally beyond the distal edge of the first layer are easily cuttable from a remaining portion of the braid, wherein the braid angle is an angle between strands of the braid.
The devices of aspects 1 to 3, wherein a braid angle of the second layer is greater than 90 degrees and, more particularly, between 140 and 150 degrees, to sufficiently secure the first layer to the shaft.
The device of aspects 1 to 4, wherein a braid angle of the third layer is greater than 90 degrees and, more particularly, between 140 and 150 degrees, to be sufficiently high to secure the first and second layers of the braid to the shaft.
The device of aspects 1 to 5, wherein a diameter of the reduced cross-sectional area portion of the shaft is reduced relative to other portions of the shaft by an amount equal to a total thickness of the braid so that an outer profile of the shaft including the braid is substantially smooth.
The device of aspects 1 to 6, wherein the shaft further includes a second reduced cross-section area along a proximal portion thereof.
The device of aspect 7, wherein the third end point is distal of a proximal end of the second reduced cross-sectional area and the braid further includes a fourth layer extending distally over a portion of the third layer to a fourth end point proximal of a distal end of the second reduced cross-sectional area and a fifth layer extending distally over the fourth layer from the fourth end point to a proximal end that is folded over a proximal edge of the fourth layer and inserted between the braid and the shaft.
According to aspect 9, the present disclosure is also directed to a system for applying a braid to a shaft, comprising a sensor detecting features of the shaft including a distal end of a portion of a shaft over which a braid is to be applied, and distal and proximal ends of a first reduced cross-sectional area of the shaft extending along a distal portion thereof, a processor determining a start and end point along the shaft for each of first, second and third layers of the braid to be applied over the shaft based on the features detected by the sensor, and a braider applying the first, second and third layers of the braid along the shaft based on the start and end points determined by the processor.
The system of aspect 9, the present disclosure is directed to a system, wherein the braider includes a motor moving the shaft longitudinally relative thereto.
The system of aspects 9 and 10, wherein the first layer of the braid is applied proximally over the shaft from the distal end to a first end point distal of the proximal end of the first reduced cross-sectional area, a second layer of the braid applied distally over the first layer from the first end point to a second end point proximal of the distal end of the first reduced cross-sectional area, and a third layer applied proximally over the second layer proximally beyond the proximal end of the reduced cross-sectional area to a third end point along the shaft.
The system of aspects 9 to 11, further comprising a cutter for cutting portions of the first layer extending distally beyond a distal edge of the second layer of the braid to form a distal braid termination.
The system of aspects 9 to 12, wherein the braider applies the first layer of the braid over the shaft at a braid angle sufficiently low so that the portions of the first layer extending distally beyond the distal edge of the first layer are easily cuttable from a remaining portion of the braid. The braid angle of the first layer maybe less than 90 degrees and, more particularly, between 50 and 60 degrees.
The system of aspects 9 to 13, wherein the braider applies the second layer of the braid over the shaft at a braid angle sufficiently high to secure the first layer to the shaft. The braid angle of the second layer may be between 90 and 180 degrees and, more particularly, between 140 and 150 degrees.
The system of aspects 9 to 14, wherein the braider applies the third layer of the braid over the shaft at a braid angle sufficiently high to secure the first and second layers of the braid to the shaft. The braid angle of the third layer may be between 90 and 180 degrees and, more particularly, between 140 and 150 degrees.
According to another aspect, the present disclosure is also directed to a method for applying a braid over a shaft of a medical device, comprising detecting features of the shaft including a distal end of a shaft over which a braid is to be applied, and distal and proximal ends of a first reduced cross-sectional area of the shaft extending along a distal portion thereof, determining a start and end point along the shaft for each of a first, second and third layer of the braid to be applied over the shaft based on the features detected by the sensor, and applying the first layer of the braid proximally over the shaft from the distal end to a first end point distal of the proximal end of the first reduced cross-sectional area, a second layer of the braid distally over the first layer from the first end point to a second end point proximal of the distal end of the first reduced cross-sectional area, and a third layer proximally over the second layer proximally beyond the proximal end of the reduced cross-sectional area to a third end point along the shaft.
The present disclosure may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present disclosure is directed to a flexible, medical device including a braided shaft. In particular, exemplary embodiments of the present disclosure describe an endoscopic medical device comprising a flexible shaft including a braid extending along a portion of a length thereof so that torque may be transmitted along the length of the shaft. For example, a hemostatic clipping device may include a clip coupled to a handle member via a flexible shaft including a braid extending over a portion of a length thereof. Braids formed of non-annealed wire or filaments have been difficult to terminate cleanly as the filaments of the braid often spring away from a surface of the shaft upon cutting. A system and method according to an exemplary embodiment of the present disclosure includes overlapping layers of braids in a particular configuration over the shaft to provide a secure and atraumatic termination the braid at a distal end of the shaft. It will be understood by those of skill in the art that although the exemplary embodiments specifically describe a hemostatic clipping device, the braid termination of the present disclosure may be used in any medical device including a braid covering such as, for example, a stent. It should be noted that the terms “proximal” and “distal” as used herein, are intended to refer to a direction toward (proximal) and away from (distal) a user of the device.
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A direction of the braid 104 is then reversed so that the second layer 118 is then applied distally over a portion of the first layer 116 to a position along the shaft 102 proximal of the distal end 112 of the termination portion 110. A braid angle of the second layer 118 may be selected to best lock the first layer 116 to the shaft 102. The braid angle of the second layer 118 should also be selected to be as small as practicable to prevent adding any unnecessary bulk to the shaft 102. The braid angle of the second layer 118 may be between 90 degrees (i.e., 45 degrees relative to the longitudinal axis of the shaft 102) and 180 degrees (i.e., 90 degrees relative to the longitudinal axis of the shaft 102) and, more particularly, between 140 and 150 degrees. The direction of the braid 104 is once again reversed so that the third layer 120 of the braid 104 is applied proximally over the second layer 118 toward the proximal end 108 of the shaft 102 to a desired point therealong. A braid angle of the third layer 120 may be selected to provide the desired level of securement of the first and second layers 116, 118 while also providing the desired level of torsional transmission to the shaft 102. The braid angle of the third layer 120 may also range between 90 degrees and 180 degrees and, more particularly, between 140 and 150 degrees. Braid angles of the first, second and third layers 116, 118, 120, and/or a combination thereof may also be selected to increase a strength of the termination portion 110, which has a reduced cross-sectional area. A braid angle particularly suited for increasing a strength of the termination portion may be less than 135 degrees. Thus, the overlapping portion 122 of the braid 104 (i.e., the portion of the braid 104 in which all of the layers 116, 118, 120 overlap one another) is entirely between the distal and proximal ends 112, 114 of the termination portion 110. It will be understood by those of skill in the art that the first, second and third layers 116, 118, 120 form one continuous braid 104. It will also be understood by those of skill in the art that the overlapping portion 122 is applied over the reduced cross-section termination portion 110 of the shaft 102 so that an outer-most cross-sectional area (e.g., outermost diameter) of the overlapped portion 122 preferably does not extend beyond a cross-sectional area of a portion of the braid 104 extending proximally thereof along a proximal portion of the shaft 102.
Once the three layers 116, 118, 120 have been applied over the shaft 102, as desired, a portion of the braid 104 extending distally from the overlapped portion 122 (i.e., portion of the first layer 116 extending distally from the end of the overlapping portion 122) is cut to form a clean braid termination 124 at a distal end thereof, as shown in
It will be understood by those of skill in the art that the proximal end 108 of the shaft 102, and thereby a proximal end of the braid 104, is often encapsulated within the handle portion of the device 100 such that a clean proximal braid termination is not required. However, it will also be understood by those of skill in the art that, if desired, the proximal end of the braid may be terminated in a manner substantially similar to the distal braid termination 124 described above. In particular, the third layer 120 of the braid 104 extends proximally along the length of the shaft 102 to a desired proximal point along the shaft 102. Upon reaching the desired proximal point, the braid 104 reverses directions so that a fourth layer extends distally over a proximal portion of the third layer 104 for a desired distance. The braid 104 may then reverse directions again such that fifth layer extends proximally over the fourth layer toward the proximal end 108 of the shaft 102. The braid 104 may then be cut at a point proximally of the proximal edge of the fourth layer such that proximal edges of the braid 104 may be folded over the proximal edge of the fourth layer and inserted between an exterior surface of the shaft 102 and an interior surface of the third layer 120 to create a clean proximal edge of the braid 104. Similarly to the overlapping layers of braid 104 at the distal end thereof, the overlapping layers at the proximal end of the braid 104 may also extend over a termination portion of the shaft 102 having a smaller cross-section than a remaining portion of the shaft 102 such that the overlapping layers at the proximal end of the braid 104 do not result in a larger cross-sectional area than a remaining portion of the braid 104. Alternatively, the proximal end of the shaft 102 may not include a termination portion such that the overlapping layers at the proximal end may result in a larger cross-sectional area thereover. This larger cross-sectional area may provide an axial anchor for attaching a handle and/or provide a rotational connection.
As shown in
The braider 202 receives the distal end 106 of the shaft 102 to apply the braid 104 from the distal end 106 toward the proximal end 108 of the shaft 102. It will be understood by those of skill in the art that the braider 202 may include a motor for moving the shaft 102 relative to the braider 202, braiding arms for applying the braid 104 of wires or other flexible filaments over the shaft 102 moving longitudinally therewithin and any other features known in the art for application of a braid over a shaft. In particular, the braider 202 applies the braid 104 in a proximal direction as the shaft 102 is moved distally relative thereto. The sensor(s) 204 detects the distal end 106 of the shaft 102 as the shaft 102 approaches a braiding area of the braider 202. It will be understood by those of skill in the art that the braider 202 may either be running or waiting for a shaft 102 to be loaded. Using the detected distal end 106 of the shaft 102 and/or a desired braid angle of the braid 104, the processor 206 may determine a beginning point along the shaft 102 at which to begin braiding. A relative position of the shaft 102 and the braider 104 may be automatically determined by the processor 206 based on input parameters or may be overriden with values empirically developed. The braider 202 may initially apply a short section (e.g., approximately 3 mm) of braid 104 from the beginning point toward the proximal end 108 at a braid angle high enough to secure the braid 104 to the shaft 102. Once the short section of braid has been applied, the braider 202 applies the first layer 116 of the braid 104 proximally along the shaft 102. A wire clamp may be applied over the braid 104 on the shaft 102 at the start/end of any section of braid 104 to enable sharp changes in braid angle between sections. In another example, the braider 202 may also be stopped for sections, as desired, to enable a braid angle of zero between sections. For example, the braider 202 may be stopped between the short section of high braid angle and the lower braid angle of the first layer 116.
Before or during the application of the first layer 116, the sensor(s) 204 detect features of the shaft 102 indicating the termination portion 110. For example, the sensors 204 may detect cross-sectional changes in the shaft 102 to identify distal and proximal ends 112, 114 of the termination portion 110. The distal and proximal ends 112, 114 of the termination portion 110 may be used to calculate a length and position of the termination portion 110 along the shaft 102. Using this information, the processor 206 determines a desired end point of the first layer 116 and/or a length of the first layer 116 to be applied so that the braider 202 may apply the first layer 116 of the braid 104 proximally along the shaft 102 over the termination portion 110 to a point distal of the proximal end 114 of the termination portion 110. Features of the termination portion 110 may also be used to calculate end points of the second layer 118 and/or a length of the second layer 118 to be applied distally over the first layer 116. It will be understood by those of skill in the art that there may be more than one sensor 204 for detecting the various features of the shaft 102 such as, for example, the distal end 106 of the shaft 102 and the distal and proximal ends 112, 114 of the termination portion 110.
As described above, the first layer 116 is applied at a low braid angle to facilitate cutting of the braid 104 at the braid termination point 124. The braider 202 applies the first layer 116 to the calculated end point thereof and may additionally apply a short section of braid at a higher braid angle proximally of the calculated end point to secure the proximal end of the first layer 116 to the shaft 102 and prevent the braid 104 from sliding when the braid direction is reversed for application of the second layer 118 of the braid 104. It will be understood by those of skill in the art that the braid applied at the higher braid angle at the proximal end of the first layer 116 should not extend proximally beyond the proximal end 114 of the termination portion 110. The braider 202 then reverses a direction of the shaft 102 so that the second layer 118 of the braid 104 is applied distally over the first layer 116 to the calculated distal end thereof (e.g., within the bounds of the termination portion 110). The shaft 102 is moved proximally so that the second layer 118 may be applied distally over the first later 116. The braider 202 then reverse the direction of the shaft 102 so that the shaft 102 is once again moved distally with respect to the braider 102 to apply the third layer 120 of the braid 104 thereover, in a proximal direction. As described above, the third layer 120 is applied proximally over the second layer 118 and a portion of the first layer 116 at a braid angle sufficiently high enough to secure the underlying layers 116, 118 of braid 104 to the shaft 102. The third layer 120 extends proximally along the shaft 102 to a desired proximal point thereof. This desired proximal point may be stored in the memory 208 as an input parameter based on a desired use of the device 100. Once all of the layers 116, 118, 120 have been applied over the shaft 102, as desired, the portion of braid extending distally beyond the distal edge 126 of the second layer 118 may be cut to form the braid termination 124.
As described above, loose ends of the braid 104 at the proximal end of the third layer 120 may be captured and encapsulated within a handle portion of the device 100 so that an overlapping braid configuration is not required. If, however, a braid termination similar to the braid termination 124 is desired at the proximal end of the braid 104, the overlapped braid configuration may be similarly applied over a termination portion along a proximal portion of the shaft 102.
It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided that they come within the scope of the appended claims and their equivalents.
The present invention claims priority to U.S. Provisional Patent Application Ser. No. 62/019,582 filed Jul. 1, 2014; the disclosure of which is incorporated herewith by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62019582 | Jul 2014 | US |
