INTERVENTIONAL MEDICAL SYSTEMS AND IMPLANTABLE MEDICAL DEVICES INCLUDING TETHERING FEATURES, AND ASSOCIATED METHODS
A tethering feature includes an elongate break-away member and a base, and forms a proximal end of an implantable medical device housing. A tether attachment zone of the break-away member extends between break-away member ends, and the base includes a pair of supports, wherein each end of the break-away member is wrapped around a corresponding support. A delivery catheter tether may be attached to the device tethering feature by passing a looped portion of the tether around the tether attachment zone. The device may be untethered from the catheter by applying a pull force through the attached tether, while a distal end of a shaft of the catheter, which abuts the device proximal end, provides a back-up force, the pull force unwrapping each end of break-away member from the corresponding base support.
The present disclosure pertains to interventional medical systems, and more particularly to tethering features of relatively compact implantable medical devices and associated methods.
BACKGROUNDThe traditional implantable cardiac pacemaker includes a pulse generator device to which one or more flexible elongate lead wires are coupled. The device is typically implanted in a subcutaneous pocket, remote from the heart, and each of the one or more lead wires extends therefrom to a corresponding electrode, coupled thereto and positioned at a pacing site, either endocardial or epicardial. Mechanical complications and/or MRI compatibility issues, which are sometimes associated with elongate lead wires and well known to those skilled in the art, have motivated the development of implantable cardiac pacing devices that are wholly contained within a relatively compact package for implant in close proximity to the pacing site, for example, within the right ventricle RV of the heart. With reference to
Securing device 100 to catheter 800 with tether 880 is typically accomplished, prior to maneuvering catheter 800, with device 100 loaded therein, to the illustrated site, by looping tether 880 through a tethering feature 121 of device 100 and threading first and second lengths 881, 882 of tether 880 through one or more lumens of catheter 800 such that opposing ends thereof protrude out from a proximal opening 801 of catheter 800. After deploying device 100, the operator can grasp the ends of lengths 881, 882, for example, to tug on tether 880 to test the fixation of device 100 at the implant site, and/or to apply a greater force to tether 880 to remove device 100 from the implant site for repositioning at a more suitable site, if necessary.
If satisfied with the implant of device 100, the operator can remove the looped tether 880 from engagement with device 100 by releasing, for example, the end of length 881, and then pulling on the end of the other length 882, thereby withdrawing an entirety of length 882 proximally through delivery catheter 800 so that the other length 881 is pulled distally and through device tether tethering feature 121, out from engagement therewith.
SUMMARYEmbodiments and methods of the present disclosure pertain to improved tethering of relatively compact implantable medical devices in the context of deploying the devices to an implant site via a delivery catheter, for example, to increase the ease of tethering the devices and/or untethering, or releasing the devices, after deployment, from the delivery catheter.
According to some embodiments, a tethering feature of an implantable medical device forms a proximal end of a hermetically sealed housing that contains an electronic controller and an associated power source of the device, wherein the tethering feature includes an elongate break-away member and a base. The break-away member includes ends between which a tether attachment zone of the break-away member extends; and the base includes a pair of supports, wherein each end of the break-away member is wrapped around a corresponding support
According to some embodiments and methods, an interventional medical system is formed by attaching a tether of a delivery catheter to the device tethering feature to tether the device to catheter, for example, with the aid of a needle-like member. After an operator manipulates the delivery catheter of the system to deploy the tethered device at an implant site, for example, so that a fixation member of the device engages tissue at the site, the operator may untether the device from the catheter by applying a pull force to the tether, while a distal end of a shaft of the catheter abuts the device tethering feature to provide a back-up force, thereby unwrapping the ends of the break-away member from the base supports.
The following drawings are illustrative of particular embodiments of the present invention, and therefore do not limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments will hereinafter be described in conjunction with the appended drawings wherein like numerals denote like elements, and:
The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical examples, and those skilled in the art will recognize that some of the examples may have suitable alternatives.
With further reference to
According to an exemplary embodiment, tether 980 is formed from a polyester fiber having a fluoropolymer coating, such as PTFE, and a proximal portion of tether 980 can be clamped within handle assembly 410 via actuation of a knob 866 of a valve member 860 that is integrated into a conduit of handle assembly 410, for example, as shown in
Once device 200, 300 is tethered to catheter 400, the operator can load device 200, 300 into catheter 400, for example, by pulling proximal end 981 of tether 980, which extends out from proximal port opening 401 (
In the case of tethering feature 210 (or 210B), according to the above-described exemplary embodiment of break-away member 213, the pull force applied to tether 980 (or 880) by the operator, to untether device 200, may be generally characterized by a rapid tug, or snap, over a relatively short distance; whereas, in the case of tethering feature 310, according to the above-described exemplary embodiment of break-away member 313, the operator applies the pull force over a greater distance to untether device 300, wherein the distance is proportional to a length of each end 301, and the pull force may be of a relatively lower magnitude and applied more slowly than the rapid tug. In any case, with further reference to
In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims.
Claims
1. An implantable medical device comprising an electronic controller and an associated power source, a hermetically sealed housing containing the controller and power source, an electrode electrically coupled to the controller and mounted to the housing, a fixation member mounted to a distal end of the housing, and an tethering feature forming a proximal end of the housing, wherein the tethering feature comprises:
- a elongate break-away member including deformable ends and a tether attachment zone extending between the ends; and
- a base including a pair of supports, each deformable end of the break-away member being wrapped around a corresponding support of the pair of supports and being configured to unwrap from the corresponding support when a pull force is applied, in a proximal direction, to the tether attachment zone while an opposing back-up force is applied to the proximal end of the device housing.
2. The device of claim 1, wherein the tether attachment zone of the tethering feature break-away member forms a loophole.
3. The device of claim 1, wherein each support of the tethering feature base comprises an edge of an aperture that extends through a rim of the base, the rim surrounding an open cavity of the base, and the cavity being spanned by the tether attachment zone of the tethering feature break-away member.
4. The device of claim 1, wherein:
- the tethering feature base further includes a proximal portion, a distal shoulder, and a necked-in portion that extends between the proximal portion and the distal shoulder; and
- each deformable end of the break-away member is also wrapped around the necked-in portion of the base.
5. An interventional medical system comprising an implantable medical device and a delivery catheter for deploying the device to an implant site; the device comprising an electronic controller and an associated power source, a hermetically sealed housing containing the controller and power source, an electrode electrically coupled to the controller and mounted to the housing, a fixation member mounted to a distal end of the housing, and an tethering feature forming a proximal end of the housing; the catheter comprising an elongate shaft and an elongate tether extending within a longitudinally extending lumen of the catheter shaft, a proximal end of the tether extending out from a proximal opening of the shaft lumen, and a looped portion of the tether extending out from a distal opening of the shaft lumen; and wherein:
- the catheter shaft includes a flexible distal length terminated by a distal end that defines the distal opening of the lumen, the distal end being configured to abut the proximal end of the tethered device housing; and
- the device tethering feature comprises: an elongate break-away member including deformable ends and a tether attachment zone extending between the ends; and a pair of supports, each deformable end of the break-away member being wrapped around a corresponding support of the pair of supports and being configured to unwrap from the corresponding support, when the tether of the catheter is attached to tether attachment zone of the break-away member, and when a pull force is applied to the tether to pull the tether attachment zone in a proximal direction while an opposing back-up force is applied by the distal end of the catheter shaft abutting the proximal end of the device housing.
6. The system of claim 5, wherein the distal end of the catheter shaft is enlarged and configured to surround the break-away member tether attachment zone of the device tethering feature.
7. The system of claim 6, wherein the tethering feature break-away member is configured so that, when the deformable ends are unwrapped, the break-away member separates from a remainder of the tethering feature and becomes secured to the catheter by a press fit within the shaft lumen.
8. The system of claim 5, wherein the delivery catheter further includes an elongate outer tubular member extending around the shaft in sliding engagement therewith, the outer tubular member including a distal-most portion sized to contain the tethered medical device therein.
9. The system of claim 5, further comprising a needle-like member temporarily secured to the looped portion of the tether of the catheter, the needle-like member being configured to pass the looped portion of the tether around the break-away member tether attachment zone of the device tethering feature, for attachment of the tether thereto, and then to be separated from the tether loop.
10. The system of claim 5, wherein the tether attachment zone of the break-away member of the device tethering feature forms a loophole.
11. The system of claim 5, wherein each support of the base of the device tethering feature comprises an edge of an aperture that extends through a rim of the base, the rim surrounding an open cavity of the base, and the cavity being spanned by the tether attachment zone of the tethering feature break-away member.
12. The system of claim 5, wherein:
- the base of the device tethering feature further includes a proximal portion, a distal shoulder, and a necked-in portion that extends between the proximal portion and the distal shoulder; and
- each end of the break-away member of the device tethering feature is also wrapped around the necked-in portion of the base.
13. A method for deploying a relatively compact implantable medical device to an implant site, the method comprising:
- attaching a tether of a delivery catheter to a tethering feature of the device to tether the device to the catheter;
- loading the tethered device into the delivery catheter such that a distal end of a shaft of the catheter abuts a tethering feature of the device and a distal-most portion of an outer tubular member of the catheter contains the device;
- maneuvering the distal-most portion of the catheter with the tethered device loaded therein into proximity with the implant site;
- retracting the outer tubular member of the catheter with respect to the catheter shaft to expose the device for engagement with tissue at the implant site, the outer tubular member being slideably engaged around the catheter shaft; and
- unwrapping each end of a break-away member of the tethering feature of the engaged device from around a corresponding support of a base of the tethering feature by applying a pull force to the attached tether, thereby separating the break-away member and the tether from the engaged device, the pull force being backed up by the distal end of the catheter shaft abutting the device tethering feature.
14. The method of claim 13, further comprising pulling on the tether to secure the separated break-away member of the device tethering feature to the catheter by press fitting the separated break-away member within a lumen of the catheter shaft.
15. The method of claim 13, wherein attaching the delivery catheter tether to the device tethering feature comprises:
- inserting a needle-like member between the tethering feature break-away member and the tethering feature base to pass a looped portion of the tether around the tether attachment zone of the break-away member; and
- separating the needle-like member from the looped portion of the tether.
Type: Application
Filed: May 7, 2015
Publication Date: Nov 10, 2016
Inventors: Thomas A. Anderson (New Hope, MN), Vladimir Grubac (Brooklyn Park, MN), Michael C. Jacobs (Granger, IN)
Application Number: 14/706,662