Retractable Fixation Sheath for Implantable Medical Device Anchoring
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Solution Overview
Problem
Implantable medical devices (IMDs) face challenges in stable positioning during testing and implantation, particularly with active fixation devices, which can cause tissue injury when moved between multiple sites for testing.
Innovation Solution
An IMD with a retractable and advanceable fixation sheath that allows the device to be moved to multiple testing sites without fixation, minimizing tissue contact, and then deploys the fixation member to anchor the device at the selected implant site.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If active fixation devices are used to anchor the IMD, then stable positioning at the implant site is improved, but tissue injury occurs when moving between multiple testing sites
Solution Approach 1:
The fixation sheath is designed to be dynamically movable between retracted and advanced positions relative to the housing. During testing, the sheath remains retracted allowing free movement of the IMD. At the final implant site, the sheath is advanced to deploy fixation members and provide stable anchoring. This dynamic configuration resolves the contradiction by providing stability only when needed while enabling movement during testing.
Solution Approach 2:
The fixation system is segmented into a movable fixation sheath portion and a stationary housing portion. The sheath can be independently advanced or retracted relative to the housing, allowing the fixation members to be deployed only at the final implant site rather than during intermediate testing positions. This segmentation enables selective fixation that avoids tissue injury during testing while ensuring stability at implantation.
2Stability of the object's composition
If fixation devices are deployed during testing, then stable positioning at test sites is improved, but repositioning to other test sites becomes difficult or challenging
Solution Approach 1:
The fixation sheath is designed with dynamic mobility relative to the housing, allowing it to be retracted during testing to enable easy repositioning. When stable positioning is needed at a test site, the sheath can be temporarily advanced and then retracted again for repositioning. This dynamic design resolves the contradiction by providing on-demand stability without compromising repositioning capability.
Solution Approach 2:
The fixation sheath is prepared in a retracted state during testing, allowing the IMD to be freely repositioned between test sites. The fixation members are held in readiness but not deployed until the final implant site is selected. This preliminary configuration resolves the contradiction by maintaining ease of operation during testing while preserving the ability to provide stability when needed.
3Stability of the object's composition
If the fixation sheath is advanced to deploy fixation members, then stable anchoring at the implant site is improved, but tissue contact during testing increases
Solution Approach 1:
The fixation sheath transitions from a retracted position during testing to an advanced position at implantation. When retracted, the fixation members do not contact tissue, eliminating harmful effects during testing. When advanced at the final implant site, the fixation members deploy to provide stable anchoring. This dynamic position change resolves the contradiction by separating the testing phase from the implantation phase in terms of fixation member deployment.
Solution Approach 2:
The fixation system is divided into a sheath portion that can be independently advanced or retracted relative to the housing. This segmentation allows the fixation members to remain concealed within the sheath during testing, preventing tissue contact. Only when the sheath is advanced at the final implant site do the fixation members contact tissue to provide anchoring, thus resolving the contradiction between stability and tissue contact.
Data Source
AI summary
An implantable medical device has a housing having a proximal end, a distal end and an outer sidewall extending from the proximal end to the distal end. A fixation sheath includes a housing sheath portion extending along the outer sidewall of the housing, and a fixation member portion extending from the housing sheath portion. The housing sheath portion is advanceable from a first position along the outer sidewall of the housing in which the fixation member portion is retracted toward the proximal end of the housing to a second position along the outer sidewall of the housing in which the fixation member portion is deployed to extend away from the housing distal end for anchoring the implantable medical device at an implant site.