Externalized Battery Housing for Compact Implantable Stimulators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable medical devices face challenges in increasing battery capacity without expanding their size, volume, or surface area, which is crucial for delivering continuous electrical stimulation therapy for conditions like bladder dysfunction without reducing device longevity.
Innovation Solution
The implementation of an externalized battery configuration, where the battery is attached externally to the device housing, forming a single-hull design, allowing for increased capacity without increasing the overall size or volume of the implantable medical device, and utilizing hermetic sealing to ensure biocompatibility and environmental exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the battery size is increased to improve battery capacity, then the battery capacity and longevity are improved, but the overall size and volume of the implantable medical device increases
Solution Approach 1:
The device is segmented into two separate housings: a device housing containing the electronics and a battery housing containing the battery. This segmentation allows the battery to be optimized for capacity while the device housing maintains a compact implantable size. The battery housing can be sized independently to maximize battery capacity without constraining the device housing volume.
Solution Approach 2:
The battery housing is positioned externally to the device housing, utilizing spatial arrangement in another dimension rather than embedding the battery within the device housing. This external positioning allows the battery to extend beyond the implantable device boundaries, effectively increasing battery capacity without increasing the volume of the implantable portion.
2Duration of action of moving object
If the battery is externalized to increase capacity, then battery capacity improves, but device complexity increases due to additional housing and attachment requirements
Solution Approach 1:
The battery housing and device housing are merged into a single integrated assembly through hermetic sealing and attachment mechanisms. This merging approach, while adding external structure, creates a unified device system where the battery housing serves both as a protective enclosure and as an integrated power source module, reducing overall system complexity compared to separate replaceable battery designs.
3Reliability
If the battery housing is hermetically sealed to ensure biocompatibility, then reliability and biocompatibility improve, but manufacturing precision requirements increase
Solution Approach 1:
A biocompatible coating or intermediate layer is applied to the battery housing to ensure biocompatibility while simplifying the hermetic sealing requirements. This intermediary layer acts as a barrier between the battery components and the biological environment, allowing for more relaxed sealing tolerances while maintaining reliability and biocompatibility standards.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An example medical device includes a device housing configured to be implantable within a patient, the device housing including an internal surface in contact with a voltaic cell of the battery, and a battery external to the device housing and comprising a battery housing configured to be hermetically sealed. The battery is configured to provide electrical power to an electrical component housed within the device housing, and the battery housing is configured to be attached to the device housing. The battery housing includes an internal surface in contact with a voltaic cell of the battery, and an external surface in contact with the biocompatible electrical insulator.an external surface in contact with the biocompatible electrical insulator.