How Cochlear Implants Use Free-Spinning Magnets to Survive MRI Scans
A cochlear implant design that uses a freely rotating internal magnet to prevent the device from being pulled or damaged by the strong magnetic fields of an MRI machine.
Original patent title: “USRE45701E1 - Reducing effect of magnetic and electromagnetic fields on an implant's magnet and/or electronics”
A cochlear implant design that uses a freely rotating internal magnet to prevent the device from being pulled or damaged by the strong magnetic fields of an MRI machine. Granted to MED EL Elektromedizinische Geraete GmbH in 2015 with 26 claims and 24 forward citations.
Key facts
Coverage
What does this patent actually cover?
This patent describes a cochlear implant system where the internal magnet is housed in a way that allows it to rotate freely in any direction without moving out of its designated spot. Because the magnet can spin, it aligns itself with the powerful magnetic fields of an MRI machine rather than resisting them. This prevents the magnet from experiencing high torque, which could otherwise damage the implant or cause pain to the patient. The system also includes a housing that keeps the magnet in place while allowing this rotation, ensuring the external and internal coils remain aligned for power and data transmission.
The gap
What does this patent NOT cover?
- Does not cover magnets that are fixed in place and cannot rotate freely.
- Does not cover systems that rely on external mechanical clamps or non-magnetic fasteners to hold the device in place.
- Does not cover the specific electronic signal processing algorithms used to convert sound into electrical stimulation.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
Instead of trying to shield the magnet from the MRI's magnetic field, the inventors designed the housing to allow the magnet to pivot and align with the field, effectively neutralizing the torque that would otherwise cause mechanical damage.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
MED-EL cochlear implant systems
MRI-compatible cochlear implant internal receivers
Why it matters
The bigger picture
Before this technology, patients with cochlear implants often faced significant risks or were completely barred from undergoing MRI scans due to the potential for the implant's magnet to be dislodged or demagnetized. This design allows patients to safely receive necessary medical imaging without needing surgery to remove the implant first, significantly improving the quality of life for those with hearing loss.
Filed
October 24, 2012
Granted
September 29, 2015
Market context
Who's building on this
Companies in this space
MED-EL, the original assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, continues to lead in this space, having integrated this technology into their modern implant series. Other major cochlear implant manufacturers like Cochlear Limited and Advanced Bionics have also developed their own proprietary solutions for MRI safety, often utilizing similar principles of rotatable or removable magnets.
Market impact
This patent helped establish a new standard of care for cochlear implant users, effectively turning MRI compatibility into a requirement for the industry. It reduced the need for invasive revision surgeries and increased the long-term viability of implants for patients who may require frequent medical imaging.
Claim 1 — Plain English
What this patent covers
This patent describes a cochlear implant system where the internal magnet is housed in a way that allows it to rotate freely in any direction without moving out of its designated spot. Because the magnet can spin, it aligns itself with the powerful magnetic fields of an MRI machine rather than resisting them. This prevents the magnet from experiencing high torque, which could otherwise damage the implant or cause pain to the patient. The system also includes a housing that keeps the magnet in place while allowing this rotation, ensuring the external and internal coils remain aligned for power and data transmission.
The clever bit
Instead of trying to shield the magnet from the MRI's magnetic field, the inventors designed the housing to allow the magnet to pivot and align with the field, effectively neutralizing the torque that would otherwise cause mechanical damage.
What it does not cover
- Does not cover magnets that are fixed in place and cannot rotate freely.
- Does not cover systems that rely on external mechanical clamps or non-magnetic fasteners to hold the device in place.
- Does not cover the specific electronic signal processing algorithms used to convert sound into electrical stimulation.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Strong
Citation count
28/40
Moderately cited
Claim breadth
17/20
Very broad protection
Recency
5/20
Granted 10–20 years ago
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$96K – $306K
Midpoint $191K · 6.4 yr remaining · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
26 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Hochmair, E., & Zimmerling, M. (2015). How Cochlear Implants Use Free-Spinning Magnets to Survive MRI Scans (U.S. Patent No. RE45,701). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/RE45701/bladeless-fan-air-multiplier
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Cochlear Implants Use Free-Spinning Magnets to Survive MRI Scans cover?
A cochlear implant design that uses a freely rotating internal magnet to prevent the device from being pulled or damaged by the strong magnetic fields of an MRI machine.
Who owns patent US RE45701?
MED EL Elektromedizinische Geraete GmbH owns this patent, granted in 2015.
When does this patent expire?
This patent is expected to expire on September 29, 2035, when the invention enters the public domain.
What is patent US RE45701 cited by?
This patent has been cited by 24 later patents that build on its ideas.
What problem does this patent solve?
Before this technology, patients with cochlear implants often faced significant risks or were completely barred from undergoing MRI scans due to the potential for the implant's magnet to be dislodged or demagnetized. This design allows patients to safely receive necessary medical imaging without needing surgery to remove the implant first, significantly improving the quality of life for those with hearing loss.
What does this patent NOT cover?
Does not cover magnets that are fixed in place and cannot rotate freely.
Patent monitoring