Control of electrically driven corrosion of medical implants
Inventors
Ahn, Jeongmin • Welles, Thomas
Assignees
Publication Number
US-12186208-B2
Publication Date
2025-01-07
Expiration Date
2042-05-06
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
A dampening device that can be coupled to a medical implant to eliminate harmful electrical oscillations. The device includes circuity that detects harmful electrical oscillations in the implant. The device also includes circuity that generates cancelling electrical signals that counter the detected electrical oscillations. Alternatively, in a medical implant having a taper junction such as a standard hip implant, resistance welding of the taper junction just prior to surgical implanting may be performed after the appropriately dimensioned components are selected to eliminate a metal on metal interface where corrosion is most likely to occur.
Core Innovation
The invention provides a solution to the problem of electrically driven corrosion in medical implants, particularly those made of metal such as CoCrMo alloys used in hip arthroplasty. It is based on the discovery that low-level electrical oscillations, originating from common ambient electromagnetic radiation, can initiate corrosion processes that match those found in failed implants retrieved from patients. This type of corrosion can lead to significant health problems including tissue necrosis, device failure, and release of toxic metal ions into the body.
To address this issue, the patent introduces a dampening device that can be attached to a medical implant. The device comprises circuitry capable of detecting harmful electrical oscillations in the implant, as well as generating and applying cancelling electrical signals to counter these oscillations, thus reducing or eliminating electrical activity on the implant and preventing electrochemical corrosion. The device can be analog or digital and may leverage technologies from active noise cancelling systems, targeting oscillations in the frequency range of 60 Hz to GHz.
Alternatively, the invention discloses resistance welding of the taper junction in modular implants, such as hip prostheses, to eliminate the presence of a metal-on-metal interface where corrosion is most likely to occur. This welding is performed after appropriate components are selected, creating a continuous metal junction that prevents synovial fluid penetration and reduces the sites prone to corrosion. The overall approach is to mitigate the electrochemical activity considered a primary initiating mechanism for implant breakdown, beyond traditional theories centered on mechanical wear alone.
Claims Coverage
There are two independent claims in the patent, each directed to a distinct inventive feature for reducing corrosion in medical implants.
Dampening circuit for reducing electrical potential oscillations in a medical implant
A device comprises: - A medical implant. - A dampening circuit coupled to the implant, configured to detect the presence of any electrical potential oscillations in the implant. - The dampening circuit generates a signal that will at least partially dampen the electrical potential oscillations in the implant. This feature explicitly requires circuitry that both senses electrical oscillations and generates a counteracting signal to suppress those oscillations directly on the implant.
Method for protecting a medical implant against corrosion using a dampening circuit
A method includes: 1. Coupling a dampening circuit to the medical implant. 2. The dampening circuit is configured to detect the presence of any electrical potential oscillations in the medical implant. 3. The dampening circuit generates a signal that will at least partially dampen the electrical oscillations in the medical implant. This method centers on the application of a dampening circuit to directly mitigate electrical activity leading to corrosion.
In summary, the inventive features center on detecting and counteracting electrical oscillations in medical implants to inhibit corrosion, both through specific devices employing dampening circuits and corresponding methods for their application.
Stated Advantages
Mitigates or eliminates electrical oscillations in the implant to prevent electrochemical corrosion and device failure.
Reduces the risk of harmful effects such as tissue necrosis, metal ion toxicity, implant loosening, and revision surgeries resulting from corrosion.
Prevents the penetration of synovial fluid and formation of corrosion-prone interfaces in modular implants through resistance welding of junctions.
Documented Applications
Use in metal-containing medical implants, particularly hip implants with modular components, to reduce electrically driven corrosion.
Application in implanted biosensors, such as continuous glucose monitoring systems, to prevent corrosion of metal-based electrodes during implantation.
Interested in licensing this patent?