Wireless Optogenetic Implant Resolves Tether and Mass Trade-off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless optogenetic systems for animals are limited by their size and mass, which restricts the targeting of central nervous structures and hinders animal movement and behavior, as they are too large to be left attached for prolonged periods and cannot be implanted internally for optogenetic control of neural circuits.
Innovation Solution
A wirelessly powered, fully internal implantable device with a resonant cavity for energy transfer, a power receiving coil, and a micro-LED for optogenetic stimulation, designed to be as small as 10 to 25 mm3 in volume and 20 to 50 mg in mass, allowing implantation on or near the brain, spinal cord, or nerve endings, and capable of untethered animal movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tethered optical fiber-based systems are used, then stable brain-skull interface and persistent optogenetic modulation are achieved, but animal freedom of movement and behavioral testing are constrained
Solution Approach 1:
The patent removes the tethered optical fiber from the system by implanting a wireless device directly into the brain. The wireless device receives power and control signals inductively through the skull, extracting the need for physical tethers while maintaining optogenetic stimulation capability. This resolves the contradiction by eliminating the constraint on animal movement while preserving the stimulation function.
Solution Approach 2:
The patent replaces the mechanical tethered fiber optic system with an inductively powered wireless device. The mechanical connection (tether) is substituted with electromagnetic induction for power and signal transfer, allowing the device to be fully implanted without external connections. This enables animal freedom of movement while maintaining stable brain stimulation.
2Adaptability or versatility
If wireless headmounted systems with batteries are used, then tether-free operation is achieved, but device mass and size increase, limiting targeting of central nervous structures
Solution Approach 1:
The patent extracts the battery from the system by using inductive power transfer. The wireless device receives power through electromagnetic induction from an external source, eliminating the need for onboard batteries. This dramatically reduces device mass and size, enabling implantation in the brain and spinal cord while maintaining tether-free operation.
Solution Approach 2:
The patent introduces electromagnetic induction as an intermediary for power transfer. Instead of storing energy in a battery, the system uses inductive coupling between an external transmitter and an implanted receiver to transfer power wirelessly. This mediator enables the device to operate without a battery, reducing mass to less than 2 grams.
3Extent of automation
If wirelessly powered devices with remote control are used, then optogenetic control capability is improved, but device size increases, preventing prolonged attachment and hindering animal behavior
Solution Approach 1:
The patent merges the power receiving coil, control electronics, and LED driver into a single integrated wireless device. This consolidation allows the device to receive both power and control signals inductively while maintaining a compact form factor of less than 2 grams. The merged design enables remote control capability without increasing device size, allowing prolonged implantation and normal animal behavior.
4Use of energy by moving object
If devices weighing 0.7 to 3 g are used, then wireless power transfer is achieved, but devices protrude beyond skin and cannot be left attached for prolonged periods
Solution Approach 1:
The patent replaces mechanical attachment systems with a fully implanted device that receives power inductively through the skull. This substitution eliminates the need for external mounting hardware, allowing the device to be completely internalized. The inductive power transfer enables the device to remain implanted indefinitely without protruding beyond the skin, extending attachment duration from hours to prolonged periods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables sophisticated optogenetic manipulation of neural circuits with minimal tissue heating and disruption of animal behavior, allowing animals to move freely and engage in normal interactions, expanding the diversity of stimulation targets beyond the brain and demonstrating effective optogenetic control of the spinal cord and peripheral nervous system.
Implementation Method 1
a resonant cavity configured to generate electromagnetic energy and having a surface upon which an animal can be placed, and a wirelessly powered implantable device adapted to be implanted in the animal, the implantable device comprising a circuit board, a power receiving coil coupled to the circuit board and adapted to receive electromagnetic energy from the resonant cavity
Implementation Method 2
a rectifier coupled to the circuit board and the power receiving coil and adapted to convert RF energy generated in the power receiving coil into a DC current
Implementation Method 3
a micro-LED coupled to the circuit board and adapted to provide optogenetic stimulation to the animal
Data Source
AI summary
A power transmitter is provided that can include a microwave cavity resonant at a desired operating frequency, a hexagonal mesh top to leak evanescent fields out of the cavity, and a plurality of orthogonal monopole feeds with 90 degrees phase differences creating circularly polarized waves. The power transmitter can be configured to transmit energy to a wireless device implanted in an animal passing through the evanescent fields. Implantable devices are also described which can receive wireless energy from the power transmitter and stimulate the animals (e.g., optogenetic or electrical stimulation).