Burst-Operation Pressure Sensor With Battery-Free Energy Harvesting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable devices with non-rechargeable batteries become inoperable when the battery dies, while those with rechargeable batteries eventually fail due to cell degradation, leading to the need for replacement or explantation, and existing wireless pressure sensors require sophisticated electronics and provide limited information.
Innovation Solution
An implantable device without an electrochemical cell, utilizing an inductor coil, storage capacitor, and active circuitry to harvest energy during bursts from an external device, allowing it to perform sensor measurements and communications during quiet periods, reducing noise interference and enabling continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a non-rechargeable battery is used in an implantable device, then the device structure is simple, but the device becomes inoperable when the battery dies
Solution Approach 1:
The patent removes the battery component entirely from the implantable device, extracting the energy storage element that causes both structural simplicity and operational limitations. The device operates without an electrochemical cell, eliminating the battery death problem while maintaining simplicity through passive components only.
Solution Approach 2:
The patent introduces an external energy source as an intermediary - a non-implanted device that wirelessly transfers energy to the implantable device through an inductor coil. This external energy source acts as a mediator, providing continuous power without requiring a battery within the implantable device itself.
2Reliability
If a rechargeable battery is used in an implantable device, then the device can be reused, but the battery eventually degrades and the device can no longer be charged
Solution Approach 1:
The patent removes the rechargeable battery component, extracting the source of eventual degradation. By eliminating the electrochemical cell entirely, the device avoids the fundamental limitation of battery chargeability while maintaining reusability through passive components that can operate indefinitely with external energy input.
Solution Approach 2:
The patent uses an external energy source as an intermediary that continuously supplies power to the implantable device without undergoing degradation. This external device acts as an infinite energy reservoir, eliminating the battery chargeability issue while allowing the implantable device to be reused indefinitely.
3Ease of operation
If an LC resonant circuit is used in the implantable pressure sensor, then wireless interrogation is enabled, but the electronics architecture becomes sophisticated and expensive
Solution Approach 1:
The patent extracts the active electronic components from the implantable device, retaining only the passive LC resonant circuit. This simplification enables wireless interrogation through the resonant frequency method while dramatically reducing the electronics architecture complexity and cost within the implantable device.
Solution Approach 2:
The patent employs a passive resonant circuit that serves itself through its inherent electrical properties. The LC circuit naturally responds to external electromagnetic fields at its resonant frequency, eliminating the need for sophisticated active electronics to enable wireless interrogation while maintaining the capability.
4Productivity
If active circuitry is continuously powered in the implantable device, then sensor measurements can be obtained continuously, but energy consumption increases without a battery
Solution Approach 1:
The patent implements periodic operation where the implantable device alternates between energy reception phases and measurement/communication phases. The active circuitry operates periodically during quiet periods when external energy is being received, enabling continuous measurement capability while managing energy consumption through temporal separation of functions.
Solution Approach 2:
The patent performs preliminary energy accumulation during burst periods when external energy is available, storing energy in the inductor coil before the device needs to perform measurements and communications. This advance energy preparation allows the active circuitry to operate during subsequent quiet periods without immediate energy consumption constraints.
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
The device remains functional without battery replacement, providing reliable sensor measurements with reduced noise interference, and supports continuous monitoring of physiologic parameters like pulmonary artery pressure.
Implementation Method 1
using the storage capacitor to accumulate and store energy received via the inductor coil from a non-implanted device
Implementation Method 2
a pressure sensing capacitor, whose capacitance changes with changes in pressure (and is thus indicative of pressure)
Data Source
AI summary
Embodiments described herein relate to an implantable device that include an inductor coil, a storage capacitor, active circuitry, and a sensor, but doesn't include an electrochemical cell, and methods for use therewith. During first periods of time, the storage capacitor accumulates and stores energy received via the inductor coil from a non-implanted device. During second periods of time, interleaved with the first periods of time, and during which energy is not received from the non-implanted device, the active circuitry of the implantable device is powered by the energy stored on the storage capacitor and is used to perform at least one of a plurality of predetermined operations of the implantable device, including, e.g., obtaining a sensor measurement from the sensor of the implantable device, transmitting a communication signal including a sensor measurement to the non-implanted device, and/or receiving a communication signal from the non-implanted device.