Reservoir Fill Level Detection Using Resistor Strip and Inductive Coil
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable fluid delivery devices lack effective methods for accurately determining the fill status of therapeutic fluid reservoirs, which is crucial for ensuring proper treatment delivery and preventing under or over-infusion of therapeutic agents.
Innovation Solution
The system includes a reservoir fill level detector with a contact pad and resistor strip that monitors resistance changes as the pad moves along a predetermined path during filling and emptying, and an inductive coil and magnetic block setup that repositions with the reservoir, allowing for real-time detection of fill status through a processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reservoir fill level detector with contact pad and resistor strip is implemented, then measurement precision of fill status is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical level sensing mechanisms with an electrical resistance-based detection system. The contact pad moves along a resistor strip, converting mechanical displacement (caused by reservoir fill level changes) into electrical resistance changes, which are then processed to determine fill status. This substitution simplifies the overall detector structure while maintaining measurement precision.
Solution Approach 2:
The resistor strip serves as an intermediary element between the mechanical movement (contact pad displacement) and the electrical signal processing. It converts the mechanical position into a proportional resistance value, enabling indirect measurement of fill level through electrical properties rather than direct mechanical sensing.
2Reliability
If an inductive coil and magnetic block system is used for fill detection, then reliability of fill status monitoring is improved, but device complexity increases
Solution Approach 1:
The patent replaces direct mechanical contact-based detection with an inductive sensing system. The magnetic block moves with the reservoir fill level, altering the magnetic flux through the inductive coil. This generates voltage changes that indicate fill status, eliminating mechanical wear and contact issues while improving reliability.
Solution Approach 2:
The system detects fill level changes by monitoring changes in magnetic field parameters (flux density and magnetic flux) through the inductive coil. As the magnetic block moves with fill level, it changes the magnetic circuit parameters, producing detectable voltage signals that reliably indicate reservoir fill status.
3Productivity
If real-time fill status detection is implemented, then productivity of pump operation is improved, but use of energy increases
Solution Approach 1:
The patent implements periodic sampling of the resistance value rather than continuous monitoring. The processor reads the resistance at discrete intervals during pump operation, balancing real-time awareness of fill status with minimal energy consumption. This periodic action allows the pump to adjust operation based on fill level while avoiding constant energy expenditure.
Solution Approach 2:
The detector system is designed to be passively monitored by the existing pump processor. The resistance changes occur automatically with fill level, and the processor simply reads the resistance value without requiring active sensing circuits or continuous power to the detector itself, reducing overall energy consumption while maintaining productivity.
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 accurate monitoring of reservoir fill levels, preventing low volume alerts and ensuring precise delivery of therapeutic agents, facilitating real-time pocket fill detection during refills and improving the accuracy of pump operation.
Implementation Method 1
a resistor strip mounted on the inside of the chamber whereby the resistor strip is in continual contact with the contact pad along the entire predetermined path, an energy source for providing a current along the resistor strip whereby the total resistance of the resistor strip is variable depending on the position of the contact pad
Implementation Method 2
an inductive coil positioned relative to the reservoir, a lever arm hingedly attached relative to the reservoir in a predetermined position relative to the inductive coil whereby the lever arm moves in coordination with the moveable surface of the reservoir, and a magnetic block operably attached to the lever arm whereby filling and emptying the reservoir with therapeutic fluid causes the at least one surface of the reservoir to move such that the lever arm and the magnetic block are repositioned and the magnetic block is moved relative to the coil
Data Source
AI summary
A medical device system comprises a reservoir configured to store a therapeutic fluid and a medical pump configured to deliver the therapeutic fluid from the reservoir to a patient. The system also comprises a reservoir fill level detector configured to detect a fill status of the reservoir, the reservoir fill level detector including a contact pad operably attached to the reservoir whereby the contact pad moves in a predetermined path during the emptying and filling of the reservoir. A resistor strip mounted on the inside of the chamber is in continual contact with the contact pad and the resistance of an electric current passed through the resistor strip is monitored by a processor to determine the position of a selected portion of the reservoir. The position of the reservoir is directly related to the fill status.