Capacitive Sensor Module for Precise Drug Volume Detection
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Solution Overview
Problem
Current methods for monitoring drug delivery in automated systems are prone to mechanical failures and inaccuracies due to mechanical gearing systems, which are susceptible to manufacturing issues and shifts in motor rotations.
Innovation Solution
A capacitive sensor module that directly measures the amount of drug in a container using electrodes positioned along the outer surface of the container, forming a capacitor, with a substrate embedded in insulating material and a spring latch mechanism to secure contact, allowing for accurate capacitance measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If electro-mechanical gearing system is used to monitor drive shaft rotation, then automated drug delivery can be achieved, but measurement precision deteriorates due to manufacturing issues and mechanical failures
Solution Approach 1:
The patent replaces the electro-mechanical gearing system with a capacitive sensing system that directly measures the position of the plunger rod. The capacitive sensor detects changes in capacitance caused by the movement of the plunger rod, providing direct measurement without mechanical linkages. This substitution eliminates the mechanical failures and manufacturing tolerances inherent in gearing systems while maintaining automated control capability.
Solution Approach 2:
The patent introduces a capacitive sensor as an intermediary between the drive system and the measurement system. Instead of mechanically coupling the measurement to the drive shaft rotation, the capacitive sensor acts as an intermediary that electrically detects the position of the plunger rod through capacitive coupling, providing accurate measurement without direct mechanical contact or complex mechanical linkages.
2Extent of automation
If mechanical links between motor, plunger rod, and stopper are used, then automated plunger actuation can be achieved, but reliability deteriorates due to failures and breakdowns
Solution Approach 1:
The patent replaces mechanical linkages for position detection with a capacitive sensing system. The capacitive sensor detects plunger rod position through electrical fields rather than mechanical contact, eliminating wear, friction, and failure points associated with mechanical links while preserving automated actuation capability.
Solution Approach 2:
The capacitive sensor system is self-servicing in that it requires no mechanical maintenance, lubrication, or adjustment. The sensor automatically detects position changes through capacitive coupling without mechanical contact, eliminating the need for maintenance that would be required for mechanical linkages between motor, plunger rod, and stopper.
3Ease of operation
If electro-mechanical gearing system is used, then drive shaft rotation can be monitored, but measurement precision deteriorates due to shifts in motor rotations and gearing tolerances
Solution Approach 1:
The patent substitutes mechanical rotation monitoring with direct capacitive position sensing of the plunger rod. Instead of inferring drug delivery from drive shaft rotation through mechanical gearing, the system directly measures plunger rod position via capacitive coupling, eliminating errors from motor rotation shifts and gearing tolerances.
Solution Approach 2:
The capacitive sensor creates an electrical copy or representation of the plunger rod position without physical contact. By measuring capacitance changes that correspond to plunger rod position, the system creates an accurate electrical model of the mechanical state without the inaccuracies of mechanical transmission through gearing systems.
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
Provides direct and accurate measurement of drug volume by correlating capacitance with the amount of drug remaining, reducing mechanical failures and improving measurement precision.
Implementation Method 1
the first and second electrodes and the container form a capacitor. The sensor module can further include circuitry that is configured to measure a capacitance across the first and second electrodes. The measured capacitance can be correlated with an amount of the substance in the container.
Data Source
AI summary
A sensor module is disclosed. The sensor module can include a housing body that is disposed about a cavity that is sized and shaped to receive a container in which a substance is disposed in an operational configuration of the sensor module. The sensor module can include a first electrode that is coupled to or formed with the housing body. The first electrode is disposed at a first peripheral position on the housing body. The sensor module can include a second electrode that is coupled to or formed with the housing body. The second electrode is disposed at a second peripheral position on the housing body that is opposite the first peripheral position. The cavity is disposed between the first and second electrodes in the operational configuration of the housing body.