Drug Delivery Switch Failure Detection via Motion Sensing
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Solution Overview
Problem
Existing electronic systems in drug delivery devices may fail to detect dose delivery operations due to malfunctioning rotary switches, posing health risks to patients by leading to undetected malfunctions and potential overdoses.
Innovation Solution
An electronic system with a first switch, a second switch, and a motion sensor system that provides position data to distinguish between different positions of the first and second members, enabling failure detection of the second switch during dose delivery operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a rotary switch is used to detect dose delivery operation, then the device complexity is reduced, but the reliability deteriorates due to potential switch failure
Solution Approach 1:
The patent changes the detection parameter from switch position (discrete states) to motion position data (continuous measurement). The motion sensor system measures the actual position of the drive mechanism throughout the dose delivery operation, providing continuous feedback rather than relying on discrete switch states. This allows detection of the full range of motion and identification of abnormal positions that would indicate switch failure or malfunction.
Solution Approach 2:
The patent replaces the mechanical rotary switch with a motion sensor system that uses optical, magnetic, or capacitive fields to detect position. Instead of mechanical contacts that can fail, the system uses non-contact sensing to monitor the drive mechanism's position, eliminating the mechanical failure mode while maintaining detection capability.
2Reliability
If a motion sensor system is added to detect switch failure, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The motion sensor system serves multiple functions: it detects the position of the drive mechanism during dose delivery, verifies proper operation of the dosing mechanism, and provides failure detection by identifying abnormal positions. This multi-functionality reduces the need for separate detection systems and integrates monitoring capabilities into the existing dose delivery control architecture.
Solution Approach 2:
The motion sensor system provides continuous feedback on the position of the drive mechanism throughout the dose delivery operation. This feedback allows the control system to verify that the mechanism is moving through the expected range of motion and to detect any deviations that would indicate failure, enabling real-time monitoring and safety verification.
Data Source
AI summary
An electronic system for a drug delivery device comprising a dose setting and drive mechanism with a first member, wherein the first member performs a specific movement relative to a second member during a dose delivery operation. The electronic system comprises a first switch configured to be activated by a pre-defined user operation, wherein the pre-defined user operation includes a user operation that is expected in conjunction with dose delivery operation, a second switch for indicating the specific movement, and a sensor arrangement for a motion sensor system for providing position data that allows to distinguish between different positions of the first member relative to the second member.