Adaptive Occlusion Detection in Fluid Infusion Devices
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Solution Overview
Problem
Existing fluid infusion devices, such as insulin pumps, face challenges in accurately detecting occlusions and ensuring proper reservoir seating due to reliance on fixed threshold forces, which can lead to false alarms or delayed detection, and are prone to reservoir dislodgment during physical activities or contact with objects.
Innovation Solution
The implementation of a method that uses a force sensor to monitor rewind forces and determine adaptive threshold ranges for occlusion detection and reservoir seating, allowing for real-time corrective actions and adaptive occlusion detection based on force variations during fluid delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed threshold force is used for occlusion detection, then the device structure is simple, but the detection accuracy is reduced and false alarms occur
Solution Approach 1:
The patent implements dynamic threshold adjustment by continuously monitoring the relationship between motor current and pump speed. The occlusion detection threshold is no longer fixed but adapts based on real-time operational parameters, allowing the system to distinguish between normal variations and actual occlusions, thereby improving detection accuracy without requiring complex additional hardware
Solution Approach 2:
The system employs feedback mechanisms by monitoring motor current and pump speed relationships. The detected occlusion status feeds back to adjust the detection threshold dynamically, creating a closed-loop system that improves measurement precision while maintaining relatively simple device architecture through intelligent control algorithms
2Reliability
If a fixed threshold force is used for occlusion detection, then the device is easier to operate, but false alarms are generated
Solution Approach 1:
The alarm system reliability is improved by dynamically adjusting detection thresholds based on real-time motor current and pump speed data. This dynamic approach reduces false alarms caused by fixed threshold limitations while maintaining ease of operation through automated adaptation without requiring user intervention or complex manual calibration
Solution Approach 2:
The system performs self-adjustment of detection parameters by automatically monitoring operational conditions and adapting thresholds accordingly. This self-service capability improves alarm reliability by eliminating false alarms while keeping the device easy to operate, as the system autonomously handles the complexity of threshold optimization without user involvement
3Reliability
If the reservoir cap is made loose for easy removal, then the ease of operation is improved, but the reservoir may become dislodged during physical activities
Solution Approach 1:
The reservoir cap design employs dynamic engagement characteristics with multiple engagement positions. The cap can be easily inserted and removed by users, yet during normal use it maintains secure engagement through its mechanical design that provides stable seating, thus resolving the contradiction between ease of operation and reliability during physical activities
Solution Approach 2:
The cap-reservoir interface is designed with specific local structural features that provide different engagement characteristics for different operations. The interface allows easy linear insertion and removal while preventing rotational dislodgment during physical activities, achieving both ease of operation and reliable retention through localized structural quality differences
4Reliability
If the force sensor threshold is set at maximum expected force to avoid false alarms, then false alarms are reduced, but occlusion detection is delayed
Solution Approach 1:
The system uses feedback from real-time monitoring of motor current and pump speed relationships to detect occlusions earlier. By continuously analyzing the dynamic relationship between these parameters, the system can identify occlusion conditions before the force reaches maximum expected levels, reducing detection time while maintaining alarm reliability through intelligent pattern recognition
Solution Approach 2:
The system performs preliminary detection by monitoring operational parameters before occlusion forces reach maximum levels. The continuous monitoring of motor current and pump speed relationships allows early identification of developing occlusion conditions, enabling earlier intervention while maintaining system reliability through proactive rather than reactive detection
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
This approach enhances the accuracy and speed of occlusion detection and ensures proper reservoir seating, reducing false alarms and improving the reliability of fluid infusion devices by adapting to changing conditions and physical interactions.
Implementation Method 1
uses a force sensor to monitor rewind forces and determine adaptive threshold ranges for occlusion detection and reservoir seating
Data Source
AI summary
A device for delivering fluid to a user includes a housing, a drive motor assembly in the housing, a force sensor, and an electronics module. The drive motor assembly regulates delivery of fluid by actuating a piston of a fluid reservoir, and the force sensor generates output levels in response to force imparted thereto during, for example, fluid delivery operations. The electronics module processes the output levels of the force sensor to assess the operating health of the force sensor, to check for occlusions in the fluid delivery path, and to monitor the seating status of the fluid reservoir.