Syringe Pump Occlusion Detection via Pressure Slope Analysis
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Solution Overview
Problem
Conventional drug infusion pumps fail to detect occlusions in the fluid path reliably, leading to delayed detection and potential harm to patients, especially during bolus injections and varying flow rates, as they only trigger alarms when pressure exceeds a predetermined threshold, without indicating building pressure issues.
Innovation Solution
The system monitors pressure values over time using existing transducers, calculates a slope, and compares it to an expected relationship optimized for syringe size, type, and delivery rate, initiating an alarm if it deviates, and includes features for steady state detection and bolus infusion management to reduce false occlusion alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pump uses a predetermined pressure threshold to trigger an occlusion alarm, then the alarm is simple to implement, but the detection is delayed and may not indicate building pressure issues until the threshold is exceeded
Solution Approach 1:
The system performs preliminary analysis by calculating the slope of pressure change before the pressure actually exceeds the alarm threshold. This allows the system to detect occlusion trends early and trigger an alarm before the predetermined threshold is reached, eliminating detection delay while maintaining simplicity.
Solution Approach 2:
The system continuously monitors pressure and provides feedback by calculating the rate of pressure change (slope). This feedback mechanism allows the system to detect occlusion conditions based on the trend of pressure building rather than waiting for a fixed threshold, improving detection reliability and reducing time loss.
2Reliability
If the pressure threshold is set to a relatively high value to avoid false occlusion alarms, then false alarms are reduced, but the detection period is extended to hours
Solution Approach 1:
By calculating the slope of pressure change in advance, the system can detect occlusion trends at lower pressure levels. This preliminary detection approach allows the use of higher thresholds to avoid false alarms while still achieving rapid detection through slope analysis, thus reducing both false alarms and detection period.
Solution Approach 2:
The system replaces the simple threshold-based mechanical alarm system with a computational approach that analyzes the rate of pressure change. This substitution allows the system to distinguish between normal pressure variations and actual occlusion conditions, reducing false alarms while maintaining short detection periods.
3Device complexity
If conventional pumps monitor only force between pusher and plunger or pressure in syringe, then the system is simple, but occlusion detection is unreliable during varying flow rates and bolus injections
Solution Approach 1:
The system transitions from static threshold monitoring to dynamic slope analysis. By continuously calculating the rate of pressure change, the system adapts to varying flow rates and bolus injection patterns, maintaining reliability without significantly increasing device complexity.
Solution Approach 2:
The system changes the monitoring parameter from absolute pressure values to the rate of pressure change (slope). This parameter transformation allows the system to reliably detect occlusions during varying flow rates and bolus injections while maintaining system simplicity, as the same transducer is used but with different analysis.
4Measurement precision
If a disposable sensor is positioned within the actual delivery line, then occlusion detection is accurate, but the system cost increases significantly
Solution Approach 1:
The system creates a virtual model of the delivery line pressure conditions by analyzing the slope of pressure change in the syringe. This copying approach allows accurate occlusion detection without physically placing sensors in the delivery line, maintaining measurement precision while avoiding the high cost of disposable sensors.
Solution Approach 2:
The existing pressure transducer in the syringe is made multi-functional by using it not only for monitoring syringe pressure but also for detecting occlusions through slope analysis. This universality eliminates the need for additional expensive sensors in the delivery line while maintaining detection accuracy.
Data Source
AI summary
An apparatus, method and program product detects an occlusion in a fluid line by determining if a relationship between force measurements departs from an expected relationship.