Medical Pump On-Site Calibration Using Air Bubble Detection
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Solution Overview
Problem
Medical pumps require frequent calibration to ensure accurate fluid delivery and sensor functionality, but existing methods often require off-site testing and are not efficient for on-site verification.
Innovation Solution
A method and apparatus for on-site calibration testing of medical pumps using a specialized tube set that injects an air bubble to measure pumping accuracy and sensor accuracy, allowing for simultaneous testing of pumping volume, force sensor accuracy, and bubble detector calibration without increasing pressure in the tube.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If off-site lab testing is used for calibration, then measurement precision is improved, but loss of time and device complexity increase
Solution Approach 1:
The pump performs self-calibration by automatically detecting the air bubble position and measuring its volume to determine pumping accuracy, eliminating the need for external lab technicians and reducing downtime
Solution Approach 2:
An air bubble is introduced as an intermediary substance to serve as a measurable marker that allows the pump to self-measure its pumping volume and detect occlusion events without requiring external calibration equipment
2Measurement precision
If off-site lab testing is used for calibration, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The pump incorporates built-in sensors and processing capability that enable it to autonomously perform calibration measurements and detect anomalies, eliminating dependency on external lab equipment and reducing overall system complexity
Solution Approach 2:
The air bubble serves multiple functions simultaneously: it acts as a volume marker for pumping accuracy testing, an occlusion detection trigger, and a sensor calibration reference, reducing the need for multiple separate testing procedures
3Measurement precision
If air bubble volume is increased for better detection, then measurement precision improves, but the pump must pump larger volumes affecting productivity
Solution Approach 1:
The system changes the detection parameter from absolute bubble volume to relative bubble position and volume ratio, allowing accurate detection with smaller bubbles while maintaining pump productivity through proportional scaling
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 efficient on-site calibration of medical pumps, ensuring accurate fluid delivery and sensor functionality, reducing the need for off-site testing and improving operational reliability.
Implementation Method 1
the pump is used to further pump a volume of liquid so as to compress the air bubble
Implementation Method 2
Based on knowing the measured volume of the bubble and the volume of liquid pumped in order to compress the bubble, an expected increase in pressure in the tube is assessed
Implementation Method 3
the pump is activated so as to advance the air bubble to the bubble detector of the pump. While the pump is pumping, the pump automatically measures the volume of liquid that is being pumped, such that when a downstream edge of the bubble is detected by the bubble detector
Data Source
AI summary
A method and apparatus are provided for use with a pump. The method includes, (a) placing liquid in a tube coupled to the pump, (b) injecting an air bubble into the tube in a manner that does not increase pressure within the tube, and such that there is a predetermined volume of liquid between the air bubble and the pump, (c) using the pump to advance the air bubble along the tube to the bubble detector of the pump, (d) using the pump, assessing accuracy of the pump by automatically measuring the volume of liquid pumped to advance the air bubble to the bubble detector, and (e) using the pump to continue advancing the air bubble along the tube, past the bubble detector, and using the pump to measure a volume of the air bubble. Other applications are also described.