Heart Reference Sensor Tubing for Stable Blood Pressure
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Solution Overview
Problem
Flexible PVC tubing used in heart reference sensors for non-invasive blood pressure measurement systems experiences fluid volume increase due to plasticizer migration, leading to bulging bladders and inaccurate readings over time.
Innovation Solution
Employing non-plasticized or chemically inert tubing, such as flexible polymers like polyurethane or fluoropolymer, to prevent oil-plasticizer mixture buildup and maintain stable pressure measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If flexible PVC tubing is used in heart reference sensors, then the tubing is flexible and easy to install, but plasticizer migration causes fluid volume increase and bladder bulging over time
Solution Approach 1:
The patent changes the chemical composition parameters of the tubing by switching from plasticized PVC to non-plasticized or chemically inert materials. This parameter change eliminates plasticizer migration while maintaining flexibility, resolving the contradiction between ease of installation and measurement accuracy over time
Solution Approach 2:
The patent employs composite material structures by combining flexible polymers with chemically inert liners or coatings. This composite approach provides both the necessary flexibility for installation and chemical stability to prevent fluid volume changes, thereby maintaining pressure measurement reliability
2Stability of the object's composition
If PVC tubing with plasticizer is used, then the tubing remains flexible, but oil-plasticizer mixture buildup causes bladder bulging and zeroing drift
Solution Approach 1:
The patent extracts and removes the plasticizer component from the tubing system by using non-plasticized or chemically inert materials. This extraction eliminates the source of oil-plasticizer mixture buildup, preventing bladder bulging and maintaining zeroing stability over extended periods
Solution Approach 2:
The patent creates a chemically inert environment within the tubing by using chemically inert materials that do not react with or migrate into the oil-filled bladder. This inert environment prevents chemical interactions that would cause fluid volume changes, thereby maintaining composition stability and zeroing accuracy over time
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 solution stabilizes the signal over extended periods, preventing bladder bulging and ensuring accurate zeroing functions, thereby improving the resilience and reliability of heart reference sensors.
Implementation Method 1
The HRS connects a liquid filled bladder located at the patient's heart level to a pressure sensor located at the patient's finger or wrist unit through a liquid filled tube
Implementation Method 2
The gravity generated pressures between the patient's heart level and finger level are measured by the HRS
Data Source
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AI summary
A blood pressure measurement system comprising: a heart reference sensor (HRS) including a bladder for mounting proximate the patient's heart level, tubing, and a pressure sensor; a finger cuff attachable to a patient's finger; and a blood pressure measurement controller coupled to the HRS and the finger cuff to perform blood pressure measurement functions. The pressure sensor is located at approximately the same height level of the finger cuff and the tubing extends from the bladder of the HRS to the pressure sensor, the bladder of the HRS including liquid in fluid communication with liquid in the tubing connected to the pressure sensor at the patient' s finger level such that gravity generated pressure differences between the patient's heart level and finger level are measurable by the pressure sensor of the HRS to be subtracted from the blood pressure measurement, wherein the tubing is non- plasticized tubing or chemically inert tubing.