Dialyzer Flow Rate Estimation via Acoustic Impedance Sensors
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Solution Overview
Problem
Hemodialysis treatments face challenges in accurately monitoring ultrafiltration rates due to difficulties in measuring flow rates, which can lead to fluid imbalance and complications such as hypotension, and existing methods like trans-membrane pressure and gravimetric scales are not reliable for real-time control.
Innovation Solution
A system using pressure sensors in dialyzers to estimate flow rates by applying pressure readings to adaptive models, allowing for continuous monitoring and alerting caregivers to deviations from expected flow rates, thereby optimizing fluid balance and preventing complications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If trans-membrane pressure or gravimetric scales are used to monitor ultrafiltration rates, then monitoring capability is provided, but measurement precision and reliability for real-time control are insufficient
Solution Approach 1:
The patent replaces mechanical measurement systems (gravimetric scales) and pressure-based monitoring (trans-membrane pressure) with an acoustic measurement system using impedance sensors to detect flow rates through acoustic signal analysis in the fluid conduit
Solution Approach 2:
The patent introduces acoustic impedance sensors as an intermediary measurement mechanism that indirectly detects flow rates by analyzing acoustic properties of the fluid rather than directly measuring flow or weight, enabling more precise real-time monitoring
2Reliability
If flow rates are not accurately monitored, then treatment can proceed without complex monitoring equipment, but fluid imbalance and complications such as hypotension occur
Solution Approach 1:
The patent replaces complex mechanical flow measurement systems with acoustic impedance sensing that uses sound wave propagation characteristics to detect flow rates, reducing mechanical complexity while improving measurement reliability
Solution Approach 2:
The acoustic impedance sensors utilize the fluid itself as the transmission medium for acoustic signals, eliminating the need for separate measurement conduits or complex sensor assemblies, thereby reducing overall system complexity
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 provides more accurate and real-time monitoring of ultrafiltration rates, reducing the risk of dialysis-induced hypotension and optimizing treatment by adjusting flow rates automatically, thus improving patient safety and treatment efficacy.
Implementation Method 1
an acoustic impedance sensor to provide a flow rate of the fluid
Implementation Method 2
a pressure sensor to provide a pressure of the fluid at a port of the dialyzer
Implementation Method 3
The fresh dialysate collects excess impurities passing through the straw-like tubes by diffusion
Implementation Method 4
The fresh dialysate collects excess water through an ultrafiltration process due to a pressure drop across the membranes
Data Source
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AI summary
Embodiments of the disclosure include a method and system for estimating flow rates of a fluid or medium though a dialyzer during a dialysis treatment (e.g., a hemodialysis treatment). Pressure sensors are incorporated in dialyzers used for hemodialysis to achieve continuous monitoring of fluid balance of the body. During dialysis, obtaining fluid input and output pressures experienced at various inlets and outlets of dialyzers is easier than obtaining flow rates at these inlets and outlets, but using flow rates is better in determining the effectiveness of a dialyzer during hemodialysis. Embodiments of the disclosure thus use pressure measurements at inlets and outlets of a dialyzer along with a dialyzer model to determine fluid flow rates through the dialyzer. The fluid flow rates are used to determine whether there are leakages or occlusions in tubing during the dialysis treatment.