Blood Line Pressure Monitoring for CRRT Disconnection Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CRRT systems fail to reliably detect disconnection events in blood lines, leading to potential blood loss or air embolism risks, and often generate false alarms, without requiring hardware upgrades.
Innovation Solution
An apparatus and method using pressure sensors and a control unit to calculate and monitor pressure differences in blood withdrawal and return lines, adjusting for hydrostatic pressure and blood flow, to accurately detect disconnections and prevent alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If return pressure monitoring is used to detect disconnection events, then disconnection detection capability is provided, but false alarms occur and reliability is reduced
Solution Approach 1:
The invention changes the monitoring parameter from simple return pressure to the derivative dPret/dt (rate of change of return pressure). This parameter transformation allows the system to detect disconnection events more reliably by identifying sudden pressure changes rather than absolute pressure values, thereby resolving the contradiction between detection reliability and measurement precision.
2Reliability
If pressure threshold alarms are used, then disconnection events can be detected, but false alarms are generated reducing system reliability
Solution Approach 1:
The invention transforms the monitoring approach by using the derivative dPret/dt instead of absolute pressure thresholds. This parameter change simplifies the alarm logic while improving reliability, as the rate of change provides a more specific indicator of disconnection events without requiring complex multi-parameter analysis.
3Measurement precision
If venous return pressure monitoring is implemented, then disconnection detection is possible, but false alarms occur reducing measurement precision
Solution Approach 1:
The invention addresses false alarms by changing from monitoring venous return pressure absolute values to monitoring its rate of change dPret/dt. This parameter transformation makes the detection more precise by focusing on the characteristic sudden change that occurs during disconnection, while filtering out gradual pressure variations that cause false alarms.
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
Enhances the reliability of disconnection event detection, reduces false alarms, and maintains safety without additional hardware costs or complexity.
Implementation Method 1
a pressure sensor configured to detect pressure in the blood circuit
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus for extracorporeal blood treatment is configured for detecting a disconnection between a connector (6a, 7a) for connection to a vascular access device (400) fixed to a patient (P) and the vascular access device (400) by: calculating a hydrostatic pressure difference (PH_patient) due to a difference in height between the vascular access device (400) and a pressure sensor (25, 26); calculating a section pressure drop (ΔPline) due to a section of the blood circuit from the connector (6a, 7a) to the pressure sensor (25, 26); calculating a disconnection pressure (Pdisc) from the hydrostatic pressure difference (PH_patient) and the section pressure drop (ΔPline); receiving a measured pressure (P) from the pressure sensor (25, 26); detecting a disconnection of the connector (6a, 7a) from the vascular access device (400) by comparing the measured pressure (P) with a pressure alarm threshold (Pthresh) function of the disconnection pressure (Pdisc).