Venous Needle Dislodgment Detection with Kalman-Filtered Pressure Signals
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Solution Overview
Problem
Existing methods for detecting blood vessel needle dislodgment, particularly venous needle dislodgment, lack sensitivity and accuracy, leading to potential life-threatening situations if not promptly addressed.
Innovation Solution
A method involving a blood line pressure sensor to record datasets at predefined intervals, using a Kalman filter to process these datasets, and a Wald test to detect potential dislodgment, confirmed or disproved by a static blood line pressure measurement, ensuring high accuracy and rapid response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional needle dislodgment detection methods are used, then the system is simple to operate, but the sensitivity and accuracy of detection are insufficient
Solution Approach 1:
The patent introduces a blood line pressure sensor as an intermediary element to detect needle dislodgment indirectly through pressure changes in the blood line, rather than directly monitoring needle position. This mediator enables high-accuracy detection while keeping the overall system relatively simple.
Solution Approach 2:
The patent replaces complex mechanical detection systems with a pressure-based detection method using a pressure sensor and statistical analysis. This substitution achieves higher detection accuracy through measuring pressure variations caused by needle dislodgment events.
2Loss of time
If conventional detection methods are used, then the system is easy to implement, but the response time is delayed and blood loss increases
Solution Approach 1:
The patent performs preliminary filtering of pressure data using a Kalman filter and preliminary testing using a Wald test before final detection. These preliminary actions prepare the system to rapidly respond to actual dislodgment events while filtering out false alarms, thus reducing response time and improving reliability.
Solution Approach 2:
The patent implements a feedback mechanism where the pressure sensor continuously monitors blood line pressure, the Kalman filter processes the data in real-time, and the Wald test provides continuous evaluation. This closed-loop feedback system enables rapid detection and response to needle dislodgment events.
3Measurement precision
If simple pressure monitoring is used, then the system is simple to operate, but false alarms and missed detections occur frequently
Solution Approach 1:
The patent employs dynamic adaptive filtering using the Kalman filter, which adjusts its parameters based on the statistical characteristics of the pressure signal. This dynamic approach optimizes detection specificity by adapting to changing conditions while maintaining ease of operation through automated parameter adjustment.
Solution Approach 2:
The patent changes the parameters of the pressure monitoring system dynamically - using the Kalman filter to adaptively adjust filtering parameters and the Wald test to adjust detection thresholds based on observed pressure variations. These parameter changes improve detection specificity without requiring manual intervention.
Data Source
AI summary
Disclosed is a method for blood vessel needle dislodgment detection, which comprises carrying out a blood treatment and/or an analysis on a patient using a blood analysis loop at a predefined blood flow and recording at predefined time intervals blood line pressure datasets using a blood line pressure sensor of the blood analysis loop. The method comprises filtering the recorded blood line pressure datasets using a processor, which is configured to filter the recorded datasets using a predefined filter function and testing the filtered blood line pressure datasets using the processor, which is further configured to test the filtered blood line pressure datasets based on a test function. A potential blood vessel needle dislodgment is then detected based on a detecting function resulting from the testing. Finally, the potential blood vessel needle dislodgment is confirmed or disproved by a static blood line pressure measurement performed by stopping the blood flow and keeping a blood line of the blood analysis loop not isolated from the patient.