Hemodialysis Fluid Replacement Blockage Detection
Solution Overview
Problem
Existing hemodialysis systems face challenges in detecting blockages in fluid replacement passages, which can lead to incomplete fluid replacement during dialysis treatments, as current methods rely on pressure rise detection and may fail to identify blockages if the passage is closed.
Innovation Solution
A blockage detection device that operates the dialysate pump at a set flow rate to measure total discharge time, then uses the fluid replacement pump to discharge a portion of the dialysate at a set flow rate for a predetermined time, and finally determines blockage by comparing the remaining discharge time to the total discharge time within an allowable error range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure rise detection is used to detect blockage in fluid replacement passage, then blockage detection capability is improved, but detection accuracy deteriorates when passage is closed at preparation stage
Solution Approach 1:
The system performs preliminary actions by measuring the discharge time of dialysate from the supply chamber before fluid replacement begins. This baseline measurement is stored and used for later comparison to detect blockages, allowing the system to establish normal operating conditions before problems occur
Solution Approach 2:
The system continuously monitors the discharge time of dialysate and compares it against the baseline measurement. When the discharge time exceeds the baseline by a predetermined threshold, the system generates an alarm, providing real-time feedback about potential blockages in the fluid replacement passage
2Productivity
If fluid replacement pump operates at predetermined flow rate for predetermined time, then fluid replacement efficiency is improved, but detection time for blockage increases
Solution Approach 1:
The system continuously measures the discharge time of dialysate from the supply chamber throughout the fluid replacement process. This continuous monitoring allows for real-time detection of blockages without interrupting the fluid replacement operation, maintaining productivity while enabling timely detection
Solution Approach 2:
The system replaces mechanical blockage detection methods with a time-based measurement system. By measuring the discharge time of dialysate and comparing it to baseline values, the system detects blockages through temporal analysis rather than mechanical pressure sensing, enabling non-intrusive monitoring
Data Source
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AI summary
To detect presence or absence of blockage in a fluid replacement passage 6 for use in a hemodialyzer 1. A controller C executes a first operation of operating a dialysate pump 27 at a predetermined set flow rate, in a state where a supply chamber 21a is filled with dialysate, to obtain total discharge time until the dialysate in the supply chamber runs out. Next, the controller executes a second operation of operating a fluid replacement pump 19 to discharge a part of the dialysate supplied to fill the supply chamber to a blood circuit 3, and continuously executes a third operation of operating the dialysate pump 27 to obtain remaining discharge time until residual dialysate remaining in the supply chamber runs out. At this time, in a case where the remaining discharge time matches the total discharge time, it can be determined by the second operation that the dialysate supplied to fill the supply chamber is not discharged to the blood circuit at all, and hence it can be determined by a fourth operation that the fluid replacement passage 6 is blocked. Presence or absence of blockage in a fluid replacement passage 6 can be detected without adding any special configuration.