A design about the system of leak detection of hemodialysis machine / 中国医学装备

ABSTRACT

Objective:To design an intelligent system of leak detection for AK200Shemodialysis machine so as to fast troubleshoot the range of leaked point for helpingengineer. Methods: The likely leaked part of flow paths of hemodialysis were simplified basedon routine detection experiment and the statistical record and data of faults. And then, testmode of pressure when hemodailysis implemented self-inspection for leakage was imitated. There was a air pumpwas connected with aimed flow paths, and the positive and negative pressure generated by controlling an externalair pump and the connected magnetic valve were applied at different time and different section, respectively. Afterincreased pressure, depended on the comparison of intra pressures from pressure sensors for one part of pipelinebetween pre- and post of one spell to analyze and decide whether this section exist leak. And the judgment standardwas if the difference of pressure was less than 5mmHg, there was not leak in this flow path, otherwise, the likely leakpoint should be troubleshot in further detection. Results: 183 detections were implemented at AK200S/AK200USwhich once happened alarm of leakage. And in the 183 detections, the detection system for leakage has found theranges of leaked point in 171 detection. The distribution of leaked points was 73 times were from filter to DRVAsection, 19 times were from DRVA section to DIVA section, 79 times were from DIVA section to champ of flexiblepipe at terminal of EVVA. On the other hand, in the leaked points, 162 points were at seal ring, 1 point was at filmof valve, 8 points were at connector, and the success rate of detection for leaked fault was more than 90%. Besides,the success rate of detection for leakage on flow paths of prepare troubleshooting under normal temperature was100%. Conclusion: The detection system of self-dependant development for leakage can help engineer to save timeof troubleshooting for leaked point and enhance the work efficiency.