Determining the absence or presence of fluid in a dialysis system

摘要

This disclosure relates to detecting fluid in medical tubing. In certain aspects, a method is performed by a data processing apparatus. The method includes controlling repetitive activation of the ultrasonic transmitter. The method also includes receiving a signal from the ultrasonic receiver during an activation of the ultrasonic transmitter. The method also includes determining that fluid is absent or present in a portion of the medical fluid tube based on a comparison between the signal and a threshold value.

主权项

1. A dialysis system comprising:
a dialysis machine; a control unit; a medical fluid tube connected to the dialysis machine; an ultrasonic transmitter positioned adjacent to the medical fluid tube; an ultrasonic receiver positioned adjacent to the medical fluid tube configured to receive one or more signals in response to the activation of the ultrasonic transmitter; and a computer storage medium encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising:
controlling repetitive activation of the ultrasonic transmitter, wherein controlling repetitive activation of the ultrasonic transmitter comprises, for each repetition:
activating the ultrasonic transmitter for a first period of 2 to 15 milliseconds; anddeactivating the ultrasonic transmitter for a second period of 998 to 985 milliseconds;receiving a signal from the ultrasonic receiver during an activation of the ultrasonic transmitter; anddetermining that fluid is absent or present in a portion of the medical fluid tube based on a comparison between the signal and a threshold value.