Patent ID: 9500188
Filing Date: 2016-11-22
CPC Classification: A61M,F04B

Claim Text:
1. A medical fluid pumping system, comprising: a medical fluid cassette defining a fluid pump chamber; a medical fluid pumping machine defining a cassette compartment and comprising an electromagnetic piston that aligns with the fluid pump chamber of the medical fluid cassette when the medical fluid cassette is disposed in the cassette compartment, the electromagnetic piston comprising an electromagnet connected to a wire winding, the electromagnet being configured to receive electrical power through the wire winding to magnetize the electromagnet, wherein the electromagnetic piston is configured to be coupled to the medical fluid cassette when the electromagnet is magnetized and to be decoupled from the medical fluid cassette when the electromagnet is not magnetized, wherein the medical fluid cassette is configured to be removed from the cassette compartment; a sensor electrically connected to the wire winding of the electromagnetic piston, the sensor being configured to detect an electrical characteristic across the wire winding and to generate an electrical signal indicative of the detected electrical characteristic, the electric characteristic being indicative of coupling between the electromagnetic piston and the medical fluid cassette, wherein the electromagnetic piston is configured to be coupled to and decoupled from the medical fluid cassette; and a controller configured to receive the electrical signal from the sensor connected to the wire winding, and adjust the electrical power delivered through the wire winding to the electromagnetic piston based on determining whether the electrical signal indicates that the electromagnetic piston and the medical fluid cassette are coupled.