PUMPING SYSTEMS FOR CASSETTE-BASED DIALYSIS

摘要

A dialysis machine includes: a hardware unit including at least one pump actuator, at least one valve actuator and a cassette interface, the cassette interface including: (i) a plate that abuts the cassette; (ii) at least one pump aperture defined by the plate; (iii) at least one pump head moveable out of and retractable into the at least one pump aperture to operate a pumping portion of the cassette; (iv) at least one valve aperture defined by the plate; (v) at least one valve apparatus moveable out of and retractable into the at least one valve aperture to operate a valve portion of the cassette; (vi) at least one sensor aperture defined by the plate; and (vii) at least one sensor located in the least one sensor aperture, the at least one sensor operable with a sensor portion of the cassette.

主权项

1. A peritoneal dialysis method comprising:
enabling a disposable pumping cassette to be aligned so that (i) a soft side of the disposable pumping cassette faces towards a vacuum chamber and a rigid piston head of a peritoneal dialysis machine, the rigid piston head attached to a rigid piston shaft that is connected mechanically to a stepper motor via a coupler, and (ii) a dialysis fluid supply line, a patient line and a drain line extend from a hard part of the disposable cassette to the outside of the peritoneal dialysis machine and communicate with a respective dialysis fluid supply container, a patient and a drain; positioning the rigid piston head relative to the vacuum chamber such that the rigid piston shaft translates back and forth within the vacuum chamber; applying a vacuum from a negative pressure source communicating pneumatically through the vacuum chamber such that the soft side of the disposable pumping cassette is pulled into contact with a surface of the rigid piston head to at least partially mate the soft side of the disposable pumping cassette with the rigid piston head; operating a stepper motor such that the rigid piston head and the soft side of the disposable pumping cassette extend at least partially into the hard part of the disposable pumping cassette so as to push (i) fresh dialysis fluid from the disposable pumping cassette, through the patient line or (ii) used dialysis fluid from the disposable cassette, through the drain line and to the drain; and operating the stepper motor such that the rigid piston head retracts from the hard part of the disposable pumping cassette while the negative pressure source applies a vacuum through the vacuum chamber to the soft side of the disposable pumping cassette to hold the soft side in at least partial contact with the surface of the rigid piston head so as to draw (i) fresh dialysis fluid from the dialysis fluid supply container through the supply line and into the disposable pumping cassette through the supply line or (ii) used dialysis fluid from the patient through the patient line and into the disposable pumping cassette.