Peritoneal dialysis system including manifold assembly and peristaltic pump
A peritoneal dialysis (“PD”) system includes a cycler including an actuation surface having a peristaltic pump actuator; at least one pair of capacitive sensing plates; a manifold assembly including a rigid manifold having at least one chamber, the rigid manifold configured and arranged to be abutted against the actuation surface for operation, wherein the at least one pair of capacitive sensing plates is positioned to be operable with the at least one chamber; a peristaltic pump tube; and a control unit configured to actuate the peristaltic pump actuator to pump dialysis fluid to the at least one chamber, receive a signal from the at least one pair of capacitive sensing plates, count a number of revolutions of the peristaltic pump actuator, determine a current volume per revolution for the peristaltic pump actuator, and use the current volume per revolution for a subsequent operation of the peristaltic pump actuator.
1. A peritoneal dialysis (“PD”) system comprising:
a cycler including
an actuation surface having a peristaltic pump actuator, and
a pair of capacitive sensing plates;
a manifold assembly including
a rigid manifold having first, second and third chambers, the rigid manifold configured and arranged to be abutted against the actuation surface for operation, wherein the pair of capacitive sensing plates is positioned to be operable with the first chamber, and
a peristaltic pump tube extending from the first chamber to the second chamber of the rigid manifold; and
a control unit configured to (i) cause the peristaltic pump actuator to actuate the peristaltic pump tube at a known revolutions per minute (“rpm”) to empty dialysis fluid from the first chamber to the second chamber, wherein air backfills the first chamber from the third chamber, (ii) receive a signal from the pair of capacitive sensing plates indicating that the first chamber is empty, (iii) record a time duration Δt needed to empty the dialysis fluid from the first chamber to the second chamber, (iv) determine a current volume per revolution for the peristaltic pump actuator by performing a first division of a known volume of the first chamber by the time duration Δt and a second division of a result of the first division by the known rpm, and (v) use the current volume per revolution for at least one subsequent operation of the peristaltic pump actuator.
2. The PD system of claim 1 , wherein the control unit is configured to use the signal from the pair of capacitive sensing plates to confirm that the first chamber is full of the dialysis fluid prior to performing the (i).
3. The PD system of claim 1 , wherein the current volume per revolution is for a first direction of the peristaltic pump actuator, and wherein the control unit is further configured to (vi) cause the peristaltic pump actuator to actuate the peristaltic pump tube at a known revolutions per minute (“rpm”) in a second direction to fill the first chamber with the dialysis fluid from the second chamber, wherein the third chamber accepts the air displaced from the first chamber, (vii) receive a signal from the pair of capacitive sensing plates indicating that the first chamber is full, (viii) record a time duration Δt needed to fill the dialysis fluid from the second chamber to the first chamber, (ix) determine a current volume per revolution for the peristaltic pump actuator in the second direction by performing a third division of the known volume of the first chamber by the time duration Δt needed to fill the dialysis fluid from the second chamber to the first chamber and a fourth division of a result of the third division by the known rpm in the second direction, and (x) use the current volume per revolution in the second direction for an additional at least one subsequent operation of the peristaltic pump actuator.
4. The PD system of claim 3 , wherein the first direction is a patient fill direction and the second direction is a patient drain direction.
5. The PD system of claim 3 , wherein the control unit is configured to repeat the (i) to the (v) and/or the (vi) to the (x) in each of a plurality of cycles of a PD treatment.
6. The PD system of claim 1 , wherein the cycler includes a door that encloses the rigid manifold after the rigid manifold is abutted against the actuation surface for the operation, the actuation surface containing one of the plates of the pair of capacitive sensing plates, and the door containing the other plate of the pair of capacitive sensing plates.
7. The PD system of claim 6 , wherein the one of the plates of the pair of capacitive sensing plates contained by the actuation surface is parallel to and directly opposes the other plate of the pair of capacitive sensing plates contained by the door.
8. The PD system of claim 1 , wherein the use of the current volume per revolution for the at least one subsequent operation of the peristaltic pump actuator includes multiplying the current volume per revolution by a number of revolutions recorded by the control unit during each of the at least one subsequent operation.
9. The PD system of claim 8 , wherein the number of revolutions takes into account a fraction of a revolution.