DIALYSIS SYSTEM AND APPARATUS WITH FLUID FLOW CONTROL
A dialysis fluid apparatus includes a flexible dialysis fluid container, a holder structured such that the flexible dialysis fluid container is held vertically within the holder and conforms to a shape of the holder, a pressure sensor positioned and arranged to sense a pressure of a fluid held within the flexible dialysis fluid container, and a control unit configured to (i) store at least one cross-sectional area of the flexible dialysis fluid container, (ii) calculate a head height using the pressure of the fluid held within the flexible dialysis fluid container, and (iii) calculate a volume of the fluid held within the flexible dialysis fluid container using the cross-sectional area and the head height.
1 . A dialysis fluid apparatus comprising:
a flexible dialysis fluid container;
a holder structured such that the flexible dialysis fluid container is held vertically within the holder and conforms to a shape of the holder;
a pressure sensor positioned and arranged to sense a pressure of a fluid held within the flexible dialysis fluid container; and
a control unit configured to (i) store at least one cross-sectional area of the flexible dialysis fluid container, (ii) calculate a head height using the pressure of the fluid held within the flexible dialysis fluid container, and (iii) calculate a volume of the fluid held within the flexible dialysis fluid container using the cross-sectional area and the head height.
2 . The apparatus of claim 1 , wherein the flexible dialysis fluid container includes a flexible bag.
3 . The apparatus of claim 1 , wherein the holder is structured as a clamshell having open sides.
4 . The apparatus of claim 1 , wherein the control unit is configured to calculate the head height as a difference in head height of the fluid held within the flexible dialysis fluid container prior to and after a delivery of the fluid to or from the flexible dialysis fluid container.
5 . The apparatus of claim 1 , wherein the head height is a first head height and the volume is a first volume, and wherein the control unit is configured to calculate a second head height and a second volume of the fluid held within the flexible dialysis fluid container using the second head height.
6 . The apparatus of claim 5 , wherein a cross-sectional area for the calculation of the second volume is the same as the cross-sectional area for the calculation of the first volume.
7 . The apparatus of claim 5 , wherein a cross-sectional area for the calculation of the second volume is different than the cross-sectional area for the calculation of the first volume.
8 . The apparatus of claim 5 , wherein the control unit is further configured to (i) store a lookup table that correlates the measured pressure of the fluid held within the flexible dialysis fluid container with cross-sectional area and (ii) obtain the different cross-sectional areas using the lookup table and first and second measured pressures corresponding respectively to the first and second head heights.
9 . The apparatus of claim 5 , wherein the control unit is further configured to determine a difference between the first and second volumes to determine an amount of the fluid delivered to or removed from the flexible dialysis fluid container.
10 . The apparatus of claim 5 , wherein the control unit is further configured to determine a flowrate of the fluid delivered to or removed from the flexible dialysis fluid container by dividing the difference between the first and second volumes by a time duration between first and second measured pressures corresponding respectively to the first and second head heights.
11 . The apparatus of claim 1 , wherein the control unit is further configured to determine the flowrate on a periodic basis.
12 . The apparatus of claim 1 , wherein calculating the head height in (ii) is dependent on a density of the fluid, and wherein the control unit stores a look-up table that correlates fluid density to fluid type.
13 . The apparatus of claim 1 , wherein calculating the head height in (ii) is dependent on the density of the fluid, and wherein the control unit is configured such that when the fluid held within the flexible dialysis fluid container is mixed, the control unit is configured to use different densities for different head height calculations.
14 . The apparatus of claim 1 , further comprising a level sensor placed in operable communication with the flexible dialysis fluid container, the level sensor communicatively coupled to the control unit,
wherein the control unit configured to at least one of (a) cause an alarm or (b) halt delivery of the fluid to or removal of the fluid from the flexible dialysis fluid container when a level of the fluid falls so as to be detected by the level sensor.
15 . The apparatus of claim 14 , wherein the level sensor is located so as to sense an area above the flexible dialysis fluid container that transitions in cross-sectional area towards a delivery tube in fluid communication with the flexible dialysis fluid container.
16 . The apparatus of claim 1 , wherein the pressure sensor includes a pressure pouch in pressure transmission communication with a pressure transducer, the pressure pouch mounted to the holder such that the flexible dialysis fluid container contacts the pressure pouch.
17 . A dialysis fluid apparatus comprising:
a flexible dialysis fluid container;
a peristaltic pump tube placed in fluid communication with the flexible dialysis fluid container;
a holder structured such that the flexible dialysis fluid container is held vertically within the holder and conforms to a shape of the holder;
a pressure sensor positioned and arranged to sense a pressure of a fluid pumped to or from the flexible dialysis fluid container via the peristaltic pump tube; and
a control unit configured to (i) store at least one cross-sectional area of the flexible dialysis fluid container, (ii) calculate a head height using the pressure of the fluid pumped to or from the flexible dialysis fluid container via the peristaltic pump tube, and (iii) calculate a volume of the fluid held within the flexible dialysis fluid container using the cross-sectional area and the head height.
18 . The apparatus of claim 17 , wherein the peristaltic pump tube is additionally placed in selective fluid communication with at least one of: a fluid source, a fluid heater, or a patient line.
19 . A dialysis fluid apparatus comprising:
a flexible dialysis fluid container;
a holder structured such that the flexible dialysis fluid container is held vertically within the holder and conforms to a shape of the holder;
a pressure sensor including a pressure pouch positioned and arranged to contact a bottom of the flexible dialysis fluid container and a pressure transducer in pressure transmission communication with the pressure pouch to sense a pressure of a fluid held within the flexible dialysis fluid container; and
a control unit configured to (i) store at least one cross-sectional area of the flexible dialysis fluid container, (ii) calculate a head height using the pressure of the fluid held within the flexible dialysis fluid container, and (iii) calculate a volume of the fluid held within the flexible dialysis fluid container using the cross-sectional area and the head height.
20 . The apparatus of claim 17 , wherein the pressure pouch and the pressure transducer are in pneumatic communication.