Loading patent…
AssigneeFresenius Medical Care Holdings, Inc.
InventorsStephen R. Ash, Thomas A. Sullivan, David Carr, Michael James Beiriger
Estimating the term…
In one aspect of the invention, a method includes determining an amount of carbon dioxide (CO2) in dialysate flowing through a dialysis system using a CO2 sensor associated with the dialysis system, determining, using a pH sensor associated with the dialysis system, a pH level of the dialysate, and calculating a level of bicarbonate in the dialysate based at least in part on the determined amount of CO2 measured in the gas and the determined pH level of the dialysate.
A method in a dialysis system comprising a carbon dioxide (CO2) sensor and a pH sensor, the method comprising:
A method comprising:
A dialysis system comprising:
A dialysis fluid chamber comprising
A dialysis system comprising:
A gas emission device configured to be connected to a dialysis machine in a manner such that dialysis fluid can be forced into the gas emission device, the gas emission device comprising:
A method comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Concerning the measuring method or the display, e.g. intermittent measurement or digital display: by measuring the rate of variation of the…
Physical characteristics of the dialysate fluid: before use, i.e. upstream of dialyser
Physical characteristics of the dialysate fluid: after use, i.e. downstream of dialyser
Dialysates therefor: apparatus for preparing dialysates
About 5 years 11 months of term left · ends 24 Sep 2032 (estimated)
This invention relates to measuring chemical properties of a sample fluid in dialysis systems.
Dialysis is a treatment used to support a patient with insufficient renal function. The two principal dialysis methods are hemodialysis and peritoneal dialysis.
During hemodialysis (“HD”), the patient's blood is passed through a dialyzer of a dialysis machine while also passing a dialysis solution or dialysate through the dialyzer. A semi-permeable membrane in the dialyzer separates the blood from the dialysate within the dialyzer and allows diffusion and osmosis exchanges to take place between the dialysate and the blood stream. These exchanges across the membrane result in the removal of waste products, including solutes like urea and creatinine, from the blood. These exchanges also regulate the levels of other substances, such as sodium and water, in the blood. In this way, the dialysis machine acts as an artificial kidney for cleansing the blood.
FIG. 1 is a perspective view of a hemodialysis system that includes a hemodialysis machine connected to a module with a sorbent device for recycling spent dialysate.
FIG. 2 is a diagram of fluid flow in the dialysis system of FIG. 1.
FIG. 3 is a diagram of an apparatus of the dialysis system of FIG. 1 that is used in measuring bicarbonate.
FIG. 1 shows a hemodialysis system 100 that includes a module 105 fluidly coupled to a hemodialysis machine 110. The module 105 includes, among other things, a sorbent device holder 115 that holds a sorbent device 120. The module also includes a bicarbonate measurement unit 125 that is connected to a manifold 130 of the module 105 via inlet and outlet lines 132, 134. As will be described in greater detail below, the module 105 is used to recycle spent dialysate so that the spent dialysate can be reused for hemodialysis treatment. During use of the hemodialysis system 100, dialysate is pumped from the module 105 to the hemodialysis machine 110. The dialysate is then passed through a dialyzer 135 connected to the hemodialysis machine 110 at the same time that a dialysis patient's blood is passed through the dialyzer 135. As a result, toxins, such as urea, migrate across a permeable membrane (e.g., hollow fibers) of the dialyzer 135 from the patient's blood to the dialysate, producing spent dialysate (i.e., dialysate that contains toxins removed from the patient's blood). The spent dialysate is pumped to the module 105 where it passes through the sorbent device 120, which removes toxins from the spent dialysate. As a result of chemical reactions that occur within the sorbent device 120, the recycled dialysate exiting the sorbent device 120 typically contains gas, such as carbon dioxide. After exiting the sorbent device 120, the recycled dialysate travels into the module 105 and then is drawn into the bicarbonate measurement unit 125 via the inlet line 132, which is connected to the manifold 130 of the module 105. The recycled dialysate is then forced from the bicarbonate measurement unit 125 back into the module 105 via the outlet line 134, which is connected to the manifold 130 of the module 105. The recycled dialysate is then cycled back through the dialysate circuit and reused to cleanse the dialysis patient's blood.
Certain desired substances (e.g., magnesium, calcium, potassium, and sodium) may be stripped from the dialysate as the dialysate passes through the sorbent device 120. Those stripped substances can be added to the dialysate exiting the sorbent device 120 (e.g., prior to drawing the dialysate into the bicarbonate measurement unit 125). As shown in FIG. 1, an infusate solution container 136 and a sodium chloride solution container 138 are connected to a manifold 140 of the module 105 via fluid lines 137 and 139, respectively. The infusate solution (e.g., a solution including magnesium, calcium, and potassium) and sodium chloride can be drawn into the dialysate flowing within the module 105 by activating associated valves and pumps within the module 105. The module 105 may also include a bicarbonate container 191 that is connected to the manifold 140 of the module 104 via fluid line 192. Using a process similar to that discussed above with regard to the infusate solution and the sodium chloride, bicarbonate can be drawn into the dialysate flowing within the module 105 by activating associated valves and pumps within the module 105.
As shown in FIG. 1, a dilution water container 141 is connected to the dialysis machine 110 via a fluid line 143. In some cases, certain substances, such as sodium, may be added to, rather than stripped from, the dialysate as the dialysate passes through the sorbent device 120. As a result, the sodium concentration in the dialysate exiting the sorbent device 120 may exceed a maximum desired concentration. In such cases, dilution water can be added to dialysate that is exiting the hemodialysis machine 110 and flowing into the module 105 toward the sorbent device 120. The dilution water can be added to the dialysate exiting the hemodialysis machine 110 by activating a pump within the hemodialysis machine 110. Activating this pump draws the dilution water from the dilution water container 141 and fluid line 143 into the dialysate exiting the hemodialysis machine 110 such that the sodium concentration of the dialysate exiting the hemodialysis machine 110 (and eventually flowing through the module 105) is reduced, as will be described in greater detail below.