# US 2014/0190876 A1 · Sorbent cartridge to measure solute concentrations

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- Number: US 2014/0190876 A1
- Document ID: US20140190876A1
- Status: Published application
- Kind: A1
- Application number: 13/791,755
- Filed: 2013-03-08
- Published: 2014-07-10
- Earliest claimed: 2013-01-09
- Assignees: Medtronic, Inc.
- Inventors: Thomas E. Meyer; David B. Lura; Bryant J. Pudil; Martin T. Gerber
- Web page: https://patentgrep.com/patent/US20140190876A1

## CPC

- A61M 1/1696: {with dialysate regeneration}
- A61M 1/284: {Continuous flow peritoneal dialysis [CFPD]}
- A61M 1/287: {Dialysates therefor}
- A61M 1/288: {Priming (priming in extracorporeal blood circuits A61M1/3643)}
- A61M 1/3406: {Physical characteristics of the filtrate, e.g. urea}
- A61M 1/3413: {Diafiltration}
- A61M 1/3472: {with treatment of the filtrate}
- A61M 1/3486: {Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents}
- A61M 1/3679: {by absorption (A61M1/3675 takes precedence)}
- B01J 20/0292: {Phosphates of compounds other than those provided for in B01J20/048}
- B01J 20/048: {containing phosphorus, e.g. phosphates, apatites, hydroxyapatites}
- B01J 20/06: comprising oxides or hydroxides of metals not provided for in group B01J20/04
- B01J 20/08: comprising aluminium oxide or hydroxide; comprising bauxite
- B01J 20/20: comprising free carbon; comprising carbon obtained by carbonising processes
- B01J 20/28052: {Several layers of identical or different sorbents stacked in a housing, e.g. in a column}
- B01J 39/10: Oxides or hydroxides
- B01J 39/12: Compounds containing phosphorus
- B01J 39/18: Macromolecular compounds (B01J39/17 takes precedence)
- B01J 41/10: Inorganic material
- B01J 41/12: Macromolecular compounds
- B01J 47/012: using portable ion-exchange apparatus
- B01J 47/026: using columns or beds of different ion exchange materials in series
- B01J 47/14: Controlling or regulating
- A61M 2205/3303: Using a biosensor
- A61M 2205/3317: Electromagnetic, inductive or dielectric measuring means
- A61M 2205/3334: Measuring or controlling the flow rate
- A61M 2205/50: with microprocessors or computers
- B01J 2220/49: Materials comprising an indicator, e.g. colour indicator, pH-indicator
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

A sorbent based monitoring system for measuring the solute concentration of at least one component of a fluid. The system has a sorbent regeneration system for regeneration of the fluid and has a sorbent cartridge that has at least one material layer. The fluid is conveyed through the sorbent cartridge and contacts at least one sensor after having contacted at least one material layer.

## Claims

### Claim 1

A sorbent based monitoring system for measuring a solute concentration of at least one component of a fluid, comprising:
a sorbent regeneration system for regeneration of the fluid, wherein the sorbent regeneration system has a sorbent cartridge having at least one material layer, wherein the fluid is conveyed through the sorbent cartridge and contacts at least one sensor after having contacted at least one material layer.

### Claim 2 (depends on 1)

The system of claim 1, wherein the fluid is a dialysate for hemodialysis or hemodiafiltration and the sorbent cartridge receives a spent dialysate containing at least one species from the dialysate outlet port of a dialyzer and removes at least a portion of a species from the dialysate to regenerate the dialysate for recirculation of at least a portion of the regenerated dialysate to the dialysate inlet port of a dialyzer.

### Claim 3 (depends on 1)

The system of claim 1, wherein the fluid is a filtrate and the sorbent cartridge receives a filtrate containing at least one species from the filtrate outlet port of a hemofilter and removes at least a portion of a species from the filtrate to regenerate a replacement fluid for return of at least a portion of the regenerated replacement fluid to a conduit of an extracorporeal circuit.

### Claim 4 (depends on 1)

The system of claim 1, wherein the fluid is a dialysate for peritoneal dialysis and the sorbent cartridge receives a spent dialysate containing at least one species from a subject receiving treatment and removes at least a portion of a species from the dialysate to regenerate the dialysate for recirculation of at least a portion of the regenerated dialysate to the subject receiving treatment.

### Claim 5 (depends on 1)

The system of claim 1, wherein said sorbent regeneration system comprises at least 2 material layers.

### Claim 6 (depends on 1, 2, 3, 4)

The system of any one of claim 1, 2, 3 or 4, wherein the at least one sensor measures conductivity of the fluid.

### Claim 7 (depends on 1, 2, 3, 4)

The system of any one of claim 1, 2, 3 or 4, wherein the at least one sensor measures at least one characteristic of the fluid selected from the group of pH and ammonium ion.

### Claim 8 (depends on 1)

A sorbent based monitoring system for measuring the solute concentration of at least one component of a fluid, comprising:
the sorbent system of claim 1 having a first sensor contacting either a first position of the at least one material layer or a first position from a sampled flow stream; and
a second sensor contacting either a second position of the at least one material layer or a first position from a sampled flow stream,
wherein the first sensor and the second sensor determine the amount or concentration of at least one solute.

### Claim 9 (depends on 1, 8)

The system of claim 1 or 8, wherein the monitoring system comprises at least two sensors.

### Claim 10 (depends on 1, 8)

The system of claim 1 or 8, wherein the monitoring system comprises a plurality of sensors.

### Claim 11 (depends on 9)

The system of claim 9, wherein at least one of said sensors forms part of a conductivity meter.

### Claim 12 (depends on 10)

The system of claim 10, wherein at least one of said sensors forms part of a conductivity meter.

### Claim 13 (depends on 1, 8)

The system of claim 1 or 8, wherein a plurality of sensors measures one or more solute concentrations.

### Claim 14 (depends on 11)

The system of claim 11, wherein said meter measures the conductivity of at least one solute concentration.

### Claim 15 (depends on 12)

The system of claim 12, wherein said meter measures the conductivity of at least one solute concentration.

### Claim 16 (depends on 1, 8)

The system of claim 1 or 8, wherein the monitoring system comprises a plurality of sensors that can measure the conductivity of a plurality of separate material layers and flow streams.

### Claim 17 (depends on 1)

The system of claim 1, further comprising at least two sensing points within any one of the material layers.

### Claim 18 (depends on 1)

The system of claim 1, further comprising at least two sensing points within different material layers.

### Claim 19 (depends on 1)

The system of claim 1, wherein the plurality of material layers include one or more selected from a urease-containing material, alumina, zirconium phosphate, magnesium phosphate, zirconium oxide, and activated carbon.

### Claim 20 (depends on 19)

The system of claim 19, wherein the solute concentration of urea is measured.

### Claim 21 (depends on 20)

The system of claim 20, wherein the solute concentration of urea in the fluid entering a material layer is determined by obtaining a first measurement from the fluid before contacting a urease containing layer and a second measurement from the fluid after having contacted a urease containing layer.

### Claim 22 (depends on 21)

The system of claim 21, wherein the first and second measurements are conductivity measurements.

### Claim 23 (depends on 19)

The system of claim 19, wherein the first and second measurements are pH measurements.

### Claim 24 (depends on 19)

The system of claim 19, wherein the at least one sensor is an ammonium sensor and the solute concentration of urea in the fluid is determined in part by measurement of an ammonium ion concentration in the fluid after contacting a urease containing layer.

### Claim 25 (depends on 19)

The system of claim 19, wherein a solute concentration of urea from an amount of carbon dioxide release from said urease-containing material is measured.

### Claim 26 (depends on 1)

The system of claim 1, further comprising a fluid flow path in fluid communication with the sorbent regeneration system.

### Claim 27 (depends on 26)

The systems of claim 26, further comprising a fluid flow monitor attached to said fluid flow path for determining an amount of fluid flowing through the sorbent regeneration system.

### Claim 28 (depends on 27)

The system of claim 27, wherein said fluid flow monitor calculates a mass flow rate of urea contained in the fluid stream.

### Claim 29 (depends on 28)

The system of claim 28, wherein said fluid flow monitor calculates a total amount of urea removed in a time interval.

### Claim 30 (depends on 29)

The system of claim 29, wherein the total amount of urea removed is used to determine what portion of the regenerative capacity of the sorbent cartridge has been consumed.

### Claim 31 (depends on 30)

The system of claim 30, wherein an estimate of a conductivity meter of a subject undergoing treatment is used to estimate the Urea Reduction Ratio for the treatment.

### Claim 32 (depends on 30)

The system of claim 30 wherein the total amount of urea removed is used to determine an amount of bicarbonate released from the sorbent regeneration system.

### Claim 33 (depends on 30)

The system of claim 30, wherein a determination of an amount of bicarbonate released from a sorbent system is used to determine a further amount, if any, to be infused by reconstitution system.

### Claim 34 (depends on 1)

The system of claim 1, further comprising a multiplexer receiving signals from the at least one sensor.

### Claim 35 (depends on 34)

The system of claim 34, further comprising at least one processor for processing the signals received from the multiplexer.

### Claim 36 (depends on 1)

The system of claim 1, wherein the sorbent cartridge has a plurality of material layers, wherein spent dialysate exiting a dialyzer is conveyed through the sorbent cartridge and does not contact the at least one the material layers in a sequential order; and
at least one sensor in contact with fluid that has contacted at least one material layer within the sorbent system.

### Claim 37 (depends on 1, 8)

The system of claim 1 or 8, wherein said monitoring system is used to monitor the progress of a treatment session.

### Claim 38 (depends on 1, 8)

The system of claim 1 or 8, wherein said monitoring system is used to detect system performance problems.

### Claim 39

A sorbent regeneration system containing one or more material layers, wherein the one or more material layers include a divalent ion capturing resin selective for at least calcium ions and/or magnesium ions.

### Claim 40 (depends on 39)

The system of claim 39, wherein the divalent ion capturing resin includes an ion exchange resin.

### Claim 41 (depends on 40)

The system of claim 40, wherein the divalent ion capturing resin includes a chelating resin.

### Claim 42 (depends on 39)

The system of claim 39, wherein a first conductivity measurement is taken for fluid that has not contacted the divalent ion capturing resin and a second conductivity measurement is taken after the fluid has contacted the divalent ion capturing resin and wherein the total combined magnesium and calcium ion concentration of a fluid is determined from the first conductivity reading and the second conductivity reading.

### Claim 43 (depends on 40)

The system of claim 40, wherein the divalent ion capturing resin gives off hydrogen ions in exchange for calcium and magnesium ions.

### Claim 44 (depends on 43)

The system of claim 43 wherein the hydrogen ions released by the divalent ion capturing layer causes an increase in ammonium ions and a decrease of ammonia molecules in a fluid containing urea that has contacted a urease containing layer.

### Claim 45 (depends on 1)

The system of claim 1, further comprising a dialysate flow path in fluid communication with the sorbent cartridge wherein the dialysate flow path is a controlled compliant flow path.

### Claim 46 (depends on 1)

The system of claim 1, further comprising a dialysate flow path in fluid communication with the sorbent cartridge wherein the dialysate flow path has a small volume and a control valve for selectively metering fluid in and out of the first recirculation flow path.

### Claim 47 (depends on 46)

The system of claim 46, wherein the system selectively meters fluid into and out of the first recirculation flow path using any one of a control pump, a water pump, an acid concentrate pump, a replacement fluid pump, and combinations thereof.

### Claim 48 (depends on 1)

The system of claim 1, further comprising a dialysate flow path in fluid communication with the sorbent cartridge wherein the dialysate flow path is capable of moving fluid bi-directionally in the first recirculation flow path.

### Claim 49 (depends on 1)

The system of claim 1, wherein the at least one material layer of the sorbent cartridge includes a first material layer including an ion exchange resin, a second material layer including a urease material, and a third material layer including a sorbent material, the second material layer being positioned between the first material layer and the third material layer.

### Claim 50 (depends on 49)

The system of claim 49, wherein the fluid contacts the first material layer prior to contacting the third material layer.

### Claim 51 (depends on 1)

The system of claim 1, wherein the at least one material layer of the sorbent cartridge includes a first material layer including a urease, a second material layer including zirconium phosphate and zirconium oxide, and a third material layer including a sorbent material, the second material layer being positioned between the first material layer and the third material layer.

### Claim 52 (depends on 51)

The system of claim 51, wherein the second material layer includes a first sub-layer including zirconium phosphate and a second sub-layer including zirconium oxide, the second sub-layer being positioned between the first sub-layer and the third material layer.

### Claim 53 (depends on 52)

The system of claim 52, wherein the third material layer includes activated carbon.