MODULAR HEMODIALYSIS SYSTEM

• US 20130213890A1
• Filed: 08/15/2012
• Published: 08/22/2013
• Est. Priority Date: 08/16/2011
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kelly, Thomas D., Lyu, SuPing, Pudil, Bryant J., Meyer, Thomas E.
• Granted Patent: US 10,857,277 B2
• Time in Patent Office: Days
• US Class Current: 210/646
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1607 before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1609 after use, i.e. downstream of dialyser
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2230/207 hematocrit
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Apparatuses, systems, and methods for the performance of kidney replacement therapy having or using a dialyzer, control components, sorbent cartridge, and fluid reservoirs configured to be of a weight and size suitable to be worn or carried by an individual requiring treatment are disclosed. The system has a controlled compliance dialysis circuit, where a control pump controls the bi-directional movement of fluid across a dialysis membrane. A first sorbent cartridge is provided for use in a portable treatment module having activated carbon and zirconium oxide. The system also provides for the monitoring of an inlet and outlet conductivity of a sorbent cartridge containing urease to provide a facility to quantify or monitor the removal of urea by a detachable urea removal module.

Claims

1. A system, comprising:

an extracorporeal module having a blood pump that pumps blood from a subject through an extracorporeal circuit, the extracorporeal circuit having one or more attachments for fluidly connecting to either a portable treatment module or to a urea removal module; and

a dialyzer having a dialysis membrane where blood is conveyed from the subject to the dialyzer and back to the subject,

wherein a flux of fluid moving between the extracorporeal circuit and either the portable module or the urea removal module is changed by the rate at which a control pump operates.

2. The system of claim 1, wherein the extracorporeal module is connected to one or more of the portable treatment module and the urea removal module, wherein the portable treatment module comprises:

a first sorbent cartridge consisting essentially of activated carbon and zirconium oxide,

a first dialysis circuit and a first dialysate pump for conveying a dialysate from the first sorbent cartridge to the dialyzer and back to the first sorbent cartridge, wherein the dialyzer has a dialysis membrane where blood is conveyed from a subject to the dialyzer, contacted with the dialysis membrane and conveyed back to the subject,

a first control pump for moving fluid bi-directionally into and out of the first dialysis circuit and a first control reservoir, and

wherein the portable module has one or more attachments for connecting to the extracorporeal module containing the extracorporeal circuit; and

wherein the urea removal module comprises;

a second sorbent cartridge comprising urease and zirconium phosphate or magnesium phosphate,

a second dialysis circuit and a second dialysate pump for conveying a dialysate from the second sorbent cartridge to the dialyzer and back to the second sorbent cartridge, wherein the dialyzer has a dialysis membrane where blood is conveyed from a subject to the dialyzer and back to the subject such the blood contacts the dialysis membrane, and

a second control pump for moving fluid bi-directionally into and out of the second dialysis circuit and a first control reservoir, wherein the urea removal module has one or more attachments for connecting to the extracorporeal module containing the extracorporeal circuit.

3. The system of claim 2, wherein the first dialysis circuit or the second dialysis circuit is a controlled compliance dialysis circuit.

4. The system of claim 2, wherein a volume of fluid removed from the first dialysis circuit by the first control pump is substantially the same volume of fluid transferred from the body of the subject to the portable module, or wherein a volume of fluid removed from the second dialysis circuit by the second control pump causes the same volume of fluid transferred from the body of the subject via the extracorporeal circuit to the urea removal module.

5. The system of claim 2, with the proviso the first dialysate pump or the second dialysate pump is not a pulsatile pump.

6. The system of claim 2, wherein a void volume space for accommodating the dialysate in the first sorbent cartridge, the dialyzer, and conduits comprising the first dialysis circuit has a substantially inflexible volume, or wherein a void volume space for accommodating the dialysate in the second sorbent cartridge, the dialyzer, and conduits comprising the second dialysis circuit has a substantially inflexible volume.

7. The system of claim 2, further comprising one or more controllers for controlling the operation of the first control pump and the first dialysate pump, wherein one or more controllers control operation of the first control pump to intermittently switch between an efflux direction to move fluid across the dialysis membrane from the extracorporeal circuit to the first dialysis circuit and an influx direction to move fluid across the dialysis membrane from the first dialysis circuit to the extracorporeal circuit, or

further comprising one or more controllers for controlling the operation of the second control pump and the second dialysate pump, wherein the one or more controllers control operation of the second control pump to intermittently switch between an efflux direction to move fluid across the dialysis membrane from the extracorporeal circuit to the second dialysis circuit and an influx direction to move fluid across the dialysis membrane from the second dialysis circuit to the extracorporeal circuit.

8. The system of claim 2, wherein the one or more controllers control a ratio of a rate of blood flow through the dialyzer and a rate of dialysate through the dialyzer to be from about 1:

1.5 to about 3;

1.

9. A portable modular system for ultrafiltration, comprising:

an extracorporeal circuit having a blood pump for pumping blood from a subject through the extracorporeal circuit, the extracorporeal circuit comprising one or more attachments for connecting to either a portable module or to a urea removal module; and

a hemofilter with a hemofiltration membrane where blood is conveyed from the subject to the hemofilter and back to the subject;

wherein

the one or more attachments is connected to the portable module comprising an ultrafiltration system, the ultrafiltration system having a filtrate pump for applying a negative pressure to the hemofilter to cause ultrafiltrate to pass through the hemofiltration membrane.

10. The system of claim 9, further comprising a relative blood volume monitor to determine the relative blood volume hydration status (RBVHS) of the blood in the extracorporeal circuit, the relative blood volume monitor configured to send information to one or more controllers that control the rate of the filtrate pump, wherein the relative blood volume monitor determines the level of one or more solutes in the blood at a first time (C₀) and determines the level of the one or more solutes in the blood at a second time later than the first time (C_t), and the relative blood volume hydration status is calculated by the formula RBVHS=C₀/C_t.

11. The system of claim 9, with the proviso that the system does not have a sorbent for absorbing a waste species.

12. A method, comprising:

attaching the vasculature of a subject to an extracorporeal circuit having a first end that draws blood from the patient and a second end that returns blood to the patient;

attaching the extracorporeal circuit to a portable module comprising a first sorbent cartridge having activated carbon therein and a first dialysis circuit;

conveying blood from the patient through the extracorporeal circuit and a dialyzer having a dialysis membrane and returning blood to the patient;

conveying dialysate through the first dialysis circuit such that the dialysate moves from the first sorbent cartridge to the dialyzer and back to the first sorbent cartridge wherein the blood and the dialysate are in fluid communication through the dialysis membrane and one or more waste species move from the blood to the dialysate;

removing the one or more waste species from the blood of the patient for a first period of time wherein the one or more waste species are absorbed by the first sorbent cartridge;

attaching the extracorporeal circuit to a urea removal module comprising a second sorbent cartridge having at least urease and zirconium phosphate or magnesium phosphate therein and a second dialysis circuit;

conveying dialysate through the second dialysis circuit such that the dialysate moves from the second sorbent cartridge to the dialyzer and back to the second sorbent cartridge wherein the blood and the dialysate are in fluid communication through the dialysis membrane and urea diffuses from the blood to the dialysate; and

removing urea from the dialysate for a second period of time wherein the urea is removed by the second sorbent cartridge.

13. The method of claim 12, further comprising monitoring the conductivity of the dialysate at a location between the dialyzer and an inlet end of the second sorbent cartridge with a first conductivity meter;

monitoring the conductivity of the dialysate at a position between an outlet end of the second sorbent cartridge and the dialyzer with a second conductivity meter; and

calculating an amount of urea absorbed by the second sorbent cartridge based at least in part upon the conductivity measured at the inlet end of the second sorbent cartridge and at the outlet end of the second sorbent cartridge.

14. The method of claim 12, further comprising operating a control pump that adds fluid from a control reservoir to the first or second dialysis circuit in an influx direction via a conduit or removes fluid from the first or second dialysis circuit to the control reservoir in an efflux direction via the conduit, and intermittently switching the control pump between the efflux direction to move fluid across the dialysis membrane from the extracorporeal circuit to the first or second dialysis circuit and the influx direction to move fluid across the dialysis membrane from the first or second dialysis circuit to the extracorporeal circuit,

wherein the intermittent switching of the pump accomplishes the convective clearance of at least one waste species having a molecular weight less than about 66000 g/mol and greater than about 1000 g/mol.

15. The method of claim 14, wherein the control pump operates to pump a larger volume in the efflux direction compared with the influx direction over a period of time.

16. The method of claim 14, wherein the control pump operates to pump a volume in the efflux direction that is at least about 10% greater compared to a volume pumped in the influx direction over a period of time.

17. A method, comprising:

attaching the vasculature of a subject to an extracorporeal circuit having a first end that draws blood from the patient and a second end that returns blood to the patient;

attaching the extracorporeal circuit to a portable module for ultrafiltration, the portable module comprising a filtrate pump;

conveying blood from the patient through the extracorporeal circuit and a hemofilter having a hemofiltration membrane and returning blood to the patient, the hemofilter having a structure to allow for operation as a dialyzer and the hemofiltration membrane having a structure to allow for operation as a dialysis membrane;

operating the filtrate control pump to separate and remove an ultrafiltrate from the blood in the extracorporeal circuit for a first period of time;

attaching the extracorporeal circuit to a urea removal module comprising a second sorbent cartridge having at least urease and zirconium phosphate or magnesium phosphate therein and a second dialysis circuit;

conveying dialysate through the second dialysis circuit such that the dialysate moves from the second sorbent cartridge to the hemofilter functioning as a dialyzer and back to the second sorbent cartridge, wherein the blood and the dialysate are in fluid communication through the hemofiltration membrane and one or more waste products diffuses from the blood to the dialysate; and

removing the one or more waste products from the dialysate for a second period of time wherein the urea is removed by the second sorbent cartridge.

18. The method of claim 17, further comprising operating a second reservoir pump that adds fluid from a second control reservoir to the second dialysis circuit in an influx direction via a conduit or operating a control pump that adds fluid from a control reservoir to the second dialysis circuit in an influx direction via a conduit, and operating the control pump to remove fluid from the second dialysis circuit to the control reservoir in an efflux direction via a conduit, and intermittently switching between pumping fluid in the efflux direction to move fluid across the dialysis membrane from the extracorporeal circuit to the second dialysis circuit and the influx direction to move fluid across the dialysis membrane from the second dialysis circuit to the extracorporeal circuit,

wherein the intermittent switching between pumping in the efflux and influx directions accomplishes the convective clearance of at least one waste species having a molecular weight less than about 66000 g/mol and greater than about 1000 g/mol.

19. The method of claim 17, wherein pumping in the efflux and influx directions is intermittently switched between the efflux direction and the influx direction at least once every minute.

20. The method of claim 17, wherein the control pump operates to pump a larger volume in the efflux direction compared with the influx direction over a period of time.