ELECTROLYTE AND pH MONITORING FOR FLUID REMOVAL PROCESSES

• US 20120273420A1
• Filed: 03/20/2012
• Published: 11/01/2012
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Lyu, SuPing, Manda, VenKatesh R., Gerber, Martin, Burnes, John, Pudil, Bryant
• Granted Patent: US 9,192,707 B2
• Time in Patent Office: Days
• US Class Current: 210/647
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/6866 Extracorporeal blood circuits, e.g. dialysis circuits
• CPC Class Codes: A61M 1/00 Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems catheters A61M25/00; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; devices for taking samples of blood A61B5/15; filters implantable into blood vessels A61F2/01
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1603 Regulation parameters
• CPC Class Codes: A61M 1/1605 Physical characteristics of the dialysate fluid
• CPC Class Codes: A61M 1/1607 : before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1613 : Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/28 : Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/34 : Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 : Regulation parameters
• CPC Class Codes: A61M 1/342 : Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3607 : Regulation parameters
• CPC Class Codes: A61M 1/3609 : Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/361 : before treatment
• CPC Class Codes: A61M 1/3612 : after treatment
• CPC Class Codes: A61M 2205/04 : implanted
• CPC Class Codes: A61M 2205/18 : with alarm
• CPC Class Codes: A61M 2205/33 : Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3303 : Using a biosensor
• CPC Class Codes: A61M 2205/3306 : Optical measuring means
• CPC Class Codes: A61M 2205/3313 : used specific wavelengths
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3375 : Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/3523 : using telemetric means
• CPC Class Codes: A61M 2205/50 : with microprocessors or computers
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/60 : with identification means
• CPC Class Codes: A61M 2205/70 : with testing or calibration facilities
• CPC Class Codes: A61M 2230/00 : Measuring parameters of the user
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/20 : Blood composition characteristics
• CPC Class Codes: A61M 2230/207 : hematocrit
• CPC Class Codes: A61M 2230/208 : pH-value
• CPC Class Codes: A61M 2230/65 : Impedance, e.g. conductivity, capacity
• CPC Class Codes: B01D 2321/12 : Use of permeate
• CPC Class Codes: B01D 2321/40 : Automatic control of cleaning processes
• CPC Class Codes: B01D 61/00 : Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor separation of gases or vapours by diffusion B01D53/22
• CPC Class Codes: B01D 61/32 : Controlling or regulating
• CPC Class Codes: B01D 65/02 : Membrane cleaning or sterilisation ; Membrane regeneration
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• 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
• CPC Class Codes: G16H 50/70 : for mining of medical data, e.g. analysing previous cases of other patients
• CPC Class Codes: G16Z 99/00 : Subject matter not provided for in other main groups of this subclass

Abstract

Methods include monitoring indicators of blood pH or blood electrolyte levels during a blood fluid removal session and adjusting concentrations of pH buffers or electrolytes in dialysate or replacement fluid used during the session based on the monitored indicators. Blood fluid removal systems may employ sensors that monitor blood pH or electrolyte levels to adjust the fluid parameters during a blood fluid removal session.

Claims

1. A system comprising:

a blood fluid removal device comprising

(i) an inlet for receiving blood from a patient,

(ii) an outlet for returning blood from the patient,

(iii) a medium for removing fluid and contaminants from the blood, the medium being positioned between the inlet and the first outlet, and

(iv) a fluid source for carrying a fluid, the fluid selected from dialysate and replacement fluid, wherein if the fluid is dialysate the fluid source carries the fluid to the medium, and wherein if the fluid is replacement fluid the fluid source carries the fluid to the blood after the blood exits the medium;

a concentrate source for housing a concentrate solution comprising concentrated electrolyte or pH buffer;

a concentrate flow control element for controlling the rate that the concentrate solution enters the fluid source;

a first sensor configured to monitor an indicator of blood electrolyte concentration or blood pH; and

control electronics in operable communication with the sensor and the concentrate flow control element,

wherein the control electronics are configured, via the concentrate flow control element, to adjust the rate at which the concentrate solution enters the fluid source based on data obtained from the sensor.

2. The system of claim 1, wherein the first sensor is configured to monitor blood before the blood enters the medium.

3. The system of claim 2, further comprising a second sensor configured to monitor an indicator of blood electrolyte concentration or blood pH, the second sensor being configured to monitor blood after the blood exits the medium.

4. The system of claim 3, wherein the control electronics are in operable communication with the second sensor and are configured to compare data acquired from the first sensor to data acquired from the second sensor, and wherein the control electronics are configured to adjust the rate at which the concentrate solution enters the fluid source based on the comparison of the data acquired from the first sensor and the second sensor.

5. The system of claim 1, wherein the first sensor is configured to monitor the indicator in fluid removed from the blood after the fluid removed from the blood exits the medium.

6. The system of claim 5, wherein the control electronics are configured to derive the blood pH or blood electrolyte concentration based on data acquired from the first sensor.

7. The system of claim 5, further comprising a second sensor configured to monitor the indicator in dialysate in the fluid source before the dialysate enters the medium, wherein the control electronics are control electronics are in operable communication with the second sensor and are configured to compare data acquired from the first sensor to data acquired from the second sensor, and wherein the control electronics are configured to adjust the rate at which the concentrate solution enters the fluid source based on the comparison of the data acquired from the first sensor and the second sensor.

8. The system of claim 1, wherein the first sensor is configured to monitor the indicator in the blood after the blood exits the medium and before replacement fluid is added to the blood.

9. The system of claim 8, further comprising a second sensor configured to monitor the indicator in the blood after the replacement fluid has been added to the blood.

10. The system of claim 1, wherein the control electronics, or components thereof, are housed within a housing of the blood fluid removal device.

11. The system of claim 1, further comprising a computer readable medium, wherein the computer readable medium comprises instructions that cause the control electronics to control the concentrate flow control element to adjust the rate at which the concentrate solution enters the fluid source based on data obtained from the sensor.

12. A method carried out by a blood fluid removal device or system, comprising:

initiating blood fluid removal procedure for a patient in need thereof, wherein the procedure comprise use of a fluid selected from a dialysate fluid or a replacement fluid, and wherein the fluid has an initial pH buffer composition or electrolyte composition;

monitoring an indicator of blood electrolyte concentration or blood pH of the patient during the blood fluid removal session; and

adjusting the pH buffer composition or the electrolyte composition of the fluid based on a value of the monitored indicator.

13. The method of claim 12, wherein monitoring the indicator comprises monitoring the indicator in blood before passing the blood through a blood fluid removal medium and after passing the blood through the blood fluid removal medium.

14. The method of claim 13, further comprising comparing a value of the indicator monitored before the blood is passed through the medium to a value of the indicator monitored after passing the blood through the medium, wherein adjusting the pH buffer composition or the electrolyte composition comprises adjusting the composition based on the comparison.

15. The method of claim 12, wherein adjusting the composition comprises adding a concentrated electrolyte solution or buffer solution to the fluid.

16. The method of claim 12, further comprising (i) determining whether a value of the monitored indicator crosses a threshold;

and (ii) providing an alert if the value of the monitored indicator is determined to cross the threshold.

17. The method of claim 12, wherein monitoring the indicator comprises monitoring the indicator in fluid removed from the blood.

18. The method of claim 17, further comprising determining a blood electrolyte concentration or pH from a value of the monitored indicator of the fluid removed from the blood.

19. The method of claim 17, wherein the fluid for use in the blood fluid removal procedure is dialysate, and wherein monitoring the indicator further comprises monitoring the indicator in the dialysate prior to the dialysate entering a blood fluid removal medium, and wherein the method further comprises comparing a value of the monitored indicator in fluid removed from the blood to a value of the monitored indicator in the dialysate prior to entering the blood fluid removal medium.

20. The method of claim 12, wherein the fluid for use in the blood fluid removal procedure is replacement fluid, and wherein monitoring the indicator comprises monitoring the indicator in blood downstream of a blood fluid removal medium and upstream of addition of the replacement fluid to the blood.

21. The method of claim 20, wherein monitoring the indicator further comprises monitoring the indicator in the blood downstream of the addition of the replacement fluid, wherein the method further comprises comparing a value of the monitored indicator obtained upstream of the addition of replacement fluid to a value of the monitored indicator obtained downstream of the addition of replacement fluid.

22. A system comprising:

a medium housing defining a major chamber;

a blood flow removal membrane disposed in the housing and sealingly dividing the major chamber into first and second minor chambers;

a first inlet and a first outlet in fluid communication with the first minor chamber, wherein the system is configured such that blood enters the first minor chamber through the first inlet and exits the first minor chamber through the first outlet;

a second inlet and a second outlet in fluid communication with the second minor chamber, wherein the system is configured such that dialysate enters the second minor chamber through the second inlet and exits the second minor chamber through the second outlet;

a dialysate regeneration medium in fluid communication with and disposed in a dialysate flow path between the second inlet and the second outlet;

a concentrate source for housing a concentrate solution comprising concentrated electrolyte or pH buffer;

a concentrate flow control element for controlling the rate that the concentrate solution enters the dialysate flow path downstream of the dialysate regeneration medium and upstream of the second inlet;

a sensor configured to monitor an indicator of electrolyte concentration or pH of dialysate in the dialysate flow path downstream of the dialysate regeneration medium and upstream of the second inlet; and

control electronics in operable communication with the sensor and the concentrate flow control element,

wherein the control electronics are configured, via the concentrate flow control element, to adjust the rate at which the concentrate solution enters the dialysate flow path based on data obtained from the sensor.

23. A method carried out by a blood fluid removal device or system, comprising:

initiating blood fluid removal procedure for a patient in need thereof, wherein the procedure comprises use of a dialysate fluid and a dialysate membrane, as at least a part of a blood fluid removal medium, across which electrolytes may be exchanged between blood and the dialysate fluid;

monitoring an indicator of blood electrolyte concentration or blood pH during the blood fluid removal session; and

adjusting the flow rate of the dialysate fluid or blood based on a value of the monitored indicator.

24. The method of claim 23, wherein monitoring the indicator comprises monitoring the indicator in blood before passing the blood through the blood fluid removal medium and after passing the blood through the blood fluid removal medium.

25. The method of claim 23, further comprising comparing a value of the indicator monitored before the blood is passed through the medium to a value of the indicator monitored after passing the blood through the medium, wherein adjusting the flow rate of the dialysate fluid or the blood comprises adjusting the composition based on the comparison.

26. The method of claim 23, wherein monitoring the indicator comprises monitoring the indicator in fluid removed from the blood.

27. The method of claim 23, further comprising determining a blood electrolyte concentration or pH from a value of the monitored indicator of the fluid removed from the blood.