Fluid volume monitoring for patients with renal disease

• US 8,951,219 B2
• Filed: 03/20/2012
• Issued: 02/10/2015
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gerber, Martin, Burnes, John, Lyu, Suping, Pudil, Bryant, VenKalesh, Manda R.
• Primary Examiner(s): DEAK, LESLIE R
• Application Number:
  US13/424,454
• Publication Number:
  US 20120277655A1
• Time in Patent Office: 1,057 Days
• Field of Search: 604/5.01, 604/5.04, 604/6.09, 604/6.11, 604/4.01, 210/645, 210/646, 210/746
• US Class Current: 604/6.09
• 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

A method includes initiating a blood fluid removal session of a patient; monitoring an indicator of tissue fluid volume of the patient, or a portion thereof, during the blood fluid removal session; monitoring an indicator of blood fluid volume of the patient during the blood fluid removal session; determining whether a ratio of the indicator of tissue fluid volume to indicator of blood fluid volume is outside of a predetermined range; and altering the rate of fluid removal during the blood fluid removal session if the ratio is determined to be outside of the predetermined range. A blood fluid removal system may be configured to carry out the method.

Claims

1. A method carried out by a blood fluid removal system comprising:

initiating a blood fluid removal session of a patient;

monitoring an indicator of tissue fluid volume of the patient, or a portion thereof, during the blood fluid removal session;

monitoring an indicator of blood fluid volume of the patient during the blood fluid removal session;

determining whether a ratio of the indicator of tissue fluid volume to indicator of blood fluid volume is outside of a predetermined range; and

altering the rate of fluid removal during the blood fluid removal session if the ratio is determined to be outside of the predetermined range.

2. The method of claim 1, wherein the predetermined range is based on measurements of the indicator of tissue fluid volume and the indicator of blood fluid volume obtained prior to initiating the blood fluid removal session.

3. The method of claim 1, wherein if the ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume is outside the predetermined range and is indicative of exceeding a threshold of tissue fluid volume to blood fluid volume, then the rate of fluid removal is decreased.

4. The method of claim 1, wherein if the ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume is outside the predetermined range and is indicative of a falling below a threshold of tissue fluid volume to blood fluid volume, then the rate of fluid removal is increased.

5. The method of claim 1, further comprising monitoring the indicator of tissue fluid volume of the patient prior to initiating the blood fluid removal session or monitoring the indicator of blood fluid volume of the patient prior to initiating the blood fluid removal session;

and setting an initial fluid volume removal prescription for the blood fluid removal session based on the indicator of tissue fluid volume monitored prior to initiating the blood fluid removal session or the indicator of blood fluid volume monitored prior to initiating the blood fluid removal session.

6. The method of claim 5, wherein monitoring the indicator of tissue fluid volume of the patient prior to initiating the blood fluid removal session or monitoring the indicator of blood fluid volume of the patient prior to initiating the blood fluid removal session comprises chronically monitoring the indicator of tissue fluid volume.

7. The method of claim 6, further comprising (i) determining whether the indicator of tissue fluid volume or the indicator of blood fluid volume monitored prior to initiating the blood fluid removal session crosses a predetermined threshold value, and (ii) scheduling the blood fluid removal session or providing an alert if the indicator crosses the threshold value.

8. The method of claim 1, further comprising

determining whether the indicator of tissue fluid volume is outside of a predetermined range or determining whether the indicator of blood fluid volume is outside of a predetermined range;

and

altering the rate of fluid removal if the indicator of tissue fluid volume is determined to be outside of a predetermined range or if the indicator of blood fluid volume is determined to be outside of a predetermined range.

9. The method of claim 8, wherein the predetermined range of the indicator of tissue fluid volume or the predetermined range of blood fluid volume is determined based on the ratio of the indicator of tissue fluid volume to blood fluid volume.

10. The method of claim 8, wherein a determination as to whether the indicator of tissue fluid volume is outside of a predetermined range is made.

11. The method of claim 1, wherein the indicator of tissue fluid volume is impedance of flow of electricity through tissue of the patient.

12. The method of claim 11, wherein the impedance is measured between two electrodes placed in contact with the patient'"'"'s skin.

13. The method of claim 1, wherein monitoring the indicator of blood fluid volume comprises measuring a hematocrit level, or an indicator thereof.

14. The method of claim 13, wherein measuring the hematocrit level or the indicator thereof comprises measuring oxygenated hemoglobin concentration.

15. A method carried out by a blood fluid removal system, comprising:

initiating a blood fluid removal session of a patient;

monitoring an indicator of tissue fluid volume of the patient, or a portion thereof, during the blood fluid removal session;

calculating a value indicative of tissue fluid volume based on the monitored indicator of tissue fluid volume;

monitoring an indicator of blood fluid volume of the patient during the blood fluid removal session;

calculating a value indicative of blood fluid volume based on the monitored indicator of blood fluid volume;

determining whether a ratio of the value indicative of tissue fluid volume to the value indicative of blood fluid volume is outside of a predetermined range; and

altering the rate of fluid removal during the blood fluid removal session if the ratio is determined to be outside of the predetermined range.

16. A system comprising:

a blood fluid removal device comprising

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

(ii) a first 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,

(iv) a fluid rate removal controller; and

(v) a second outlet for flow of the removed fluid and contaminants;

a first sensor for monitoring an indicator of tissue fluid volume;

a second sensor for monitoring an indicator of blood fluid volume;

control electronics in operable communication with the sensor for monitoring an indicator of tissue fluid volume, the sensor for monitoring an indicator of blood fluid volume; and

the fluid rate removal controller,

wherein the control electronics are configured to adjust the rate at which fluid is removed based on a ratio of data obtained from the first sensor configured to monitor an indicator of tissue fluid volume of the patient and the second sensor configured to monitor an indicator of blood fluid volume of the patient.

17. The system of claim 16, further comprising a non-transitory computer readable medium, wherein the computer readable medium comprises instructions that cause the control electronics to (i) calculate a ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume based on data obtained from the first and second sensors, respectively;

(ii) determine whether the calculated ratio is outside of a predetermined range; and

(iii) alter the rate of fluid removal if the ratio is determined to be outside of the predetermined range.

18. The system of claim 16, further comprising a non-transitory computer readable medium, wherein the computer readable medium comprises instructions that cause the control electronics to (i) calculate a value indicative of tissue fluid volume based on data obtained from the first sensor;

(ii) calculate a value indicative of blood fluid volume based on data obtained from the second sensor;

(iii) determine whether a ratio of the value indicative of tissue fluid volume to the value indicative of blood fluid volume is outside of a predetermined range; and

(iv) alter the rate of fluid removal if the ratio is determined to be outside of the predetermined range.

19. The system of claim 16, wherein the fluid rate removal controller comprises one or more of a blood flow control component, a negative pressure control component, a dialysis flow control component, and a fresh fluid flow control component.

20. The system of claim 16, wherein the medium for removal of fluid and contaminants from the blood comprises a filtration membrane.

21. The system of claim 16, wherein one or more components of the first sensor, the second sensor and the control electronics are housed within the blood fluid removal device.