Monitoring fluid volume for patients with renal disease

• US 8,926,542 B2
• Filed: 03/20/2012
• Issued: 01/06/2015
• 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, Manda, VenKatesh R., Pudil, Byant
• Primary Examiner(s): DEAK, LESLIE R
• Application Number:
  US13/424,467
• Publication Number:
  US 20120277604A1
• Time in Patent Office: 1,022 Days
• Field of Search: 604/5.01, 604/5.04, 604/6.09, 604/6.11, 210/645, 210/646, 210/746
• US Class Current: 604/5.01
• 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 monitoring an indicator of fluid volume of a patient via a sensor device, and setting an initial fluid volume removal prescription for a blood fluid removal session based on the monitored indicator of fluid volume. The method may further include transmitting data regarding the indicator of fluid volume from the implantable sensor device to fluid removal device. In some embodiments, the fluid removal device sets or calculated the initial fluid volume removal prescription based on the data received from the implantable sensor. The indicator of fluid volume may be an indicator of tissue fluid volume or an indicator of blood fluid volume.

Claims

1. A system comprising:

(i) an implantable sensor device configured to monitor impedance of interstitial fluid of a patient, the implantable sensor device comprising

a first electrode,

a second electrode,

electronics operably coupled to the first and second electrodes for monitoring impedance of current flow between the two electrodes, and

a first communication circuit configured to transmit data regarding the monitored impedance;

(ii) a fluid removal device for removing fluid from a patient, the device comprising

an inlet for receiving blood from a patient;

a medium for removing fluid from the blood, the medium being in communication with the inlet;

an outlet in communication with the medium for returning blood to the patient;

a flow controller in communication with the inlet, outlet or medium configured to control the rate at which the fluid is removed from the medium;

(iii) a second communication circuit configured to wirelessly receive the data regarding the impedance from the implantable sensor device;

(iv) electronics in communication with the second communication circuit and the flow controller wherein the electronics are configured to set an initial fluid removal prescription for a fluid removal session based in part on the impedance data received prior to the start of the session and to control the flow controller regarding the rate of fluid removal based on the received impedance data.

2. The system of claim 1, wherein the electronics of the fluid removal device are configured to alter the initial fluid removal rate or profile during a fluid removal session based in part on the impedance data received during the session.

3. The system of claim 1, wherein the first communication circuit of the sensor device and the second communication circuit of the fluid removal device communicate directly.

4. The system of claim 1, wherein the control electronics are disposed in a housing of the blood fluid removal device.

5. The system of claim 4, wherein the housing is a conductive housing.

6. The system of claim 1, wherein the electronics are further configured to determine whether the impedance of interstitial fluid crosses a predetermined threshold value, and provide an alert to the patient if the impedance of interstitial fluid is determined to cross the threshold value.

7. The system of claim 6, wherein the alert provided is selected from at least one of an audible signal and a vibration mechanism.

8. The system of claim 1, wherein the electronics comprise a computer readable medium that, when implemented, causes the electronics to calculate the initial fluid rate removal prescription based on data received from the sensor and instructs the flow controller to operate according to the initial fluid rate removal prescription.

9. The system of claim 1, wherein the fluid removal device is implantable in the patient.

10. The system of claim 1, wherein the fluid removal device is external to the patient.

11. The system of claim 10, wherein the fluid removal device is wearable by the patient.

12. The system of claim 1, wherein the sensor further comprises a power source.

13. The system of claim 1, wherein the electronics further comprise a processor and a memory for storing acquired impedance data and removal proscription instructions.

14. The system of claim 1, wherein the flow controller further comprises a power source.

15. The system of claim 1, comprising multiple sensors, wherein at least one sensor is configured to monitor impedance of interstitial fluid of a patient.

16. The system of claim 1, further comprising at least one additional sensor device configured to monitor any one of the concentration of an electrolyte, extension or contraction of tissue, modulus or stress-strain curves for tissue, stress relaxation or creep profile of tissue, lung noise, and any combination thereof.

17. The system of claim 1, further comprising an additional sensor device configured to monitor an indicator of blood fluid volume, wherein setting the initial fluid volume removal prescription for the blood fluid removal session comprises setting the initial fluid volume removal prescription based in part on the monitored interstitial fluid and the blood fluid volume.

18. The system of claim 17, wherein monitoring an indicator of blood fluid volume comprises monitoring at least one of hematocrit levels, hemoglobin levels, total blood protein concentration, albumin concentration, blood pressure, blood viscosity, and any combination thereof.

19. The system of claim 1, wherein impedance of interstitial fluid of a patient is monitored for a predetermined period of time to establish a suitable baseline.

20. The system of claim 1, wherein the electronics are further configured to determine whether a rate of increase of interstitial fluid volume exceeds a predetermined threshold value, and provide an alert to the patient if the rate of increase is determined to cross the threshold value.