Fluid volume monitoring for patients with renal disease

Patent metadata

Field	Value
Publication number	US-9597440-B2
Application number	US-201514613725-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	Apr 29, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

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.

First claim

We claim:

1. A method, comprising:
initiating a blood fluid removal session of a patient with an initial blood fluid removal rate;
monitoring an indicator of tissue fluid volume of the patient during the blood fluid removal session;
monitoring an indicator of blood fluid volume of the patient during the blood fluid removal session;
determining a first indicator of tissue fluid volume and a first indicator of blood fluid volume;
acquiring a first set of data regarding the physiological health of the patient;
altering the rate of blood fluid removal to a second blood fluid removal rate;
determining a second indicator of tissue fluid volume and a second indicator of blood fluid volume;
acquiring a second set of data regarding the physiological health of the patient;
determining a preferable outcome measure based on the first and second sets of physiological data; and
altering the rate of blood fluid removal so that an indicator of tissue fluid volume and an indicator of blood fluid volume are within a pre-determined range of the preferable outcome measure.

2. The method of claim 1 , wherein the outcome measure is any one of a degree of hypotension, a deviation from dry weight, or combinations thereof.

3. The method of claim 1 , further comprising determining a ratio of the indicator of blood fluid volume to the indicator of tissue fluid volume; and
altering the rate of blood fluid removal so that the ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume is within a pre-determined range of the preferable outcome measure.

4. The method of claim 1 , further comprising:
determining whether the indicator of tissue fluid volume or the indicator of blood fluid volume crosses a predetermined threshold during the blood fluid removal session.

5. The method of claim 4 , wherein if the indicator of blood fluid volume or the indicator of tissue fluid volume crosses the predetermined threshold, altering the rate of blood fluid removal.

6. The method of claim 1 , wherein the indicator of tissue fluid volume is tissue impedance.

7. The method of claim 1 , wherein the indicator of blood fluid volume is a hematocrit level, or an indicator thereof.

8. The method of claim 7 , wherein measuring the hematocrit level comprises measuring oxygenated hemoglobin concentration.

9. The method of claim 1 , wherein one or both of the indicator of tissue fluid volume and the indicator of blood fluid volume are measured with one or more implantable sensors.

10. The method of claim 1 , wherein the blood fluid removal session is carried out with an implantable blood fluid removal device.

11. The method of claim 1 , wherein the blood fluid removal session is carried out with a wearable blood fluid removal device.

12. The method of claim 1 , wherein if the indicator of tissue fluid volume or the indicator of blood fluid volume is outside of a pre-determined range, an alert is provided.

13. 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 the indicator of tissue fluid volume and the indicator of blood fluid volume are outside of a predetermined range; and
altering the rate that replacement fluid is added to the blood if the indicator of tissue fluid volume or the indicator of blood volume is determined to be outside of the predetermined range.

14. The method of claim 13 , wherein the replacement fluid is added to the blood prior to fluid being removed from the blood.

15. The method of claim 13 , wherein the replacement fluid is added to the blood after fluid being removed from the blood.

16. The method of claim 13 , further comprising obtaining a ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume;
determining whether the ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume is outside of a predetermined range; and
altering the rate that the replacement fluid is added to the blood if the ratio of the indicator of tissue fluid volume to the indicator of blood fluid volume is outside of the predetermined range.

17. The method of claim 13 , wherein if the indicator of tissue fluid volume or the indicator of blood fluid volume is outside of a pre-determined range, an alert is provided.

18. The method of claim 13 , further comprising altering a rate of blood fluid removal if the indicator of tissue fluid volume or the indicator of blood volume is determined to be outside of the predetermined range.

19. 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 carry out the method of claim 1 .

20. The system of claim 19 , wherein the medium for removal of fluid and contaminants from the blood comprises a filtration membrane.

21. The system of claim 19 , wherein one or more components of the first sensor, the second sensor and the control electronics are housed within the blood fluid removal device.

Assignees

• Medtronic Inc

Inventors

• Gerber Martin
• Burnes John
• Lyu Suping
• Manda Venkatesh R
• Pudil Bryant

Classifications

• A61B5/14546

  for measuring analytes not otherwise provided for, e.g. ions, cytochromes · CPC title

• A61M2205/70

  with testing or calibration facilities · CPC title

• A61M2230/20

  Blood composition characteristics · CPC title

• A61B5/026

  Measuring blood flow {(A61B3/1233, A61B3/1241 take precedence)} · CPC title

• A61B5/0031

  Implanted circuitry · CPC title