Dialysis catheter including pressure and impedance sensors

1 . A system, comprising:

a catheter comprising:

an elongated catheter body defining a lumen and a longitudinal axis;

a channel extending parallel to the longitudinal axis and formed in a portion of an outer wall of the elongated catheter body,

wherein at least a portion of the elongated catheter body is disposed between the lumen and the channel; and

a plurality of sensors comprising:

a pressure sensor configured to generate a pressure signal indicative of a pressure of fluid within the lumen or external to the lumen, and

an impedance sensor disposed on or in the catheter and configured to generate an impedance signal indicative of an impedance of an electrical path within the lumen or external to the lumen, wherein, when the impedance sensor generates the impedance signal, the impedance sensor is disposed within a patient,

wherein at least one of the plurality of sensors is disposed within the channel;

an outer cover configured to partially cover the channel and the elongated catheter body,

wherein the outer cover includes at least one opening aligned with the at least one of the plurality of sensors disposed within the channel;

wherein the at least one of the plurality of sensors disposed within the channel is positioned such that the at least one of the plurality of sensors extends beyond an outermost surface of the outer cover;

and

processing circuitry configured to:

receive the pressure signal and the electrical impedance signal;

adjust a sampling frequency, based on a duration of therapy administered to the patient, of at least one of the plurality of sensors;

determine a first parameter related to peritoneal dialysis treatment based on the pressure signal and the electrical impedance signal,

wherein the first parameter includes a volume of the fluid within a peritoneal cavity; and

determine a second parameter related to the peritoneal dialysis treatment based on the electrical impedance signal,

wherein the second parameter is indicative of a need to remove additional effluent fluid from the peritoneal cavity.

2 . The system of claim 1 , wherein the pressure signal is indicative of pressure of fluid within the lumen, and wherein the processing circuitry is configured to determine the parameter related to peritoneal dialysis treatment by at least:

comparing a characteristic of the pressure signal to a predetermined threshold pressure value; and

determining a status of the catheter based on the comparison.

3 . The system of claim 2 , wherein the processing circuitry is configured to compare the characteristic of the pressure signal to the predetermined threshold pressure value by at least determining whether the characteristic is greater than or less than the predetermined threshold pressure value, and determine the status of the catheter by at least detecting a blockage of the catheter based on whether the characteristic is greater than or less than the predetermined threshold pressure value.

4 . The system of claim 2 , wherein the status of the catheter comprises an impairment that reduces a fluid flow rate through the lumen.

5 . The system of claim 2 , wherein the processing circuitry is further configured to control a peritoneal dialysis cycler based on the status of the catheter.

6 . The system of claim 5 , wherein the processing circuitry is configured to control the peritoneal dialysis cycler based on the status of the catheter by at least controlling the peritoneal dialysis cycler to deliver a bolus of fluid through the lumen of the catheter.

7 . The system of claim 2 , further comprising a user interface, wherein the processing circuitry is further configured to present a notification via the user interface based on the status of the catheter.

8 . The system of claim 1 , wherein the pressure signal is indicative of pressure of fluid within the lumen, and wherein the processing circuitry is configured to:

determine a trend in a characteristic of the pressure signal over time; and

determine a status of the catheter based on the determined trend.

9 . The system of claim 8 , wherein the status of the catheter comprises an impairment that reduces a fluid flow rate through the lumen, and wherein the processing circuitry is configured to detect the impairment in response to determining the trend indicates the pressure is increasing over time.

10 . The system of claim 9 , wherein the processing circuitry is further configured to control a peritoneal dialysis cycler in response to detecting the impairment of the catheter.

11 . The system of claim 9 , further comprising a user interface, wherein the processing circuitry is further configured to present a notification via the user interface in response to detecting the impairment of the catheter.

12 . The system of claim 1 , wherein the pressure signal is indicative of pressure of fluid internal to the lumen, and wherein the processing circuitry is configured to:

at least one of (1) compare a characteristic of the pressure signal to a predetermined threshold pressure value or (2) determine a rate of change of the characteristic of the pressure signal over time; and

control an operation of a peritoneal dialysis cycler based on the comparison or the determined rate of change.

13 . The system of claim 12 , wherein the processing circuitry is configured to compare the characteristic of the pressure signal to the predetermined threshold pressure value by at least determining the characteristic is less than or equal to the predetermined threshold pressure value, and wherein the processing circuitry is configured to control the operation of the peritoneal dialysis cycler by at least controlling the peritoneal dialysis cycler to decrease an amount of fluid the peritoneal dialysis cycler removes from a peritoneal cavity of a patient in response to determining the characteristic is less than or equal to the predetermined threshold pressure value.

14 . The system of claim 12 , wherein the processing circuitry is configured to determine if the rate of change indicates the pressure is decreasing by greater than or equal to a predetermined threshold rate of change value, and to control the operation of the peritoneal dialysis cycler by at least controlling the peritoneal dialysis cycler to decrease an amount of fluid the peritoneal dialysis cycler removes from a peritoneal cavity of a patient in response to determining the rate of change indicates the pressure is decreasing by greater than or equal to the predetermined threshold rate of change value.

15 . The system of claim 1 , wherein the pressure signal is indicative of pressure external to the lumen and the electrical impedance signal is indicative of electrical impedance of fluid external to the lumen, and wherein the processing circuitry is configured to:

at least one of compare a characteristic of the pressure signal to a predetermined threshold pressure value or determine a first rate of change of the characteristic of the pressure signal over time;

at least one of compare a characteristic of the electrical impedance signal to a predetermined threshold electrical impedance value or determine a second rate of change of the characteristic of the electrical impedance signal over time; and

control an operation of a peritoneal dialysis cycler based on at least one of the comparison of the characteristic of the pressure signal to the predetermined threshold pressure value or the first rate of change, and based on at least one of the comparison of the characteristic of the electrical impedance signal to the predetermined threshold electrical impedance value or the second rate of change.

16 . The system of claim 15 , wherein the processing circuitry is configured to control the operation of the peritoneal dialysis cycler by at least modifying an ultrafiltration volume used by the peritoneal dialysis cycler in response to determining:

at least one of:

the characteristic of the pressure signal is greater than or equal to the predetermined threshold pressure value; or

the first rate of change is greater than or equal to a first predetermined rate of change; and

at least one of:

the characteristic of the electrical impedance signal is less than or equal to the predetermined electrical impedance value; or

the second rate of change is greater than or equal to a second predetermined rate of change.

17 . The system of claim 15 , wherein the processing circuitry is configured to control the operation of the peritoneal dialysis cycler by at least modifying a concentration of an osmotic agent in a dialysate delivered to a peritoneal cavity of a patient by the peritoneal dialysis cycler in response to determining:

at least one of:

the characteristic of the pressure signal is greater than or equal to the predetermined threshold pressure value; or

the first rate of change is greater than or equal to a first predetermined rate of change; and

at least one of:

the characteristic of the electrical impedance signal is less than or equal to the predetermined electrical impedance value; or

the second rate of change is greater than or equal to a second predetermined rate of change.

18 . The system of claim 15 , where in the processing circuitry is configured to control the operation of a peritoneal dialysis cycler by at least modifying a dwell period applied by the peritoneal dialysis cycler in response to determining:

at least one of:

the characteristic of the pressure signal is greater than or equal to the predetermined threshold pressure value; or

the first rate of change is greater than or equal to a first predetermined rate of change; and

at least one of:

the characteristic of the electrical impedance signal is less than or equal to the predetermined electrical impedance value; or

the second rate of change is greater than or equal to a second predetermined rate of change.

19 . The system of claim 1 , wherein the electrical impedance signal is indicative of impedance of an electrical path within the lumen, and wherein the processing circuitry is configured to determine the parameter related to peritoneal dialysis treatment by at least:

comparing a characteristic of the electrical impedance signal to a predetermined threshold electrical impedance value; and

determining a status of the catheter based on the comparison.

20 . The system of claim 19 , wherein the processing circuitry is configured to compare the characteristic of the electrical impedance signal to the predetermined threshold electrical impedance value by at least determining whether the characteristic is less than or equal to the predetermined threshold electrical impedance value and determine the status of the catheter by at least detecting a blockage of the catheter based on whether the characteristic is less than or equal to the predetermined threshold electrical impedance value.

21 . The system of claim 1 , wherein the electrical impedance signal is indicative of electrical impedance of fluid external to the lumen, and wherein the processing circuitry is configured to:

determine a rate of change of a characteristic of the electrical impedance signal over time; and

control an operation of a peritoneal dialysis cycler based on the determined rate of change.

22 . The system of claim 21 , wherein the processing circuitry is configured to determine if the rate of change indicates the electrical impedance is increasing by greater than or equal to a predetermined threshold rate of change value, and to control the operation of the peritoneal dialysis cycler by at least controlling the peritoneal dialysis cycler to decrease an amount of fluid the peritoneal dialysis cycler removes from a peritoneal cavity of a patient in response to determining the rate of change indicates the electrical impedance is increasing by greater than or equal to a predetermined threshold rate of change value.

23 . The system of claim 1 , further comprising at least one electrical conductor configured to electrically connect at least one sensor of the plurality of sensors to processing circuitry, wherein the at least one electrical conductor is positioned between the outer cover and the catheter body.

24 . The system of claim 1 , wherein at least one of the pressure sensor or the impedance sensor is configured to wirelessly transmit the respective pressure signal or impedance signal to processing circuitry.

25 . The system of claim 1 , wherein the at least one opening is radially aligned with the at least one of the plurality of sensors disposed within the channel.

26 . The system of claim 1 , wherein the opening is cutout through the outer cover to expose the at least one of the plurality of sensors disposed within the channel to the fluid within the peritoneal cavity, when the system is disposed within the peritoneal cavity of the patient.

27 . The system of claim 1 , wherein the channel terminates at a distal end of a distal most sensor of the at least one of the plurality of sensors disposed within the channel.

28 . The system of claim 1 , wherein the at least one of the plurality of sensors disposed within the channel is positioned such that the at least one of the plurality of sensors extends beyond an outermost surface of the elongated catheter body.

29 . A system, comprising:

a catheter comprising:

an elongated catheter body defining a lumen and a channel,

a pressure sensor configured to generate a pressure signal indicative of a pressure of fluid within the lumen or external to the lumen, and

an impedance sensor configured to generate an electrical impedance signal indicative of a characteristic of fluid within the lumen or external to the lumen; and

a cover at least partially covering the channel,

wherein at least one of the pressure sensor or the impedance sensor are positioned in the channel, the cover defining an opening aligned with the at least one of the pressure sensor or the impedance sensor;

wherein at least one of the pressure sensor or the impedance sensor is positioned within the channel such that the at least one of the pressure sensor or the impedance sensor extends beyond an outermost surface of the cover; and

processing circuitry configured to:

receive the pressure signal and the electrical impedance signal;

determine a parameter related to peritoneal dialysis treatment based on the pressure signal and the electrical impedance signal,

wherein the parameter includes at least one of a patient parameter, a parameter indicative of a catheter patency status, a parameter indicative of a peritoneal cavity status, a parameter indicative of a peritoneal hemodynamic status, or a volume of fluid; and

control an operation of a peritoneal dialysis cycler based on the parameter.

30 . The catheter of claim 29 , wherein an outer surface of the catheter body defines the channel and the cover is radially outward of the catheter body.

31 . A method comprising:

receiving, by processing circuitry, a pressure signal from a pressure sensor indicative of a pressure of fluid within a lumen defined by an elongated catheter body of a catheter or external to the lumen,

receiving, by the processing circuitry, an impedance signal from an impedance sensor indicative of an impedance of an electrical path within the lumen or external to the lumen,

wherein the impedance sensor is disposed within a channel extending parallel to a longitudinal axis defined by the elongated catheter body and formed in a portion of an outer wall of the elongated catheter body,

wherein at least a portion of the elongated catheter body is disposed between the lumen and the channel,

wherein the catheter includes an outer cover configured to partially cover the channel and the elongated catheter body,

wherein the outer cover includes an opening aligned with the impedance sensor disposed within the channel;

wherein the impedance sensor disposed within the channel is positioned such that the impedance sensor extends beyond an outermost surface of the outer cover;

adjusting, by the processing circuitry, a sampling frequency of at least one of the pressure signal, the impedance signal, or any combination thereof, based on a duration of a peritoneal dialysis therapy administered to a patient; and

determining a parameter related to the peritoneal dialysis treatment based on the pressure signal and the impedance signal.

32 . The method of claim 31 , wherein determining the parameter related to peritoneal dialysis treatment comprises:

at least one of:

comparing, by the processing circuitry, a characteristic of the pressure signal to a predetermined threshold pressure value,

determining a trend in the characteristic of the pressure signal over time, or determining a rate of change of the characteristic of the pressure signal over time; and

determining, by the processing circuitry, a status of the catheter based on the comparison, the determined trend, or the determined rate of change.

33 . The method of claim 32 , further comprising controlling a peritoneal dialysis cycler based on the status of the catheter.

34 . The method of claim 31 , further comprising:

at least one of:

comparing, by the processing circuitry, a characteristic of the pressure signal to a predetermined threshold pressure value, or

determining a rate of change of the characteristic of the pressure signal over time; and

controlling, by the processing circuitry, an operation of a peritoneal dialysis cycler based on the comparison or the determined rate of change.

35 . The method of claim 31 , wherein determining the parameter related to peritoneal dialysis treatment comprises:

at least one of:

comparing a characteristic of the impedance signal to a predetermined threshold impedance value,

determining a trend in the characteristic of the impedance signal over time, or

determining a rate of change of the characteristic of the impedance signal over time; and

determining a status of the catheter based on the comparison, the trend, or the rate of change.

36 . The method of claim 31 , further comprising:

determining a rate of change of the characteristic of the impedance signal over time; and

controlling, by the processing circuitry, an operation of a peritoneal dialysis cycler based on the determined rate of change.

37 . The method of claim 31 , wherein the pressure signal is indicative of pressure external to the lumen and the impedance signal is indicative of impedance of fluid external to the lumen, the method further comprising:

at least one of comparing, by the processing circuitry, a characteristic of the pressure signal to a predetermined threshold pressure value or determining, by the processing circuitry, a first rate of change of the characteristic of the pressure signal over time;

at least one of comparing, by the processing circuitry, a characteristic of the impedance signal to a predetermined threshold impedance value or determining, by the processing circuitry, a second rate of change of the characteristic of the impedance signal over time; and

controlling, by the processing circuitry, an operation of a peritoneal dialysis cycler based on at least one of the comparison of the characteristic of the pressure signal to the predetermined threshold pressure value or the first rate of change, and based on at least one of the comparison of the characteristic of the impedance signal to the predetermined threshold impedance value or the second rate of change.