Peritoneal dialysis systems, devices, and methods
View Patent ↗An automated peritoneal dialysis system provides various features including prescription-driven dialysis fluid preparation, an integrated disposable fluid circuit, and sensor capabilities that allow accurate filing and draining control with high safety margins. Features include a peritoneal fluid circuit with a pressure sensor at either end and methods and devices for using the pressure signals. Other features and embodiments are disclosed.
1. A method of performing a peritoneal dialysis treatment, comprising:
pumping peritoneal dialysis fluid with a pump into a dialysate supply line;
using a dialysate supply line, the dialysate supply line having a tubular body, a proximal end into which peritoneal dialysis fluid is supplied and from which spent peritoneal dialysis fluid is withdrawn, and a distal end which is connected to a patient's peritoneal access;
generating a proximal pressure signal using a pressure detector located at the proximal end of said dialysate supply line;
generating a distal pressure signal using a pressure detector located at the distal end of said dialysate supply line;
continuously monitoring the distal pressure signal at least during a fill cycle of the peritoneal dialysis treatment and reducing a flow rate of the pump in response to the distal pressure signal exceeding a predefined threshold value of the patient's peritoneal cavity;
determining presence of a kink in the tubular body of the dialysate supply line between the proximal end and the distal end of the dialysate supply line based on a pressure drop between the proximal pressure signal and the distal pressure signal; and
controlling the flow rate of the pump in response to the determination of the presence of the kink.
2. The method of claim 1 , wherein peritoneal dialysis fluid is supplied at a variable rate which is adjusted by a controller responsively to both the distal and proximal pressure signals.
3. The method of claim 1 , wherein the controlling includes calculating a height of a fluid column responsively to a difference in the proximal and distal pressures and supplying peritoneal dialysis fluid at a rate that is responsive to said height.
4. The method of claim 1 , wherein the controlling includes
varying a rate of pumping of peritoneal dialysis fluid responsively to a difference between the proximal and distal pressure signals such that an input pressure of fluid at a point of entry into the peritoneum is maintained, the input pressure corresponding to a predefined pressure stored in a controller that controls the flow rate of the pump.
5. The method of claim 1 , wherein the controlling is effective to limit a pressure difference determined by a controller between the proximal and distal pressure signals.
6. The method of claim 1 , wherein the controlling includes generating a user interface output that is responsive to said determination of the presence of the kink.
7. The method according to claim 1 , wherein the determining includes:
storing a historical record of the proximal and distal pressure signals; and
fitting the historical record to a curve that characterizes identifiable conditions.
8. The method according to claim 1 , wherein
the determining the presence of the kink is performed directly from the pressure drop without calculating the flow rate through the tubular body of the dialysate supply line.
9. A method of performing a dialysis treatment, comprising:
using a pump and a dialysate supply line to transport peritoneal dialysis fluid, the dialysate supply line having a proximal end into which peritoneal dialysis fluid is supplied and from which spent peritoneal dialysis fluid is withdrawn, and a distal end which is connected to a patient's peritoneal access;
during a drain cycle in which spent peritoneal dialysis fluid is pumped from the patient, generating proximal and distal pressure signals using pressure detectors located at both the proximal and distal ends, respectively, of said dialysate supply line;
responsively to the proximal and distal pressure signals, detecting a characteristic of a pressure difference between the distal and proximal ends whose magnitude is compared with a predicted change in peritoneal dialysis fluid properties; and
responsively to the characteristic, generating a signal indicating a change in at least peritoneal dialysis fluid viscosity.
10. The method of claim 9 , further comprising generating a display indicating the change in the peritoneal dialysis fluid viscosity based on the generated signal.
11. The method of claim 9 , further comprising recording in a non-volatile data store, an indicator of a potential pathology event including an identifier of the peritoneal dialysis fluid viscosity and an identifier of the patient.
12. The method of claim 11 , further comprising transmitting a message to a care provider service, the message indicating the pathology event.
13. The method according to claim 9 , further comprising:
storing a historical record of the proximal and distal pressure signals; and
fitting the historical record to a curve that characterizes fluid viscosity.
14. A method of performing a dialysis treatment, comprising:
using a pump and a dialysate supply line to transport peritoneal dialysis fluid, the dialysate supply line having a proximal end into which peritoneal dialysis fluid is supplied and from which spent peritoneal dialysis fluid is withdrawn, and a distal end which is connected to a patient's peritoneal access;
during a drain cycle in which spent peritoneal dialysis fluid is pumped from the patient, generating first and second pressure signals using at least two pressure detectors located at least at a first location and a second location along a line conveying the dialysis fluid during the drain cycle, respectively;
responsively to the first and second pressure signals, detecting a characteristic of a pressure difference between the first and second locations whose magnitude is compared with a predicted change in peritoneal dialysis fluid properties; and
responsively to the characteristic, generating a signal indicating a change in at least peritoneal dialysis fluid viscosity.
15. The method according to claim 14 , further comprising generating a display indicating the change in the peritoneal dialysis fluid viscosity based on the generated signal.
16. The method of claim 14 , further comprising recording in a non-volatile data store, an indicator of a potential pathology event including an identifier of the peritoneal dialysis fluid viscosity and an identifier of the patient.
17. The method of claim 16 , further comprising transmitting a message to a care provider service, the message indicating the pathology event.
18. The method according to claim 14 , further comprising:
storing a historical record of the first and second pressure signals; and
fitting the historical record to a curve that characterizes fluid viscosity.
19. The method according to claim 14 , wherein
the first location is on the proximal end of the dialysate supply line, and
the second location is on the distal end of the dialysate supply line.