DUAL LUMEN PATIENT LINE SYSTEM AND METHOD HAVING KINK DETECTION

Abstract

A peritoneal dialysis (“PD”) system includes a housing; a PD fluid pump housed by the housing; a dual lumen patient line extending from the housing, the dual lumen patient line including a fill lumen and a return lumen; a PD fluid fill line in fluid communication with the fill lumen and an outlet of the PD fluid pump; a PD fluid return line in fluid communication with the return lumen and an inlet of the PD fluid pump; a fill pressure sensor configured to detect PD fluid pressure along the PD fluid fill line; a return pressure sensor configured to detect PD fluid pressure along the PD fluid return line; and a control unit configured to use outputs from the fill and return pressure sensors to determine if one of the fill lumen or the return lumen of the dual lumen patient line is occluded.

Claims

1. A peritoneal dialysis (“PD”) system comprising: a housing; a PD fluid pump housed by the housing; a dual lumen patient line extending from the housing, the dual lumen patient line including a fill lumen and a return lumen; a PD fluid fill line in fluid communication with the fill lumen and an outlet of the PD fluid pump; a PD fluid return line in fluid communication with the return lumen and an inlet of the PD fluid pump; a fill pressure sensor configured to detect PD fluid pressure along the PD fluid fill line; a return pressure sensor configured to detect PD fluid pressure along the PD fluid return line; and a control unit configured to use outputs from the fill and return pressure sensors to determine if one of the fill lumen or the return lumen of the dual lumen patient line is occluded.

2. The PD system of claim 1, wherein the control unit is further configured to operate the PD fluid pump and to determine if the PD fluid pump is pumping PD fluid or not.

3. The PD system of claim 1, wherein the PD fluid fill line is located within the housing, along a surface of the housing, or behind a door provided by the housing.

4. The PD system of claim 1, wherein the PD fluid return line is located within the housing, along a surface of the housing, or behind a door provided by the housing.

5. The PD system of claim 1, further comprising: a user interface in operable communication with the control unit, the control unit configured upon determining an occlusion to cause the user interface to provide an alarm detailing whether the fill lumen is occluded, the return lumen is occluded, or a patient's transfer set is occluded.

6. The PD system of claim 1, wherein the control unit is configured to expect the outputs from the fill and return pressure sensors to be the same or almost the same if the PD fluid pump is not being actuated.

7. The PD system of claim 1, wherein the control unit is configured to expect the outputs from the fill and return pressure sensors to be different by a pressure drop amount if the PD fluid pump is being actuated.

8. The PD system of claim 7, wherein the PD fluid pump, the PD fluid fill line, the fill lumen, the PD fluid return line and the return lumen form a closed loop, and wherein the pressure drop amount includes a pressure drop in both the fill lumen and the return lumen.

9. The PD system of claim 7, further comprising: a valve under control of the control unit, the valve positioned to close the PD fluid return line, and wherein the pressure drop amount includes a pressure drop in the fill lumen but not the return lumen while the return lumen is closed by the valve.

10. The PD system of claim 1, wherein the control unit is configured to determine (i) an occlusion in the fill lumen if the output from the fill pressure sensor is greater than an expected output from the fill pressure sensor by at least a first predetermined amount, (ii) an occlusion in the return lumen if the output from the return pressure sensor is less than an expected output from the return pressure sensor by at least a second predetermined amount, and (iii) an occlusion in a patient's transfer set if both (i) and (ii) are met.

11. The PD system of claim 10, wherein the first and second predetermined amounts are at least substantially the same.

12. The PD system of claim 1, wherein the control unit is configured to determine (i) an occlusion in the fill lumen if the output from the fill pressure sensor meets or exceeds a first predetermined pressure amount, (ii) an occlusion in the return lumen if the output from the return pressure sensor is less than a second predetermined pressure amount, and (iii) an occlusion in a patient's transfer set if both (i) and (ii) are met.

13. The PD system of claim 12, wherein the first and second predetermined pressure amounts are at least substantially the same.

14. The PD system of claim 1, wherein the fill lumen and the return lumen of the dual lumen patient line merge into a single lumen in a connector located at the distal end of the dual lumen patient line.

15. The PD system of claim 1, wherein the fill lumen and the return lumen of the dual lumen patient line extend into a connector located at the distal end of the dual lumen patient line, the connector configured to connect to a dual lumen patient transfer set for performing continuous flow peritoneal dialysis.

16. A peritoneal dialysis (“PD”) system comprising: a housing; a PD fluid pump housed by the housing; a dual lumen patient line extending from the housing, the dual lumen patient line including a fill lumen and a return lumen; a fill pressure sensor configured to detect PD fluid pressure in the fill lumen of the dual lumen patient line; a return pressure sensor configured to detect PD fluid pressure in the return lumen of the dual lumen patient line; and a control unit configured to use outputs from the fill and return pressure sensors to determine if one of the fill lumen or the return lumen of the dual lumen patient line is occluded.

17. The PD system of claim 16 wherein the control unit is configured to determine (i) an occlusion in the fill lumen if the output from the fill pressure sensor is greater than an expected output from the fill pressure sensor by at least a first predetermined amount, (ii) an occlusion in the return lumen if the output from the return pressure sensor is less than an expected output from the return pressure sensor by at least a second predetermined amount, and (iii) an occlusion in a patient's transfer set if both (i) and (ii) are met.

18. The PD system of claim 17, wherein the first and second predetermined amounts are at least substantially the same.

19. The PD system of claim 16, wherein the control unit is configured to determine (i) an occlusion in the fill lumen if the output from the fill pressure sensor meets or exceeds a first predetermined pressure amount, (ii) an occlusion in the return lumen if the output from the return pressure sensor is less than a second predetermined pressure amount, and (iii) an occlusion in a patient's transfer set if both (i) and (ii) are met.

20. The PD system of claim 19, wherein the first and second predetermined pressure amounts are at least substantially the same.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0049] FIG. 1 is a schematic view of one embodiment of a system during a patient fill or dwell, the system including an automated peritoneal dialysis (“PD”) machine or cycler having a dual lumen patient line.

[0050] FIG. 2 is a schematic view of the system of FIG. 1 during a patient drain.

DETAILED DESCRIPTION

[0051] Referring now to the drawings and in particular to FIG. 1, an embodiment of an automated peritoneal dialysis (“PD”) system 10 and associated methodology of the present disclosure includes a PD machine or cycler 20. Cycler 20 includes a housing 22 that holds reusable or durable flow components. Housing 22 may be made of metal, e.g., steel stainless steel, or aluminum, and/or plastic, e.g., polyvinylchloride (“PVC”) or a non-PVC material, such as polyethylene (“PE”), cross-linked polyethylene (“PEX”), polyurethane (“PU”) or polycarbonate (“PC”). Housing 22 is compact, lightweight and transportable in various embodiments.

[0052] Housing 22 holds a PD fluid pump 24. PD fluid pump 24 may be an electrically operated piston, gear, membrane or centrifugal pump, which may be inherently volumetrically accurate so that a separate PD fluid volume measurement apparatus, such as a flowmeter, balance chamber or an apparatus using the ideal gas law, is not needed. Here, PD fluid flows through the body of durable PD fluid pump 24, which is disinfected after treatment. In an alternative embodiment, PD fluid pump 24 includes a pump actuator that actuates a tube or flexible sheet of a disposable set through which the PD fluid flows. Pump actuator 24 may for example be (i) a peristaltic pump actuator that operates with a pumping tube or (ii) a pneumatic or electromechanical pump actuator (e.g., stepper motor and piston) that operates with a flexible pumping sheet. The pump actuators are reusable and do not contact fluid so they do not need to be disinfected after treatment. The pumping tube or flexible sheet may be discarded after each treatment or may be disinfected and reused for multiple treatments. In any embodiment discussed above, PD fluid pump 24 may be bidirectional or unidirectional, and a single pump may be provided. PD fluid pump 24 may also be continuous.

[0053] Housing 22 also holds plural valves, e.g., valve 26a to 26c located along the PD fluid lines to open or occlude flow as desired. It should be appreciated that machine or cycler 20 provides additional valves, which are not shown for ease of illustration. Nevertheless, each of the valves, including valves 26a to 26c may be electrically actuated solenoid valves, e.g., energized open for failsafe operation. Here, PD fluid flows through the bodies of valves 26a to 26c, which are disinfected after treatment for reuse. Valves 26a to 26c may alternatively be pinch valve actuators, e.g., electromechanical or pneumatic valve actuators that pinch closed flexible tubing or a flexible sheet. Here, valve actuators 26a to 26c are reusable and do not contact fluid so they do not need to be disinfected after treatment. The flexible pumping tubing or flexible sheeting may be discarded after each treatment or may be disinfected and reused for multiple treatments.

[0054] In the illustrated embodiment of FIGS. 1 and 2, a return valve 26a is positioned along an internal, reusable return line 28a, which is in fluid communication with a return lumen 40r of a dual lumen patient line 40. Reusable PD fluid return line 28a leads to an inlet of PD fluid pump 24. If return valve 26a is closed during an occlusion pressure checking sequence described below, then return lumen 40r of dual lumen patient line 40 is a static pressure line. If return valve 26a is instead open during the occlusion pressure checking, then return lumen 40r of dual lumen patient line 40 may be a dynamic pressure line in which a closed loop is formed with the two lumens 40f and 40r and reusable PD fluid lines 28a and 28b interfacing with PD fluid pump 24.

[0055] Machine or cycler 20 of system 10 in the illustrated embodiment of FIGS. 1 and 2 also includes a fill valve 26b located along a reusable PD fluid fill line 28b and a drain valve 26c located along a reusable PD fluid drain line 28c. In FIG. 1, drain valve 26c is closed and fill valve 26b is open (return valve 26a may be open or closed) to prevent fresh PD fluid from being delivered to drain and to allow the fresh PD fluid to be delivered along PD fluid fill line 28b and fill lumen 40f of dual lumen patient line 40 to patient P. In FIG. 2, return and drain valves 26a and 26c are open while and fill valve 26b is closed to prevent used PD fluid from being returned to patient P and to instead allow the used PD fluid to be removed from patient P and delivered along return lumen 40r of dual lumen patient line 40, PD fluid return line fill line 28b and PD fluid drain line 28c to a house drain or drain container 106.

[0056] In the illustrated embodiment, housing 22 also houses a pressure sensor 30a, 30b provided for each lumen 40r, 40f of dual lumen patient line 40. Pressure sensors 30a, 30b reside along reusable PD fluid lines 28a, 28b, respectively, which interface between PD fluid pump 24 and the dual lumens. Pressure sensors 30a, 30b may be inline, reusable pressure sensors having durable bodies through which the PD fluid flows. Pressure sensors 30a, 30b may alternatively be pod pressure sensors, e.g., disposable, which are formed along their respective PD fluid line 28a, 28b and have a fluid contacting side and an air transmission side that transmits the fluid pressure to a pressure transducer via an air transmission line. Pressure sensors 30a, 30b may further alternatively be force sensors that accept flexible portions of respective PD fluid lines 28a, 28b, and which obtain pressure readings by measuring the force applied by the flowing fluid through the flexible portions.

[0057] In the illustrated embodiment, housing 22 also houses an inline heater 32, which is positioned to heat fresh PD fluid prior to being delivered to patient P. Inline heater 32 is in one embodiment able to heat PD fluid from room temperature to body temperature, e.g., 37° C., at a flowrate of at least 200 milliliters (“ml”)/minute. In alternative embodiments, system 10 may employ batch heating, e.g., which occurs in a supply or dedicated heating container or bag instead of inline heater 32. One or more upstream or downstream temperature sensor (not illustrated) may be provided for outputting feedback and possibly feedforward information for the control of the PD fluid heater. System 10 may include other sensors, such as conductivity, priming, level sensors, a flow switch, and/or a leak detection sensor (not illustrated).

[0058] FIGS. 1 and 2 illustrate that PD machine or cycler 20 of system 10 of the present disclosure includes a control unit 50 having one or more processor 52 and one or more memory 54 that controls PD fluid pump 24, valves 26a to 26c (and any other valves), inline heater 32, and which receives signals or outputs from pressure sensors 30a, 30b and any of the other sensors listed above and processes the signals or outputs for feedback and/or display. Control unit 50 uses pressure feedback from pressure sensors 30a, 30b for the occlusion detection discussed below and to control dialysis fluid pump 24 to run at or within safe patient pressure limits during treatment, e.g., by controlling a level of current, a pulse width, or a pneumatic pressure to PD fluid pump 24. A positive patient pressure limit may for example be one to five psig (e.g., two psig (14 kPa)). A negative patient pressure limit may for example be −1.0 psig to −3.0 psig (e.g., −1.3 psig (−9 kPa)). Control unit 50 uses temperature feedback to control dialysis fluid heater 32 to heat the fresh dialysis fluid to, e.g., body temperature or 37° C. Control unit 50 may use temperature compensated conductivity readings to analyze fresh and/or used dialysis fluid.

[0059] Control unit 50 also includes a video controller 56 that interfaces with a user interface 58, which may include a display screen 60 operating with a touchscreen and/or one or more electromechanical button, such as a membrane switch. User interface 58 may also include one or more speaker for outputting alarms, alerts and/or voice guidance commands. User interface 58 may be provided with cycler 20 as illustrated in FIGS. 1 and 2 and/or be a remote user interface operating with control unit 50. Control unit 50 may also include a transceiver (not illustrated) and a wired or wireless connection to a network, e.g., the internet, for sending treatment data to and receiving prescription instructions from a doctor's or clinician's server interfacing with a doctor's or clinician's computer.

[0060] Dual lumen patient line 40 may be disinfected and reused for multiple treatments or may be discarded after treatment. In one embodiment, dual lumens 40f and 40r of patient line 40 merge together at the distal end of the patient line to form a single lumen in a connector 42 that connects to the patient's transfer set 44 and communicates fluidly with the patient's indwelling catheter. In an alternative embodiment, dual lumens 40f and 40r of patient line 40 do not merge together and instead connect respectively to separate lumens of the patient's transfer set 44 and communicate fluidly with a dual lumen indwelling catheter to perform continuous flow peritoneal dialysis (“CFPD”). In CFPD, fresh PD fluid flows to the patient, while used PD fluid is removed from the patient. Regardless of whether dual lumens 40f and 40r of patient line 40 merge into a single lumen upstream of the patient's transfer set 44 or not, fresh PD fluid is delivered through fill lumen 40f of dual lumen patient line 40 via PD fluid pump 24.

[0061] System 10 provides a disposable set 100 for operation with cycler 20. Disinfecting and reusing dual lumen patient line 40 reduces the amount of disposable items needed with disposable set 100. In such case, disposable set 100 includes one or more supply container or bag 102 having a disposable supply line 104 that connects to one or more internal and reusable supply line 28s located within housing 22. In an alternative embodiment, the at least one supply line 104 is reusable and has a distal end configured to plug into cycler 20 after treatment to create a closed loop for disinfection. The PD fluid supplied from at least one supply container or bag 102 may hold different dextrose or glucose level dialysis fluids, such as 1.36% glucose dialysis fluid, 2.27% glucose dialysis fluid and/or a last bag of a different formulation of PD fluid, such as icodextrin. Disposable set 100 may also include a drain container or bag 106 having a disposable drain line 108 that connects to reusable PD fluid drain line 28c located within housing. Drain container or bag 106 may alternatively be eliminated using a house drain, such as a toilet or bathtub. Drain line 108 may alternatively be reusable and have a distal end configured to plug into cycler 20 after treatment to create a closed loop for disinfection.

[0062] Reusable PD fluid lines 28a to 28d are illustrated as being located inside of housing 22 but may alternatively be mounted on an outer surface of the housing or be mounted inside a door of PD machine or cycler 20. Here, the PD fluid lines 28a to 28d are typically single use disposable and operate with face mounted valves but could alternatively be disinfected after treatment for reuse. Any of the tubing located inside or outside of housing 22 may be metal, e.g., stainless steel, or plastic, e.g., polyvinylchloride (“PVC”) or a non-PVC material, such as polyethylene (“PE”), cross-linked polyethylene (“PEX”), polyurethane (“PU”) or polycarbonate (“PC”).

Occlusion Detection

[0063] Control unit 50 of system 10 is also configured to monitor the outputs of pressure sensors 30a, 30b to look for an occlusion in dual lumen patient line 40. If there is no flow in either lumen 40f or 40r of dual lumen patient line 40, then control unit 50 expects the pressures measured in each lumen by pressure sensors 30a, 30b to be the same or almost the same. Control unit 50 knows when there is no flow in either of lumens 40f or 40r because control unit 50 commands PD fluid pump 24 and thus knows when it is actuated or not.

[0064] In FIG. 1, when PD fluid pump 24 is filling patient P with fresh PD fluid, which control unit 50 commands and thus knows is taking place, and a suspected line kink or other partial or full occlusion is detected by control unit 50, a dynamic closed loop may be formed with PD fluid pump 24, reusable PD fluid lines 28a and 28b, and dual lumen patient line 40 return and patient valves 26a and 26b open and drain valve 26c closed. Control unit 50 is programmed here to expect the fluid pressure in fill lumen 40f, as measured by pressure sensor 30b, to be different than the fluid pressure in return lumen 40r, as measured by pressure sensor 30a, by a known amount of pressure drop (e.g., empirically determined) in the closed loop caused by the flow of fresh PD fluid. As mentioned above, lumens 40f and 40r converge to a single lumen at connector 42, allowing pressure sensor 30a to also see positive filling pressure when both lumens 40f and 40r are fully primed. If the pressure difference between the readings of pressure sensors 30a and 30b is different than the expected pressure drop difference, e.g., by more than a set margin of error, then control unit 50 in an embodiment runs an algorithm to determine if the mismatch in pressure difference is due to an occlusion in either or both of the lumens 40f and 40r of patient line 40. If the fill lumen pressure reading at pressure sensor 30b is at or above a predetermined amount, e.g., one psig (0.07 bar) or perhaps more, then control unit 50 determines that there is an occlusion in fill lumen 40f of dual lumen patient line 40. If the return lumen pressure reading at pressure sensor 30a is lower than a predetermined amount, e.g., one psig (0.07 bar) or perhaps more, then control unit 50 determines that there is an occlusion in return lumen 40r of dual lumen patient line 40. If both (i) the fill side pressure sensor reading at pressure sensor 30b is at or above the predetermined pressure, e.g., one psig (0.07 bar) or perhaps more, and (ii) the return side pressure sensor reading at pressure sensor 30a is lower than the predetermined pressure, e.g., one psig (0.07 bar) or perhaps more, then control unit 50 determines that there is an occlusion in transfer set 44 of patient P.

[0065] In any of the above scenarios, control unit 50 alarms at user interface 58 of machine or cycler 20 and temporarily pauses treatment. User interface 58 under control of the control unit 50 may for example provide an audio, visual or audiovisual message to the user detailing the location(s) of the occlusion.

[0066] In the patient drain of FIG. 2, where PD fluid pump 24 removes used PD fluid from patient P, which control unit 50 again knows is taking place, return and drain valves 26a and 26c are open while fill valve 26b is closed. Pressure sensor 30b can nevertheless sense negative pressure due to the convergence of lumens 40f and 40r to a single lumen at connector 42. Here, fill lumen 40f is a static line. A pressure drop in negative pressure (which can be determined empirically and stored in control unit 50) occurs beginning at the inlet of PD fluid pump 24 (highest negative pressure) and extends through reusable PD fluid return line 28a and return lumen 40r to the convergence point at connector 42 (lowest negative pressure), which is in essence the pressure that pressure sensor 30a sees via static negative pressure fill lumen 40f If the measured pressure drop between pressure sensors 30a and 30b is less than expected (e.g., by a margin of error), then control unit 50 determines that there is an occlusion in return lumen 40r and alarms the patient or user in a manner described herein. If the measured pressure drop between pressure sensors 30a and 30b is less than expected (e.g., by a margin of error), then control unit 50 determines that there is a leak, for example, at connector 42.

[0067] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. It is therefore intended that any or all of such changes and modifications may be covered by the appended claims.