Portable peritoneal dialysis cycler

In a solenoid valve means for controlling the flow of fluid within a collapsible tube, a body, a plunger contained within a bore of said body, said plunger being axially shiftable between an extended, closed position and a retracted, open position, spring means for biasing said plunger to one of said open and closed positions, electrically-operated coil means for axially shifting said plunger to the other of said open and closed positions, said plunger terminating at one end in a tube-contacting nose portion, the improvement comprising:

• (a) a shallow grove in an end surface of the body, said groove extending transversely thereof, said groove intersecting said bore, which is proximal to said nose portion;
• (b) a member pivotable between a first position wherein it overlies said groove in parallel spaced relationship to said body end surface and a second position remote from said groove, handle means on said member for manually shifting said member between said first and second positions, said second position enabling easy placement of said collapsible tube in said groove and said first position retaining said collapsible tube within said groove, a portion of said member being chamfered such that said member can be shifted to said first position over said groove and said collapsible tube requiring substantially zero force, and said plunger and nose portion, when in said extended, closed position, collapsing said collapsible tube against said member to preclude fluid flow through said tube.

A method of performing peritoneal dialysis upon a patient, said method comprising the following steps:

• (a) providing a peritoneal dialysis cycler of the gravity-type which includes a single load cell supporting at least one fluid exchange bag and at least one fluid drain bag, a fill control valve and a drain control valve, computing means for controlling the operation of said fill and drain control valves via electrical interfacing circuitry, a set of tubing for transferring liquids from said at least one fluid exchange bag into the patient via said fill control valve, and a set of tubing for transferring liquids into said at least one fluid drain bag from the patient via said drain control valve;
• (b) providing the patient with start-up instructions for a dialysis procedure of one or more cycles, via a video monitor under the control of said computing means, said start-up instructions including options for operating the cycler in manual or automatic mode, options for predetermining amounts of infusate and drain fluids, and options for controlling the timing parameters of each cycle by entering information into said computing means before the commencement of the overall dialysis procedure;
• (c) commencing the dialysis procedure which comprises for each cycle thereof the additional steps of:
• (1) measuring the gross weight supported by said load cell at the start of each cycle, including said at least one fluid exchange bag and said at least one fluid drain bag, to establish a first reference gross weight for that cycle;
• (2) filling the patient's peritoneal space with infusate fluid by opening said fill control valve while keeping said drain control valve in a closed position;
• (3) periodically measuring the gross weight supported by said load cell during said filling step and comparing said gross weights to said first reference gross weight and thereby periodically determining the differential weight of infusate fluid which has passed into the patient;
• (4) stopping said filling step by closing said fill control valve via said computing means when said differential weight at least equals a predetermined value entered in said computing means;
• (5) retaining the infusate fluid within the patient's peritoneal space for a predetermined dwell time interval by maintaining both fill and drain control valves closed;
• (6) at the end of said predetermined dwell time, measuring the gross weight supported by said load cell to establish a second reference gross weight for that cycle;
• (7) draining the patient's peritoneal space by opening said drain control valve while keeping the fill control valve in a closed position;
• (8) periodically measuring the gross weight supported by said load cell during said draining step and comparing said gross weights to said second reference gross weight and thereby periodically determining the differential weight of fluid which has drained from the patient;
• (9) stopping said draining step by closing said drain control valve via said computing means when said differential weight of said drain fluid at least equals a predetermined value entered in said computing means;
• (10) performing any additional cycles of said dialysis procedure according to steps 1 through 9;
• and
• (d) providing the patient with the results of the completed dialysis procedure via said video monitor under the control of said computing means, including in said results information as to how much infusate fluid was placed into the patient's peritoneal space and how much fluid was drained from the patient's peritoneal space during each of said cycles.