Dialysis unit priming

Dialysis unit with vacuum removal therethrough of priming saline and selective circulation therethrough of dialysate and other fluids. The dialyzer unit includes a drain configured to sealingly cooperate with a tubing set having a cap with a central conduit portion and sealing fins for cooperating with the drain, and a venturi in a main effluent passage in fluid communication with the drain.

FIELD OF THE INVENTION 
This invention relates to dialysis units, and more particularly to 
provision therein of improved saline disposal. 
BACKGROUND OF THE INVENTION 
It is known to prime a dialysis unit with saline, connecting a tubing set 
between a saline bag and a waste bucket. 
SUMMARY OF THE INVENTION 
A dialysis unit may provide for saline disposal through conduits of the 
unit. 
In preferred embodiments, a drain is selectively cooperative with an 
ordinary operating hydraulic circuit and a saline priming circuit; the 
ordinary operating circuit includes a handle longitudinally and 
rotationally movable between a position implementing the ordinary 
operating hydraulic circuit and a position implementing a saline priming 
circuit; the saline priming circuit includes a cap selectively engageable 
with the drain; and both circuits include means to create vacuum 
therethrough. 
PREFERRED EMBODIMENT 
The presently preferred embodiment is shown in the drawings, and its 
structure and operation then described.

STRUCTURE 
Turning now to the drawings, there is indicated generally at 10 a dialysis 
unit. 
Mounted on the control panel portion of the dialysis unit 10 by means not 
shown is waste handling housing 12, which is shown in FIGS. 2 and 3, 
somewhat diagrammatically, as having its panel contact rim 14 at an angle, 
while in fact the rim lies in a vertical plane, for engagement therein 
with the control panel portion above mentioned. 
Handle 16 is fixedly secured to shaft 18 which is axially movable relative 
to bushing 20 mounted on housing 12. Shaft 18 is biased toward housing 12 
by spring 22, which is compressed between bushing 20 and washer 24 
supported by snap ring 26 carried in a groove in shaft 18. 
Bushing 20 has within it camming surfaces (not shown) which cooperate with 
pins on shaft 18 (not shown) to rotate handle 16 so as to align the axes 
of valve unit 54 and drain 32, when the handle is not prevented from such 
movement (as, by insertion of a cap 44 in the drain). 
Snap ring 28, carried in a groove in bushing 20, retains bushing 20 in 
housing 12. 
Also retained in housing 12, by snap ring 30 in a groove therein is drain 
32, which includes integrally portion 34, a slightly smaller diameter 
portion 38, a frustoconical portion 40, and a smallest diameter portion 
36. Internally, drain 32 contains a counterbore in which seats seating fin 
42 of priming cap 44. The hole in drain 32 adjacent said counterbore is of 
diameter to sealingly accept sealing fins 46 of cap 44, and of depth so 
that the end 48 of cap 44 does not reach it. 
Handle 16 is an integral plastic piece carrying three holes. One, 
counterbored, shown in FIG. 4, carries stem 18. Hole 50, 1/8 inch in 
diameter, connects the hole from stem 18 with hole 52 through valve unit 
indicated generally at 54. Hole 50 is done by drilling, followed by 
plugging the hole so as to produce the imperforate wall 56 as shown in 
FIG. 4. 
Cap 44, as best shown in FIG. 3, is Dowlex 2535 LLDPE injection molded in 
one piece. Longitudinal portion 84 has extending through its length a 
hole, defined by two female luer portions intersecting longitudinally 
centrally thereof. Luer threads 86, 88 are provided. Loop 90 permits 
hanging on IV poles. There is provided breather cap portion 92, with 
longitudinal grooves and a pair of notched fins which in combination force 
air to make three 90.degree. turns. There are also a pair of catches 94. 
Referring now to FIG. 2, from drain 32 extends tubing 96, into check valve 
98, from which tubing 100 extends to check valve 102, from which tubing 
104 extends into the sidearm of venturi 106. 
The lower end of shaft 18 is connected into tubing 108, which extends to 
tee 110, connected also by tubing 112 to venturi 106. 
Valve unit 54 includes plastic body 58 with circumferential groove 60 
carrying circumferential lip 62 of silicone rubber boot 82, 
circumferential lip 64 of which is seated in circumferential groove 66 of 
stem 68. The stem 68 is of ABS plastic, and includes the larger portion 70 
which carries groove 66, the smaller diameter portion 72 which extends for 
most of its length, and circumferential groove 74 in which is seated 
O-ring 76, which in turn is seated in chamfer 78. Spring 80 is compressed 
between surface 83 of body 58 and surface 84 of stem 68. The boot 82 has a 
thickness between lips of 1/64 of an inch. A right-angled hole with 
portions 85a and 85b is provided in stem 68. 
OPERATION 
In use, fluid constantly flows through dialysis unit 10, whether for 
example water, dialysate, or bleach. This effluent constantly moves 
through tee 110, tubing 112, venturi 106, and out through exit conduit not 
shown. 
Except when it is desired to prime, by filling dialyzer and tube set with 
saline, valve unit 54 (FIG. 3) is seated in place in drain 32. The action 
of spring 22 in pulling handle 16 down causes the lower surface of stem 72 
to engage the counterbore in drain 32 already referred to and move up stem 
72, moving O-ring 76 out of valving engagement with chamfer 78. 
The vacuum pulled in the sidearm of venturi 106 by the flow through it 
already mentioned then draws a portion of that flow through the loop 
consisting of, successively, tee 110, tubing 108, stem 18, handle 16 
through the open valve unit 54, down the drain 32, continuing with tubing 
96, check valve 98, tubing 100, check valve 102, tubing 104, through 
venturi 106 to mingle with mainstream effluent. In this mode of operation, 
no cap 44 (which would prevent the rotational stem 18 movement above 
mentioned) is in place. 
When saline priming is desired, handle 16 is moved upward by hand, and 
rotated to permit insertion of cap 44, as shown in FIG. 3. This, through 
the action of spring 80, no longer overridden by the drain counterbore 
surface above mentioned, closes the O-ring 76 valve in valve unit 54 and 
stops flow in the circuit above enumerated. 
Desirably, tube sets are provided with at least one cap 44 already in 
place, for insertion as above described. The other end is then spiked into 
a saline bag (preferably using as a connector, although its other 
functions are there irrelevant, a cap 44). Saline is then drained through 
that portion of the loop above enumerated between drain 32 and the sidearm 
of venturi 106. 
The invention thus provides for clean, easy, and safe disposal of waste 
saline. 
Inclusion as described of the vacuum means insures that whenever there is a 
change from priming mode to other mode, or the reverse, the downstream 
line to which connection is selectively made is empty. 
Contamination between patients is prevented by a number of features. During 
priming, the blood pump turns backward, so that pressure is adverse to 
backflow into the tubing set. Further insurance thereagainst is provided 
by check valves 98 and 102. The cap 44 used to connect a tubing set to the 
drain is to be used only once. Even if by mistake it is used a second 
time, its configuration as above described prevents contamination. Because 
of the fins 46 and the spacing of the end 48, the fluid passages of the 
tubing set are never in contact with the dialysis unit 10. The entire 
fluid circuit is cleaned and disinfected after each patient. 
OTHER EMBODIMENTS 
Other embodiments within the invention will occur to those skilled in the 
art. 
The vacuum means may be, for example, an orifice plate rather than a 
venturi.