U.S. patent number RE32,303 [Application Number 05/781,031] was granted by the patent office on 1986-12-09 for peritoneal dialysis apparatus.
This patent grant is currently assigned to American Medical Products Corp.. Invention is credited to Bruce E. Jarrell, Norman Lasker.
United States Patent |
RE32,303 |
Lasker , et al. |
December 9, 1986 |
Peritoneal dialysis apparatus
Abstract
A peritoneal dialysis apparatus comprising a plurality of
components including a catheter, a fluid heater, a fluid weighing
means and a control device. The components are interconnected by
conduits so that fluid can flow from the heater to the peritoneal
cavity by way of the catheter, and then from the peritoneal cavity
to the weighing means. The weighing means measures the quantity of
discharged fluid as a result of the introduction of the dialysis
fluid to check that the dialysis fluid is causing fluid to drain
from the peritoneal cavity. The flow of fluid between the
components of the system is controlled by valves which are
selectively opened and closed.
Inventors: |
Lasker; Norman (Philadelphia,
PA), Jarrell; Bruce E. (Richmond, VA) |
Assignee: |
American Medical Products Corp.
(Freehold, NJ)
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Family
ID: |
27010557 |
Appl.
No.: |
05/781,031 |
Filed: |
March 24, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
384316 |
Jul 31, 1973 |
03872863 |
Mar 25, 1975 |
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Current U.S.
Class: |
604/29 |
Current CPC
Class: |
A61M
1/1643 (20140204); A61M 1/28 (20130101) |
Current International
Class: |
A61M
1/28 (20060101); A61M 1/16 (20060101); A61M
005/00 (); A61M 001/03 () |
Field of
Search: |
;128/213,214R,214E,214Z,227,230,273,274 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1964588 |
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Jul 1971 |
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DE |
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1964733 |
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Jul 1971 |
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DE |
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2017408 |
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Oct 1971 |
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DE |
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Other References
Lasker et al.-Trans. Amer. Soc. Artific. Inter. Orgs., vol. XII,
1966, pp. 94-97..
|
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Panitch, Schwarze, Jacobs &
Nadel
Claims
We claim:
1. A dialysis apparatus comprising first means for supplying
dialysis fluid, second means for measuring a predetermined quantity
of dialysis fluid, a catheter, third means for detecting a minimum
quantity of dialysis fluid, means for supporting said first means
above said second means, said second means above said catheter, and
said third means below said catheter so that dialysis fluid moves
through said apparatus under the force of gravity, fluid flow
conduits interconnected between said first and second means.[.,.].
.Iadd.and between .Iaddend.said second means and said catheter and
.Iadd.between .Iaddend.said catheter .[.in.]. .Iadd.and
.Iaddend.said third means, fourth means .Iadd.including a single
actuator for plural valves .Iaddend.for .Iadd.simultaneously
.Iaddend.regulating the flow of dialysis fluid .[.and.]. .Iadd.in
.Iaddend.said .[.conduits.]. .Iadd.conduit .Iaddend.between said
first and second means and .Iadd.the conduit between .Iaddend.said
catheter and said third means .Iadd.in a manner so that flow is
simultaneously on or off.Iaddend., fifth means .Iadd.including a
single actuator for plural valves .Iaddend.for .Iadd.simultaneously
.Iaddend.regulating the flow of dialysis fluid .Iadd.in the conduit
.Iaddend.between said second means and said catheter.[.,.]. and
.Iadd.a conduit .Iaddend.from said third means .Iadd.in a manner so
that flow is simultaneously on or off.Iaddend., and means for
controlling said .Iadd.actuators for said .Iaddend.fourth and fifth
means to alternately permit flow of dialysis fluid in the conduits
regulated thereby so that the dialysis fluid is permitted to flow
through said apparatus and a patient and then from said third
means.
2. A dialysis apparatus as defined in claim 1 including an alarm,
means coupling said third means to said alarm, and means for
enabling said alarm if said third means fails to detect a minimum
quantity of dialysis fluid.
3. A dialysis apparatus as defined in claim 2 wherein said third
means comprises a frame, an arm, said arm being pivotally supported
by said frame intermediate its ends, a fluid receptacle coupled to
said arm on one side of said pivot, means comprising a
counterweight coupled to said arm on the other side of said pivot,
and said means for enabling said alarm is disposed adjacent said
arm for actuation thereby if the weight of dialysis fluid in said
fluid receptacle is insufficient to overcome the force of said
counterweight means.
4. A dialysis apparatus as defined in claim 1 wherein said second
means .[.includes.]. .Iadd.is removably mounted in a housing
.Iaddend.means for heating dialysis liquid .[.therein.]. .Iadd.in
said second means .Iaddend.to a predetermined temperature.
5. A dialysis apparatus as defined in claim 1 including a fluid
flow conduit extending from said third means, and a discharge
receptacle connected to said last named fluid flow conduit to
receive dialysis fluid from said third means.
6. A dialysis apparatus as defined in claim 1 wherein said control
means comprises a shaft, first and second cams mounted on said
shaft, one of said cams controlling said fourth means
.Iadd.actuator.Iaddend., the other cam controlling said fifth means
.Iadd.actuator.Iaddend., energizable means for rotating said shaft,
and means for selectively energizing and de-energizing said
energizable means to selectively rotate said shaft.
7. A dialysis apparatus comprising first means for supplying
dialysis fluid, second means for measuring a predetermined quantity
of dialysis fluid, a catheter, third means for detecting a minimum
quantity of dialysis fluid, said third means comprises a frame, an
arm, said arm being pivotedly supported by said frame intermediate
its ends, a .Iadd.removable .Iaddend.fluid receptacle coupled to
said arm on one side of said pivot, means comprising a counter
weight coupled to said arm on the other side of said pivot, and
said means for enabling said alarm is disposed adjacent said alarm
for actuation thereby if the weight of dialysis fluid on said fluid
receptacle is insufficient to overcome the force of said counter
weight means, fluid flow conduits interconnected between said first
and second means, said second means and said catheter, and said
catheter and said third means, fourth means for
.Iadd.simultaneously .Iaddend.regulating the flow of dialysis fluid
in said conduits between said first and second means and said
catheter .[.in.]. .Iadd.and .Iaddend.said third means, fifth means
for .Iadd.simultaneously .Iaddend.regulating the flow of dialysis
fluid between said second means and said catheter, and from said
third means, and means for controlling said fourth and fifth means
to alternately permit flow of dialysis fluid in the conduits
regulated thereby so that the dialysis fluid is permitted to flow
through said apparatus and the patient and then from said third
means, said control means comprises a shaft, first and second cams
mounted on said shaft, one of said cams controlling said fourth
means, and other cam controlling said fifth means, energizable
means for rotating said shaft, and means for selectively energizing
and de-energizing said energizable means to selectively rotate said
shaft.
8. A dialysis apparatus comprising first and second means for
regulating the flow of dialysis fluid through said apparatus, means
coupling said first and second regulating means to each other so
that when said coupling means is a first position said first
regulating means stops the flow of dialysis fluid and said second
regulating means permits the flow of dialysis fluid, and when said
coupling means is in a second position said first regulating means
permits the flow of dialysis fluid while said second regulating
means stops the flow of dialysis fluid, selectively energizable
means for alternatively positioning said coupling means between its
first and second positions, said selectively energizable means
being mechanically connected to said coupling means, first, second
and third timers, said first timer for controlling the duration of
time in which said coupling means is in a first position, said
first timer including means to emit a control signal when said
first timer times out, electrical means for transmitting said
control signal from said first timer to said selectively
energizable means, said selectively energizable means adapted to be
energized in response to said control signal so that said
selectively energizable means causes said coupling means to be
positioned in the second position, said electrical means also to
transmit said control signal to said second and third timers, said
second and third timers to automatically reset and start timing out
in response to such signal, said third timer for controlling the
duration of time in which said coupled regulating means are in the
second position, said third timer including means to emit a control
signal when said third timer times out, electrical means for
transmitting said control signal from said third timer to said
selectively energizable means, said selectively energizable means
adapted to be energized in response to said control signal so that
said selectively energizable means causes said coupling means to be
positioned in the first position, said electrical means also to
transmit said control signal to said first timer, said first timer
to automatically reset and start timing out in response to such
signal, an energizable alarm and a switch, said switch being
operative to enable said alarm upon a condition, said second timer
having a shorter timing duration than said third timer and being
electrically connected to said third timer and said energizable
alarm so that if the alarm is enabled when said second timer times
out, said alarm is energized and said third timer stops timing out
until said condition no longer exists.
9. A dialysis apparatus defined in claim 8, including overriding
means for selectively generating a control signal to said first
timer in said selectively energizable means, said first timer to
automatically rewind and start timing out in response to said
control signal, said selectively energizable means to be energized
in response to said control signal so that selectively energizable
means causes said coupling means to be positioned in the first
position, said overriding means to be operable independently of
said first, second or third timers.
10. A dialysis apparatus defined in claim 8, including overriding
means for selectively generating a control signal to said second
and third timers and to said selectively energizable means, said
second and third timers to automatically rewind and start timing
out in response to said control signal, said selectively
energizable means to be energized in response to said control
signal so that selectively energizable means causes said coupling
means to be positioned in the second position, said overriding
means to be operable independently of said first, second or third
timers. .Iadd.
11. A prepackaged sterilized peritoneal dialysis apparatus
comprising:
(a) a first collapsible measuring bag adapted to receive dialysis
fluid and having a single inlet-outlet,
(b) a second collapsible weighing bag adapted to receive dialysis
fluid from a patient and having a single inlet-outlet,
(c) at least six lengths of flexible tubing,
(d) a first length of said tubing having one end directly connected
to the inlet-outlet of said first bag, a second length of said
tubing having one end connected at a junction to the other end of
said first length of tubing, the other end of said second length of
tubing being adapted to be connected to a source of dialysis
fluid,
(e) a third length of said tubing having one end adapted to be in
communication with a catheter, the other end of said third length
of tubing being connected through a junction to the interconnected
ends of said first and second lengths of tubing,
(f) a fourth length of said tubing having one end directly
connected to the inlet-outlet of said second bag,
(g) a fifth length of said tubing having one end in communication
with said third tubing, the other end of said fifth length of
tubing being connected through a junction to the other end of said
fourth length of tubing,
(h) a sixth length of tubing having one end adapted to be connected
to a waste disposal, the other end of said sixth length of tubing
being connected at the last mentioned junction to the
interconnected ends of said fourth and fifth lengths of tubing,
(i) whereby said third length of tubing may be used to feed fluid
to a patient and the fifth tubing may be used to transfer fluid
drained from a patient to said second bag via said fourth tubing.
.Iaddend.
Description
This invention relates to a dialysis apparatus and more
particularly to a peritoneal dialysis apparatus.
Peritoneal dialysis is a well known medical procedure for removing
impurities from the blood stream. It is accomplished by introducing
a suitable dialysis fluid into the peritoneal cavity and then
withdrawing the fluid after a suitable period of time. During the
time that the dialysis fluid is in the peritoneal cavity,
impurities in the blood stream are drawn through the walls of the
blood vessels on the abdominal wall and in the viscera, and through
the peritoneum membrane against which they lie through the osmotic
effect of the dialysis fluid. The entire procedure may take up to
36 hours since the dialysis fluid must be replaced from time to
time as the concentration of impurities in it increase.
Heretofore, peritoneal dialysis has been done in hospitals because
of the high risk of infection and because trained personnel need to
be available to perform the procedure.
Accordingly, the invention relates to a peritoneal dialysis
apparatus which can be used by a patient at home thereby enabling
the hospital bed to be free for use by others, and thus reducing
the cost of the dialysis to the patient.
To this extent, the apparatus comprises means for supplying
dialysis fluid to a means for measuring predetermined quantities
and means for conducting the dialysis fluid to a catheter. The
catheter is connected to the peritoneal cavity of a patient and to
a means for detecting a minimum quantity of dialysis fluid. Means
are provided for regulating the flow of dialysis fluid through the
apparatus.
The invention can best be described by referring to the attached
drawings wherein a presently preferred form of the invention is
illustrated and wherein
FIG. 1 is a schematic drawing of a preferred form of the
apparatus.
FIG. 2 is a sectional view of the means for controlling the flow of
fluid through the apparatus.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a sectional view taken along line 4--4 of FIG. 2.
FIG. 5 is a perspective view of a portion of the apparatus
illustrated in FIG. 1 for weighing fluid discharged from the
peritoneal cavity.
FIG. 6 is a perspective view of a portion of the apparatus shown in
FIG. 1 which is used for heating the dialysis liquid.
FIG. 7 is an end view taken along line 7--7 of FIG. 6.
FIG. 8 is a schematic view of the circuitry for operating the
apparatus.
FIG. 9 is a drawing graphically portraying the operation of the
apparatus.
Now referring to the drawing for a detailed description of the
invention, a peritoneal dialysis apparatus is schematically
illustrated by the numeral 10 in FIG. 1.
The apparatus 10 comprises a container 14 in which a supply of
dialysis fluid is stored for use as needed, a means 16 for metering
and heating the dialysis fluid after it is dispensed from container
14, a catheter (schematically) 18, a means for detecting discharge
of fluid from the patient 20, a means for receiving fluid
discharged from the apparatus 22 and a means for controlling the
flow of dialysis fluid through the apparatus 24.
A pump or other positive driving means may be used to move the
fluid through the apparatus. However, its construction is greatly
simplified and its reliability is substantially increased by
relying on the force of gravity.
Accordingly, the components of the apparatus are supported by a
suitable means indicated schematically by numeral 21 at
successively lower heights than the preceding components. The
successive components in the apparatus may be interconnected by
suitable resilient flexible plastic conduits. A typical plastic is
commercially available and is sold as tubing under the trademark
"TYGON."
The container 14 may be of any convenient size. Preferably it
should contain enough dialysis fluid to enable a complete dialysis
procedure to be performed and should be constructed so that the
dialysis fluid can be kept sterile. An outlet 25 in the bottom of
the container connects it with the rest of the system. Fluid used
in peritoneal dialysis are commercially available and are well
known to those skilled in the art. A typical fluid is sold under
the trademark "DIANEAL" by Travenol Laboratories.
The means for metering and heating the dialysis fluid 16 is best
seen in FIGS. 6 and 7. It includes an outer housing 26 which may be
of any convenient shape. A heating unit is supported in housing 26
by a plurality of fasteners 28. It comprises front and rear
thermally conductive plates 30 and 32 which are arranged in spaced
parallel relation to each other. Each of plates 30 and 32 supports
a heating element 34 and 36. The heating elements cover a
substantial area of plates 30 and 32 to rapidly bring the plates to
the desired temperature. A collapsible sterile bag 35 which may be
made from "TYGON" is supported within housing 26. A typical means
for supporting the bag may include suspending it from a rod 36
which is slipped through a sleeve along one edge of the bag. The
bag 35 may have any convenient volume. However it is preferred that
the volume be about two liters since introduction and discharge of
this volume of fluid into the peritoneal cavity at intervals during
the procedure achieves satisfactory results. A bag of reduced
volume may be selected when the patient is a child.
The plates 30 and 32 are connected in a circuit which enables them
to bring the dialysis fluid in bag 35 to a temperature of about
30.degree. C. The circuit which will be described herein includes a
thermal switch 38 in contact with the bag 35. An outlet 39 in the
bottom of the bag connects it to the rest of the apparatus. Since
the bag 35 is collapsible it can be filled and emptied without
exposing its contents to the air.
The catheter 18 may be permanently implanted in the patient or it
may be a disposable catheter. Both types of catheters are well
known and are commercially available for use in peritoneal
dialysis.
The means for detecting discharge of fluid from the patient 20 can
best be seen in FIG. 5. It may be mounted to a support frame (not
shown) by a bracket 44. The bracket supports a pin 46 which serves
as a fulcrum for an elongated lever arm 48. A collapsible bag 50
for collecting fluid discharged from the patient is supported at
one end of lever arm 48. The other end of lever arm 48 is connected
to a counterweight such as spring 52. A second bracket 53 on the
support frame carries a microswitch 54 so that the operator of the
microswitch is in contact with the lower surface of lever arm
48.
The volume of bag 50 may be about three liters so that if any fluid
has collected in the peritoneal cavity, it also will be discharged
along with the dialysis fluid. The counterweight is selected so
that microswitch 54 is closed until a sufficient volume of fluid,
preferably about 1500 grams, is collected in bag 50. At 1500 grams,
the force of the counterweight is overcome and the lever arm 48
rotates about pin 46 to open microswitch 54. The microswitch is
connected to an alarm signal in a manner which will be explained
herein.
Normally, microswitch 54 is closed. However, if at a predetermined
interval microswitch 54 is still closed, the alarm is activated to
notify the patient that the expected quantity of fluid has not
drained from the peritoneal cavity.
The means for receiving fluid discharged from the apparatus 22 may
comprise any convenient receptacle such as a disposable bag. In the
alternative it could be a conventional drain.
The container 14 is connected to both the means for heating and
metering dialysis fluid 16 and the inlet of catheter 18. To this
extent a length of tubing 60 is connected between the bottom
opening 25 in container 14 and an arm of a "T" 62. Another length
of tubing 64 is connected between the second arm of the "T" 62 and
the opening 38 in the means for heating and metering dialysis fluid
16. The third arm of "T" 62 is connected by a length of tubing 66
to the catheter 18.
The outlet of the catheter 18 is connected to both the means for
detecting discharge of fluid from the patient 20 and the means for
receiving discharged fluid 22. To this extent a length of tubing 70
is connected between the catheter 18 and one arm of a "T" 72.
Another length of tubing 74 is connected between a second arm of
"T" 72 and the bag 50. The third arm of "T" 72 is connected to the
means for receiving discharged fluid 22 by a length of tubing
76.
The lengths of tubing 60, 66, 70 and 76 pass through control means
24.
From FIG. 1 it is apparent that the control means 24 may comprise
first and second valves 80 and 82. First valve 80 selectively opens
and closes tubes 60 and 70. Second valve 82 selectively opens and
closes tubes 66 and 76. The valves regulate the flow of fluid
through the apparatus.
When valve 80 is open and valve 82 is closed, the fluid in
container 14 is permitted to flow through tubes 60 and 64 into the
heating and metering means 16. Simultaneously, fluid is drained
from the patient through the catheter 18 and tubes 70 and 74 into
bag 50.
When the valve 82 is open and valve 80 is closed, fluid flows from
the heating and metering means through tubes 64 and 66 into
catheter 18 and thence into the patient. Simultaneously fluid is
drained from the bag 50 through conduits 74 and 76 into the
discharge receiving means 22.
Thus, by controlling the duration of time for which the valves 80
and 82 are opened and closed and by regulating the volume of
dialysis fluid which can be stored in the heating and metering
means 16, an efficient, safe peritoneal dialysis apparatus is
achieved. Significantly, it should be noted that bag 50 is provided
on the downstream side of the patient in order to detect an
insufficient drainage of fluid from the peritoneal cavity.
The control means 24 is illustrated in FIGS. 2-4. It comprises a
housing 86 which rotatably supports a shaft 88 in bearings 89. The
shaft 88 is connected by way of a clutch 90 to the output shaft 92
of a motor 94. Output shaft 92 is rotatably supported by bearing
95.
Shaft 88 supports cams 100 and 102 which operate valves 80 and 82
respectively, and cam 104 which operates microswitches 108 and 110.
Cams 100 and 102 have profiles that correspond to FIG. 9 wherein it
is seen that each valve 80, 82 opens slowly and closes quickly. The
microswitches 108 and 110 are supported by housing 86 so that their
operators can be displaced into a notch formed in the cam (see FIG.
8). Hence rotation of cam 104 through a complete revolution causes
each microswitch to be tripped once. The cams 100 and 102 are
supported on shaft 88 so that they are 180.degree. out of phase
with respect to each other. Thus when one of valves 80 and 82 is
open, the other is closed. As will be explained in greater detail
herein, the power to motor 94 is supplied through microswitches 108
and 110. When the switch operators fall into the notch in the cam,
the motor 94 is stopped. This positions the valves 80 and 82 in
accordance with the configuration of cams 100 and 102 until the
motor is energized through the microswitch whose operator is not in
the notch.
Each valve includes a stem 114 with a cross bar 118 at one end and,
if desired, a roller 120 at its other end. Each valve stem 114
includes a radially directed flange 122 near roller 120.
The valve stems 114 are supported in apertures 123 formed in a
support member 124 mounted in housing 86. Each of valve stems is
biased toward its respective cam 100, 102 by a spring 126 which
bears against the flange 122.
A plate 130 is supported in spaced relation from the front wall of
housing 86 by a suitable hinge 132. Suitable latching means such as
member 134 may be provided for retaining plate 130 in the position
illustrated in FIG. 2.
Plate 130 supports a housing 138 having the appearance of a frame
with a central opening 139. The housing 138 is comprised of two
separate members 140, 142 which have grooves in which the tubes can
be received. When the members 140, 142 are assembled the tubes are
held in the position illustrated in FIGS. 2 and 4. Thus, tubes 60
and 70 are positioned so that they can be pinched closed by valve
80. Tubes 66 and 76 are positioned so that they can be pinched
closed by valve 82.
A layer of relatively soft backing material 148 such as foam
rubber, felt or the like is secured to plate 130 adjacent tubes 60,
70, 66 and 76.
Suitable means is provided for selectively energizing motor 94 at
predetermined intervals during the dialysis treatment. The motor
causes shaft 88 to rotate with the result that the tubes 60 and 70,
and 66 and 76 are alternately pinched and released to permit fluid
to flow through the apparatus.
The energization means for the motor comprises the circuit
illustrated schematically in FIG. 8.
The circuit comprises timers 150A, 150B and 150C, a two-position
latching relay 156, an alarm signal 158 and a counter 160.
Additionally, the circuit includes the heating plates 34 and 36,
thermal switch 38, switch 54, motor 94 and switches 108 and
110.
The circuit is energized by closing on-off switch 162. Switch 164,
which may be called the fill switch, is operative when closed to
cause the dialysis fluid in bag 35 to enter the patient by way of
catheter 18. Switch 166, which may be called the drain switch, is
operative when closed to cause the dialysis fluid in the patient to
be discharged therefrom into bag 50.
On-off switch 162 may be a two-position push button switch. When
the switch is "OFF" a circuit is completed across terminals 170 and
172. When the switch is "ON" a circuit is completed across
terminals 174 and 176. Fill switch 164 may be a push button switch
which is biased to a normally "OPEN" position. However, when the
push button is monentarily "CLOSED," a circuit is enabled across
terminals 180 and 182.
Drain switch 166 may be a push button switch of the same type as
switch 164 in that it is biased to a normally "OPEN" position. In
its "OPEN" position it enables a circuit across terminals 186 and
188. When this switch is momentarily "CLOSED" a circuit is enabled
across terminals 190 and 192.
Timers which may be used satisfactorily in the invention are
identified commercially as Singer Industrial Timers, Type GTD, 30
minutes. These timers may be set to run for a maximum time of 30
minutes. Each timer 150A, 150B and 150C is essentially the same.
Thus, the same part in each timer is identified by the same
reference numeral with the different timers being distinguished by
the letters "A," "B" and "C" following the numerals.
The following description will suffice for all timers 150. Each
timer includes a switch 196 which is comprised of contacts 198 and
200 and throw 202. It also includes a timer motor which is
connected by an electrically energized clutch to throw 202.
The timer motor runs continuously as long as power is applied to
motor terminal 204.
The clutch is energized as long as power is applied to clutch
terminal 206. Every time the clutch is energized, the timer is
reset to the maximum time thereon (this feature is an aspect of the
particular timer identified herein).
Both the timer motor and the clutch are connected to common
terminal 208. While the motors are connected to the throws by the
clutches, the throws 202 engage contacts 198 in each switch 196.
When each timer has run out, the throws 202 move from contacts 198
to contacts 200.
Relay 156 includes three separate but interconnected single throw
switches. In each switch the throw, 210 212 and 214, respectively
is movable between first and second contacts 210A and 210B, 212A
and 212B and 214A and 214B.
The throws are shifted by energizing coil "L1" or "L2".
Energization of coil "L1" completes a circuit through contacts
210A, 212A and 214A. Energization of coil "L2" completes a circuit
through contacts 210B, 212B and 214B. The throws remain in
engagement with the contacts until the other coil ("L1" or "L2") is
energized, then they shift.
The source of electromotive force 221, which may be an ordinary
electrical outlet, is connected by way of fuse 223 to terminals 170
and 174 on on-off switch 162.
The circuit is designed so that when the apparatus is shut off the
relay throws are at rest on contacts 210A, 212A and 214A. Therefore
the apparatus always starts on that portion of its cycle which
permits fluid to be drained from the patient into bag 50. The
mechanism by which this occurs is explained herein.
Upon the closing of on-off switch 162 on terminals 174 and 176 a
number of circuits are completed or enabled from the source of
power 221 and fuse 223. These circuits permit fluid to be
discharged from the patient for a predetermined interval as will be
explained herein.
Thus, a circuit is completed to motor 94 from on-off switch
terminal 176 by way of lines 220, 222 and through switch 108. A
circuit is completed to thermal switch 38 and heater plates 34, 36
by way of lines 220, 224, 226, 228 and 230.
The motors and clutches on timers 150B and 150C are energized and
the timers begin to wind down by virtue of circuit through drain
switch 166 and relay 156. The circuit includes lines 224, terminals
190, 186 and 188, line 232, relay contact 214A and line 234.
The motor and clutch of timer 150C is energized by way of line 234
and lines 236 and 238 which are connected to timer motor terminal
204C and clutch terminal 206C.
Switch 196C receives power by way of lines 234, 240 and throw 202C.
Since throw 202C is touching contact 198C, a circuit is completed
by way of line 242 to the motor terminal 204B in timer 150B. An
indicator lamp may be connected to line 242 to indicate when the
timer motor is energized. Clutch terminal 206B receives power from
line 236 by way of line 244.
The motor 94 causes shaft 88 to rotate in the direction indicated
by the arrow in FIG. 8 until the operator of switch 108 falls into
the notch in cam 104. This opens the circuit to the motor thereby
halting the rotation shaft 88. By virtue of the positions of cams
100 and 102 on shaft 88 they have been rotated to the position
illustrated in FIG. 2 where valve 80 is open and valve 82 is
closed. As illustrated in FIG. 1, when the valves are in this
configuration dialysis fluid is permitted to drain from container
14 to the heating and metering means 16 and at the same time fluid
is permitted to drain from the patient by way of catheter 18 into
the bag 50.
If for some reason, cam 104 is not in the position illustrated when
on-off switch 162 is closed and switch 108 is open, the motor 94
will not operate since the valves 80 and 82 will be in the correct
positions to permit fluid to be drained from the patient.
Timer 150C is set to run for a shorter time than timer 150B. Timer
150C cooperates with switch 54 to indicate that fluid is draining
from the patient at an adequate rate. To this extent a circuit is
normally enabled through switch 54 by way of contact 200C in timer
150C, line 254, switch contact 256 and line 258 to alarm 158. But
when the weight of fluid in bag 50 reaches 1500 grams, or any
predetermined weight deemed desirable, the throw in switch 54 is
moved to contact 260.
With the foregoing in mind, when timer 150C runs out, as for
example fifteen minutes after it is energized, throw 202C moves to
contact 200C. If the predetermined quantity of fluid is not in bag
50, the circuit through alarm 158 is completed by way of line 254,
contact 256 and line 258. The alarm 158 may be visible, audible or
a combination of both, provided it alerts the patient to the fact
that inadequate drainage from the body is taking place. Since there
is no power in line 242, the motor in timer 150B is stopped. Thus,
the apparatus remains in the drain portion of the cycle and the
alarm 158 remains energized until the apparatus is shut off or the
fill switch 164 is depressed.
In an adequate amount of fluid is in bag 50 when timer 150C runs
out, the alarm is bypassed and power to motor terminal 204B is
achieved by way of line 254, contact 260 and line 242.
Assuming that there has been adequate drainage to bag 50, when the
time on timer 150B runs out, throw 202B moves to contact 200B to
start filling the patient with dialysis fluid. This energizes coil
"L-2" in relay 156 by way of lines 226, 264, throw 202B, contact
200B, lines 266 and 268. Coil "L2" moves all of the throws in the
relay clockwise so that circuits are completed to terminals 210B,
212B and 214B.
Energization of coil "L2" energizes counter 160 by way of lines
266, 270 and 272. Hence a count is taken on each time the circuit
shifts to cause dialysis fluid to enter the patient.
Clockwise movement of the relay throws 210, 212 and 214 completes
or enables a number of circuits.
A circuit is completed to motor 94 through line 222, relay contact
212B and through switch 110. The switch is closed since the notch
in cam 104 is now adjacent switch 108. The motor rotates shaft 88
until the operator on switch 110 falls into the notch whereupon the
motor stops rotating the shaft. At this point valves 80 and 82 are
in the positions illustrated in FIG. 1 wherein fluid is permitted
to fill the patient by way of catheter 18 from the heating and
metering means 16 and the fluid in bag 50 is permitted to be
discharged to the drain means 22.
The motor and clutch on timer 150A are energized and the timer
begins to wind down by way of a circuit through relay throw 214,
relay contact 214B and line 276. Line 276 is connected to motor
terminal 204A and clutch terminal 206A. An indicator lamp may be
coupled to motor terminal 204 to indicate that the motor is
energized.
The throw 202A in switch 196A is on contact 198A while the timer is
running. When the time on timer 150A runs out, after, for example
30 minutes, throw 202A shifts to contact 200A to complete a circuit
through coil "L.sub.1 " by way of line 280, relay throw 202A and
lines 282, 284 and 286.
Energization of coil "L.sub.1 " shifts all the relay throws in
relay 156 counterclockwise so that they engage contacts 210A, 212A
and 214A. This completes a circuit through timer 150B and timer
150C so that the cycle is repeated as described above. In the event
that timer 150C should run out before an adequate amount of fluid
is received in bag 50, alarm 158 will be energized.
When timer 150B runs out the relay 156 shifts and the motor 94
energized to rotate shaft 88 to permit dialysis fluid to again fill
the patient. At the same time, timer 150A is energized.
Significantly, it should be noted that the timers are reset to the
maximum time thereon each time they are energized. In timers 150A
and 150B the maximum time is externally adjustable. To this extent,
they may be mounted on a panel and have knobs extending therefrom
for that purpose.
On the other hand, timer 150C is designed to be non-adjustable.
Thus, it may be set at the factory. It is preferably permanently
mounted within an enclosing structure so that it cannot be tampered
with by the user.
At any time in its cycle the apparatus may be shut down by moving
switch 162 to the "OFF" position so that it completes a circuit
across terminals 170 and 172.
If the relay throws are in their clockwise positions when on-off
switch 162 is moved to its "OFF" position, a circuit is completed
to coil "L1" from terminals 170 and 172 by way of line 290, relay
contact 210B, and lines 292, 284 and 286. This moves the throws
counterclockwise which then opens the circuit from on-off switch
162 since relay contact 210A is not connected to the rest of the
circuit.
If, on the other hand, the relay is closed on contact 210A, moving
switch 162 to its "OFF" position so that it completes a circuit
across terminals 170 and 172 merely shuts down the apparatus.
The apparatus can be switched from the drain cycle to the fill
cycle or from the fill cycle to the drain cycle by depressing fill
switch 164 or drain switch 166 respectively.
For example, if the apparatus is draining fluid from the patient
and it is desired to switch it to fill the patient, switch 164 is
depressed momentarily to complete a circuit across terminals 180
and 182. This completes a circuit from the source of electromotive
force through contacts 174 and 176, line 220, through switch 164 by
way of terminals 180 and 182, and line 294. Counter 160 is
energized by way of lines 294 and 272. Coil "L2" is energized by
way of lines 294, 270, and 268. When coil L2 is energized, it
shifts the throws (they are in their counterclockwise position when
fluid is draining from the patient). This completes a circuit to
relay contact 212B and a circuit to relay contact 214B so that
circuits are completed through switch 110 to motor 94 and to timer
motor and clutch terminals 206A and 204A in timer 150A. Shaft 86
rotates until switch 110 opens thereby deenergizing motor 94. This
opens valve 82 to fill the patient from the metering and heating
means 22.
When the time on timer 150A runs out, throw 202A moves to contact
200A. This completes a circuit from terminal 176 in on-off switch
162 to coil "L1" by way of line 280, throw 202A, contact 200A and
lines 282, 284 and 286. Energization of coil "L1" shifts the relay
throws counterclockwise to energize and reset timers 150B and 150C
and motor 94 (through switch 108) to start the drain portion of the
cycle.
The drain cycle continues as explained above with both timers 150C
and 150B being energized. If timer 150C runs out before an adequate
amount of fluid is in bag 50 an alarm is sounded.
On the other hand, if an adequate amount of fluid is in bag 50 when
timer 150B runs out, the relays are again thrown and the fill
portion of the cycle takes over.
If the apparatus is in the fill portion of its cycle and it is
desired to shift it to the drain portion, switch 166 is depressed
momentarily to complete a circuit across terminals 190 and 192.
This completes a circuit to coil "L1" by way of terminal 192 and
lines 296 and 286. Energization of coil "L1" shifts the relay
throws counterclockwise to complete circuits to relay contacts 212A
and 214A so that circuits are completed to motor 94 and to timers
150B and 150C. In this regard, the circuit components assume the
same configuration that they have when on-off switch 162 is moved
to its "ON" position as described in detail above.
From the foregoing it is apparent that at any part of its cycle the
apparatus can be shifted to the opposite part of the cycle.
In order to use the apparatus described, each of the components of
the system, namely, container 14, metering and heating means 16,
the patient and catheter 18, the weighing means 20 and the drain 22
are arranged so that each component has a higher elevation than the
component following it so that the natural tendency of the dialysis
fluid in container 14 is to flow through the apparatus.
The sequence of operation of the apparatus is shown in FIG. 9. The
apparatus can go through a complete cycle in up to one hour. Up to
30 minutes can be used to fill the patient and up to 30 minutes can
be used to drain the patient. The duration of the fill and drain
intervals are controlled by timers 150A and 150B. Since the timers
are externally adjustable these periods can be varied as
desired.
The motor 94 is energized at the end of each fill and each drain
interval. The motor is selected so that each time it is energized
shaft 88 rotates through half a turn in about 30 seconds. As
explained earlier the motor is energized at the end of each fill
and drain interval. Cams 100 and 102 are profiled to enable valves
80 and 82 to gradually open over each thirty second interval of
shaft rotation, but to close abruptly. This is so that the dialysis
fluid does not surge or drip through the tubing. During each thirty
second period of cam rotation, the positions of valves 80 and 82
are reversed, and, due to cam 104, one of microswitches 108, 110 is
opened while the other is closed.
A commercial embodiment of the invention would comprise sufficient
dialysis fluid in container 14 to discharge a two liter does of
dialysis fluid into the patient every half hour with the succeeding
half hour being consumed in withdrawing the dialysis fluid. Thus,
the heater bag acts as a measuring device in order to control the
amount of fluid being introduced to the peritoneal cavity in any
given time.
It is contemplated that with the present apparatus a complete
dialysis can be achieved in a period of about 10 hours as opposed
to an interval of 36 to 72 hours as in present procedures.
The substantial reduction in time is achieved by virtue of the fact
that the dialysis fluid is changed rather rapidly.
Thus, it is a well known fact that in an osmotic process, as the
fluids on each side of the membrane approach equilibrium, the rate
of exchange across the membrane decreases. Thus, it is advantageous
to change the dialysis fluid as the rate of transfer across the
peritoneal membrane begins to slacken.
This can readily be done with the present apparatus by merely
externally adjusting the time available on timers 150A and
150B.
At the same time since the presence of an attendant is not
necessary in order to change the fluid in container 14, a
sufficient amount of fluid in order to perform the entire dialysis
may be made available at one time. It is contemplated that an
adequate amount of fluid to satisfactorily dialyze an adult patient
would be about 20 liters. Thus, over a period of 10 hours, at a
rate of 2 liters per cycle, the entire quantity of fluid would be
consumed.
Significantly, at the end of each cycle of the apparatus, the fluid
discharged from the peritoneal cavity is weighed in order to assure
that the patient is draining properly. In the event that inadequate
drainage is taking place, a suitable alarm is activated.
A further safety device is present by virtue of the fact that when
the apparatus is initially turned on as, by pushing switch 162 to
close a circuit across terminals 174 and 176 the apparatus
automatically starts on a drain cycle. Thus, there is no
possibility that two liters of dialysis fluid would be in the
patient as two additional liters are being introduced.
Finally, it should be noted that the apparatus always shuts off in
the drain position.
While the invention has been described with respect to one
preferred embodiment thereof, it is apparent that many other forms
and embodiments will be obvious to those skilled in the art in view
of the foregoing description. Thus, the scope of the invention
described herein should not be limited by that description but,
rather, only by the scope of the claims appended hereto.
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