U.S. patent number 3,737,096 [Application Number 05/211,194] was granted by the patent office on 1973-06-05 for blood processing control apparatus.
This patent grant is currently assigned to International Business Machines Corporation. Invention is credited to Alan L. Jones, George T. Judson, Robert M. Kellogg, Victor R. Kruger.
United States Patent |
3,737,096 |
Jones , et al. |
June 5, 1973 |
BLOOD PROCESSING CONTROL APPARATUS
Abstract
Apparatus for processing blood, and particularly for washing
blood cells, including a centrifuge head in which is arranged a
flexible blood container connected by a rotating seal to tubing
which permits the entrance and exit of wash liquid and supernatant.
The flow of liquid in the tubing is controlled by valve
arrangements which are operable to permit the entrance of wash
liquid and removal of supernatant liquid. The flexible container
fits over a flexible membrane also arranged inside the centrifuge
head about a solid central core. The volume defined by this
membrane and the core communicates via a passage in the core with a
fluid reservoir by means of a control pump which allows fluid to
enter and exit from the volume defined by the membrane. During
operation the unwashed blood may be entered into the container or
blood bag before or after the bag is placed in the centrifuge. The
centrifuge is spun until cells have settled against the outside
wall at which time the valve arrangements and the control pump are
activated such that fluid is pumped into the centrifuge under the
volume defined by the membrane thereby forcing a supernatant to
flow out to a collect container. The centrifuge is then stopped and
the wash solution enters the blood container through another valve
arrangement, thereby allowing the removal of fluid from the volume
inside the flexible membrane. Removal of the wash liquid is
accomplished by the same process of removal as the removal of
supernatant previously described. Provisions are made for
electrical control of all the operations including an agitate
operation in which the centrifuge is spun in alternate directions
for only a few revolutions or goes through alternate
accelerate-decelerate cycles while rotating in the same direction
to thereby agitate the material in the blood bag or flexible
container during the time that a wash solution is entering. The
circuit arrangements are such that a high degree of flexibility in
the programming of the various operations can be obtained.
Inventors: |
Jones; Alan L. (Endwell,
NY), Judson; George T. (Whitney Point, NY), Kellogg;
Robert M. (Endwell, NY), Kruger; Victor R. (Apalachin,
NY) |
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
22785925 |
Appl.
No.: |
05/211,194 |
Filed: |
December 23, 1971 |
Current U.S.
Class: |
494/9; 494/5;
494/10; 494/12; 494/41; 494/55; 494/7; 494/11; 494/29; 494/45;
494/84 |
Current CPC
Class: |
A61M
1/3692 (20140204); A61M 1/3696 (20140204); A61M
1/3698 (20140204); B04B 5/0442 (20130101); A61M
1/0011 (20130101); A61M 1/025 (20130101); A61M
5/1483 (20130101); A61M 2202/0429 (20130101) |
Current International
Class: |
B04B
5/04 (20060101); B04B 5/00 (20060101); A61M
1/36 (20060101); A61M 1/02 (20060101); A61M
1/00 (20060101); A61M 5/145 (20060101); A61M
5/148 (20060101); B04b 011/00 () |
Field of
Search: |
;233/1D,1A,19R,19A,14R,14A,26,27,28,2R ;340/267 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Krizmanich; George H.
Claims
What is claimed is:
1. In a blood processing apparatus including a motor-driven
centrifuge having a flexible membrane therein under which fluid may
be forced to alter the volume above the membrane, a collapsible
blood bag adapted to fit in the centrifuge over said flexible
membrane, rotatable seal means for connecting said blood bag to a
tubing manifold, valve means for controlling the flow of fluids to
and from said blood bag, and motor-driven control pump means for
supplying or removing fluid from the space below said membrane,
said system having a plurality of possible modes of operation
during a cycle of operation, the combination with foregoing of
control means for governing the operation of said apparatus
comprising,
a plurality of manually operated switches, one for each mode of
operation of said system,
electrically interlocked control means for providing a sequence of
output control signals corresponding to said modes of
operation,
automatic programming means effective to supply inputs to said
interlocked control means in a predetermined sequence corresponding
to the sequential operations of said manually operated
switches,
and selection means for selectively connecting said interlocked
control means to said manually operated switches or to said
automatic programming means.
2. In a blood processing system as claimed in claim 1, the further
improvement comprising,
at least one timing means settable to a plurality of different time
intervals and providing an output signal at the end of the settable
time interval following energization of the timing means,
first circuit means connecting said timing means to said automatic
programming means to energize said timing means at least one
preselected point in the operating cycle of said system, and
second circuit means connecting said timing means to said
interlocked control means to supply output signals to said control
means to thereby initiate the next step in the operating cycle of
said system.
3. In a blood processing system as claimed in claim 3, the further
improvement comprising,
first and second manually-settable motor speed control means for
said centrifuge and said control pump respectively, whereby the
speeds of said centrifuge and said pump may be set individually and
variably by the operator.
4. In a blood processing system as claimed in claim 3, the further
improvement comprising a low voltage power source, and
motor control switching means for selectively connecting the motor
for said centrifuge to said first motor speed control means or to
said low voltage source.
5. In a blood processing system as claimed in claim 3, the further
improvement comprising,
motor speed sensing means connected to the motor of said
centrifuge, and
circuit means governed by said speed sensing means for advancing
the sequence of operation of said system in response to said
centrifuge reaching a predetermined speed.
6. In a blood processing system as claimed in claim 5, the further
improvement comprising,
said speed sensing means comprising a relay selectively connected
to the drive circuit of the motor of said centrifuge during dynamic
braking of said motor.
7. In a blood processing system as claimed in claim 1, the further
improvement comprising,
packed blood cell detection means for detecting the presence of
packed red blood cells in the tubing connected to said blood bag,
and means governed by said detector for advancing the control means
to the next successive mode of operation when and only when packed
red blood cells are detected in said tubing.
8. In a blood processing system as claimed in claim 7, the
improvement comprising,
said packed blood cell detection means comprising means responsive
only to the presence of a predetermined quantity of packed red
blood cells in said tubing for a time interval greater than a
predetermined minimum time interval.
9. In a blood processing system as claimed in claim 1, the
improvement comprising,
status hold means connected to said interlocked control means and
effective to selectively hold said control means in any mode of
operation in which said status hold means is operative.
10. In a blood processing system as claimed in claim 9, the further
improvement comprising,
said status hold means comprising manually operated hold switch
means connected to said control means to maintain it in the status
effective when said hold switch is operated, and manually operated
continue switch means effective to negate said hold switch
means.
11. In a blood processing system as claimed in claim 1, the further
improvement comprising,
a first fluid reservoir for maintaining fluid pressure near
atmospheric pressure in the fluid system during spin operation,
and
a second fluid reservoir to allow the system to accommodate
different size wash solutions at each step in said blood washing
procedure.
Description
FIELD OF THE INVENTION
This invention relates generally to blood processing apparatus, and
in particular, to an improved arrangement for processing previously
frozen blood cell volumes for transfusion.
DESCRIPTION OF THE PRIOR ART
It is known that the time of storage of red blood cells can be
extended by freezing the cells prior to storage and subsequent
thawing, with the addition of an appropriate additive to protect
the cells during these processes. Most of these additives must be
removed from the cells before they are transfused to a recipient.
This washing can be done by washing the cells with various
solutions and resuspending the the cells in the isotonic saline
solutions, albumin, or plasma. The principal deterrent heretofore
to the widespread use of frozen red blood cells is the lack of an
easy-to-use, inexpensive cell washing method with all parts which
come in contact with the blood being disposable and sufficiently
economical that they may be disposed after a single use.
The present invention is an improvement on the configuration shown
in the IBM Technical Disclosure Bulletin for December 1967 at pages
944 and 945, in that a completely designed apparatus, arranged for
either manual or automatic programming is provided by the present
invention.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide an
improved blood processing system, especially for the washing of
preservatives from thawed red blood cells.
A more particular object of the present invention is to provide an
improved blood washing system which is economical in construction
and which utilizes disposable elements for those parts which come
in contact with the blood.
Still another object of the present invention is to provide a blood
washing system which can provide a plurality of different
operations all selectable by the machine operator.
Yet another object of this invention is to provide an improved
blood processing apparatus in which automatic programming of the
various cycles of operation can be utilized.
Still another object of the invention is to provide a blood cell
washing system of the centrifuge type, employing a disposable
centrifuge container.
Other objects of the invention and features of novelty and
advantages thereof will become apparent from the detailed
description to follow taken in connection with the accompanying
drawings.
In practicing this invention a centrifuge container or bowl is
provided, having a vertical shaft, in the upper portion of which a
flexible membrane is provided which can communicate with the
hydraulic reservoir via the hollow core of the centrifuge shaft.
The centrifuge is arranged to be rotated by an electrical motor
arranged so that it can be accelerated, decelerated and
reversed.
Placed within the centrifuge container is a disposable bag
containing the thawed blood volume to be processed, or the thawed
cells may be introduced after the empty disposable bag is placed in
the centrifuge container. A centrally-located rotating seal device
permits fluid to enter or leave the flexible container while the
container is being rotated. By the supply of suitable hydraulic
fluid to the underside of the flexible membrane, the volume of the
blood container can be varied during the washing process. A
plurality of valves are provided for controlling the inlet and
outlet of fluids to and from the blood container, as well as
controlling the flow of hydraulic fluid from the enclosed space
below the flexible membrane, to the fluid reservoir. The hydraulic
fluid is pressurized by a suitable control pump, preferably of the
piston type driven by an appropriate drive mechanism such as, for
example, a rack and pinion motion operated by a suitably controlled
reversible electric motor, whereby the amount and direction of
hydraulic flow can be varied. The apparatus also includes a
plurality of electrical circuits including timing mechanisms which
may be connected by appropriate wiring and switching means to
provide a flexible programming ability so that the operator may
vary the sequence and length of the steps in the washing process.
The sequence and timing may be governed by manually operated
switches, or by automatic sequence control circuits.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a highly-schematic illustration of a blood cell washing
system illustrating the broad principles of the present
invention;
FIG. 2 is an elevational view of the centrifuge bowl and its
supporting shaft elements;
FIG. 3 is a diagrammatic plan view of the apparatus, showing the
top of the centrifuge bowl, and a view of the operator's control
panel as seen from above;
FIG. 4 is a diagrammatic front elevational view, showing the
hydraulic fluid control pump and reservoir, along with certain
components of the electrical control system and illustrating the
placement of the centrifuge and the operator's panel with respect
to this portion of the machine;
FIG. 5 is a diagrammatic elevational view looking from the
right-hand side of the machine, in which further detail of the
hydraulic control pump drive and the centrifuge drive can be
seen;
FIG. 6 is a diagrammatic elevational view of the machine from the
left-hand side, showing the centrifuge drive, the rack and pinion
control pump mechanism, a portion of the hydraulic apparatus and
some components of the electrical power supply;
FIG. 7 is a front elevational view of the operator's control panel,
which includes the pinch-off type of valve mechanisms;
FIG. 8 is a schematic illustration of the motor drive and other
auxiliary circuits in the machine;
FIGS. 9a and 9b, when joined in the manner shown, form a
diagrammatic illustration of a portion of the control circuits for
the machine; and
FIG. 10 is a diagrammatic illustrating of additional control
circuit employed in the machine.
FIG. 11 is a diagrammatic illustration of an interface detector
circuit employed in the machine.
Similar reference characters refer to similar parts in each of the
several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawings, there is shown in highly
schematic form an illustration of a blood cell washing device
showing some of the elements of the present invention.
Centrifuge CC comprises a centrifuge bowl 1, provided with a
suitable cover and having a flexible membrane 7 therein, separating
the bowl into upper and lower portions. The upper portion also
receives a flexible blood cell container, the walls of which are
co-extensive with the flexible membrane and the upper portion of
the centrifuge bowl. This container is connected via a rotating
seal RS to a tubing system which is connected to a plurality of
fluid receptacles, which can contain various types of washing fluid
such as Wash 1, Wash 2, and Wash 3, and also a waste receptacle
designated waste. The blood container can communicate with any one
of these receptacles via separate and independently operable valves
V1, V2, V3 and V4. The space below the flexible membrane 7 is
occupied by a hydraulic fluid which is supplied to the space via
the hollow central core of the centrifuge shaft 9. Also, the
permanent seal PS provides an appropriate sealable connection
between the rotating portion of the centrifuge and the stationary
hydraulic apparatus, which includes the hydraulic control pump HP,
a hydraulic reservoir HR and one or more valves such as the valve
V5. The pump is arranged to be reversible and it will be apparent
that the volume of hydraulic fluid contained within the space
defined by the flexible membrane 7 can be altered by pumping fluid
in or out of the space by suitable operation of the control pump HP
and the valve V5. Accordingly, the effective volume of the
centrifuge chamber can be controllably varied. As indicated in the
drawing, during centrifuging, the blood cells are forced to the
wall of the blood bag or container and the centrifuge wall by a
centrifugal force occurring during rotation of the centrifuge
bowl.
At various times during a complete operating cycle, the wash
solutions may be admitted to the bag via valves V1, V2 or V3, and
supernatant solution may be delivered to the waste receptacle via
the valve V4. The drive mechanism connected to the centrifuge CC is
arranged to either spin the centrifuge head at a constant speed or
to vary the speed and/or direction of rotation of the head in an
agitation cycle.
To wash blood cells, the blood bag is placed in a centrifuge either
already filled with the blood cell-cryopreservative mixture or
filled via the tubing and seal connections. Thereafter the
centrifuge is spun until the cells have settled against the outside
wall. During the spinning operation the valve V5 which connects the
volume under the flexible membrane to the fluid reservoir is open.
When the centrifuge bowl begins to spin, the blood cell mixture in
the flexible container will be pressed against the outside wall of
the centrifuge bowl. This will result in a negative pressure in the
fluid system under the flexible membrane. Therefore, since the
fluid reservoir is connected to atmosphere, fluid will be forced up
into the centrifuge bowl until the bowl is full, at which time the
pressure at the lower rotating seal will be dictated by the
difference in head between the seal and the top of the fluid in the
reservoir. Hydraulic fluid in now pumped into the centrifuge by
means of the control pump HP, the resulting expansion of the
flexible membrane 7 forcing the supernatant solution to flow to the
waste receiver through valve V4, which is open at this time. During
this pumping operation valve V5 is closed. The centrifuge is then
stopped and put into an agitation mode in which it revolves for a
few cycles in alternate directions on a continuing basis and the
wash solution is entered by opening a suitable one of valves V1, V2
and V3 and pumping hydraulic fluid out of the central volume by
means of hydraulic control pump HP. During the agitation mode valve
V5 is again opened. Therefore, fluid may drain from the centrifuge
bowl to the reservoir faster than the hydraulic fluid pump rate.
This process may be continued as many times as desired and the
operation of the entire system is readily and variably controlled
either by manual control or through the internal programming of the
system, to be described in detail subsequently.
Referring now to FIG. 2 of the drawings, there is shown an
elevational view of the centrifuge bowl and its contents, as well
as the supporting structure for the rotating apparatus and the
seals which permit the flow of hydraulic fluid and also of the
blood and was solutions. Reference character 11 denotes the upper
wall and reference character 13 denotes the lower wall of the
flexible blood bag or container shown shown in a nearly-empty
condition within the centrifuge structure. Beneath this bag is the
flexible membrane 15, below which hydraulic fluid is admitted from
openings which communicate with the central core of the centrifuge
shaft. The tubing 17 is connected to the hydraulic pumps and fluid
reservoir via appropriate valves, as will be subsequently
described. The tube 19 leads from the flexible blood bag to a
disposable rotating seal, now shown which provides communication
between the blood bag while in the centrifuge and the various
reservoirs via the valve mechanisms located on the operator's
panel. The centrifuge is covered by a cover 21, which is held on by
any suitable clamping means, such as a plurality of screws using a
combined slot and hole technique for permitting relatively rapid
removal and replacement of the cover. To hold the flexible bag in
place, two or more upstanding bosses 23 are provided, from the
upper surface of the centrifuge central element, and openings or
holes in the blood bag, with their edges appropriately sealed, are
provided to fit down over these bosses or studs. In this manner,
when the cover 21 is then put in place the bag will be retained in
position. A drive pulley, not shown, is located on the lower
portion of the centrifuge shaft, which rides in a bearing assembly
25, and a roller bearing 27 acts as a bearing against lateral or
axial thrust. The drive pulley located on the lower end of the
shaft is belted to a suitable drive motor, by which the entire
centrifuge assembly may be spun at relatively high speeds. The
tubing 17 communicates with the hollow interior of the centrifuge
shaft via the seal connections PS, which provide for a suitable
passage of hydraulic fluid into the interior of the rotating
centrifuge shaft, as previously explained.
FIG. 3 of the drawings is a top plan view of a blood washing
machine in accordance with the present invention. One manner of
attachment of the cover plate to the bowl portion of the centrifuge
is clearly illustrated in this figure, showing the plurality of
hold-down screws, which cooperate with a slot and hole arrangement
in the cover so that the cover may be placed down over the screws,
rotated clockwise to engage the slots, and thereafter the screws
may be fastened to securely hold the cover in place during the
centrifuging operation. The bosses 23, which center and align the
blood container, are shown, as well as the center connection 19,
where the tubing is attached to the blood container. A pair of
sliding transparent doors 27 and 29 are arranged to meet at the
center of the machine with a suitable opening for the connection
19, so that the top of the centrifuge can covered during operation.
The outline of the centrifuge drive motor is shown in dotted lines
in this figure. Also, to be seen in this figure is the top view of
the hydraulic control pump assembly, which is here constituted,
comprises a pair of cylinders 31, with pistons tied by a yoke 33 at
the top end thereof, which in turn is fastened to a rack 35. The
rack is moved up and down by a pinion driven by a motor and gear
assembly 37, so that by suitable circuit control the hydraulic
control pump may be utilized to either force fluid into the
centrifuge bowl or remove it therefrom. Certain of the fittings to
the pump may also be seen in this view.
FIG. 4 of the drawings shows a front elevation view of the machine.
In this view, the relationship between the pump cylinders, piston
rods and the rack drive for the control pump may be clearly seen.
At the top of the rack, as shown in FIG. 4, a limit switch 39 is
provided, which indicates the upper limit of travel of the pump
pistons. This indication is used in the control circuitry to be
subsequently described. FIG. 4 additionally shows the the location
of the hydraulic fluid reservoir 41, as well as certain of the
electrical components. The transformers shown on the lower left
portion of the figure are utilized in the power supplies for the
machine. In the central portion of the figure there is shown a
recessed enclosure containing a plugboard 43, by which varying
operating programs may be arranged at the convenience of the
operator by connecting the various jacks with suitable jumper
wires. A stepping switch 45 is also visible in this figure, this
stepping switch being utilized in conjunction with the plugboard 43
for automatic program control. Reference character 47 designates a
relay mounting gate, which is utilized for mounting the various
relays utilized in the control of the electrical portion of the
machine.
FIGS. 5 and 6 are the right-side and left-side views, respectively,
of the machine. The drive motor 49 for the centrifuge is shown
toward the center of the machine, driving the centrifuge by a
pulley 51 and drive belt 53, which rotates a driven pulley on the
centrifuge shaft. The centrifuge drive motor is provided with
suitable control circuitry which allows the speed and direction of
rotation of the motor to be variably and accurately controlled. The
components shown in the lower portion of FIG. 6 are electronic
elements which are utilized in the power supplies of the machine
and since their actual construction is not germane to the present
invention, they are not described in detail.
OPERATION OF APPARATUS
As already explained, the present invention comprises apparatus for
the washing of preservatives or other materials from a single unit
volume of red blood cells. Under machine control, the cells are
diluted with a wash solution, mixed, and then centrifuged to
separate the wash solution from the cells. The supernatant is then
removed and a new wash solution is entered. This is therefore a
batch-oriented apparatus.
To wash a unit of cells, an empty blood bag is placed in the
centrifuge bowl. The bag is connected to the cell mixture, the wash
solutions and the supernate collect container via a flexible tubing
harness arrangement. The cell mixture is then run into the bag by
gravity. The bowl is next spun at a predetermined velocity, to
provide a predetermined centrifugal force.
The cells sediment to the outside of the bag with the supernatant
(or plasma) collecting at the center. After sufficient
sedimentation, the waste valve is opened and the control pump is
started. This forces the flexible membrane against the bottom of
the blood bag, expelling supernatant. The volume of supernatant
expelled is controlled by the amount of fluid pumped under the
flexible membrane. Centrifuge rotation continues.
The supernatant (or plasma) is pumped to waste (or saved) until the
red cells appear in the fluid line above the rotating seal at the
interface detector. At this point, a first wash cycle starts as
follows: the centrifuge is braked to a low speed. The machine
senses this low speed, the first wash valve opens, the pump
reverses, the bowl goes into an agitate cycle. Since the pump has
been reversed, hydraulic fluid is now being removed from under the
membrane. This in turn allows wash solution to run by gravity into
the blood bag. The 37 agitate" or oscillation of the bowl serves to
mix the cells and the incoming wash solution during this time. When
the first wash solution is in, the machine is ready for another
spin. This process can be repeated for as many cycles as desired.
The cell washer can provide either packed cells or resuspended
cells depending on where the process is stopped.
The operation of the blood cell washer is controlled from a console
on top of the machine, illustrated in FIG. 7 of the drawings. The
various controls and indication lights include:
Power on light 55 -- Indicates the machine power is on.
Ready light 57 -- This light must be on before the machine can be
started. There may be several seconds delay between "power" on and
"ready" on. It indicates that the sliding covers are closed and
that other functions are ready for operation.
Automatic/manual switch 59 -- This two-position switch sets the
machine in either a manual or automatic mode.
Start/spin 61 -- lighted Pushbutton - At the beginning of a machine
run in either automatic or manual, when the READY eight is on and
with the centrifuge stopped, pressing the START/SPIN pushbutton
will cause the machine to go into a SPIN mode. The centrifuge will
rotate at the rate set by the setting on the centrifuge speed
control 63. The SPIN light in pushbutton 61 comes on whenever the
machine is in the SPIN mode. Pressing the START/SPIN switch 61
while in the AGITATE mode will transfer the machine's operation
into the SPIN pushbutton while in the SUPERNATE OUT mode will not
transfer the machine into the SPIN mode. Premature pressing of the
SPIN pushbutton while in AGITATE mode may not allow the full volume
of wash solution to be entered.
Supernate out 65 -- lighted Pushbutton -- Initiation of this
function can occur only from the SPIN mode of operation. If in the
MANUAL mode, transfer into the SUPERNATE OUT mode occurs by
pressing the SUPERNATE OUT button after the cells have sedimented.
In the AUTOMATIC mode, transfer occurs automatically upon time out
of the SPIN mode timers ST1 or ST2; but it can be initiated
manually by pressing the button at any time while in SPIN.
Agitate/wash in 67 -- lighted Pushbutton -- Initiation of this
function can occur only from the SUPERNATE OUT mode of operation.
If in the MANUAL mode, transfer into the AGITATE/WASH IN mode
occurs by pressing the AGITATE/WASH IN pushbutton. In the AUTOMATIC
mode, transfer occurs automatically upon activation of the
end-of-travel switch on the hydraulic pump assembly or detection of
the red cell interface by the photo detect assembly 103 and 107;
but it can be initiated manually by pressing the button at any time
while in SUPERNATE OUT.
Hold 69 -- lighted Pushbutton -- This can be initiated during any
of the machine functions:
a. In MANUAL spin, HOLD does not cause any functional change. In
AUTOMATIC spin, the timers are stopped until the CONTINUE button 71
is pressed.
b. In SUPERNATE OUT, the hydraulic pump is stopped both in MANUAL
and AUTOMATIC modes.
c. In AGITATE/WASH IN, the pump and the agitation are stopped for
both MANUAL and AUTOMATIC modes.
Continue 71 -- Pushbutton -- Initiation of this function switches
the Hold function off and restores the machine to the condition
prior to initiation of hold.
Stop 73 -- lighted Pushbutton -- Initiation of this function is at
the end of a run or if it is desired to halt a run prematurely.
STOP can be activated from any of the operational modes. Initiation
of STOP aborts the run completely. The STOP light ON in pushbutton
73 indicates an abnormal condition. The only time the STOP light
will come on is when either the home position or end-of-travel
switch has failed and the control pump has driven past these
switches to hit the pump over-drive safety switches. When this
occurs, the machine will stop all functions.
Interface detector 103, 107 -- the tubing leading from the rotating
seal RS to the plurality of solenoid valves passes through the
interface detector. This detector determines when the blood cells
are beginning to be pumped out of the flexible container during the
SUPERNATE OUT mode.
Centrifuge speed control 63 -- this controls centrifuge speed.
Pump speed control 75 -- this controls the pumping rate for
SUPERNATE OUT to WASTE. The SUPERNATE OUT pumping rate should not
exceed the gravity fill rate of the WASH SOLUTIONS.
Solution selector switch 37 -- this three-position switch selects
either V1, V2 or V3 solenoid operated valves during AGITATE cycle
in the MANUAL mode of operation. The selected solenoid valve will
energize, opening a path for fluid to flow from the wash solution
containers to the blood bag in the centrifuge. This is inoperative
during AUTOMATIC mode.
The solenoid valves are provided with pinch levers, which extend
outward through the control panel, as shown at the left-hand side
of FIG. 7, and co-acting with a stationary element, selectively
pinch-off tubing threaded through the structure to either permit or
prevent fluid flow. The valves are accordingly, indicated as V1,
V2, V3 and V4 in FIG. 7.
Spin timers st1, st2 -- these timers are only operable in the
AUTOMATIC mode of operation. They control the length of the spins.
Two timers are available. SPIN TIMER ST1 permits spins up to 15
minutes in length. SPIN TIMER ST2 permits spins up to 4 minutes in
length. The programmable plugboard 43 is jumper-wired to select the
desired timer for each SPIN mode cycle.
Programmable plugboard 43 -- the programmable plugboard allows the
operator to specify the order of the wash solutions used and the
length of the spins when in AUTOMATIC operation. The upper half
controls the order of the washes. A jumper wire from the first
column to either of the other three columns indicates which wash
valve will open during that AGITATE/WASH IN cycle. The lower half
of the plugboard indicates which spin timer controls each spin
cycle. If the machine is in MANUAL operation, the condition of the
plugboard is immaterial.
READYING MACHINE FOR OPERATION
To ready the machine for operation, the sliding covers over the
centrifuge well are rolled out of the way and the cover of the
centrifuge is then removed. The bag can then be placed in the bowl.
The two large holes in the bag are placed snugly over the raised
bosses and the edge of the bag is pressed into the bowl as far as
possible. If there are too many wrinkles in the bag, it will not be
possible to put the maximum amount of blood into the bag. The neck
of the bag with the integrally connected seal is then threaded up
through the hole in the center of the cover and the cover is then
replaced. When the plastic covers are closed, they hold the seal in
place. The tubing harness is placed in the valves on the console
and connected to the stem from the bag after removing the cap from
the bag stem. The blood can flow into the bag from a side "tee"
connection or may be connected through the Wash 1 valve. In either
case, this line is opened and the blood allowed to flow into the
bag.
MANUAL OPERATION
All the blood will not enter the bag at first due to air in the
system. Air is purged from the bag by pressing the SPIN button with
the line open to the supply blood bag. As the bowl accelerates, air
will pass from the bag up to the supply blood bag via the tubing
harness. When the air is out of the inlet line, the STOP button is
pressed. After the bowl stops, the remaining blood is allowed to
flow into the bag and then the line is pinched off. If the supply
blood bag is used in the WASH 1 cycle, the line is placed in valve
V1 at this point. If the supply blood bag is not used in this way,
the supply line is merely pinched off.
After the blood has flowed into the machine, the SOLUTION SELECTOR
77 is placed to the appropriate position and the CENTRIFUGE SPEED
CONTROL 63 and the PUMP SPEED CONTROL 75 set to their desired
values. Also, the upper limit switch is set so that the desired
volume of supernatant will be pumped out. The position of the upper
limit switch can be changed by rotating the knob 79. The first SPIN
can then be initiated. After the cells have sedimented
sufficiently, the SUPERNATE OUT button is pressed. The supernate
will continue to flow to waste until the AGITATE/WASH IN button is
pressed or the pump hits the UPPER LIMIT SWITCH or cells are
detected by the INTERFACE DETECTOR. When the supernate has been
removed, the AGITATE/WASH IN button is pressed. One of the wash
solutions (according to the position of the SOLUTION SELECTOR
SWITCH) will flow into the bag until the SPIN is pressed or the
pump hits the lower limit switch. These steps are repeated until
the last SUPERNATE OUT step is completed. At this time, packed
cells are available. If any wash solution is either physiological
saline or plasma, or any other suitable resuspending fluid, then
the packed cells can be reconstituted by turning the SELECTOR
SWITCH to that position and pressing the AGITATE/WASH IN button. To
shut the machine down, the STOP button is pressed. This will stop
the centrifuge and send the pump to the home position. The sliding
covers can then be opened and the centrifuge bowl cover removed.
The tubing harness is disconnected and is removed. The bag is then
removed from the machine and the cells are ready for use.
AUTOMATIC OPERATION
For AUTOMATIC operation, the machine is prepared as described
above. In addition, the programmable plugboard on the front of the
machine is appropriately wired. The SPIN TIMERS ST1 and ST2 must be
set for the desired lengths of spin. Also, the upper limit switch
on the pump is set at the desired waste volume by turning the large
knob 79 on top of the console. Each turn of the knob will alter the
setting by some predetermined amount. Turning this knob clockwise
raises the switch and increases the volume pumped. Counterclockwise
rotation of the knob decreases the volume.
After these settings have been made and the AUTOMATIC/MANUAL switch
has been set to AUTOMATIC, the machine is started by pressing the
START/SPIN button 61. Form this point on, the operation is
automatic. The bowl will spin until the time elapsed is that preset
by the program timer. At this point, the WASTE valve will open and
the pump will start. Supernatant will be pumped to WASTE until the
upper limit switch is operated or cells are reused at the INTERFACE
DETECTOR. At this time, the pump will reverse and the first wash
solution will be allowed to flow into the bag. Also, the bowl
starts agitating thereby mixing the cells with the incoming wash
solution. The AGITATE mode will continue until the lower limit
switch on the pump is tripped at which point the bowl goes into the
second spin. This continues until the last supernatant has been
removed, at which time the machine shuts down.
It should be pointed out that it is possible to go from one mode to
the next ahead of time. For example, the AGITATE/WASH IN button 67
can be pressed while in SUPERNATE OUT mode. The AUTOMATIC cycling
will continue. Also, it is possible to obtain a longer spin by
pressing HOLD button 69. This will stop the timer until the
CONTINUE button 71 is pressed.
Prior to the start of a first run the hydraulic system is checked
for adequate priming, as follows:
a. The CENTRIFUGE SPEED 63 is set to zero.
b. The upper limit switch is adjusted for maximum hydraulic pump
drive travel (full clockwise rotation on the knob) and START/SPIN
button 61 and the SUPERNATE OUT button 65 are depressed.
c. When the pump hits the upper limit switch, the PUMP SPEED 75 is
set to zero and the STOP button 73 is pressed.
d. After the diaphragm is drawn tight against the bottom of the
centrifuge cavity, the PUMP SPEED 75 is set to maximum.
The machine is ready for use when the READY light goes on.
Referring to FIG. 8 of the drawings, there is shown the details of
the power supply circuitry and the motor control circuitry for
control of the pump motor and the centrifuge motor. Power at the
conventional line voltage and frequency is supplied over a pair of
input conductors L1 and L2, and through a main power switch S1,
protected by a line fuse F1, from whence it is distributed to a
plurality of elements each having an associated fuse bearing the
references F2 through F6. The pump motor control circuit includes a
fullwave motor control governed by the pump speed control 75, and
supplying power to the pump motor field and also through a
plurality of braking and reversing contacts to the pump motor
armature. It can be seen that power to the pump motor armature is
governed by the operation of contacts of relay 8R, while the
polarity of the energy supplied to the pump motor is governed by
combinations of contacts on relays 3R, 5R, 6R, and 7R. In these
circuit diagrams, as is the customary practice, the contacts of the
relays are not necessarily shown with their controlling coils, but
the same reference character is applied at or near the contacts as
is applied to the control coil. The detailed operation of the
control and braking contacts will be explained subsequently.
Power for the operation of the various control circuits is obtained
by a conventional 48-volt D.C. power supply, supplying energy to
the terminals designated +48 and COMMON, which will appear at
various points throughout the circuit drawings. A
continuously-running motor which operates cam contacts for
determining the agitation cycles is connected to the power busses
through fuse F5 as shown. The centrifuge motor is connected to a
full-wave motor control governed by the operation of centrifuge
speed control 63, with direction, speed and braking being governed
by contacts of relays HD1, HD2 and HD3. Relays HD2 and HD3 also
serve to connect the winding of a speed sensing relay designated
SSR across the centrifuge motor at specified times.
In general, the sequence of operation of the machine is governed by
a plurality of relays which are governed by circuitry shown in
FIGS. 9a and 9b, arranged in that order from left to right, so that
the corresponding circuit lines match on the drawings, as well as
additional timing and stepping relay circuitry shown in FIG. 10 of
the drawings.
The relay circuitry is generally arranged so that a proper sequence
of steps must be followed either during automatic or manual
operation of the machine, as insured by appropriate logical
interlocking of the control circuits for the various relays
controlling the different modes of operation. It is considered that
the description of these circuits will be enhanced by describing
the operation of this portion of the machine under different
operating conditions.
In readying the machine for operation, the main power on switch
must be turned on to energize the relay power supply, thereby
supplying a 48-volt output from the power supply shown in FIG. 8.
At this time the power on light L1, shown in FIG. 9a, lights. Also,
at this time the ready light L2 will come on assuming that the pump
is in its home position and the sliding covers on the centrifuge
are closed. This action is obtained by the use of relays R1 and
R14. Relay R1 is controlled by contacts on the pump home position
switch SW3, and contact on the end of the travel switch, SW2. With
the stop relay R12 de-energized, a circuit can be traced through
the normally closed contacts of relay R12 and through the home
position switch and the end-of-travel switch to pick the ready
relay R1. With the covers closed, the cover interlocks switches S15
and S16 will be closed and relay R14 will be energized, and with
relay R1 energized, a circuit is established for lighting ready
light L2.
If the pump is not in its home position at the time the main power
switch is on, it will go to the home position, providing the pump
speed control knob is not set at zero. When it does reach the home
position, the home limit switch will close and complete the circuit
to energize relay R1, thereby establishing the ready condition and
turning on the ready light. The machine is now ready for use either
in manual or automatic mode, as determined by the setting of the
manual or automatic switch.
In the manual mode, with the bag in place and the centrifuge cover
locked with the sliding covers closed and locked and the ready
light turned on, the desired centrifuge speed is set on the
centrifuge control. Next, the desired wash solution is selected by
the solution selector switch after which the spin control
pushbutton is operated. This is the only function that can be
activated at this time, as the first step after ready condition,
because all functions are interlocked to only permit sequencing
from start through the supernate out and agitate cycles.
Initiation of the spin by operation of spin pushbutton establishes
a circuit to energize relay R2, which in turn energizes relays HD1
and HD2. When HD2 picks up, the dynamic brake circuit is removed
from the permanent magnet centrifuge drive motor armature circuit.
HD1 establishes the direction of spin and HD2 connects the output
of the motor controller across the centrifuge drive armature, as
shown in FIG. 8. The output of the controller is established by the
setting of the centrifuge speed control knob on the operator's
console. The centrifuge will then start and accelerate up to the
preestablished speed and maintain its speed there until the
SUPERNATE OUT switch or the STOP switch is operated.
Operating the SUPERNATE OUT switch does not alter the centrifuge
spin condition, but does establish a circuit for energizing relay
R3 and thereafter R2 is de-energized or released. With relay R3
picked up, the SUPERNATE OUT mode is established. Relay R3
establishes a holding circuit for itself, and also energizes relay
R10, which in turn is held by its own holding circuit and the fact
that relay R2 has been released. The picking up of relay R3 also
opens the normally closed waste solution solenoid and closes the
normally open hydraulic solution solenoid. The control pump motor
will now start at the speed determined by the pump speed control
knob and motor controller. The direction of operation of the pump
motor is established by relay R6, which was earlier established by
reaching the ready condition. These conditions are now maintained
until either the pump cam trips the end-of-travel switch EOT, or
the agitate/wash function is initiated or the interface detector
senses the presence of red cells. When the end-of-travel switch is
transferred, it will pick relay R6, which stops the pump motor and
releases relay R1. The pick of relay R6 also establishes the proper
direction of pump motor operation for a subsequent cycle.
The energization of relay R10, as indicated previously, establishes
a "not spin" mode. In this mode the centrifuge is still spinning
but is no longer under control of the START/SPIN mode logic
circuitry.
Operating the AGITATE/WASH IN button, energizes relays R4 and R5
through suitable logic function circuits and causes each to hold
through a holding circuit including one of their own normally open
contacts. When relay R4 is picked up, it releases relays HD1 and
HD2. When HD2 releases, dynamic motor braking is effected for the
centrifuge motor. Current flowing in the brake circuit is sensed by
the coil of the speed sense reed relay SSR, shown in FIG. 8. This
will operate the reed relay which in turn energizes relay R11.
Relay R11 will remain picked until the centrifuge speed reaches
some predetermined low level, perhaps a few rpm, as determined by
the armature back emf and the number of turns on the coil of the
speed sense reed relay. When the reed relay opens because of low
brake current, relay R11 is de-energized and drops out. At this
time relay HD3 will be picked through position 1-2 contact of the
agitate control timer. Relay HD3 will establish a holding circuit
through one of its own normally open contacts and supplies energy
from the 48-volt power supply to the centrifuge motor circuit via
the direction reversing contacts HD1. At this time relay HD1 will
be alternately picked up and released by the closing and opening of
a cam-operated contact on the agitate control timer position 1-1.
When the relay R11 was released, it also opened one of the wash
solution solenoids. The particular wash solution selected is
determined by positioning of the manual wash solution selector
switch. These solenoids are energized through an RC network
allowing the solenoid to pick at a value close to 48 volts, but
holding through the dropping resistor at approximately 20 volts.
The cycling of relay HD1 will cause the centrifuge to oscillate to
thereby agitate the solution in the blood bag.
All of the cycles described above, that is the START/SPIN,
SUPERNATE OUT, and AGITATE/WASH IN can now be repeated, or the
operation can be halted by operating the STOP pushbutton. If the
STOP pushbutton is operated, relay R12 is picked, which removes
power from all relays. Relay R12 only remains energized as long as
the STOP switch is operated. Releasing of relay HD2 applies the
dynamic braking circuit to the centrifuge motor while the release
of relays R3 and R5 stop the pump motor, close the waste and wash
solenoids and open the hydraulic drain valve. When the STOP
pushbutton is released, relay R12 is de-energized and released. The
normally closed point of relay R12 applies 48 volts to the pump
home position switch to the end-of-travel switch and to a set of
normally closed points on relay R1. If relay R1 is not operated,
which means the pump is not in the home position, the normally
closed relay R1 point will supply the energy to relay R7, causing
the pump to return to the home position. The various controls
except hold are inoperative until the pump reaches the home
position. When this position is reached, the home pump switch is
operated and energizes relay R1, which lights the ready light, as
previously explained and releases relay R7. At this time the
machine is now ready for use again.
The hold condition can be initiated at any time, but its action
will be different depending upon the particular mode of machine
operation. If the machine is in the SPIN mode, there is no visual
change in the machine operation except that relay R8 is energized.
Under these conditions the operator cannot proceed to another step
except by operating the button CONTINUE, which will drop out relay
R8. If the machine is in the SUPERNATE OUT mode, operation of the
HOLD button stops the pump by picking relay R8, which removes power
from the pump motor. Other functions will continue, and if the
CONTINUE pushbutton is operated at this time, the machine will
proceed in the SUPERNATE OUT mode. If the machine is in the AGITATE
mode, operation of the HOLD switch will again stop the pump as a
result of relay R8 picking. Relay R9 picks when relay R8 holds.
This removes power from the agitate control timer and the hold
circuit of HD3. Taken together, these two events will stop the
centrifuge agitation operation.
Under normal routine operating conditions the stop light L7 does
not light. However, in the event of failure of the home limit
switch and/or the end-of-travel switch on the hydraulic pump,
emergency stop switches S12 and/or S13, which are located at the
extreme ends of upper and lower travel of the pump piston, act to
light the stop light and also to pick relay R12, thus, causing the
machine to stop. Under these conditions the machine can only be
restored to normal operation by manually turning the shaft of the
pump motor by hand to move the pump piston shaft away from the
emergency stop switches. At this time, of course, it would be
necessary to check for and eliminate the cause of the
overtravel.
To operate the machine in the AUTOMATIC mode, the timers ST1 and
ST2 on the operator's console are set, the plugboard is
appropriately wired and the automatic manual switch is placed in
the automatic position whereupon the machine ready light is
lighted. The automatic manual switch in the automatic position
causes relay R13 to pick up, which in turn causes the motors and
pilot lights of the timers ST1 and ST2 to be energized. The stepper
switch S17 has been kept in the home position by relay R13, which
energizes the step per reset magnet. At this time pushing the
START/SPIN button will cause the same circuit action as encountered
in the MANUAL mode. Also, it will cause the stepper switch to step
one position from its home position to step 1. Upon reaching the
step 1 position, the clutch of the plugboard program spin timer is
energized which starts the time spin interval. The machine remains
in the SPIN mode until the timer reaches the end of its preset
travel. At the end of that interval that contacts in the timer
operate which result in energizing relay R3, which starts the
SUPERNATE OUT cycle. Energization and picking of relay R3 releases
relay R2, which then resets the spin timer.
SUPERNATE OUT circuit conditions are the same as those encountered
during manual operation and this cycle continues until the pump
reaches the end-of-travel switch or the packed red blood cells pass
the interface detector to be subsequently described. Assuming that
the end-of-travel operation occurs first, the end-of-travel switch
will energize relay R6 and relay R6 energizes relay R4 which
establishes the AGITATE mode of operation. It should be noted that
in automatic operation the solution selector switch is not
operative and the wash solution is instead under control of the
stepper switch. With the stepper switch at position 1, the end of
speed sense reed relay will transfer and drop relay R11 thereby
applying 48 volts through relay R5 to the selective wash solenoid.
The machine will remain in the AGITATE mode until the pump reaches
its home position at which time activation of the home limit switch
will energize relay R1. Relay R1 will energize relay R2 and this
relay establishes the SPIN mode and steps the stepper switch to
position 2. Subsequent events are the same as those described above
until the stepper switch reaches the programmed stop position. If a
stop is not programmed by suitable wiring on the plugboard, the
stepper will continue to advance to the final step or step 10 and
then will stop at the end of the next speed sense relay
operation.
A programmed stop routes the signal that otherwise would be going
to one of the wash solenoids to a pick up circuit for relay R12.
When R12 picks up the machine is stopped. Relay R12 also activates
the stepper reset solenoid resetting the stepper to home and
finishing one complete sequence.
The HOLD condition can be initiated during any step in the
AUTOMATIC cycle. During spin, the HOLD circuit will stop the spin
timer while the rest of the action is as described previously for
manual operation. With the timer stopped, the machine will remain
in spin until the CONTINUE button is pressed. This will restart the
timer and the machine sequence will continue. In the SUPERNATE OUT
mode, the HOLD condition acts exactly the same as in manual
operation. With the pump stopped, however, the machine will remain
in the SUPERNATE OUT mode because the pump cannot activate the
end-of-travel switch or interface detector. Pressing the CONTINUE
button will start the pump again. During the AGITATE mode, the
operation of the HOLD button will act as described for manual
operation again because the hydraulic pump stops and can be
restarted by operation of the CONTINUE button.
The safety interlock circuit includes two magnetically-operated
reed switches under the rear of the sliding covers over the
centrifuge well. This is to assure that the covers are closed
before the centrifuge can rotate. With the covers open, the reed
switches are open and relay R14 is de-energized. Under these
conditions the power is interrupted to the ready light and to the
START/SPIN switch. When the covers are closed, relay R14 is
energized, the ready light is lighted and the START/SPIN switch is
powered. If during operation of the machine the covers are
accidentally opened, relay R14 drops and momentarily picks relay
R12 through the action of a charge stored on a large capacitor Q1.
The momentary picking of relay R12 will initiate a stop operation
and force the machine to stop.
It may be noted in FIG. 9a that relay R4 may be energized to
initiate an AGITATE mode by the energization of a relay IFR. This
relay is governed by the circuitry shown in FIG. 11 of the
drawings. Referring to FIG. 11, the reference character 101
indicates the transparent flexible tubing which carries the blood
cells and supernatant to and from the blood bag in the centrifuge.
At a suitable location with respect to the blood bag and
centrifuge, a light source 103 with a sensitivity control of 105 is
positioned on one side of the tube, and a suitable photocell or
light detector 107 is located opposite the light source and
arranged so that packed red blood cells pass between the light
source and photocell. Interruption of the light path will cause a
signal to be supplied from the photocell 107. The photocell
spectral response is chose to allow the detection of the packed red
blood cell interface which is in the vicinity of 7,000 to 7,500
angstroms. This particular response area was arrived at by a
spectrophotometer testing of plasma, packed red blood cells and
hemolyzed samples of blood. The output of the photocell is supplied
to an emitter follower stage 109 for the purpose of impedance
matching, and thence to inverter 111. From the output of inverter
111, the signal is supplied to a second inverter 113 and the input
of a single shot 115. The purpose of the single shot is to compare,
at the input of the next following stage which constitutes an
and-invert circuit 117, at the end of the single shot time-out the
single shot output and signal through the inverter. If the signals
are the same, then the circuit 17 will supply an output to a relay
driver circuit 119 which in turn will energize the winding of relay
IFR. If the signals are different at the inputs to circuit 117,
then no signal is fed to the reed relay driver. Accordingly, the
circuit blanks out the effect of small slugs or packed red blood
cells which interrupt the light to the photocell and prevents these
minor interruptions from energizing the relay IFR and advancing the
machine to AGITATE mode. Only when a relatively continuous amount
of packed red blood cells interrupt the light beam, for a period
longer than the time out period of the single shot, will the relay
IFR be operated.
From the foregoing, it will be apparent that the present invention
provides a highly improved, compact blood processing system for
processing blood portions which have been frozen so as to remove
the glycerol or other agents preparatory to use of blood in
transfusions. The system is arranged so that it cannot only be
manually operated, but by suitable programming may be run
automatically. Various safety features are provided which insure
the proper operation of the equipment to safeguard the operation,
as well as to insure the proper sequencing in the processing of the
blood.
While the invention has been particularly shown and described with
reference to a preferred embodiment thereof, it will be understood
by those skilled in the art that the foregoing and other changes in
form and details may be made therein without departing from the
spirit and scope of the invention.
* * * * *