U.S. patent number 3,896,733 [Application Number 05/407,720] was granted by the patent office on 1975-07-29 for autotransfusion apparatus.
This patent grant is currently assigned to Pall Corporation. Invention is credited to David J. Rosenberg.
United States Patent |
3,896,733 |
Rosenberg |
July 29, 1975 |
Autotransfusion apparatus
Abstract
A continuous-flow two-reservoir fluid medicament- or blood-feed
system is provided, for administration of such fluids to patients,
composed of two reservoirs, each filled by way of check valves from
a common supply, and with common connections to a vacuum line.
Application of vacuum draws the fluid from the supply into one of
the reservoirs, while fluid is led from the other reservoir to the
patient. When the first reservoir is full and the other empty,
fluid is led from the filled reservoir, and the other empty
reservoir is now refilled, while fluid flow to the patient can be
continuous.
Inventors: |
Rosenberg; David J. (Glen Cove,
NY) |
Assignee: |
Pall Corporation (Glen Cove,
NY)
|
Family
ID: |
23613252 |
Appl.
No.: |
05/407,720 |
Filed: |
October 18, 1973 |
Current U.S.
Class: |
604/6.1; 210/446;
604/9 |
Current CPC
Class: |
A61M
1/02 (20130101); A61M 5/40 (20130101) |
Current International
Class: |
A61M
1/02 (20060101); A61M 5/40 (20060101); A61M
5/36 (20060101); A61m 005/00 (); A61m 001/03 () |
Field of
Search: |
;128/214R,214C,214.2,276,278 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Truluck; Dalton L.
Claims
Having regard to the foregoing disclosure, the following is claimed
as the inventive and patentable embodiments thereof:
1. An autotransfusion apparatus shaving two chambers with
simplified control of the cycling of the flow of fluid between the
chambers and safeguards to prevent cross-flow between the chambers
and passage of air to a patient from an empty chamber, comprising,
in combination, first and second fluid chambers each having a fluid
inlet, a fluid outlet, a line connection to a source of vacuum, and
a vent connection to atmospheric pressure; the vent being provided
with a flow-resistant filter having a pore size such that bacteria
cannot pass through it, and restricting flow into the chamber from
the atmosphere so that a vacuum can be drawn on the chamber without
closing the vent, while allowing the chamber to reach equilibrium
with atmospheric pressure when vacuum is not applied; the filter
not being wetted by the liquid in the system so as not to accept
blood or other medicament in its pores and thus block the passage
of air therethrough; a check valve at the fluid inlet restricting
flow through the inlet line to flow towards the chamber at fluid
pressures within the chamber below the pressure in the inlet line;
and means for alternately opening and closing the vacuum line to
each chamber, so that when the vacuum line is open to the first
chamber it is closed to the second; and when the vacuum line is
closed to the first chamber, it is open to the second.
2. An autotransfusion apparatus according to claim 1, having a
check valve at the fluid outlet, restricting fluid flow through the
outlet except at a higher upstream fluid pressure.
3. An autotransfusion apparatus according to claim 1, having a vent
in each chamber that is open to the atmosphere at all times.
4. An autotransfusion apparatus according to claim 1, in which the
flow-resistant filter has a pore size of less than 3 microns and an
open area less than 5%.
5. An autotransfusion apparatus according to claim 1, having two
chambers with simplified control of the foaming of fluid entering
the chambers in which the fluid inlet directs flow to impinge upon
a wall of the chamber; so as to flow in a thin film down the wall,
and afford an extended surface area for defoaming.
6. An autotransfusion apparatus according to claim 5, having a
deflector at the inlet end of the fluid inlet.
7. An autotransfusion apparatus according to claim 6 in which the
deflector is a turned end of the inlet tube.
8. An autotransfusion apparatus according to claim 5 in which the
inlet tube outlet is directed towards a wall of the chamber.
9. An autotransfusion apparatus according to claim 1, having two
chambers with simplified prevention of the passage of air to a
patient from an empty chamber, comprising, a float valve in each
chamber, moving on and with the fluid level in the chamber, and a
valve seat at the bottom of the chamber, so that when the fluid
level sinks to the level of the valve seat, the float valve sinks
into sealing engagement with the valve seat, and closes off the
fluid outlet from the chamber, preventing air from entering the
outlet.
10. An autotransfusion apparatus according to claim 9 in which the
float valve is a disc, which is free in the chamber, and is light
enough to float on the surface of the fluid, and is provided with a
resilient peripheral ring which seals against a valve seat on its
lower surface, and an annular valve seat surrounding the outlet,
against which the ring seals.
11. An autotransfusion apparatus according to claim 9 in which, at
the outlet from each chamber, below the valve seat, a coarse filter
is provided, to prevent obstruction of the outlet line.
12. An autotransfusion apparatus according to claim 11 in which the
coarse filter is a nonwoven plastic fiber cloth.
13. An autotransfusion apparatus having two chambers with
simplified control of the cycling of the flow of fluid between the
chambers and safeguards to prevent cross-flow between the chambers
and passage of air to a patient from an empty chamber, comprising,
in combination, first and second fluid chambers each having a fluid
inlet, a fluid outlet, a line connection to a source of vacuum, and
a vent connection to atmospheric pressure provided with a
flow-resistant filter having a pore size such that bacteria cannot
pass through it; a check valve at the fluid inlet in each chamber,
restricting flow through the inlet line to flow towards the chamber
at fluid pressures within the chamber below the pressure in the
inlet line; the fluid inlet directing inlet flow to impringe upon a
wall of the chamber, so as to flow in a thin film down the wall,
and afford an extended surface area for defoaming; a float valve in
each chamber, moving on and with the fluid level in the chamber,
and a valve seat at the bottom of the chamber, so that when the
fluid level sinks to the level of the valve seat, the float valve
sinks into sealing engagement with the valve seat, and closes off
the fluid outlet from the chamber, preventing air from entering the
outlet; and means for alternately opening and closing the vacuum
line to each chamber, in synchronization, so that when the vacuum
line is open to the first chamber it is closed to the second; and
when the vacuum line is closed to the first chamber, it is open to
the second.
14. An autotransfusion apparatus according to claim 13, in which
each chamber has a check valve at the fluid outlet, restricting
fluid flow through the outlet except at a higher upstream fluid
pressure.
15. An autotransfusion apparatus according to claim 13, in which
each chamber and float valve are shaped so as to guide the float
valve into sealing engagement with the valve seat.
Description
During surgery, the surgeon has the choice of discarding the blood
removed from the patient in the course of the operation and
replacing it by donor blood, or of salvaging and reinfusing the
patient's own blood. The former technique is generally referred to
as blood transfusion, although in fact the term is generic to both
cases, while the salvaging and reuse of the patient's own blood is
referred to as autotransfusion.
In many cases, of course, autotransfusion is not applicable, and
donated blood must be used. If available, however, autotransfusion
has a number of advantages. The blood used needs no time-consuming
typing or cross-matching. It is inexpensive, warm and fresh, and
contains prime factors and bactericidal properties which are absent
in banked donor blood. Moreover, blood lost in hemorrhages during
surgery can also be collected and reinfused, which practically
eliminates hemorrhaging as a dangerous problem in the course of
surgery. In addition, there are virtually no fatal reactions, and
nonfatal reactions are noted in only a small percentage of
cases.
According to Dyer, (Amer. J. of Surgery, Vol. 112, Dec. 1966,
874-878), the intraoperative autotransfusion technique originated
in 1874, when Highmore surmised, after seeing a patient become
exsanguinated after a postpartum hemorrhage, that he might have
been able to save the patient if he could have collected,
defibrinated, and reinfused the blood.
In 1885, Duncan employed intraoperative autotransfusion on a
patient with a traumatic leg amputation, and was successful. Later,
techniques were developed using mopping, lading, bulb suction and
line suction to collect the blood, with citrate or hemodilution as
an anticoagulant, and cheesecloth and fine gauze as a filter. The
blood was processed in rooms adjacent surgery, and returned for
reinfusion. These techniques were remarkably successful, and
interest in autotransfusion increased as a result during the period
from 1914 to the early 1940s.
However, during the period since World War II, interest in
autotransfusion decreased as the use of donor blood transfusions
increased, possibly assisted by ready availability of donated
blood.
In 1951, Stager ["Blood Conservation by Autotransfusion," Arch,
Surg. 63, 78 (1951)] and later, Weekes, Stone and McCann ["A Plea
for Autotransfusion," U. Obst. & Gynaec. Brit. Emp. 16, 7
(1960)] advocated a closed system of autotransfusion, using an
improvised setup incorporating a conventional donor transfusion
bottle into a tonsil suction system. Blood foaming, introduced by
suction, was minimized by floating glass balls which served to
catch fibrin. Although there was some hemolysis caused by vacuum,
this was well tolerated in the tests carried out by Stager.
Ferrara ["Autotransfusion, Its Use in Acute Hemothorax," South. M.
J., 50, 516 (1957)] reported successful closed autotransfusion in
acute hemothorax and hemoperitoneum via trocar thoracostomy and
peritoneal tap. According to Lamm ["Emergency Autotransfusion
Before Laparotomy," J.A.M.A. 185, 1043 (1965)] autotransfusion is
also being used in coronary sinus suction in cardiac bypass.
One of the difficulties in the application of autotransfusion
techniques has been the lack of suitable apparatus. Dyer, in his
article in the American Journal of Surgery referred to above, set
forth the standards and criteria for autotransfusion apparatus:
"Unquestionably, an available means of emergency, intraoperative
autotransfusion for general use would be a timely asset to the
patient, surgeon, and hospital. Such an apparatus must meet certain
standards and criteria before it would be used.
An autotransfusion apparatus must simultaneously collect, measure,
and process blood from a body cavity without disturbing the
surgical field; it must work simply, rapidly, and safely to
anticoagulate, defoam, defat, filter, and redeliver the blood. It
must be capable of handling large as well as small volumes for the
entire procedure.
The apparatus must be simple, safe, and inexpensive and should be
compact, easily stored, and unbreakable. It must be able to be set
up for use immediately, well in advance of procurement of available
donor blood. It should cause no more hemolysis than is found when
administering donor blood form a bank.
The apparatus should be a closed system, available in any operating
room for use by regular operating room personnel."
In an endeavor to meet these requirements, Dyer proposed in the
article and in U.S. Pat. No. 3,492,991, patented Feb. 3, 1970, an
autotransfusion apparatus based on one or two chambers of a
capacity from 600 to 1,000 ml. The chambers are cylindrical, with
both ends closed off by rubber or plastic seals. The upper plug is
provided with a minimum of three ports, a first to apply vacuum to
the container, a second to provide an inlet for blood from the
operative field or source of blood, and a third open to the
atmosphere to permit emptying of the chamber of blood. To prevent
foaming of the blood, the inner surface of the chamber is coated
with an antifoaming agent, or the chamber can also be filled or
partially filled with a coarse metal or plastic wool,
surface-treated with silicone. A fine wire screen is placed over
the exit port of each chamber to act as a filter to remove fibrin
or other debris from the blood. Another filter is provided in
blood-recipient apparatus connected to the outflow.
In the two-chamber system shown in FIG. 3 of the article and in
FIG. 3 of the patent, a dual tubing system connects the two
chambers to the vacuum line, the blood suction line, and the
medication line, and surgical clamps or other conventional clamping
means are used for closing the lines in a manner to permit the
chambers to be used alternately, so that blood is delivered from
one chamber while the other is being filled.
The two-chamber apparatus has certain advantages over the single
chamber. In the single chamber, it is difficult to add measured
amounts per unit volume of anticoagulant or other medicament to the
blood. It is also difficult to measure the amount of blood
delivered, except by shutting off the unit when it has been
emptied, and then refilling it, which of course interrupts the flow
of blood during the refilling.
In the two-chamber system, these problems are avoided since one
chamber can be on-stream while the other is being filled, and the
amount of anticoagulant is easily measured according to the volume
of blood in the container before the chamber is put on-stream.
However, the two-chamber system also presents problems. It is
necessary to close off all lines not on-stream, to prevent
cross-flow between the chambers during application of vacuum to one
chamber. All of the valves are manually operated, and their
operation has to be carefully synchronized, so as to maintain flow,
and prevent flow of air to the patient when the chamber on-stream
becomes empty. The system thus requires continuous attention.
During an operation, it is not always certain that attention can be
given to the apparatus at the time when it is required, which is
precisely when the chamber on-stream is empty, not sooner, and not
later.
In accordance with the invention, an improved autotransfusion
apparatus is provided, having two chambers, with simplified control
of the cycling of the flow of fluid between the chambers, and
safeguards to prevent cross-flow between the chambers, and passage
of air to a patient from an empty chamber. As soon as one chamber
is empty, influent fluid flow can be switched to the empty chamber,
while the previously filled chamber is put on-stream, without
danger of drawing air from the chamber that is filled into the
chamber being filled. When this chamber on-stream is empty, the
filled chamber is put on-stream, and so the chambers are cycled
alternately, to maintain a continuous flow of blood from the
apparatus. The apparatus also includes a device for controlling and
inhibiting foaming during entry of fluid into each chamber.
The apparatus in accordance with the invention comprises, in
combination, first and second fluid chambers each having a fluid
inlet, a fluid outlet, a line connection to a source of vacuum, and
a vent connection to atmospheric pressure; a check valve at the
fluid inlet restricting flow through the inlet line to flow towards
the chamber at fluid pressures within the chamber below the
pressure in the inlet line; optionally, a check valve at the fluid
outlet, restricting fluid flow through the outlet except at a
higher downstream fluid pressure, a vent in each chamber that is
open to the atmosphere at all times; and means for alternately
opening and closing the vacuum line to each chamber, in
synchronization, so that when the vacuum line is open to the first
chamber it is closed to the second; and when the vacuum line is
closed to the first chamber, it is open to the second.
The vent in each chamber is preferably provided with a
flow-resistant filter having a pore size such that bacteria cannot
pass through it, restricting flow into the chamber from the
atmosphere so that a vacuum can be drawn on the chamber without
closing the vent. Thus, the vent is open so the atmosphere at all
times, and allows the chamber to reach equilibrium with atmospheric
pressure when vacuum is not applied.
A suitable flow-resistant filter is glass cloth coated with
polytetrafluoroethylene and adhered to a paper base, having a pore
size of less than 3 microns and an open area less than 5%, but any
porous material of comparable pore size and open area can be
used.
The filter can be made hydrophobic or nonwetted by the liquid in
the system so as not to accept blood or other medicament in its
pores and thus block the passage of air therethrough.
The fluid is provided with a deflector directing inlet flow to
impinge upon a wall of the chamber, so as to flow in a thin film
down the wall, and afford an extended surface area for defoaming,
thereby avoiding the need for a defoaming agent. The deflector can
take the form of a turned end of the inlet tube, or the inlet tube
outlet can be directed towards a wall of the chamber, and can be
specially shaped to provide a wide thin film of fluid flowing along
the wall.
The apparatus also includes, in each chamber, a float valve, which
moves on and with the fluid level in the chamber, and when the
fluid level sinks to the level of the valve seat at the bottom of
the chamber, the float valve sinks into sealing engagement with the
valve seat, and closes off the fluid outlet from the chamber. This
prevents air from entering the outlet line leading to the
patient.
The float valve can take the form of a disc, which is free in the
chamber, and is light enough to float on the surface of the fluid.
The disc can be provided with a resilient peripheral ring which
seals flat on its lower surface against an annular valve seat
surrounding the outlet. A suitable material is a polypropylene or
other low density plastic with a rubber sealing ring about its
periphery.
At the outlet from each chamber, below the valve seat, a coarse
filter is provided, to prevent obstruction of the outlet line. A
nonwoven plastic fiber cloth can be used, such as a bonded glass,
nylon or polyester fiber mat.
The means for alternately closing and opening the vacuum lines to
the chamber in synchronization can be manually operated, such as
clamps or valves, but for fully automatic operation, such means is
operated by a photoelectric level detector or a float in each
chamber, actuating the means when the chamber is empty, to switch
the cycle so that the filled chamber is put on-stream and the empty
chamber is put on the filling cycle .
A preferred embodiment of the invention is shown in the drawings,
in which:
FIG. 1 is a top view of an autotransfusion apparatus.
FIG. 2 is a side view, partly in section, taken along the line 2--2
of FIG. 1.
FIG. 3 is another side view, partly in section, taken along the
line 3--3 of the autotransfusion apparatus of FIG. 1.
FIG. 4 is a detailed view of the vent and filter combination
encircled in dashed lines in FIG. 2.
The apparatus shown in the Figures comprises two thermoplastic
blood reservoirs 1 and 2 of polycarbonate, each in upper 3, 4 and
lower 5, 6 sections, fused together at the seam 7, 8. Each
reservoir is connected to a source of blood 9 by way of fluid lines
11, 12, 13, entering the top of blood reservoirs 1, 2 at inlets 14,
each of which is provided with and terminates in a deflector 18
directing blood flow against the wall of the upper sections 3, 4 of
the reservoirs. The reservoirs are also connected at their tops at
outlets 19, 20 to a source of vacuum 21 by way of lines 22, 23, 24,
with two clamps 15, 17 controlling the application of vacuum to one
reservoir at a time; or completely closing off both reservoirs from
the vacuum, as desired. One three-way clamp can also be used
instead of clamps 15, 17. The clamps are arranged to be operated
manually, but operation can also be controlled by an automatic
mechanism.
Each reservoir at the top is further provided with a vent 27, 28
which is in the form of a male Luer tip, and is open to the
atmosphere. The vents are each provided with a filter 29, 30 (best
seen in FIG. 4) which restricts flow into the reservoirs from the
open atmosphere, to permit maintaining a partial vacuum in the
reservoir. The vents also allow the reservoirs to reach atmospheric
pressure when vacuum is not applied, such as when the reservoir is
discharging blood or other fluid to the patient.
Also provided at the top of each reservoir is a medicament inlet
31, 32, with a female Luer socket for addition of anticoagulant or
other composition to the contents of the reservoir. Each inlet is
closed by cap 33, 34, when not in use.
There is also an integral eye 35, 36 on each reservoir, which
receives the hooks 37, 38 for suspending the reservoirs from an IV
stand 39.
Within each reservoir is a float valve 40, 41, which floats freely
on the surface of the fluid in the reservoir. At the bottom of each
reservoir is a valve seat 42, 43 and about the external periphery
of the float valve, which is a disc of polypropylene or other low
density plastic, is a sealing ring 44, 45 of resilient material
such as rubber. This seals at its lower surface against the valve
seat 42, 43, to close off the outlets 46, 47. Across the outlet
line below the valve seat is a filter 48, 49, which is supported on
a recess 51, 52 and on a plurality of ribs 53, 54 projecting
upwardly from the bottom wall of lower section 5, 6 and radially
about the outlets 46, 47. The filters 48, 49 are nonwoven mats of
polyester fiber.
Extending from the outlets 46, 47 are outlet lines 55, 56 each of
which is provided with a manually operated clamp 57, 58, but check
valves such as duckbill valves can be provided instead. A three-way
clamp can also be used, and can be automatically operated, if
desired. The lines 55, 56 join into line 59, which leads to a
further filter 61, such as a filter for microemboli, in the case of
blood. From the filter, the line 62 leads to the patient, by way of
standard administration set.
Operation of the device is as follows. Let it be supposed that
reservoir 1 is empty, and reservoir 2 filled. (In the Figures,
reservoir 1 is being filled, and reservoir 2 is being emptied, so
that the apparatus as shown is shortly beyond this point in time.)
Anticoagulant first is added through the inlet 31 into reservoir 1,
and the cap 33 is replaced. Then, clamp 15 is opened and clamp 17
is closed, so that vacuum is applied to reservoir 1 but not to
reservoir 2. Clamp 57 is closed, while clamp 58 is opened, so that
under a head of pressure of blood in reservoir 2, the blood flows
by gravity from the bottom of the reservoir through filter 49 and
outlet 47 via lines 56, 59 to the filter 61, and then through line
62, to the patient or other reference point to which blood is to be
supplied. The vent 28 is always open, permitting such flow freely;
and since the vent is protected by the bacteria filter 30, the
interior of the reservoir 2 remains sterile.
Meanwhile, vacuum from the source 21 is applied to reservoir 1 so
that blood is drawn from the supply 9 through lines 11 and 12, and
duckbill valve 16 and deflector 18 into the reservoir. The blood is
projected against the wall of the upper section 3, and courses down
the wall in a thin film allowing the foam to break and the air to
escape. The filling operation continues until the reservoir
contains one unit of blood. As the blood level rises in the
reservoir, the float valve 40, which has already been dislodged by
the application of vacuum, rises, and opens the outlet 46, but the
clamp 57 is closed, so flow from the reservoir cannot begin. Then,
the clamp 15 is closed so as to close off the application of vacuum
to the reservoir. If reservoir 2 is still not empty, the clamp 57
can remain closed until it is. When reservoir 2 is empty, the clamp
17 is opened so as to apply vacuum to reservoir 2 and the clamp 57
is opened so that the feed of blood begins from reservoir 1. Clamp
58 is closed. Now blood is drawn from the supply 9 through lines 11
and 13 into reservoir 2. This continues with the blood feed
continuing from reservoir 1 through outlet 46, lines 55 and 59 to
filter 61 to the patient. When reservoir 2 is filled, the clamp 17
is closed and clamp 15 is opened so as to put reservoir 1 on-stream
as before, and the cycle is then repeated. Throughtout the cycle,
however, blood has been continuously supplied to filter 61 and
lines 62.
If desired, by automatic operation of the clamps 15, 17, 57 and 58,
the device can be made entirely automatic with a continuous blood
flow to the patient.
The device shown is most useful for the continuous supply of blood
either in transfusion or in operations in which blood circulation
systems are used. The device can also be employed for the
administration of any kind of medicament to a patient from a source
of supply, and ensures continuous administration of the medicament
while the supply remains filled.
If desired, the filter 61 in line 59 can be replaced by two filters
which are placed in lines 55, 56, before the point of junction with
line 59. In this event, the clamps 57, 58 would follow the filters,
rather than precede it, as in the device shown.
While the check valves shown in the drawing are of the duckbill
type, any type of check valve can be used, including unbrella
valves, flap valves, and poppet valves.
* * * * *