вход по аккаунту


Патент USA US3070102

код для вставки
Dec. 25, 1962
Filed Dec. 4. 1957
2 Sheets-Sheet 1
Jul/1v AZ” Wmw
Dec. 25, 1962
Filed Dec. 4, 1957
2 Sheets-Sheet 2
Jbmv J.‘ Wu.»
M M424
United States Patent O??ce
Patented Dec. 25, 1962
respect to the composition of gases, water vapor content,
gas tension and the like.
Still another object of the invention is to provide an
apparatus and method for blood oxygenation which pro
.lohn Julian Wild, 829 10th Ave. SlL, Minneapolis, Minn,
and H. W. Heupel, Christophstrasse 79, Dusseldorf,
vides a ?ltering action to remove clotted blood, foreign
debris, air bubbles and the like.
With these and still additional objects in view the inven
Filed Dec. 4, 1957, Ser. No. 700,657
4 Ciaiins. ((11. 1213-4214)
tion broadly comprises the method of oxygenating blood
by ?lming the blood through a highly porous sponge
This invention relates to the arti?cial oxygenation of 10 material which has been pre-saturated with plasma and
simultaneously passing oxygen through the material. The
blood, a medical practice carried on primarily during
cardiac surgery.
As early as 1882, physiologists were able to oxygenate
invention here concerned also includes the ?lming surface
itself and an apparatus for carrying out the process. This
blood arti?cially. The development of thoracic surgery
apparatus generally comprises a battery of thin leaves of
and controlable coagulation, combined with recent avail
ability of a wide choice of synthetic materials, have
stimulated surgical attempts at open cardiac procedures
sponge material alternately separated by separators with
the battery mounted within a sealed container so that the
sponge leaves are supported vertically. The container
has blood inlet and outlet connections and oxygen inlet
and outlet connections for passing blood and oxygen
with arti?cial extracorporeal circulation, bypassing the
heart and lungs. The development of oxygenators for
clinical use has proven to be a difficult problem. This is 20 simultaneously through the sponge leaves.
The above mentioned and still additional objects of the
invention will be brought to light during the course of the
following speci?cation, reference being made to the ac
partially due to the fact that respiratory gas exchange is
only one function of the human lung. Another important
function is the ?ltration of emboli to safeguard delicate
organs in the systemic circulation.
Three basic successful principles of oxygenation have
emerged from past efforts. They are (1) membrane
diffusion oxygenation; (2) bubble oxygenation; and (3)
companying drawings, in which
FIG. 1 is an exploded view of the apparatus for carry
ing out the blood oxygenation process.
FIG. 2 is a side elevation of the oxygenator in as
sembled operating condition and with a side wall of the
?lm oxygenation. The present invention is concerned with
?lm oxygenation, as it is felt that this principle can more
safely and more practically be adapted to use in surgical
tank partially broken away to show the blood ?lming
FIG. 3 is a section taken along line 3—3 of FIG. 2.
Referring now more particularly to the drawings refer
Film oxygenators are characterized by exposing a con
tinuous thin ?lm of blood to an oxygen atmosphere.
ence characters will be used to denote like parts and struc
Physical and chemical properties of the ?lming surfaces
tural features in describing the oxygenator and the oxy
with respect to blood are of utmost importance and must
genation process. The numeral 10 designates generally
a tank having a top opening 11. Tank 10 is preferably
formed of transparent plastic such as polystyrene for ob
be considered in design in order to minimize blood dam
age. Since blood is a very delicate tissue when removed
from the body and exposed to surfaces and atmospheres
foreign to it, the handling of such blood becomes of vital
importance to the surgeon using extracorporeal circulation
apparatus. This is particularly true where the operative
procedure requires lengthy use of the arti?cial “heart—
servation of the interior elements of the apparatus and
the blood as it passes therethrough during the process.
One side Wall of the tank is provided with a plurality of
apertures 12 spaced longitudinally therealong.
lung” machine which is the combination of an arti?cial
openings are for admission of oxygen to the tank. The
opposing wall of the tank is provided with an oxygen out‘
heart with arti?cial lungs. Post operative deaths, where
let port 14- which is encircled by a nipple 15 for attach
such machines have been used, are attributed in part to
ment of a carry otf tube 16‘. One end wall of the tank
is provided near its bottom with a blood outlet port desig
nated at 17 for draining blood from the tank bottom.
An oxygen intake manifold designated at 18 is mounted
subtle blood damage caused by prolonged mechanical
handling of the blood.
Various chemically inert surfaces have been used for
?lm oxygenation of blood. However, inasmuch as such
on the side of the tank so as to cover all of the apertures
12. An oxygen supply line 19 is connected to the mani
fold to supply oxygen to the interior thereof. The inside
of the manifold is preferably ?lled with a ?ltering mate‘
surfaces are “non~wettable” it has been difficult to main
tain a thin ?lm of blood thereon. Other surfaces formed
by a woven mesh of silk, nylon or stainless steel have been
used but are not completely satisfactory for various
From a theoretical viewpoint, blood plasma is believed
to provide the best ?lming surface for blood. In practice
attempts have been made to provide such a surface by
rial such as the sponge 20.
This ?lters the oxygen as it
passes into the tank 10 and also assists in diffusing the oxy
gen to equalize distribution to the tank inlet apertures 12.
The blood ?lming battery sets Within the tank in and
is designated generally by the number 21. it is inserted
into the tank through the top opening 11. The battery
?lming blood over blood foam or by the absorption of
comprises a plurality of rectangular “plates” or leaves 22
protein onto plastic surfaces. One of the basic purposes
of the present invention is to provide a means for forming 60 of sponge material which are separated from each other
by rectangular grids of wax 24 which are alternately as
a plasma ?lming surface for the ?lming of blood.
A primary object of the invention is to provide a
sembled with the sponge leaves. The upper and lower
sides 25 of the separator frames 24 have an enlarged thick
method and device for the ?lm oxygenation of blood
which provides for extremely rapid oxygenation as com
ness enabling the leaves 22 to be held in clamped condi
tion between next adjacent separators While yet being
pared to heretofore known ?lming processes.
Another object of the invention is to provide a blood
spaced from the longer vertical sides 26 of the frames.
?lming surface which will distribute blood over an ex
The leaves 22 are thus lightly clamped only at the top and
tremely large surface area in a very thin ?lm to expedite
bottom. To assure separation of the central portions of
gaseous exchange during the oxygenation process.
next adjacent leaves 22, each separator frame 24 is wound
Another important object is to provide an apparatus
with nylon thread 27 the windings thereon being ver
for ?lm oxygenation of blood which allows the atmos
tically spaced. The battery may be bound together as a
phere to which the ?lm is exposed to be controlled in
unit by connecting the ends of separator ?ange portions
25 which are in fact the corners of the frames as by
more was weighed. It was found that the sponge still re
melted wax.
tained 0.63 times its original weight.
Next, it was necessary to determine the nature of the
absorbed liquid. The piece of sponge was washed in a
large amount of normal saline and the total protein con
tent of the resulting solution was determined chemically
adapted to ?t snugly over and around the top of the bat
to be 0.28 milligram. The total protein content of plasma
tery 21 leaving an enclosed chamber 3t} over the top sur
separated from a specimen of the blood used was found
face of the battery. The downwardly turned side wall
to be 0.27 milligram for a volume substantially equal to
31 of the member 2? is peripherally sealed to the battery
as by Wax to prohibit liquid ?ow from the chamber 30 10 that absorbed by the piece of sponge. It was concluded
that the liquid absorbed by the sponge matrix was plasma.
down along the sides of the battery. A peripheral ?ange
An experiment was conducted to test the effect of the
32 is provided around the exterior of the manifold to rest
sponge on streaming whole blood. A slice of “Ivalon”
against the top wall of the container 1!} so that the bat
10 x l x 0.1 centimeters in size was saturated with freshly
tery 21 is held in suspended condition within the con
let, heparinized blood and was suspended in a measuring
tainer and spaced slightly away from the bottom thereof.
cylinder. Venous blood was obtained from a subject by
In assembling the apparatus ?ange 32 is sealed to the top
a hollow needle inserted into the arm vein. This blood
of the container. A header 34 has a plurality of inlet
was dripped onto the top of the sponge strip from the
connections 35 leading through the member 29 and in
needle for sixteen minutes. The blood ?owed down the
open communication ith the chamber 30.
strip and dropped into the bottom of the cylinder. Three
Operation of the isclosed apparatus in carrying out
drops of Heparin solution were added to the strip during
our improved process of oxygenation will now be under
A blood intake manifold for admission of blood to
the oxygenator is designated generally by the number 28.
This comprises an inverted tray shaped member 29
stood. Line ‘19 is connected to a source of oxygen under
the experiment to prevent clotting.
The shed blood
amounted to 50 cubic centimeters. The blood soaked strip
pressure so that oxygen is constantly passing through the
of sponge was then immersed in a formalin ?xative.
manifold 18, ?lter 20, and apertures 12 into the tank
Frozen sections were cut from the top and the bottom of
10 and out through the port 14. As oxygen is passed
the slice, transferred dry, and examined microscopically
transversely through the tank it will obviously ?ow be
after thawing. Free ?owing erythrocytes with no evi—
tween the frame portions 26 of the separators and through
dence of clot formation were seen on the surface of the
the porous sponge elements 22.
sponge. A preparation was made and stained with
The header 34 is connected to the supply of blood B
to be oxygenated. As the blood passes through the con 30 Wright’s stain, and again no evidence of clot formation
could be found.
nectors 35 and into the compartment 30 it is distributed
With these experiments having proven successful an
over the top of the battery. From compartment 30 the
oxygenating apparatus was built in the form of that shown
blood soaks down through the sponge leaves 22 held be
in the drawings and hereinbefore described.
tween the separators 24. The blood ?lms down the
Several experiments were made testing the oxygenator
sponge leaves and runs smoothly into the bottom of the
disclosed using “Ivalon” commercial grade polyvinyl
tank and out through port 17.
formal sponge. In each experiment matched, outdated,
Thus as the blood gravitationally passes vertically
citrated blood was used with a container thereof sus
through the battery and the leaves 22 the oxygen will pass
pended above the oxygenator. The primary volume of
horizontally therethrough and edgewise through the
the equipment was 50 to 60 cubic centimeters. Oxygen
leaves and the spaces between the leaves past the blood
absorbent material with an open pore sponge structure.
Of the sponge materials available we have found that a
from a storage tank was blown directly into the oxygen
intake manifold 18 at a rate of ?fteen liters per minute.
In the ?rst experiment blood was allowed to ?ow into
the oxygenator through line 34 at a flow rate of 900 cubic
since in addition to superior ?lming qualities, a ?ltering
reducing the effective surface.
action can be obtained.
In the second experiment blood was allowed to flow
into the oxygenator at a steady rate of 250 cubic centi
meters per minute in an oxygen atmosphere. As the
blood discharged from the tank it was a bright red color.
In the third experiment showed a blood ?ow of 430
cubic centimeters per minute was the approximate upper
?lmed thereon.
The material used for leaves 22 is an inert, hydrophilic,
polyvinyl formal sponge sold in the United States under 45 centimeters per minute. The blood being discharged at
outlet 17 was found to be considerably redder in color
the trademark “Ivalon” by The Simoniz Company, Chi
than the entering blood. However, examination of the
cago, Illinois, is most satisfactory. It is felt that “Ivalon”
sponge leaves showed them to be overloaded with blood,
sponge best approaches the human lung in operation,
Since a sponge has myriads of
pores of many different sizes, the blood, in constant mild
agitation during the ?lming process, flows over a much
larger surface than would be so over a flat sheet of the
same size having a smooth surface. With the blood flow
at an optimal level erythrocytes run over a plasma-wetted
surface in a very thin ?lm, always exposed to some oxy
limit for effective oxygenation with this particular experi
gen, thus simulating a capillary ?ow. It is found that
sponge material such as “Ivalon” has the de?nite advan
tage over other known ?lming surfaces of maintaining
mental unit. At this ?ow rate the sponge structure could
a blood ?lm even with the lowest possible flows. Film
breakage over unsuitable surfaces at levels thick enough
to cause incomplete oxygenation is well known. “fvalon”
sponge can be saturated with nearly its own weight of
plasma as a preliminary procedure, and thus present a
to the bottoms of the leaves was noted.
blood-like surface to the blood which ?lms over it.
The “Ivalon” commercial sponge was tested for vari
ous characteristics prior to incorporation in the oxygena
tor. In order to test the absorptive capacity of the mate
still be discerned, indicating that the ?lming surfaces were
not overloaded and a striking color change from the tops
A sample of reduced blood obtained from the reservoir
directly prior to the third experiment was found to have
an oxygen capacity of 15.12 volumes percent, with an
oxygen content of 6.42 volumes percent, or 42.42 percent
saturation. After running through the instrument at a
?ow rate of 430 cubic centimeters per minute, the blood
sample had an oxygen content of 14.28 volumes percent
or 94.44 percent saturation.
The apparatus disclosed is not only an extremely effec
rial, a piece of absolutely dry sponge was weighed and
placed in a pool of freshly drawn, heparinized blood. 70 tive oxygenator but has the additional advantage of being
usable in a closed system where the blood is not exposed
After allowing time for maximal absorption, excess blood
to the outside atmosphere. This prevents drying of the
was allowed to drip off and the piece was weighed again.
blood by conserving water vapor.
It was found that the sponge had absorbed 9.7 times its
The apparatus with its sealed tank or container also
Weight. The piece of sponge was then squeezed thor
oughly until no blood could be seen on a blotter and once 75 allows strict control of the oxygen tension within the
tank to accelerate oxygenation where necessary. The
device may be incorporated with a closed system anes
thesia machine to control the absorption of carbon di
We have thus provided a new and improved ?lming
3. The structure of claim 2; said blood transfer and
?ltering means comprising a plurality of thin leaves of
said soft absorbent material, a plurality of impervious
separator plate elements disposed on opposite sides of
each of said thin leaves and forming open passages across
surface, apparatus, and method for e?ectively carrying
opposite sides of said leaves ‘for receiving oxygen there
out the aforementioned objectives. It is understood that
suitable modi?cations may be made in the structure as
4. The structure of claim 2; said oxygen inlet means
disclosed, provided such modi?cations come within the
comprising an oxygen inlet manifold at one side of said
spirit and scope of the appended claims. Having now 10 container, and oxygen-?lter means in said inlet manifold.
therefore fully illustrated and described our invention,
References Cited in the ?le of this patent
what We claim to be new and desire to protect by Letters
Patent is:
1. Blood oxygenating apparatus comprising a con
Masci ________________ .. Dec. 4, 1956
tainer including a closed chamber, blood inlet and outlet 15
means on said container communicating with said chamber
and de?ning a predetermined path of travel for blood
Malmros et al _________ __ May 14, 1957
Gollan ______________ _.. May 6, 1958
through said chamber, oxygen inlet and outlet means on
said container communicating with said chamber and de
“Preliminary Studies on the Sponge
?ning a path of travel for oxygen which intersects that 20 Oxygenator,” Surgery,
vol. 42, No. 2, August 1957, pg.
de?ned by said blood inlet and outlet means, blood trans
342_6. (Available in Science Library.)
fer and ?ltering means comprising at least one body of
Modern Plastics, volume 27, No. 8, page 104, April
soft, absorbent material including myriads of random
spaced and sized pores and capable of pre-saturation with
a wetting agent and promoting blood-?lming thereover 25 The Lancet, pages 711-712, Oct. 1, 1955.
Struthers et al.: “Experimental Study,” Proceedings of
in addition to ?ltering of the blood with a minimum of
Staff Meetings of the Mayo Clinic, pages 462-465,
mechanical shock to the blood, said material being dis
Oct. 5, 1955.
posed intermediately of each of the intersecting paths of
Newman et al.: “Complete, and Partial Perfusion"
2. The structure of claim 1; said blood inlet means be 30 Surgery, pages 32-33, volume 38, No. 1, July 1955.
(Available in Scienti?c Library.)
ing located above said body of material, said blood outlet
Helmsworth: “Arti?cial Oxygenation,” Journal of
means being located below said body of material, said
oxygen inlet and outlet means being located on opposite
Thoracic Surgery, volume 24, No. 2, pages 117-119, Au
sides of said body of material.
gust 1952. (Copy in Division 55.]1
Без категории
Размер файла
588 Кб
Пожаловаться на содержимое документа