U.S. patent number 3,792,978 [Application Number 05/257,537] was granted by the patent office on 1974-02-19 for envelope assembly for spool type oxygenator.
This patent grant is currently assigned to Sci-Med Life Systems, Inc.. Invention is credited to Frank B. Freedman.
United States Patent |
3,792,978 |
Freedman |
February 19, 1974 |
ENVELOPE ASSEMBLY FOR SPOOL TYPE OXYGENATOR
Abstract
The invention relates to an envelope assembly for a spool wound
artificial lung. The envelope assembly is characterized by having
unobtrusive tube attachments which allow the envelope to be wound
smoothly and evenly about the spool of the oxygenator.
Inventors: |
Freedman; Frank B. (St. Louis,
MO) |
Assignee: |
Sci-Med Life Systems, Inc.
(Minneapolis, MN)
|
Family
ID: |
22976698 |
Appl.
No.: |
05/257,537 |
Filed: |
May 30, 1972 |
Current U.S.
Class: |
422/48;
128/DIG.3; 210/321.74 |
Current CPC
Class: |
B01D
63/103 (20130101); B01D 2313/10 (20130101); Y10S
128/03 (20130101) |
Current International
Class: |
A61H
31/00 (20060101); A61m 001/03 () |
Field of
Search: |
;23/258.5 ;210/321,494
;128/DIG.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Richman; Barry S.
Attorney, Agent or Firm: Kirn, Jr.; Walter N.
Claims
I claim:
1. A gas exchange envelope assembly for a spool type oxygenator
comprising a pair of rectangularly shaped fluid permeable membrane
sheets, said sheets being cemented together to form a peripherally
extending seam and a chamber therebetween, a screen member in said
chamber in closely spaced relation to the internal boundary of said
seam, a tube having a sleeve attached at one end thereof in
surrounding relation thereto, said tube end and a portion of said
sleeve being cemented to and between said sheets within the
boundaries of said seam, said sleeve having a transversely
extending slit in straddling relation to said screen.
2. An envelope assembly according to claim 1 including a folded bib
member having folded parts and an opening along the fold line
thereof, said bib opening being in surrounding relation to said
sleeve and said folded parts being in straddling relation to said
screen.
Description
The invention relates to a new and improved envelope assembly for a
spool wound artificial lung which may also be referred to as an
oxygenator.
A spool wound artificial oxygenator as referred to above is
disclosed in U.S. Pat. No. 3,489,647 to Theodor Kolobow titled,
"Artificial Organ for Membrane Dialysis of Biological Fluids." The
envelope assembly 11 as disclosed in the Kolobow patent is more or
less schematic in nature and a practical embodiment thereof would
have to be considerably modified to be effective for its intended
purpose. The envelope 11 is wound around the spool or core 10 and,
as is characteristic of membrane type oxygenators, the principle of
gas diffusion through a membrane is utilized, there being an
exchange of oxygen and carbon dioxide under conditions similar to
those existing in the lungs. Without going unduly into detail at
this point, it is essential to obtaining optimum conditions that
the envelope be wound smoothly and evenly about the spool to avoid
channeling of the blood. Winding in this desirable manner is not
possible, however, if the tube attachments are bulky and
cumbersome.
An object of the present invention is to provide a new and improved
artificial lung or oxygenator envelope assembly having a tube
attachment which is unobtrusive so as to not interfere with the
capability of the envelope to be smoothly and evenly wound about
the oxygenator spool.
Other objects and advantages of the invention will become apparent
from the following specification, drawings and appended claims:
FIG. 1 is a fragmentary front elevational view, partly in section,
of an envelope assembly for an artificial lung which assembly
embodies the invention;
FIG. 2 is a sectional view of the envelope assembly taken on line
2--2 of FIG. 1; and
FIG. 3 is a perspective view of the envelope assembly shown in
FIGS. 1 and 2.
In the drawing, there is shown a corner section of an envelope
assembly 10 which includes an attached tube 22. The tube
construction and the manner of its attachment to the envelope is
the same whether it is to function as a gas inlet tube or a gas
outlet tube.
The envelope assembly comprises a pair of rectangularly shaped
membrane sheets 14 and 15 made of a gas permeable material such as
silicone rubber, Teflon or polypropylene. These sheets have a
thickness on the order of 0.005 inch. As the word "envelope"
implies, the four joining edges of the sheets 14 and 15 are sealed
with a suitable cement to form a seam 18 having a width on the
order of 1/4 inch.
Within the space bounded by the sealed edges of the envelope formed
by the sheets 14 and 15 is sandwiched a spacer screen 20 which may
be of any suitable material such as fiberglass, Saran or nylon and
has a thickness on the order of 0.030 inch. Spacer screen 20
functions to maintain a desired spacing between the membrane sheets
14 and 15 to provide a gas chamber which resists collapsing when
the external pressure on the sheets 14 and 15 is greater than the
internal pressure. It is of importance that screen 20 is spaced
from the seam 18 and is definitely not cemented into the seam.
Tubing means are provided for admitting and exhausting gaseous
fluids to and from the enclosed space between membrane sheets 14
and 15 which forms an enclosed chamber as stated above. Only one
tube 22 is illustrated but it will be understood that any number of
similarly constructed and installed tubes may be utilized. Tube 22
is made of silicon rubber and has a stainless steel, coiled spring
24 inserted therein in a known manner, the purpose of the spring
being to prevent kinking of the tube and to present a resistance to
the collapsing of the tube when the external environmental pressure
exceeds the internal pressure.
The end of tube 22 is force fitted onto a cylindrically shaped,
rigid plastic sleeve 26 having an internal diameter which is
nominally the same as the external diameter of tube 22. Sleeve 26
has a transversely extending slit 28 for receiving or accommodating
the screen 20.
In surrounding relation to the screen 20 and the sleeve 26 is a
folded bib member 30. Bib 30 has an opening which is centrally
located relative to the center fold 32 thereof and in closely
fitting relation to the sleeve 26. Bib 30 is made of a polyester,
cellulose acetate or other suitable plastic material and the
purpose or function of it is to protect the inside surfaces of the
membrane sheets 14 and 15 from any possibly sharp edge on the
sleeve 26.
In the manufacture of the envelope assembly the sleeve 26 is forced
onto the end of the tube 22 and the sleeve is slipped into the
opening 31 of the bib 30. The edge of the screen 20 is inserted
into the slit 28 of the sleeve 26 and the two membrane sheets 14
and 15 are then cemented together to form the seam 18 as described
above. In this operation the lower end of the tube 22 and the upper
end of the plastic sleeve 26 are in the seam proper between the
sealed edges of the membrane sheets 14 and 15. The folded edge of
the bib 30 is likewise in the seam proper between the sealed edges
of the membrane sheets 14 and 15, as illustrated.
* * * * *