US 2702035 A
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INVENTORS nz/Rai [J2/vada A una? Jl BY AT TO R N E Y OXYGENATING UNIT FOR EXTRACORPOREAL CIRCULATION DEVICES Feb. l5, 1955 (Jx'iginal Filed May 28,
Feb. 15, 1955 1 H, G|BB0N, JR., ErAL 2,702,035
OXYGENATING UNIT FOR Ex'rRAcoRPoREAL CIRCULATION DEVICES Original Filed May 28, 1949 2 SheetsSheet 2 FIG.3
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BY WM] QIMALW AT TORNEY United States Patent O OXYGENATING UNIT FOR EXTRACORPOREAL CIRCULATION DEVICES John H. Gibbon, Jr., Philadelphia, Pa., and Gustav V. A. Malmros, Binghamton, and mmund A. barber, Jr., Johnson ciiy, is. asslguurs to lne Jelterson Medical College or' fnlladelplna, Philadelphia, Pa., a nonproitt corporation or' Pennsylvania Original application May 28, 1949, Serial No. 96,114, now
Patent iso. 2,059,365, dated November 11, 1953. Dlvided and this application February 21, 1953, Serial No. 339,244
2 Claim. (Cl. 12S-214) This invention relates to extracorporeal circulation devices and particularly to venous oiood oxygenaiing units adapted ror use in eittracorporeal circulation devices to temporarily assume the xunctions ot the lungs in a human oelng or animal.
'l his application ls a division of copending application Serial No. 96,114, tiled May 28, 1949, which issued as United States t'atent 2,659,3o5 on November l i, w33.
Operative procedures upon the heart and its associated vessels could be better periormed it' the h eart was temporarily relieved of its runction of pumping blood. lf surgical operative procedures are necessary while the heart is pumping blood, the vigorous expansions and contractions ot' the pulsating member render delicate surgical procedures extremely dilicult, if not in many cases practically impossible. Relieving the heart of its normal function of pumping blood, if only for a short period ot time, would, of course, relieve many of the attendant surgical operative difficulties. However, in order to main tain life during a temporary cessation of blood ilow for an appreciable time, it is necessary to assume the cardiorespiratory functions of the subject by some other means to maintain a life-sustaining flow of blood within the subjects circulatory system.
ln general, the concept of extracorporeal circulation devices is old in the art. This invention is directed towards a mechanical blood oxygenating device to approach, if not attain, an equivalent functional replacement for the lungs in the oxygenation of venous blood.
The introduction of oxygen into venous blood in a mechanical device adapted to provide a functional replacement for the lungs is a problem beset by many difficulties. ln order to introduce adequate and predetermined amounts of oxygen into venous blood, it is necessary to provide a large surface area for oxygenating purposes and to manipulate the blood thereon in such manner as to form a continuous thin ilm of blood of controllable surface area to provide high oxygenation eciency and yet utilize only a small volume of blood at any given instant passing through the oxygenatlng atmosphere at a relatively high ilow rate without any detrimental foaming or bubbling of the blood in its passage through the unit. In every unit of this type a basic and essential operational requirement is the manipulation o( the blood in such a manner as to preclude foaming or bubbling thereof and detrimental hemolysis resulting from trauma in passage through the unit.
Another problem attendant the utilization of venous blood oxygenating in extracorporeal circulation devices is the attaining of a continuous, uniform and thin llm of blood over the oxygenating surfaces. Rivulet ilow of blood over the oxygenating surfaces greatly reduces the available blood surface area and reduces the oxygenation elliciency to negligible amounts.
In all devices of this type there must, in addition, be a simplicity and durability of construction that permits easy and repeated assembly and disassembly operations without damage to critically contoured components which must also be designed to permit easy cleaning and sterilization.
The method utilized in this device for obtaining a large surface area from a small volume of blood is to evenly distribute the blood on the inner surface of a vertical ice rotating cylinder. The centrifugal force insures the maintenance oi' a thin hun or' blood ou the inner suriace or the cylinder. lt'le olood passes, under lne miluence oi' gravity, downwardly along ine inner surface oi lne rotating cylinder and is collected in a stationary recepiacie, inio wnl'cn ine lower exireiniiy or ine revolving cylinder extends. lne presently prelerreu structure, as illustrated in ine drawings, ls an unproven device, wnlcn provides an oxygenallug system or large suilace-to-volullle ratio and oxygen-.lies ine venous blood wltn a minimum oi troming and nemolysis.
'lne object or tnis invention is the provision of an improved venous blood oxygenatlng unit adapted tor use in extraeorporeal circulation devices.
Referring to the drawings:
llg. 1 is a side sectional view of the venous blood oxygenatlng device;
rig. 2 is a side view, partially in section, of a preferred form of locking clamp;
big. 3 is a section on the line 3 3 of Fig. l; and
Fig. 4 is a side view, partially in section, ot a portion of the device illustrated in Fig. l.
Turning to the drawings, ine oxygenating device consists or' a vertical rotatable external cylinder l0, having an upper collar 12 peripherally disposed on the upper extremity ot' the cylinder. Engaging the collar 12 and serving as an upper mounting member is an upper cover 14. 'l he upper cover 14 terminates in a centrally dis posed vertical sleeve 16, which serves as a mount for a rotating raceway 18, which forms a part of the upper bearing 20. The stationary raceway 22 is mounted on a non-rotating external support member 24.
'lhe lower extremity or the cylinder 10 is pcripherally encircled by a lower collar 26. The lower collar 26 has a peripheral receptacle 28 disposed to contain a V-belt 30 utilized to rotate the cylinder lll. The lower end of the cylinder 10 terminates in an outwardly tapered edge 32 continuously formed by the wall of the cylinder l0 and a portion of the lower collar 26. The lower end of the cylinder 10, including the tapered portion 32, extends into an annular stationary collector receptacle or bowl 34.' :The collector bowl 34 is shaped so that the blood draining from the rotating cylinder 10 via the tapered edge 32 is thrown tangentially on to the adjacent surface of the bowl 34 with a minimum of impact and change of direction, i. e., the blood is llung tangentially from the cylinder into the collector bowl 34, which is shaped to receive the blood with a minimum of impact. Also, the walls and bottom of the collector bowl 34 are sloped to make the blood flow to a tapered outlet spout 36 disposed in the lowest portion of the bowl 34.
The rotating cylinder 10 and the stationary collector bowl 34 are supported bgoa lower mounting assembly disposed to support said w1 34 and said cylinder 10 in non-rotating and rotating engagement, respectively, which comprises a main base and support segment 38 supported by the main mounting struts 40. Disposed above the mounting struts 40 is a nonrotating cylindrical su port member 42, which engages and su ports the undersige of the outer surface of the collector owl 34. Disposed adjacent to the cylindrical support member 42, and in clamping engagement with the inl-ler surface of the collector bowl 34, is a non-rotating internal support member 44.. T he base segment 38, the mounting struts 40, the cylindrical support member 42, and the internal sup porting member 44, are held in compressive assembled engagement by the bolts 46 and 48.
The non-rotating cylindrical support member 42 provides a mountin for a stationary racewa 50 for the lower bearing 5 Disposed adjacent to t e stationary raceway 50 and separated therefrom by the rolling meinbers of the bearing is a rotating raceway 54, which is mounted on a rotating sleeve 56. The rotating sleeve 56 supports the rotating cylinder l0. The rotating sleeve 56 is integrally connected via the struts 58 to the rphery of the rotating cylinder 10 and through sai struts 58 supports the weight of said cylinder 10.
Within the rotating cylinder 10 and concentric with it is a stationary cylinder 60 closed at each end, as at 60a and 66h. This cylinder is so spaced within the rotating cylinder 10 so as to provide a narrow annular s ce between the external surface of th e internally dgsaposed non-rotating cylinder 60 and the internal surface of the externally disposed rotating cylinder l0. Disposed within the stationary cylinder is a narrow vertical ket 62, which serves as a rece tacle for the blood inlet )et assembly. Axially dispose on the upper surface of the internal non-rotating cylinder 60 is a shaft 64 held in non-rotative arrangement axiall within the rotating sleeve 16. Slidably disposed wit in the shaft 64 is a vertical iet positioning rod 66. Disposed adjacent to the iet positioning rod 66 within the shaft 64 is a venous blood supply tube 68. Mounted on the lower end of the jet positioning rod 66 is a horizontal iet mounting bracket 70 which terminates in the mount 72 for the )et nozzle 74 and the blood supply tube 68. The mount 72 includes a knurled thumbscrew 76 for fastenin the nozzle 74 to the mounting bracket 70. The no e 74 is disposed adiacent to the inner surface of the rotating cylinder 10. For the rates of ow utilized in the device the nozzle is designed to give the venous blood a velocity approximating that of the periphery of the rotating cylinder. In addition, the nozzle is preset in position so the direction of the blood flow is approximately tangential to the cylinder periphery. Thus, the blood .leaving the nozzle is approximately the same in magnitude and direction as the peri heral velocity of the cylinder 10. Therefore, only slig t impact occurs as the blood transfers to the cylinder. The lessening of the impact reduces hemolysis and frothing of the blood.
The iet assembly is slidably contained within the vertical pocket 62 and provides a positiye means for forming a thin film of blood on the entire inner surface of the rotating cylinder 10. The rotation of the cylinder l and the slidability of the iet assembly aid in the formation of a uniform film of blood without the formation of rivulets and provide for an even discharge of blood over the entire periphery of the cylinder. By raising the iet nozzle 74 gradually while the cylinder l0 is rotating, the blood issuing from the iet 74 contacts every inch of the surface of the cylinder and forms a uniform thin film without rivulet formation. Once the cylinder surface is wetted, the film will remain as long as the blood flows and the cylinder rota-tes: Moreover, provision has been incorporated to position the iet assembly at any intermediate level, thus giving the oxygenating device a variable oxygenating capacity.
The internal non-rotating cylinder 60 is mounted on the lower support shaft 78, which is contained within a non-rotating central supporting member 80. The nonrotating central supporting member 80 is secured to the lower base segment 38 in non-rotative engagement and is axially disposed within the rotating sleeve 56. Disposed withiri the central support member 80 adjacent to the lower support shaft 78 is the oxygen inlet tube 82. The lower mounting for a positively rotating outer cylinder 10, a non-rotating collector bowl 34. and a non-rotating inner cylinder 60.
Figure 2 shows the presently preferred construction for locking the iet assembly at any desired level. There is provided a sleeve 84 enclosing the slidable jet positioning rod 66. Secured to the sleeve 84 is a collar 86. The collar 86 serves as a mount for a vertically protruding pin 88. Disposed above the collar 86 and fitting loosely on the rod 66 is a locking collar 90. The pin 88 serves as a fulcrum to tilt the locking collar 90 into tight frictional contact with the jet positioning rod 66. Thus, whenever it is desired to lock the jet assembly in a raised position` the locking collar 90 is permitted to tilt on the pin 88. The resultant cramping action between the locking collar 90 and the jet positioning rod 66 is sufficient to hold the jet assembly 74 at any desired elevational location.
The above-described oxygenating device is the lung" of an oxygenator assembly. In operation the outer cylinder l0 is rotated by the action of the V-belt 30, and the venous blood is evenly distributed by the iet 74 upon the inside surface of the rotating cylinder 10. The rotating cylinder 10 and the stationary cylinder 60 mounted concen-trically within the outer rotating cylinder 10 provide an annular space between the two cylinders. The gas, principally oxygen with some carbon dioxide, water vapor, and ether, enters the bottom of the oxygenating device through the tube 82 and passes upward through the annular space. Since the annular space is small, all the gas in its upward 110W in this space has arrangement thus provides an excellent o portunity fof contacting the downwardly flowing film o blood. During this assage the oxygen is transferred to the blood and the ownwardly flowing venous blood is thereby oxygenated. The gas leaves the annular space at the top of the assembly and is drawn off through an air exhaust system via the tube 92.
It is desirable to prevent the escape of the oxygen and, the other gases from the space between the rotating and stationary members in the oxygenating device during operation. To prevent the escape of the gases, annular grooves, such as 94, are included between the adjacent surfaces of the stationary collector bowl 34 and the rotating collar 26 as partial gas seals. These seals, while not as effective as a sliding t e seal, are presently preferred because of reduced frictional effects and the ever-present possibility of combustion in an atmosphere of high oxygen concentration.
The entire oxy nating device, except for the rubber tubing 68 in the slidable iet assembly, the bearings 20 and 52, is preferably made of Inconel. This metal was preferred and used because of its very high resistance to corrosion from blood. Inconel is an alloy having the following composition:
79.50% nickel 13.00% chromium 6.50% iron .25% manganese .85% silicon .08% carbon .20% copper Disposed beneath the drain 36 of the collector bowl 34 is a suitable flask or container such as the longnecked flash 96 provided with a suitable drainage openin 98 for removal of the collected blood.
n accordance with the provisions of the patent statutes, we have herein described principle of operation of this invention, together with the elements which we now consider the best embodiments thereof, but we desire to have it understood that the structure disclosed is onl illustrative and the invention can be carried out by o er means. Also, while it is designed to use the various features and elements in the combinations and relations described, some of these may be altered and modified without interfering with the more general results outlined and the invention extends to such use within the scope of the appended claims.
Having thus described our invention, we claim:
l. .In an extracorporeal circulation device of the type described, an assembly for introducing oxygen into a thin continuous film of venous blood, comprising, an arinular oxygenating chamber wherein an upwardly moving stream of oxygen is passed over a downwardly moving continuous film of blood, said annular oxygenating charnber formed by a rotatable cylindrical shell open at both extremities and a non-rotatable cylinder concentrically disposed within said shell, means for initially forrigiirigk said continuous film of blood on the inner surface of said rotatable cylindrical shell, including, a vertical jet assembly receiving channel disposed in the non-rotatable cylinder, a iet assembly connected to a source of venous blood mounted on a slidable vertical positioning rod contained therein whereby said iet may be vertically positioned at any location therein, and a non-rotatable annular blood collecting bowl outwardly encompassing the lower extremity of said rotatable shell.
2. In an extracorporeal circulation device of the type described, an assembly for introducing oxygen into ai thin continuous film of venous blood, comprising, an annular oxygenating chamber wherein an upwardly moving stream of oxygen is passed over a downwardly moving continuous film of blood, said annular oxygenating chamber formed by a rotatable cylindrical shell open at both extremities and a non-rotatable cylinder concentrically disposed within said shell, means for forming said continuous film of blood on the inner surface of said rotatable cylindrical shell including a vertical jet assembly receiving channel disposed in said non-rotatable cylinder, a jet assembly connected to a source of venous blood mounted on a slidable vertical positioning rod contained therein, said iet assembly including a nozzle shaped to distribute the venous blood tangentially upon the inner surface of said rotatable shell at a velocity approaching tlie peripheral velocity of said shell, a
86 horizontal adjustable mounting bracket intermediate said nozzle and said vertical positioning md; means elternally of said outer shell for securn the vertical posh tionm asset-n ly receiving chamber, a non-rotatable annular blood collecting bowl encompassing the lower extremity of said rotatable shell, said inner surface of said rotatable shell being outwardly tapered at its lower extremity, and said adjacent surfaces of said collector bowl shaped to receive the downwardly flowing blood from said tapered surface with a minimum of impact.
rod at any desired position in said vertical iet Gibbon: "The Maintenance of Life Experimental Occlusion of the Pulmonary Artery Fo owed by Survival Su ry. Gynecology and Obstetrics. Novem- 1o ber 139, vot. 9. No. s, ma 6oz-14, page 604 am.
Copy in Div 55.
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