US3211148A

US3211148A - Rotary disk oxygenator and heater

Info

Publication number: US3211148A
Application number: US197694A
Authority: US
Inventors: Jr John E Galajda
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-05-25
Filing date: 1962-05-25
Publication date: 1965-10-12
Anticipated expiration: 1982-10-12

Description

ROTARY DISK OXYGENA'I'OR AND HEATER Filed May 25, 1962 5 Sheets-Sheet 1 Fig.

John E. Gala d0, J1:

[NV/:NTOR.

1965 J. E. -GALAJDAI, JR 3,211,148

ROTARY DISK OXYGENATOR AND HEATER Filed May 25, 1962 5 Sheets-Sheet 2 Fig.4

John E. Gala d0, Jr.

INVENTOR.

Attorneys Oct. 12, 1965 Filed May 25, 1962 Fig.8

J. E. GALAJDA, JR

ROTARY DISK OXYGENATOR AND HEATER '5 Sheets-Sheet 3 Hill John E. Ga/ajaa, Jr.

INVENTOR.

BY @mmi Oct. 12, 1965 GALAJDA, JR 3,211,148

ROTARY DISK OXYGENA'IOR AND HEATER Filed May 25, 1962 5 Sheets-Sheet 4 Ja/m E. Ga/ajaa, Jr.

INVENTOR.

ROTARY DISK OXYGENATOR AND HEATER Filed May 25, 1962 5 Sheets-Sheet 5 Fig l0 Fig l/ 330 T Ja/m E Gala/d0 J1: 382 INVENTOR.

Mm BY ZWW'EMZEW United States Patent 3,211,148 ROTARY DESK OXYGENATOR AND HEATER John E. Galajda, Jr., 35228 Center Ridge Road, North Ridgeville, Ohio Filed May 25, 1962, Ser. No. 197,694 8 (Ilaims. (Cl. 128-214) This invention comprises a novel and useful rotary disk oxygenator and heater and more particularly relates to a machine for quickly and safely oxygenating and heating large volumes of liquids and particularly blood.

The invention disclosed and claimed herein relates to similar subject matter to that set forth in my prior application Serial No. 821,229, filed June 18, 1959, entitled Driver and Heater for Disk Oxygenator, now Patent No. 3,053,229 of September 11, 1962, and constitutes improvements thereover.

During the process of complete or partial circulatory by-pass of the heart and lungs during surgery for circulatory diseases, or as a support to treatment of cardiopulmonary diseases, the rotating disk oxygenator has proved to be safe and valuable. However, the blood is subjected to cooling as it passes through the necessarily large tubing, pumps and the oxygenator unit. The oxygenator especially is a source of substantial cooling of the blood. Depending on blood flow rates, up to five liters of cold oxygen, carbon dioxide and anesthetic gases may pass through the oxygenator each minute. To offset this loss of heat, it was thought advisable to pre-heat the gases passing into the oxygenator. Tests have shown that although heat loss may be substantially reduced, this is a poor means for elevating or controlling blood temperature because of the heat diiferences in specific heats of the gases and liquid. There is also an explosion hazard involved in the heating of anesthetic gases mixed with oxygen.

Initial attempts to heat the blood in the oxygenator usually employed a resistance wire wound around the oxygenator bottle so that the blood is warmed by conduct-ion through the glass side wall of the bottle and from the exterior surface of the liquid inwardly thereof. Like all methods attempting to heat blood through the glass bottle, including infra-red heat, the surface available for heat transfer is smaller than the cooling surface presented by the disks in the relatively cooler atmosphere present Within the oxygenator and therefore the cooling effect is greater than can be handled. The result is as follows: either the temperature of the blood during the by-pass is considerably below normal, or, excessive heating of the cylinder will maintain a normal temperature of the blood but with excessive platelet destruction, hemolysis, and the collection of fibrin on the bottle.

This invention provides means by which to apply heat to the rotating disks in order to obtain multiple advantages. The first is that by heating the surface area of the disks, the area of heat exchange itself is greatly increased. Further, it is possible to heat larger volumes of blood more safely because of the increased surface area with a lower temperature gradient. Secondly, since the heat transfer will take place at the surface where gaseous exchange is taking place in the blood as well as in the immersed portion of the disks, the problem of dissolving gases coming out of physical solution with temperature rise is minimized.

Most other oxygenating systems warm the blood after the gaseous exchange has taken place with the result that tiny air bubbles are produced in the heater and may be carried through the circulatory system of the patient with deleterious effects. The process of heating blood after gaseous exchange has taken place and with the resulting change in the solubility of the gases, especially carbon dioxide, results in shifting pH. This problem can be rectified by the machine in accordance with this invention.

dilhlid Patented Oct. 12, I965 ice The convoluted disks of this machine, in order to give maximum surface area for heat transfer and gaseous exchange without creating undue turbulence and bubbling "are the par-ts of the machine which are heated.

The principal object of the invention is to provide a disk oxygenator which is safer and more satisfactorily operative than prior disk oxygenators and made so by virtue of the construction of the heating system of the disk oxygenator. The heat is preferably entrained in the system by means of the disks, and this may be the sole heating of the blood or may be used in combination with heat applied from the exterior of the cylinder in which the disks are rotatable.

Another object of the invention is to provide an oxygenator system which is so arranged as to always maintain all phases of the operation under the control of the operator at one location so that the operation of the oxygenator may be monitored at all times by one person.

A further object of the invention is to effect heat exchange from a central core or shaft upon which the disks are carried, through the hubs of the disks and radially outwardly therefrom across the entire surfaces of the disks. Thus the maximum temperature is at the axis of rotation and the heat is distributed radially therefrom by the structure of the disks themselves.

Still another object of the invention is to provide an oxygenator in which the heating operation is effected by the circulation of hot water through the central axis and hubs of the disks to thereby effect a very rapid rate of heat input into the device.

A further object of the invention is to provide a device in accordance with the foregoing object in which a rapid cooling of the liquids and gases within the enclosing chamber of the apparatus may be effected by passing refrigerated fluids through the central axis and hubs of the disks.

Still another object of the invention is to provide a heat exchange apparatus whereby heat may be introduced into or withdrawn from a liquid through the agency of a series of disks rotatable therein and wherein the enclosing casing may be sealed from the atmosphere to enable the application of any desired pressures from sub-atmospheric to supra-atmospheric within the operating chamber of the device.

Still another object is to provide a device as set forth in the preceding objects in which there is effected a uniform temperature gradient throughout the area of the convo luted disks thereby securing a more even heating of the liquid.

An additional object, in compliance with the preceding objects is to provide a device wherein the heating elements and/or the gas introducing means are compactly incorporated into the central axle of the device which carries the disks.

These together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout, and hi which:

FIGURE 1 is a view in vertical central section through a first suitable form of apparatus in accordance with this invention, arrows indicating the directions of flow of the fluids therethrough;

FIGURE 2 is a fragmentary end elevational view taken from the left end of FIGURE 1;

FIGURE 3 is a perspective view of a modified form of convoluted disk in accordance with the invention;

FIGURE 4 is an enlarged sectional view of a portion of the arrangement of FIGURE 1 but showing the mounting and disposition of the convoluted disks in the invention;

FIGURE 5 is a transverse sectional detail view taken upon an enlarged scale substantially upon the plane indicated by the section line 5--5 of FIGURE 3 and showing the laminated construction of one of the convoluted disks;

FIGURE 6 is a view in vertical central longitudinal section through a slightly modified second form of apparatus in accordance with the invention, parts being broken away;

FIGURE 7 is a view in vertical transverse section taken substantially upon the plane indicated by the section line '7-7 of FIGURE 6;

FIGURE 8 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 88 of FIGURE 6 and showing the structure and portion of a filter employed in the invention;

FIGURE 9 is a perspective view of the filter element, parts being broken away;

FIGURE 10 is a fragmentary view in vertical central longitudinal section of a third form of apparatus in accordance with this invention; and,

FIGURE 11 is a detail view in vertical longitudinal section of a further modified form of convoluted disk which may be used with any of the embodiments of the apparatus.

In the embodiments illustrated in the three forms of the invention disclosed in FIGURES 1, 6 and 10, a flat type of disk has been illustrated in the interest of simplicity, but it is to be understood that either of the convoluted forms of disks shown in FIGURES 35 and FIGURE 11 is preferred as being a more efficient type of construction.

Referring first specifically to the embodiment of FIG- URES 1-5, it will be observed that the oxygenator disclosed therein consists of a casing or tank which is sealed from the atmosphere and which may conveniently comprise a cylindrical casing or body 10 of any suitable material but preferably of a transparent nature and having removable end walls or

closure plates

12 and 14 secured to the open ends of the body and sealed thereto as by the reception of the ends of the body in circumferentially extending grooves or channels 16. Tensioning bolts 18, extending the length of the body 10 and exteriorly thereof serve to securely clamp the end walls to the body and thus form the fluid tight tank or casing which is sealed from the atmosphere and which thus provides a cylindrical liquid receiving and treating chamber therein.

The end wall 12 is provided with an internally threaded boss in which is received an externally threaded bushing 22 which constitutes a bearing or journal for the reduced and solid extremity 24 of the tubular axle or shaft 26 of a relatively good heat transmitting material. The other end of the shaft extends through the other end wall 14, and also extends into a housing indicated generally by the numeral 28. This housing consists of an annular flange 30 constituting a diametrically enlarged outer end of a tubular boss 32 which is integral with the end wall 14. An internally threaded bore 34 is provided through this boss and end wall, and the other extremity of the shaft 26 extends through this boss, it being retained in a fluid tight sealed engagement therein as by means of a stuffing box assembly 36 of a conventional design. A centrally outwardly dished cover plate 38 is detachably secured to the flange 30 as by wing nuts 40 and provides a fluid collecting chamber 42 disposed within the housing 28 and which thus receives therein the open end of the shaft 26.

As will be observed from FIGURE 1, the shaft 26 is hollow to provide a chamber or passage which terminates in the chamber 42 of the housing 23 and which has its other end closely adjacent to the journal bearing 22.

Secured in but projecting axially from the hollow shaft 26 is a tubular or cylindrical member 44 disposed in concentric relation in the passage in the shaft 26 and fixedly secured to the wall 38 in any suitable manner, not shown.

As will be further observed, the inwardly projecting end of the tubular member 44 terminates in closely spaced relation to the inward or bottom Wall of the passage in the shaft 26 so that it has free communication with this passage as shown by the arrows in FIGURE 1. The two concentric members, consisting of the tube 44 and the shaft 26, thus provide a pair of concentric passages, the innermost of which is indicated by the numeral 46, while the numeral 48 designates the outermost thereof. These passages comprise part of a means for circulating a heat exchanging fluid through the interior of the shaft 26.

It will be understood that the outermost end of the tube 44 extends through and is preferably fixedly secured to the removable closure plate 38 of the housing 28 for removement therewith, and has the end of a conduit 47 embracingly and removably secured thereto by means of which a heat exchange fluid of any suitable type has its inlet to the inner passage 46. A threaded nipple 49 extending through the cover plate 38 of the housing 28 has a conduit removably and embracingly connected thereto which constitutes the other fluid communicating passage of the circulatory heating exchange system.

When it is desired to heat or cool the contents of the chamber within the casing 10, a heating fluid such as steam, hot water or the like or any suitable cooling fluid is delivered into the tube 44 as shown by the arrows, passes through the length of the inner passage 46 of the tube 44 and then returns through the outer passage 48 of the shaft 26 which opens continuously into the collection chamber 42 and from thence passes through the nipple 49 and conduit Sit back to the source of supply or any suitable place of discharge. Thus the

conduits

46 and 50 comprise the inlet and outlet means for circulating a heat exchanging liquid or fluid through the shaft 26.

When it is desired to employ the device for cooling or chilling the contents of the casing 10, a refrigerant such as cool water or the like may be circulated by the means previously described.

A body of liquid to be treated by the device is indicated by the numeral 52 and is disposed and received within the chamber within the casing 10, being maintained at a desired liquid level such as that indicated at 54 by suitable control valves, not shown, and by which the liquid is delivered into the chamber through a fluid inlet means such as the conduit 56 and nipple 58 extending through the end wall 14, and is discharged therefrom by means of the nipple 60 extending through the end wall 12 and which is connected to a fluid outlet conduit 62.

The casing is also provided with a gas inlet and gas outlet means opening into the chamber within the casing 10 by means of which oxygen or other gases may be delivered into and discharged from the interior of the same for oxygenation of the liquid therein; or whereby any desired pressure may be maintained upon the liquid; or whereby a subatmospheric pressure may be maintained thereon, it being understood that the inlet and outlet means is connected to any suitable source of supply and discharge and is operated by means of control valves of conventional type, not shown. For this purpose there is provided an inlet conduit such as that indicated at 64 which extends through the end wall 12, and an outlet conduit 66 which extends through the end wall 14. These conduits are preferably provided adjacent the top of the chamber within the casing or well above the liquid level 54 therein so that the gaseous medium introduced into or withdrawn from the chamber will enter and leave the vapor space therein above the liquid level and will have a counter flow relative to the flow of liquid.

A previously mentioned, the arrangement is particularly adapted for the introduction of oxygen into or the passage of oxygen through the chamber therein the casing 16 for the purpose of oxygenation of the liquid 52 within which liquid may consist of blood taken from a patient and Which blood is to be treated by various means prior to its return to the patients body. Where a continuous circulation of oxygen or other gas through the chamber is desired, it is obvious that any suitable source of supply will be connected to the fluid inlet means 64 and such oxygen either under pressure from a pump, or from a tank under pressure or from the atmosphere and at a controlled temperature may be inducted into the chamber, at a controlled rate as previously mentioned, and may be withdrawn at a similar controlled rate through the outlet 66.

In order to effect a thorough and efiicent contact between the gases and liquid within the container, and in order to simultaneously impart heat thereto or to chill the same, as for example in order to maintain a given temperature of the liquid during its passage through the chamber, there are provided a plurality of mixing and heating disks each indicated generally by the numeral 70. In the form of disks illustrated in FIGURES 1, 6 and 10, the disks are centrally apertured for a snug but sliding engagement longitudinally upon the shaft 26, being separated from each other by suitable annular spacer rings as at 72, and being clamped into a rigidly secured assembly as by means of a clamping nut 74 threaded on one end of the shaft and by a retaining member in the form of a ring 76 secured upon the other end of the shaft and abutting against an adjusting nut 78 threaded in the bore 34 previously mentioned.

In this manner the disks which may thus be readily removed or replaced or varied in number are rigidly clamped together in a closely spaced relation with the hubs of the disks being in a good heat exchange relation with the exterior of the shaft 26.

As will be observed from FIGURE 1, the liquid level 54 is maintained at a height to immerse any selected portion of the surface area of the disks 70 in the liquid 52 with the remaining portion of the disk surfaces being exposed to the vapor space above the liquid level. Consequently, as the disks rotate upon rotation of the shaft, and the latter is effected by any suitable means and source of power as by means of a pulley 8t secured thereto, the rotating disks will lift liquid from the body of liquid 52, thereby coating the surface of the disks upon both sides thereof with a thin liquid film and carry this coated surface or film into the vapor space within the chamber. Thus there is obtained a highly effective contact area between the liquid and the gases within the chamber to effect the desired absorption of the gases by the liquid, as for example in order to oxygcnate blood or the like. Further, the input of heat through the shaft will radiate outwardly along the disks from the central or hub portions thereof towards the periphery thereof and thus elfect a substantially uniform heating over a very large effective area of the liquid and gases within the chamber. In the case of a coolant being circulated, it is of course evident that the reverse heat exchange relation will exist.

It will be observed that by this arrangement there is a minimum disturbance or agitation of the liquids so as to avoid producing turbulence therein which in turn would tend to produce bubbles in the liquid. At the same time,

a maximum effective area of contact between the gas and liquid within the container is effected as well as a maximum rate of heat exchange therebetween.

This apparatus is ideally adapted for use as a blood oxygenator for various types of medical equipment in view of the lack of turbulence produced in the blood during treatment, and the ability to obtain a maximum input of heat over a uniform and very great area of liquid and gas contact, without the danger of overheating the blood with detrimental affects. Obviously, it is possible to vary the heating or cooling effect and the temperature maintained in the liquid within the device by controlling the rate of flow of the heat exchange medium in the circulating passage system within the shaft 26.

A generally similar form of apparatus is disclosed in FIGURE 6 wherein the same construction of casing me is provided with

end walls

102 and 104 sealed to the casing 1% in the manner previously described and retained clamped thereto as by the fastening bolts or tension members 106. In this form of the invention there is likewise provided a gas inlet means 103 and a gase outlet means by means of which air or other gases may be supplied into the chamber within the casing 1% either by circulating a gas therethrough for gas and liquid contact therein; for producing a pressure above atmospheric therein, or for maintaining a subatmospheric pressure therein, and also, in some instances to effect a heat exchange with the liquid being treated. Also there is provided the liquid inlet means 112 and a liquid outlet means 114 provided in the two end walls 194 and 102 respectively to thereby maintain a desired liquid level as at I16 within the device.

As in the preceding form of the invention there is likewise provided a hollow shaft formed of a good heat transmitting material and having one end journaled in a suitable bearing bushing 122 provided in an externally threaded tubular boss 124 formed in the end wall 104, with a heat exchange liquid outlet conduit means 126 being connected to this boss as by means of a gland 128 to thus have continuous communication with the end of the hollow shaft 120.

The other end of the shaft extends through a suitable bearing 1% together with a packing gland or stuffing box assembly 132 formed in an axially extending and enlarged boss 134 in the end wall 102. Secured to the boss 134 is a housing or body 136 providing a chamber 138 between itself and the boss 134, the body being detachably secured as by fastening means Mt to the boss. A heat exchange fluid inlet means indicated at 142 has communication with the interior of the chamber 138, and by means of a series of circumferentially spaced apertures or ports 144 in the shaft 120 establishes communication with the interior of the shaft. Thus a heat exchange liquid, either heating or cooling, can be continuously passed in one direction through the shaft to thereby heat or cool the latter. The extremity of the shaft passes through a further packing or stufiing box assembly as at 146 and is provided with a pulley 148 or other means by which rotation of the shaft is obtained from any suitable source of power, not shown.

As in the preceding embodiment, a plurality of disks I56 encircle the shaft in spaced relation thereon and are fixedly spaced from each other as by means of spacer rings or collars 152 the assembly of disks and collars being compressibly clamped together into a rigid assembly as by means of clamping nuts 154 and 156 threadedly engaged upon correspondingly externally threaded portions of the shaft. The disks and spacers are in good heat exchange relation with the exterior surface of the shaft.

The operation of this form of the invention is identical to that previously described and a further description of the same is deemed to be unnecessary.

A third form of apparatus, of generally similar construction and operation, is illustrated in FIGURE 10. A cylindrical casing 300 is clamped between

end plates

302 and 304 by the tension bolts 3% as described in connection with the preceding embodiments. A hollow shaft 303 of a good heat conducting material extends axially through the casing 3th), being journaled therein by the

bushings

310 and 312 disposed in the end walls.

Liquid is maintained in the casing at a selected level 314 through suitable control of liquid flow through the liquid inlet means 316 and liquid outlet means 318. Gas or air inlet and outlet means 320 and 322 respectively, each provided with conventional flow control means, not shown, introduce or exhaust air or other gases for the same purposes set forth in connection with the preceding embodiments.

A gas or air inlet housing 324 is detachably secured in embracing relation upon a tubular boss 326 of the end plate 394 as by a fastening means 328. The housing 324 surrounds the end of the shaft 303, having a chamber 1? 330 supplied with gaseous fluid from any suitable source by the fitting 332. This chamber 330 is continuously in communication by cross passages 334 with an axial bore or passage 335 in the shaft 3%.

The extremity of the shaft 3% passes through sealing

elements

336 and 338 in the housing 324 on opposite walls of the chamber 330 and projects beyond the housing 324 for connection to any suitable driving means, not shown.

The other end of the shaft 308 is enlarged and has an enlarged bore or chamber 34% therein with which the bore 335 communicates. Received in the bore 348 is a sheet metal tube or sleeve 342 of a good heat conductive material. The inner end 346 of the tube 342 terminates in spaced relation to the inner or bottom wall of the chamber 343 into which the bore 335 enters providing a chamber 348. The latter serves to provide a continuous connection between the exterior of the tube 342 and the bore 335 for a purpose to be subsequently apparent.

Received within the tube 342 and entering from a housing 350 which covers the open other end thereof are the electrical conductors 352 of any conventional electric resistance heating elements 354.

The exterior surface of the shaft 3% along any desired length thereof has longitudinal channels ass which are in continuous communication with the chamber 343 and the bore 340 about the exterior of the tube 342. Fixedly but removably secured upon the shaft 308 is an assem bly of disks 360 and spacer collars 362, the latter having projecting spacer lugs 364 on one face thereof. A clamping nut 366 threaded on the shaft 368 clamps the assembly of disks and spacers in rigidly compressive relation as against the bushing 31%.

In this manner, gaseous fluids introduced from the

members

332, 330, 334, 335, 348 and 356 are uniformly diffused and vented into the vapor space above the liquid level 314 in the casing 301) and also are uniformly distributed in an intimate liquid and vapor contact with the liquid film carried by each disk 360. Thus the effective area of gas and liquid contact is greatly increased and rendered more efficient.

In some instances the electrical heating element 354 may of course be replaced by other heating or cooling mediums of the character hereinbefore set forth.

However, although the relatively flat or straight disks '70, 150 or 360 of the three preceding embodiments may in some instances be satisfactorily employed, it is pre ferred to employ a convoluted type of disk in the assemblages of FIGURES l, 6 or 10, such types of disk being shown in detail in FIGURES 3-5 and 11. struction of FIGURES 3-5, each disk designated generally by the numeral 160 is of a laminated construction and also is of a convoluted configuration. Thus, as shown best in FIGURE 5, the disk consists of a central or medially disposed plate or sheet of material 162 of a relatively high heat exchange characteristic, copper, aluminum or silver being satisfactory for this purpose. Further, there are provided a pair of outer layers or sheets of material as at 164 and 166 bonded in any suitable manner to the opposite sides of the medial layer 162. These outer sheets are preferably of a material possessing to a high degree the characteristic of being non-wettable and of relatively poor thermal conductivity in order that a relatively thin disk will conduct heat uniformly over its surface for the particular liquid with which the device is to be operated. For this purpose the outer sheets may be of nickel, chrome or of suitable plastic materials such as nylon.

As previously mentioned, the preferred form of disk 160 is convoluted in its contour. Thus there are provided a plurality of circumferentially extending ridges 158 which project upon opposite sides of the disks as shown in FIG- URES 4 and 5, there being corresponding depressions or valleys between these ridges as shown at 1'70. As will be perceived from FIGURES 4 and 5, the ridges on one In the con- 8 side of the disk are accompanied by corresponding valleys on the other side thereof so that a series of disks may be nested with respect to each other as shown in FIGURE 4.

An important feature of this invention resides in the selecting of the necessary critical proportions of curvatures of the surface of the disk between the valleys and ridges of the convolutions and also the relative depth and width of such ridges and valleys so as to produce the most effective spacing of the disks and of their nested convolutions and ridges as shown in FIGURE 4. This spacing is so chosen as to prevent the surface tension of the liquid tending to bridge the gap between adjacent disks and thus insure that each disk will be coated with a film of the liquid to be heated thereby independently of the coating of the other disks. Further, the rate of curvature of the disks is such that taking into consideration the viscosity of the liquid, the latter will not fill the valleys of the convolutions and thereby reduce the surface area for gas exchange. The rate of curvature also determines the spacing of the disks.

For convenience of illustration, FIGURE 4 shows the hub portions 172 of each disk being disposed between and clamped between adjacent spacers or collars 174 upon the shaft 26. However, it will be understood that in the interest of better heat exchange relation it may be preferred to form the hubs of the disks laterally enlarged so that they will themselves provide the necessary spacing elements therebetween.

In the flow of heat radially outwardly in a disk from the hub toward the disk periphery, a disk of uniform thickness is well known to be cooler than its hub portion. In order to overcome this disadvantage and maintain a more uniform temperature over the entire surface of the disk, a contour such as that shown in FIGURE 11 is employed.

Here a disk 380 is corrugated in the same manner as described in connection with the disk 160 of FIGURES 3 and 4 and likewise may be laminated as set forth in FIGURE 5. However, the disk has a relatively wide hub 382 where the disk is mounted in good heat exchange relation upon the central shaft and is of a progressively narrowing thickness as it approaches its rim. The rate of narrowing is in accordance with the heat flow gradient of the particular material employed so that the rate of heat emission or absorption by the disk over its surface will produce a uniform temperature thereon.

In each form of the invention as shown in FIGURES 1, 6 and 10, there is provided a filter element of a construction shown in FIGURES 8 and 9. The filter element bearing the same numerals in both FIGURES 1 and 6, serves the very important function of preventing any emboli, clots or debris from passing into the general circulation system of the patient. By the arrangement of the filter unit within the oxygenator separate and additional priming with blood is rendered unnecessary, saving both time and blood.

For convenience, the filter unit is disposed immediately adjacent to the

outlet end plates

12 or 102 of FIGURES l. and 6 respectively, being retained in place in any desired suitable manner.

The filtering device comprises a pair of rings 200 and 2 02 of a vinyl plastic or other suitable material Whose oute peripheries may be snugly and frictionally gripped by the wall of the

casing

10 and 100. Across the lower portion of each ring is an integral fiat bar 204 which divides the area of the ring into a relatively large upper opening 206 and a smaller lower opening 208.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A blood heat exchange apparatus comprising a tank having a chamber for receiving blood therein and closed from the atmosphere, a rotary shaft in said cham ber, driving means connected to said shaft for effecting rotation thereof, conduit means connected to said shaft for circulating therethrough a heat exchanging fluid, a plurality of spaced disks adapted to be at least partially immersed in the blood in said chamber and having hubs fixedly secured to said shaft in good heat exchange relation, said disks being convoluted and disposed in a spaced but nested relation, said conduit means comprising a housing encircling one end of said shaft and forming a chamber thereabout, said shaft including therein a pair of longitudinally extending passages, said passages having communication with each other within one end of said shaft, the other end of one passage being connected to said housing and inlet means and outlet means for a heating fluid connected to said housing and to the other end of the other of said passages.

2. The combination of claim 1 wherein said housing and said heating fluid inlet and outlet means are disposed upon the exterior of said tank.

3. The combination of claim 2 wherein said tank has an end wall and said housing is supported thereby.

4. An oxygenator heat exchange gas and liquid contact apparatus comprising a horizontally elongated tank having a liquid receiving chamber therein sealed from the atmosphere, said tank having end walls defining opposite ends of said chamber, means including a liquid inlet and a liquid outlet in opposite end walls for maintaining an adjustable liquid level in said chamber, means including an inlet and anoutlet in opposite end walls for effecting a flow of oxygen through said chamber above said liquid level and in counterflow to the liquid flow, a shaft in said chamber having its opposite ends journaled in and extending through said end walls and disposed for rotation about a horizontal axis normally located above said liquid level, a plurality of disks removably mounted in longitudinally spaced relation upon said shaft, each disk being in good heat exchange relation with said shaft, said disks being adapted to have their lower portions immersed in and their upper portions disposed above said maintained liquid level, means for releasably axially com pressing and clamping said disks into a rigid assembly and fixedly upon said shaft, drive means rotating said shaft, said shaft having a bore opening from one end of said shaft and extending substantially the entire length of said disk assembly, a stationary tube carried by an end wall and concentrically disposed in and extending substantially the entire length of said bore and means at the open end of said tube for establishing communication respectively with said bore and tube and for supplying a heat exchange fluid to and for withdrawing it from said shaft.

5. The combination of claim 4 wherein one of said heat exchange fluid supplying and withdrawing means comprises a boss on the exterior of an end wall, a housing secured to said boss and defining a collection chamber therewith into which said shaft bore discharges, said 10 shaft being journaled in said boss and said tube being carried by said housing.

6. The combination of claim 4 wherein said disks are of a progressively narrowing width from their centers to their peripheries suflicient to maintain a substantially uniform temperature over their surface areas.

'7. An oxygenator and heat exchange gas and liquid contact apparatus comprising a horizontally elongated tank having a liquid receiving chamber therein sealed from the atmosphere, said tank having end walls defining opposite ends of said chamber, means including a liquid inlet and a liquid outlet in opposite end Walls for maintaining an adjustable liquid level in said chamber, means including an inlet and an outlet in opposite end walls for effecting a flow of oxygen through said chamber above said liquid level and in counterfiow to the liquid flow, a shaft in said chamber having its opposite ends journaled in and extending through said end walls and disposed for rotation about a horizontal axis located above said liquid level, a plurality of disks removably mounted in longitudinally spaced relation upon said shaft, each disk being in good heat exchange relation with said shaft, means for releasably axially compressing and clamping said disks into a rigid assembly and fixedly upon said shaft, drive means rotating said shaft, said shaft having a bore therein, means for introducing a heat exchange means into said bore from one end of said shaft, means for introducing oxygen into said bore from the other end of said shaft and passages in said shaft discharging oxygen from said bore into said chamber above the liquid level therein.

8. The combination of claim 7 wherein said passages discharge into the spaces between each pair of adjacent disks whereby to contact the liquid on said adjacent disks with oxygen from said bore.

References Cited by the Examiner UNITED STATES PATENTS 254,003 2/82 Gontard 261-92 998,020 7/11 Mabee 26l-87 1,166,139 12/15 Marwedel 165-92 1,879,140 9/32 Edwards l--146 1,895,287 1/33 Lambert -1 -446 1,995,302 3/35 Goldstein 1282l4 2,680,007 6/54 Arbuckle 165-86 3,065,748 11/62 Senning et .al. 128-214 3,074,401 1/63 Friedman et a1 1282l4 FOREIGN PATENTS 408,016 4/34 Great Britain.

OTHER REFERENCES Mendelsohn et al.: Management of the Patient During Open Heart Surgery, from Surgery, vol. 45, No. 6, June 1959, pp. 949-53.

RICHARD A. GAUDET, Primary Examiner. JORDAN FRANKLIN, Examiner.

Claims

1. A BLOOD HEAT EXCHANGE APPARATUS COMPRISING A TANK HAVING A CHAMBER FOR RECEIVING BLOOD THEREIN AND CLOSED FROM THE ATMOSPHERE, A ROTARY SHAFT IN SAID CHAMBER, DRIVING MEANS CONNECTED TO SAID SHAFT FOR EFFECTING ROTATION THEREOF, CONDUIT MEANS CONNECTED TO SAID SHAFT FOR CIRCULATING THERETHROUGH A HEAT EXCHANGING FLUID, A PLURALITY OF SPACED DISKS ADAPTED TO BE AT LEAST PARTIALLY IMMERSED IN THE BLOOD IN SAID CHAMBER AND HAVING HUBS FIXEDLY SECURED TO SAID SHAFT IN GOOD HEAT EXCHANGE RELATION, SAID DISKS BEING CONVOLUTED AND DISPOSED IN A SPACED BUT NESTED RELATION, SAID CONDUIT MEANS COMPRISING A HOUSING ENCIRCLING ONE END OF SAID SHAFT AND FORMING A CHAMBER THEREABOUT, SAID SHAFT INCLUDING THEREIN A PAIR OF LONGITUDINALLY EXTENDING PASSAGES, SAID PASSAGES HAVING COMMUNICATION WITH EACH OTHER WITHIN ONE END OF SAID SHAFT, THE OTHER END OF ONE PASSAGE BEING CONNECTED TO SAID HOUSING AND INLET MEANS AND OUTLET MEANS FOR A HEATING FLUID CONNECTED TO SAID HOUSING AND TO THE OTHER END OF THE OTHER OF SAID PASSAGES.