US 3507395 A
Description (OCR text may contain errors)
April 21, 1970 D. J. BENTLEY CARDIOTOMY RESERVOIR Filed Dec. 1, 1967 FIGZ FROM
SURGICAL FIELD INVENTOR. DONALD J. BENTLEY W W, M
United States Patent O 3,507,395 CARDIOTOMY RESERVOIR Donald J. Bentley, Santa Ana, Califl, assignor to Bentley Laboratories, a corporation of California Filed Dec. 1, 1967, Ser. No. 687,230 Int. Cl. C02c 1/10 US. Cl. 210-443 5 Claims ABSTRACT OF THE DISCLOSURE Apparatus for reclaiming blood from the surgical field of a patient by drawing blood from the field to the apparatus and returning the blood directly or indirectly to the patient, characterized in that the apparatus includes a plate in the path of incoming blood for spreading the blood into a thin sheet, and a fibrous membrane surrounding the plate and interposed in the path of blood flow outwardly of the apparatus, the combined spreading and filtering action removing impurities from the blood and placing the blood in a condition for return to a patient.
BACKGROUND OF THE INVENTION Field of the invention This invention relates to apparatuses for reclaiming blood withdrawn from the surgical field of a patient and placing the blood in condition for return to the patient.
Description of the prior art Prior art patents showing related structure for accomplishing the results for which the structure of this invention is intended, are the U.S. patents to Collins No. 3,295,297; Everett No. 3,191,600; and Desmet No. 2,406,207. Generally speaking, each of these patents discloses structure for reclaiming blood drawn from the surgical field of a patient and placing it in a condition for return to the patient or to other apparatus prior to return to the patient. Desmet Patent 2,406,207 relies upon settling of the blood to remove air bubbles or defoam the blood. Collins No. 3,295,297 passes blood through a screen and also across ribbed surfaces to remove air embolisms from the blood. Everett No. 3,191,600 directs the blood against the walls of a collecting chamber so that air bubbles will be removed from the blood as the blood settles in the bottom of the chamber.
SUMMARY OF THE INVENTION This invention is directed, in brief, to the provision of an apparatus for reclaiming blood drawn from the surgical field of a patient and placing the blood in a condition for return to a patient by removing air bubbles and other foreign matter from the blood. The best mode currently contemplated for carrying out the invention comprises a generally spherical member having means, such as a nipple, for connecting the member to a source of negative pressure. Inlet nipples lead into a conduit which opens into a plate. The plate is surrounded by a filter material so that incoming blood is first spread over the plate and then passes through filter material before being pumped or gravity fed out through an outlet below the plate.
DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of the blood reclaiming apparatus of the present invention;
FIGURE 2 is an enlarged section view taken generally along the line 22 of FIGURE 1; and
FIGURE 3 is a fragmentary sectional view taken generally along the line 33 of FIGURE 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT The blood reclaiming apparatus or reservoir 10 of this invention comprises a spherical ball 12 forming a body or collecting chamber. Preferably the ball is formed by the juncture of two semi-cylindrical halves 12a and 12b which are suitably joined, such as by heat sealing or the like, along flanges 12c and 12d, respectively. The halves 12a and 12b may be made of a clear plastic or other suitable material. A first outlet means or nipple 14 is formed on portion 12a and has a hollow interior 14a which communicates with the interior 16 of the sphere 12. Nipple 14 may be connected to a roller pump or to a suitable source of negative pressure, such as a vacuum pump, for reducing the pressure in the interior 16 of the sphere to thereby draw blood from the surgical field of a patient and encourage its flow into the interior of the sphere.
The reservoir 10 is also sometimes used with a positive pressure pump positioned between the reservoir 10 and the surgical field from which blood is being withdrawn. In other words, blood is drawn from the surgical field by the positive pressure pump and then forced into the reservoir 10. In such a use, the nipple 14 may serve as a vent to atmosphere to relieve pressure within the reservoir 10 which may result from the blood being pumped into the reservoir by the positive pressure pump.
The base of sphere portion 12b has anannular opening 18 which is surrounded by depending annular flange 20. A plurality of circumferentially spaced inwardly fac ing ribs or indentations 22 are formed in portion 12b adjacent the flange 20. A blood inlet and outlet assembly 24 is fitted in the opening 18 defined by flange 20. This assembly includes a lower plate 26 having an upwardly extending flange 28 of a size and shape to generally matingly engage with the interior of the depending flange 20. For positive securement of the assembly 24 within the opening 18, the flanges 20 and 28 may be heat sealed or otherwise bonded to each other.
Inlet means in the form of a pair of inlet nipples 30 and 32 diverge outwardly from lower .plate 26. Each nipple has a hollow interior, such as 32a, which communicates with the hollow interior or through passage 34 of the upstanding cylindrical column 36 integrally formed as part of lower plate 26. Column 36, in turn, supports spreader plate 38 which is a flat disc-like planar surface extending radially about, and slightly below the open end 40 of the column 36. A second outlet means or nipple 42 depends from lower plate 26 and has a hollow interior or through passage 42a which is in communication with the interior 16 of the sphere 12.
Filter means or filter element 44 is interposed between the inlet path of blood and the outlet path therefor by being wrapped about column 36 so that it surrounds plate 38 and the open end 40 of column 36. In the illustrated embodiment, this filter element takes the form of a polypropylene filter mesh 46 enclosed within a nylon bag 48. Preferably, filter mesh 46 is coated with a well-known medical silicone anti-foaming material. Bag 48 has tie means 50 at its open end to tie bag 48 and filter mesh 46 about the column 36 below plate 38 to form a substantially enclosed chamber 52 about the column 36 and the spreader plate 38 so that any blood entering through column 36 must pass through filter element 44 before returning outwardly of the apparatus by way of the outlet nipple 42. Spreader plate 38 serves to hold the filter means 44 on column 36 and to spread the interior thereof so as to create the chamber 52 and spread the interior of the filter so that a greater surface area is exposed for filtering. A radially projecting rib 39 extends outwardly from column 3 36. The purpose of ribs 22 and 39 is to hold the filter element 44 spaced from the second outlet means 42 to prevent unintentional sealing of the outlet.
Inlet nipples 30 and 32 are connected to suitable conduit means, such as flexible rubber or plastic tubing 56 and 58, respectively, which lead from the surgical field of the patient. Nipple 14 may be connected to a source of negative pressure (VP) for creating a suction in the interior 16 of sphere 12. This draws blood inwardly through nipples 30 and 32 and up the hollow interior 34 central column 36. From there the blood passes out the open end 40 of the column 36 and is spread in thin sheets over the spreader plate 38, thereby removing some of the air bubbles which may have been entrapped in the blood. The blood then passes through the polypropylene mesh mate rial 46 and the nylon bag 48 befor returning, being pumped or solely by the influence of gravity, through the outlet nipple 42 to be sent, either directly or indirectly by tubing 60, back to a patient. Any air bubbles which escape from the blood as it passes over the plate 38 and then into the filter member 44 will be removed from the chamber 16 through the connection of the nipple 14 with the source of negative pressure. Any solid particles in the blood will be trapped within the mesh 46 and retained therein while the blood continuously passes through the mesh and down to the output nipple 42.
Preferably the filter means 44 is of such a size relative to the interior 16 of the sphere 12 that the interior chamber 46 of the filter means 44 extends well above a Plane which bisects the sphere, generally along the line of flanges 12c and 12d. This is to accommodate relatively large amounts of blood while still retaining an air space above the top level of the expected blood pool. It is undesirable for bubbling to occur outside the filter element 44 which might be the case if the filter were so small that the normal amount of blood retained within the sphere normally covered the filter. This invention envisions the provision of a chamber 61 and a filter chamber 46 of sufficient size so as to continually provide an air space within the filter chamber 46 above the normal pool of blood which would be processed by the reservoir.
It is to be noted that no valving elements are interposed in the path of blood travel or in the fitting for connection with the source of negative pressure. Continuous, even blood flow can be directly regulated by the relative difference in pressure applied to the interior of the sphere. Blood may pass freely through the inlet and outlet passages, and in the intermediate stages of being spread over plate 38 and through filter element 44, with no possibility of contamination because of the lack of any contact with moving parts, valving elements or the like. It is intended that the body 12 and inlet and outlet assembly would be made of a suitable inexpensive plastic material such as that sold by the General Electric Co., under the trademark Lexan, so that the apparatus of this invention could be made cheaply enough to be used only once and then disposed of, rather than having to sterilize the same for repeated use.
It is to be understood that in addition to the mode of operation described, the cardiotomy reservoir of this invention could be operated by means of ap lying a vacuum to nozzle 14 of sufiicient magnitude to remove the blood from the surgical field, with the blood being withdrawn from the reservoir by means of a well known roller pump interposed in the tubing 60. Another alternative operating mode would be to utilize a roller pump with the inlet tubing 58 to pump blood to the reservoir and allow the blood to drain from the reservoir by gravity.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.
1. A reservoir for the storage of blood during surgical procedures, comprising:
a blood collecting chamber having a hollow interior,
an upper portion and a lower portion;
a vent on the upper portion of the chamber;
a hollow inlet joined to the lower portion of the chamber and having a generally upright column extending into the chamber interior for admitting blood to said interior, with a blood spreading plate mounted on said column; and
blood conditioning means extending upwardly within the chamber including a self-supporting bag like filter with a hollow pouch of anti-foam material within the filter, the filter and pouch affording a generally hollow sub-chamber generally embracing the column below the blood spreading plate and extending about and above the column and blood spreading plate, said plate being located in the bottom portion of said sub-chamber, the blood conditioning means occupying a substantial portion of the volume of the chamber so that the volume of the blood in the chamber regulated by the amount intro duced through the inlet and withdrawn from the outlet may occupy a substantial portion of the interior of the chamber without covering the entire blood conditioning means.
2. The reservoir of claim 1 wherein the inlet is provided with plural fittings for connecting the inlet with more than one source of incoming blood.
3. The reservoir of claim 1 wherein the blood spreading surface is planar and lies slightly below the open end of the blood inlet.
4. The reservoir of claim 1 wherein the chamber is provided with inwardly projecting ribs adjacent to the blood outlets for providing filter supports and intermediate blood return channels for the unimpeded outflow of blood.
5. The reservoir of claim 4 wherein the column is provided with an outwardly extending filter support rib.
References Cited UNITED STATES PATENTS 2,934,067 4/1960 Calvin 1282l4 2,982,286 5/1961 Welch 128276 3,044,663 7/ 1962 Norton et al. 3,087,490 4/1963 Broman 128214 3,175,555 3/1965 Ling 128-214 3,246,767 4/1966 Pall et al. 210--505 REUBEN FRIEDMAN, Primary Examiner T. A. GRANGER, Assistant Examiner U.S. Cl. X.R. 1282l4, 276