Apparatus for evaluation of biological fluid

Abstract

The apparatus comprises a plurality of stationary cuvettes, a chamber for the fluid to be evaluated, means for placing the chamber in fluid communication with each of the cuvettes and for permitting the flow of fluid from the chamber into each of the cuvettes, a plurality of optical transmitting means in registration with each of the cuvettes for transmitting a beam of radiant energy through each of the cuvettes, and detector means for intercepting each of the beams of radiant energy and for measuring any optical changes in the radiant energy passing through the fluid in each of the cuvettes. The chamber for the fluid, the plurality of cuvettes and the fluid communication means are all housed within, preferably, a disposable, self-contained cartridge of unitary construction. The cartridge is mountable within a carriage that houses the transmitting and detector means of the apparatus. The chamber which forms the upper portion of the cartridge can be prefilled with bacterial suspension. Periodically, during the growth of the subject bacteria the suspensions are agitated by suitable means. Samples of antibiotics of varying potency are placed in the cuvettes. The cartridge is mounted in the carriage. On a signal from the detector means a portion of the suspension passes into each of the cuvettes to begin the antibiotic titer which is evaluated by means of the transmitting and detector means and associated electronic circuitry.CROSS REFERENCE TO RELATED APPLICATION

What we claim is: 
     
       1. An apparatus for evaluating biological fluid which comprises: a. a plurality of cuvettes,   b. a chamber for fluid,   c. means for placing said chamber in fluid communication with each of said cuvettes and for permitting flow of fluid from said chamber into each of said cuvettes,   d. a plurality of optical transmitting means in registration with each of said cuvettes for transmitting a beam of radiant energy through each of said cuvettes,   e. detector means for intercepting each of said beams of radiant energy and for measuring any optical change in said radiant energy passing through the fluid in each of said cuvettes, said plurality of cuvettes and said chamber form a self-contained cartridge of unitary construction, said cartridge is mountable within a carriage for housing said plurality of optical transmitting means and detector means and contains means for placing each of said cuvettes in respective registration with each transmitting and detector means, said chamber is mounted above said plurality of cuvettes and said means for placing said chamber in fluid communication with each of said cuvettes,   f. a plurality of permeable membranes, each of which is mounted between the floor of said chamber and each cuvette,   g. pneumatic valve means operably connected between said cartridge and said detector means for causing a pressure differential between said chamber and each of said cuvettes in response to a signal from said detector means for permitting flow of fluid from said chamber to each of said plurality of cuvettes, and   h. temperature control means to maintain fluid temperatures substantially constant.   
     
     
       2. The apparatus of claim 1 wherein said temperature control means comprises: a. a heat sink,   b. heating elements mounted on said heat sink,   c. forced air means for directing ambient air onto said heat sink surface,   d. electronic temperature control circuit, and   e. temperature sensor electronically connected between said cartridge and said electronic temperature control circuit. .Iadd. 3. An apparatus which comprises:   a. a plurality of cuvettes,   b. a chamber for fluid,   c. means for placing said chamber in fluid communication with each of said cuvettes and permitting flow of fluid from said chamber into each of said cuvettes,   d. a permeable membrane mounted between the floor of said chamber and said cuvettes,   e. a gas permeable means in gaseous-fluid communication with each of said cuvettes to permit gas present in said cuvettes to escape from said cuvettes when said fluid passes from said chamber into said cuvettes,   f. a plurality of optical transmitting means each of which is in registration with a corresponding cuvette for transmitting a beam of radiant energy through said cuvette,   g. detector means for intercepting each of said beams of radiant energy and for measuring any optical change in said radiant energy passing through the fluid in each of said cuvettes,   h. means for imposing pressure differential between said chamber and said cuvettes to permit flow of fluid from said chamber through said permeable membrane into said cuvettes, and   i. temperature control means to maintain the temperature of said fluid substantially constant. .Iaddend. .Iadd. 4. The apparatus of claim 3 wherein said plurality of cuvettes and said chamber for fluid form a cartridge of unitary construction. .Iaddend..Iadd. 5. The apparatus of claim 3 wherein said means for imposing a pressure differential between said chamber and said cuvettes is a pneumatic valve means operably connected between said cartridge and said detector means. .Iaddend..Iadd. 6. The apparatus of claim 4 wherein said temperature control means comprises a heat sink, heating elements mounted on said heat sink, means for directing ambient air onto the surface of said heat sink, electronic temperature control circuit and temperature sensor electronically connected to said electronic temperature control circuit. .Iaddend..Iadd. 7. The apparatus of claim 5 wherein said temperature control means comprises a heat sink, heating elements mounted on said heat sink, means for directing ambient air onto the surface of said heat sink, electronic temperature control circuit and temperature sensor electronically connected to said electronic temperature control circuit. .Iaddend..Iadd. 8. An apparatus which comprises:   a. a plurality of cuvettes,   b. a first chamber for fluid,   c. a second chamber adjacent to said first chamber and separated therefrom by a retaining wall,   d. a permeable membrane mounted between the floor of said first chamber and said cuvettes,   e. a gas permeable means disposed in said second chamber in gaseous-fluid communication with each of said cuvettes to permit gas to escape from said cuvettes into said second chamber when said fluid passes from said first chamber into said cuvettes,   f. a plurality of optical transmitting means each of which is in registration with a corresponding cuvette for transmitting a beam of radiant energy through said cuvette,   g. a detector means for intercepting each of said beams of radiant energy and for measuring any optical change in said radiant energy passing through the fluid in each of said cuvettes,   h. means for imposing pressure differential between said first chamber and said cuvettes to permit flow of fluid from said chamber through said permeable membrane into said cuvettes, and   i. temperature control means to maintain the temperature of said fluid   
     
     
        substantially constant. .Iaddend..Iadd. 9.  The apparatus of claim 8 wherein said plurality of cuvettes and said first and second chambers forms a cartridge of unitary construction. .Iaddend..Iadd. 10. The apparatus of claim 8 wherein said means for imposing a pressure differential between said first chamber and said cuvettes is a pneumatic valve means operably connected between said cartridge and detector means. .Iaddend..Iadd. 11. The apparatus of claim 8 wherein said temperature control means comprises a heat sink, heating elements mounted on said heat sink, means for directing ambient air onto the surface of said heat sink, electronic temperature control circuit and temperature sensor electronically connected to said electronic temperature control circuit. .Iaddend..Iadd. 12. The apparatus of claim 9 wherein said temperature control means comprises a heat sink, heating elements mounted on said heat sink, means for directing ambient air onto the surface of said heat sink, electronic temperature control circuit and temperature sensor electronically connected to said electronic temperature control circuit. .Iaddend.