Instrument for performing a diagnostic test on a fluidic cartridge

Abstract

A cartridge reader is configured to carry out a diagnostic test on a fluid sample contained within a fluidic cartridge. The cartridge comprises first, second and third collapsible blisters containing at least one reagent for use in the diagnostic test. The cartridge reader comprises an upper clamp, occupying a fixed position relative to the reader and a lower clamp, movable relative to the upper clamp, and wherein the upper clamp and the lower clamp are configured to receive and hold a fluidic cartridge therebetween.

1 . A cartridge reader configured to carry out a diagnostic test on a fluid sample contained within a fluidic cartridge, wherein the cartridge comprises first, second and third collapsible blisters containing at least one reagent for use in the diagnostic test, the cartridge reader comprising:
 an upper clamp, occupying a fixed position relative to the reader and a lower clamp, movable relative to the upper clamp, and wherein the upper clamp and the lower clamp are configured to receive and hold a fluidic cartridge therebetween;   first, second and third blister actuators mounted on the upper clamp, and for aligning with first, second and third collapsible blisters of a fluidic cartridge inserted into the reader, wherein the first, second and third blister actuators are movable relative to the upper clamp, between a first position in which the blister actuators are spaced apart from the collapsible blisters comprised on the fluidic cartridge received between the upper and lower clamps, and a second position in which the blister actuators depress the collapsible blisters, thereby collapsing the blisters and ejecting the reagents contained therein into a channel in the microfluidic cartridge.   
     
     
         2 . The cartridge reader of  claim 1 , wherein the cartridge further comprises a recess, comprising a mechanical valve for depressurising a region of the cartridge, the valve having first and second valve seats, wherein the first valve seat comprises one port and the second valve seat comprises two ports, and first and second valve membrane portions configured, upon actuation, to seal the first and second valve seats, respectively, and wherein the upper clamp further comprises a mechanical valve actuation assembly for actuating the first and second valve membrane portions, the mechanical valve actuation assembly comprising:
 a first actuator mechanism for actuating the first valve membrane portion and a second actuator mechanism for actuating the second valve membrane portion;   wherein the first actuator mechanism is mounted to the upper clamp and is movable relative to the upper clamp between a first position in which it is spaced apart from the first valve membrane portion and a second position in which it actuates the first valve membrane portion; and   wherein the second actuator mechanism is mounted to the first actuator mechanism by a resilient biasing means and is movable relative to the first actuator mechanism, such that it is configured to actuate the second valve membrane portion before the first actuator mechanism is moved to its second position.   
     
     
         3 . The cartridge reader of  claim 1 , wherein each of the first, second and third blister actuators comprises a housing portion from which extends a stem portion having mounted on its end a tip portion for contacting the collapsible blisters, wherein the tip portion of one or more of the first, second and third blister actuators has an outwardly-extending curved profile. 
     
     
         4 . The cartridge reader of  claim 3 , wherein the tip portion of one or more of the first, second and third blister actuators has a substantially flat profile. 
     
     
         5 . The cartridge reader of  claim 4 , wherein the first and second blister actuators has an outwardly-extending curved profile and the third blister actuator has a substantially flat profile. 
     
     
         6 . The cartridge reader of  claim 1 , further comprising an actuator controller, and wherein each of the first, second and third blister actuators are linear actuators driven by a stepper motor, the actuator controller coupled to each stepper motor and configured, upon actuation, to maintain each of the first, second and third blister actuators in their second positions for at least 2 seconds, preferably at least 5 seconds, preferably at least 8 seconds, preferably at least 10 seconds to collapse the blisters and eject the reagents contained therein. 
     
     
         7 . The cartridge reader of  claim 1 , wherein each blister actuator has a travel of between and 70 mm between its first and second positions, preferably between 40 mm and preferably 44 mm. 
     
     
         8 . The cartridge reader of  claim 3 , wherein one or more of the first, second and third blister actuators comprises a spring mounted around the stem portion, between the housing portion and the tip portion to provide damping. 
     
     
         9 . A fluidic cartridge for carrying out a diagnostic test on a sample contained therein, the cartridge comprising first, second and third collapsible blisters containing at least one reagent for use in the diagnostic test and a mechanical valve for isolating the sample with the cartridge, and configured for use with a cartridge reader of  claim 2 , the first, second and third collapsible blisters configured to be collapsed by the first, second and third blister actuators, respectively, and the mechanical valve configured to be moved from an open position to a closed position by the mechanical valve actuation assembly. 
     
     
         10 . A cartridge reader for carrying out a diagnostic test on a fluid sample contained in a fluidic cartridge in the cartridge reader, the fluidic cartridge comprising bellows for moving the fluid sample along a network of channels, a plurality of pneumatically actuated valves in the network of channels and a pneumatics interface, the cartridge reader comprising:
 a pneumatics system, comprising:   a pneumatics interface, comprising a plurality of pneumatic interface ports, configured to couple to the pneumatics interface on the fluidic cartridge;   a positive pressure sub-system comprising first and second positive pressure reservoirs and a first pump configured to provide a supply of positive pressure to maintain the first and second positive pressure reservoirs at first and second positive pressures, respectively, wherein the first and second positive pressures are different; and   a negative pressure sub-system comprising a negative pressure reservoir and a second pump configured to provide a supply of negative pressure to maintain the negative pressure reservoir at a negative pressure;   a valve system comprising a plurality of solenoid valves, each connected to a pneumatic interface port and configured to couple to that pneumatic interface port at least one of: the first and second positive pressure reservoirs and the negative pressure reservoir; and processing means configured to operate the first and second pumps and the plurality of solenoid valves according to a predetermined cycle during the diagnostic test such that during the cycle:   a first subset of pneumatic interface ports is selectively coupled to either the first positive pressure reservoir or the negative pressure reservoir for actuating the bellows and the pneumatic valves on the cartridge; and   a second subset of pneumatic interface ports is coupled to the second positive pressure reservoir for evacuating a surplus fluid from at least a portion of the network of channels in the fluidic cartridge.   
     
     
         11 . The cartridge reader of  claim 10 , wherein the positive pressure sub-system further comprises a pressure regulator connected between the second positive pressure reservoir and a reference-pressure solenoid valve, and wherein the processing means is configured to operate the reference-pressure solenoid valve such that a reference-pressure pneumatic interface port is coupled to the second positive pressure reservoir via the pressure regulator for providing a reference pressure to the fluidic cartridge. 
     
     
         12 . The cartridge reader of  claim 10 , wherein the first positive pressure is a positive gauge pressure of 1 bar. 
     
     
         13 . The cartridge reader of  claim 10 , wherein the negative pressure is a negative gauge pressure of 0.5 bar. 
     
     
         14 . The cartridge reader of  claim 11 , wherein the reference pressure is a gauge pressure of between 0 and 1 bar and the pressure regulator is configured to maintain the reference pressure at 0.5% full scale accuracy. 
     
     
         15 . The cartridge reader of  claim 10 , wherein the positive pressure sub-system further comprises one or more fluid traps between a corresponding one or more pneumatic interface ports and their respective solenoid valves. 
     
     
         16 . The cartridge reader of  claim 15 , wherein the one or more fluid traps includes a fluid trap between each of the second subset of pneumatic interface ports and their respective solenoid valves. 
     
     
         17 . The cartridge reader of  claim 15 , when dependent on  claim 11 , wherein the one or more fluid traps includes a fluid trap between the reference-pressure solenoid valve and the reference-pressure pneumatic interface port. 
     
     
         18 . The cartridge reader of  claim 10 , wherein the pneumatic interface comprises eleven pneumatic interface ports aligned in first and second rows, consisting of five pneumatic interface ports and four pneumatic interface ports, respectively, wherein the pneumatic interface ports of the first and second rows are offset from each other. 
     
     
         19 . The cartridge reader of  claim 18 , wherein pneumatic interface port number 1 is situated at one end of the first row, and each subsequently numbered port is adjacent the preceding port of the opposite row. 
     
     
         20 . The cartridge reader of  claim 19 , wherein the first subset of pneumatic interface ports consists of port numbers 1, 2, 3, 4, 6, 8, 10 and 11.