Blood component processing systems and methods using capacitive sensing of fluid conditions

Abstract

Blood component processing systems and methods are adapted to be coupled to a blood component processing device. The systems and methods employ a fluid circuit comprising at least one fluid pressure actuated pump station, at least one fluid flow path communicating with the pump station, and at least one valve in the fluid flow path. A control module sized and configured to interact with the fluid circuit includes an actuator to selectively apply fluid pressure to the pump station in concert with operation of the valve to pump fluid through the fluid flow path in response to a control program. A circuit board assembly is associated with the actuator in electrical conductive interaction with fluid in the pump station. The circuit board assembly comprises a part of a capacitive sensing circuit. The circuit board assembly can comprise, e.g., a printed circuit board assembly, or a flexible circuit, or a molded circuit. The circuit board assembly can, e.g., be face-mounted on the actuator or comprise an integrated component of the actuator.

We claim:  
     
         1 . A blood component processing system adapted to be coupled to a blood component processing device comprising 
 a fluid circuit comprising at least one fluid pressure actuated pump station, at least one fluid flow path communicating with the pump station, and at least one valve in the fluid flow path,    a control module sized and configured to interact with the fluid circuit including an actuator to selectively apply fluid pressure to the pump station in concert with operation of the valve to pump fluid through the fluid flow path in response to a control program, and a circuit board assembly associated with the actuator in electrical conductive interaction with fluid in the pump station, the circuit board assembly comprising a part of a capacitive sensing circuit, and    a controller coupled to the control module including the control program, a first function that commands the control module to selectively apply fluid pressure to the pump station in concert with operation of the valve to convey a fluid through the fluid circuit, and a second function that registers changes in capacitance in the capacitive sensing circuit as a result of passage of fluid through the pump chamber and generates an output.    
     
     
         2 . A system according to  claim 1   wherein the second function outputs a fluid flow rate.    
     
     
         3 . A system according to  claim 1   wherein the second function outputs a fluid volume.    
     
     
         4 . A system according to  claim 1   wherein the circuit board assembly comprises a printed circuit board assembly.    
     
     
         5 . A system according to  claim 1   wherein the circuit board assembly comprises a flexible circuit.    
     
     
         6 . A system according to  claim 1   wherein the circuit board assembly comprises a molded circuit.    
     
     
         7 . A system according to  claim 1   wherein the circuit board assembly is face-mounted on the actuator.    
     
     
         8 . A system according to  claim 1   wherein the circuit board assembly is an integrated component of the actuator.    
     
     
         9 . A method of carrying out blood component processing using a fluid circuit comprising at least one preformed, fluid pressure actuated pump station, at least one fluid flow path communicating with the pump station, and at least one valve in the fluid flow path, the method comprising the steps of 
 placing the fluid circuit into interaction with a control module including an actuator to selectively apply fluid pressure to the pump station in concert with operation of the valve to pump fluid through the fluid flow path in response to a control program,    placing a circuit board assembly into associated with the actuator in electrical conductive interaction with fluid in the pump station, the circuit board assembly comprising a part of a capacitive sensing circuit, and    registering changes in capacitance in the capacitive sensing circuit as a result of passage of fluid through the pump chamber to generate an output.    
     
     
         10 . A method according to  claim 9   wherein the registering step outputs a fluid flow rate.    
     
     
         11 . A method according to  claim 9   wherein the registering step outputs a fluid volume.    
     
     
         12 . A method according to  claim 9   wherein the placing step comprises placing a printed circuit board assembly into association with the actuator.    
     
     
         13 . A method according to  claim 9   wherein the placing step comprises placing a flexible circuit into association with the actuator.    
     
     
         14 . A method according to  claim 9   wherein the placing step comprises placing a molded circuit into association with the actuator.    
     
     
         15 . A method according to  claim 9   wherein the placing step comprises face-mounting the circuit board assembly on the actuator.    
     
     
         16 . A method according to  claim 9   wherein the placing step comprises integrating the circuit board assembly into the actuator.