Systems and methods for capacitive fluid level detection, and handling containers

Abstract

A fluid container holder includes a body having a receptacle configured to receive a container. The body has a conductive outer surface for connection to an electrical ground or voltage source, and the holder is not formed solely of an electrically conductive metal. A fluid container handling assembly includes a drawer having a holder supporting a fluid container, and a frame supporting the holder. The frame is movable between a first position providing access to the holder and a second position positioning the holder within the instrument. The assembly also includes a first lock securing the holder to the frame when the frame is at the first frame position and unlocking the holder from the frame when the frame is at the second frame position. The assembly also includes a holder transporter configured to move the holder between a first holder position and a second holder position within the instrument.

What is claimed is: 
     
         1 . A holder for supporting one or more containers of fluid, the holder comprising:
 a bottom wall comprising a first electrically nonconductive portion and a first electrically conductive metal coating (i) affixed to an outer surface of the first electrically nonconductive portion, (ii) forming an outer surface of the bottom wall, and (iii) for connection to an electrical ground or voltage source;   a top surface defining one or more openings;   one or more receptacles, wherein each receptacle of the one or more receptacles extends from an opening of the one or more openings towards the bottom wall, and wherein each receptacle is configured to receive at least one container of the one or more containers;   first and second side walls, wherein the one or more receptacles are between the first and second side walls, and wherein at least one of the first and second side walls comprises a second electrically conductive metal coating (i) affixed to an outer surface of a second electrically nonconductive portion of the at least one of the first and second side walls, (ii) forming an outer surface of the at least one of the first and second side walls, (iii) contiguous with the first electrically conductive metal coating of the bottom wall, and (iv) for connection to the electrical ground or voltage source; and   an RFID tag affixed to an electrically non-conductive surface of the holder.   
     
     
         2 . The holder of  claim 1 , wherein the first electrically nonconductive portion of the bottom wall and the second the electrically nonconductive portion of the at least one of the first and second side walls each comprise an electrically non-conductive plastic. 
     
     
         3 . The holder of  claim 1 , wherein the first electrically conductive metal coating of the bottom wall and the second electrically conductive metal coating of the at least one of the first and second side walls are both made of either aluminum or copper. 
     
     
         4 . The holder of  claim 1 , wherein the one or more receptacles include multiple receptacles. 
     
     
         5 . The holder of  claim 1 , wherein the first electrically nonconductive portion of the bottom wall includes an inner surface, and each receptacle of the one or more receptacles extends from one of the one or more openings on the top surface to the inner surface of the bottom wall opposite the outer surface. 
     
     
         6 . The holder of  claim 1 , wherein the second electrically conductive metal coating of the at least one of the first and second side walls covers about 20% to about 30% of a vertical height of the second electrically nonconductive portion of the at least one of the first and second side walls. 
     
     
         7 . The holder of  claim 1 , wherein the second electrically conductive metal coating of the at least one of the first and second side walls covers substantially the entirety of the second electrically nonconductive portion of the at least one of the first and second side walls. 
     
     
         8 . The holder of  claim 1 , wherein the second electrically conductive metal coating of the at least one of the first and second side walls has a thickness between about 0.5 mils and about 2.0 mils. 
     
     
         9 . The holder of  claim 1 , wherein the first electrically conductive metal coating of the bottom wall has a thickness between about 0.5 mils to about 2.0 mils. 
     
     
         10 . The holder of  claim 1 , wherein the first and second electrically nonconductive portions comprise the same material. 
     
     
         11 . The holder of  claim 1 , wherein the first and second electrically conductive metal coatings comprise the same metal. 
     
     
         12 . The holder of  claim 1 , wherein:
 the first electrically conductive metal coating of the bottom wall has a thickness between about 0.5 mils to about 2.0 mils;   the second electrically conductive metal coating of the at least one of the first and second side walls has a thickness between about 0.5 mils and about 2.0 mils;   the first and second electrically nonconductive portions comprise the same material; and   the first and second electrically conductive metal coatings comprise the same metal.   
     
     
         13 . The holder of  claim 12 , wherein the second electrically conductive metal coating of the at least one of the first and second side walls covers about 20% to about 30% of a vertical height of the second electrically nonconductive portion of the at least one of the first and second side walls. 
     
     
         14 . The holder of  claim 12 , wherein the second electrically conductive metal coating of the at least one of the first and second side walls covers substantially the entirety of the second electrically nonconductive portion of the at least one of the first and second side walls. 
     
     
       15. The holder of clam 1, wherein each receptacle has a size and shape that matches a size and shape of a fluid filled container to be received in the receptacle.  
     
     
       16. The holder of  claim 1 , further comprising one or more knobs extending from the bottom wall.  
     
     
       17. The holder of  claim 16 , wherein the one or more knobs comprise a first knob aligned with each receptacle of the one or more receptacles.  
     
     
       18. The holder of  claim 17 , wherein each first knob comprises a post portion extending from the bottom wall and a flange extending outwardly from a distal end of the post portion.  
     
     
       19. The holder of  claim 17 , wherein the one or more knobs comprise a second knob aligned with each receptacle of the one or more receptacles.  
     
     
       20. The holder of  claim 4 , further comprising a crevice formed in the first and second side walls and the bottom wall that separates each of the multiple receptacles.  
     
     
       21. The holder of  claim 1 , further comprising:
 a first side and a second side, wherein the first side and the second side are opposing sides of the holder; and   a channel formed in the top surface on both the first side and the second side of the holder.    
     
     
       22. The holder of  claim 21 , wherein each channel is at least partially bounded by a spring arm.  
     
     
       23. The holder of  claim 1 , further comprising:
 a flange extending outwardly from a top portion of the holder, wherein an upper surface of the flange defines the top surface; and   an extension extending downwardly from the flange and including two slots oriented upwardly into the extension.    
     
     
       24. A compartment for storing fluids in an instrument, the compartment comprising:
 one or more holders, wherein each holder of the one or more holders includes:   a top surface defining one or more openings;   a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source, wherein the holder is not formed solely of an electrically conductive metal; and   a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall,   wherein each holder of the one or more holders defines one or more receptacles, and wherein each receptacle of the one or more receptacles extends between an opening of the one or more openings and the bottom wall; and   one or more containers containing a fluid, wherein each container of the one or more containers is (a) positioned in a receptacle of the one or more receptacles, and (b) is configured to receive a fluid transfer device adapted for capacitive fluid level sensing, and wherein at least one of the one or more containers includes an electrically conductive seal that the fluid transfer device passes through when the fluid transfer device enters the container.    
     
     
       25. An instrument configured to analyze one or more samples, comprising:
 one or more holders for supporting one or more containers of fluid, wherein each holder includes:   a top surface defining one or more openings;   first and second side walls, wherein at least one of the first and second side walls comprises a first electrically nonconductive portion and a first electrically conductive metal coating outer surface (i) affixed to an outer surface of the first electrically nonconductive portion, (ii) forming an outer surface of the at least one of the first and second side walls, and (iii) configured to be connected to an electrical ground;   one or more receptacles, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, and wherein each receptacle is configured to receive at least one container of the one or more containers;   a bottom wall comprising a second electrically nonconductive portion and a second electrically conductive metal coating (i) affixed to an outer surface of the second electrically nonconductive portion, (ii) forming an outer surface of the bottom wall, and (iii) configured to be connected to the electrical ground or a voltage source; and   a fluid transfer device adapted for capacitive fluid level sensing, wherein the one or more containers are accessible by the fluid transfer device.    
     
     
       26. The instrument of  claim 25 , further comprising:
 an electrically conductive brush configured to contact at least one of the bottom wall and the at least one of the first and second side walls to electrically ground the electrically conductive outer surface of at least one of the bottom wall and the at least one of the first and second side walls; and   a transporter configured to move at least one holder of the one or more holders from a first location to a second location in the instrument, wherein the second location includes the electrically conductive brush.    
     
     
       27. The instrument of  claim 25 , wherein the one or more holders are positioned on, or proximate to, a surface of the instrument such that the electrically conductive outer surface of a first holder of the one or more holders is electrically grounded by a direct or indirect physical contact with the surface.  
     
     
       28. The instrument of  claim 25 , wherein each holder of the one or more holders further includes a cover configured to retain the one or more containers in each holder while providing access to the one or more containers by the fluid transfer device, the cover including an electrically nonconductive portion that extends at least partially over the one or more containers.  
     
     
       29. A method of detecting a fluid level in a container including a fluid, comprising:
 positioning the container in a receptacle of a holder, wherein:
 the holder comprises:
 a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source; 
 a top surface defining one or more openings; 
 a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall, and 
 one or more receptacles including the receptacle, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, wherein the receptacle is configured to receive the container, and wherein the holder is not formed solely of an electrically conductive metal, and 
 
 the container is positioned such that a bottom surface of the container is disposed on, or is positioned proximate to, the bottom surface of the holder; and 
   inserting a fluid transfer device having a probe tip configured for capacitive fluid level sensing into the container to detect a level of the fluid in the container.    
     
     
       30. A method of extracting fluid from a container, comprising:
 positioning the container in a receptacle of a holder, wherein the holder comprises:
 a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source; 
 a top surface defining one or more openings; 
 a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall, and 
 one or more receptacles including the receptacle, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, wherein the receptacle of the one or more receptacles is configured to receive the container, and wherein the holder is not formed solely of an electrically conductive metal, 
   inserting a fluid transfer device having a probe tip configured for capacitive fluid level sensing into the container;   detecting a level of the fluid in the container using the probe tip; and   extracting fluid from the container using the fluid transfer device.    
     
     
       31. The method of  claim 30 , wherein the method further comprises:
 electrically grounding the electrically conductive surfaces of the holder by contacting the bottom surface or the side surface to the electrical ground or the voltage source via an electrically conductive brush, wherein contacting the side surface to an electrical ground includes moving the holder from a first location to a second location to contact the side surface with the electrically conductive brush.    
     
     
       32. The method of  claim 30 , wherein the bottom wall is connected to the electrical ground via an electrically conductive spring.