Back Pressure Chamber

Neuma designed, procured components, and assembled a fixture which is capable of dynamically adjusting a back pressure while a drug delivery device delivers fluid onto a precision lab balance

Back Pressure Chamber


  • Design the mechanical layout, including the pressure vessel, electronics, pneumatics, and graphical user interface
  • Spec out and procure a precision balance which meets the customer’s requirements
  • Procure various mechanical, electrical, and pneumatic off-the-shelf components as well as custom machined components
  • Write a Windows compatible application which the user can modify on the fly and capture data in real time

Key Accomplishments

  • Fully functional fixture which measures mass-delivery data in real time and is displayed graphically during testing. Data is output directly to an Excel file.  Back-pressure parameters can be manually set by the user by means of a simple interface or can be dynamically altered by software as more mass is delivered.  Safety features are built-in so that the pressure vessel cannot be over-pressurized or opened while pressurized.  The pressure vessel is easily disassembled for fluid removal and a replaceable septum can be changed out after multiple needle pierces.
  • 3D CAD for the mechanical layout
  • Pneumatics schematic
  • Altium files for the electrical layout
  • Integrated precision balance
  • Final fixture assembly performed in house
  • Application can be loaded onto any Windows-based PC