Apparatus and process for reagent fluid dispensing and printing

A method of assaying for an analyte comprising the steps of:

• (1) dispensing precise quantities of at least one diagnostic reagent fluid and at least one fluid sample by:
• (a) generating at least one electrical pulse of selected predefined characteristics;
• (b) altering the volume of a chamber containing the fluid by electro-mechanical means in response to the electrical pulse such that at least one droplet of fluid of a selected predetermined and reproducible volume is jetted from the chamber;
• and
• (c) repeating steps (a) and (b) until a desired quantity of fluid has been dispensed;
• and
• (2) detecting a reaction result produced by the fluid mixture.

A method of manufacturing a diagnostic test device, the test device of the type including a chemically treated test medium, the method comprising the steps of:

• (a) positioning a test device medium relative to a jetting chamber;
• (b) generating at least one electrical pulse of selected predetermined characteristics;
• (c) altering the volume of a chamber containing a reagent fluid by electro-mechanical means in response to the selected electrical pulse such that reagent fluid jetted from the chamber is in the form of a predetermined and reproducibly sized droplet and impacts the test device medium;
• and
• (d) repeating steps (a) through (c) until a desired pattern of reagent fluid has been formed on the test device medium.

A diagnostic fluid dispensing apparatus comprising:

• a jetting chamber comprising an orifice and a fluid intake aperture;
• a collapsible fluid reservoir containing at least one diagnostic reagent fluid connected to the intake aperture of the jetting chamber;
• and
• a transducer adapted to alternately expand and de-expand the jetting chamber to expel fluid droplets;
• the jetting chamber, reservoir and transducer cooperating such that capillary action at the orifice produces a pressure differential between the interior and exterior of the fluid reservoir upon emittance of fluid from the jetting chamber.

A method of manufacturing a diagnostic test device comprising the steps of:

• (a) positioning a test device medium relative to a jetting chamber;
• (b) applying pressurized diagnostic reagent fluid to a jetting chamber with an orifice such that fluid is expelled through the orifice;
• (c) altering the volume of the chamber by electro-mechanical means such that the expelled fluid is in the form of a stream of distinct uniformly sized droplets;
• and
• (d) directing at least one of the (1) expelled fluid and (2) the test device medium such that the fluid impacts the medium in a desired manner.