Invalidating a continuous glucose monitor (CGM) micro-needle patent using 1980s commercial inkjet printer manuals.
A leading medical device manufacturer was sued over a patent claiming a micro-fluidic capillary needle array used in painless Continuous Glucose Monitors (CGMs).
The patent claimed this specific micro-structure was novel because it used a highly specific geometric arrangement of micro-capillaries to draw interstitial fluid without hitting nerve endings.
Cut-off Date: Prior to 2008
Standard searches focused entirely on medical devices, syringes, and blood testing. However, prior to 2008, medical fluid extraction relied almost entirely on traditional macro-scale hypodermic needles.
Previous search firms restricted their queries to A61B (Diagnosis; Surgery; Identification). If the micro-fluidic geometry was used outside of healthcare, it would never appear in the search results.
We stripped away the "blood" and "glucose" jargon. The core physics was simply: a geometric array of micro-capillaries designed to move microscopic droplets of fluid.
We asked: What other industry mastered the movement of microscopic fluid droplets long before the medical field? Answer: The commercial printing industry.
To prove obviousness (103), we found a 2002 biomedical engineering paper suggesting that commercial inkjet nozzle manufacturing techniques could be repurposed for transdermal drug delivery.
Our researchers bypassed patent databases and dug into 1980s commercial hardware documentation. We uncovered a 1988 service manual for a commercial inkjet printer.
The manual detailed the exact geometric arrangement of micro-capillaries used in the printer's ink-deposition nozzle. The physics of moving a micro-droplet of ink were identical to the physics of drawing a micro-droplet of interstitial fluid.