Smart Card Diagnostics: FlexCard™ Technology

Existing point-of-care testing technologies span a spectrum of analytical performance. At the low end of the performance spectrum there are qualitative or semi-quantitative strips (immunoassay strips, glucose test strips and the like) that cost only pennies to manufacture and retail at about $1 per test. These technologies are affordable for use in distributed testing applications where daily test volume is very low because reagent cost is low and they operate with low cost instrumentation or no instrumentation at all. At the other end of the performance spectrum there are quantitative test cards, rotors, discs or cartridges costing dollars to manufacture that require more complex and expensive instrumentation. Now, for the first time Epocal will deliver the high-end performance of the quantitative devices at the low manufacturing cost of qualitative paper strips.

Epocal is implementing an entire blood diagnostic "laboratory on a chip" in a smart card format similar to conventional cheque and telephone cards. Epocal's FlexCard diagnostic card comprises Biosensors-on-Flex™ circuit modules and/or Fluidics-on-Flex™ circuit modules in a credit card-sized housing. The company manufactures the devices at ultra low cost, leveraging already existing high volume, low cost production technologies for smart cards.

In the EPOC™ system, FlexCard diagnostic cards are used with ultra low cost readers. The card reader is a wireless i/o device similar to the card-swipe at a supermarket check-out: a `black box' whose primary function is to acquire sensor signals from the test card and to drive the card's fluidics. Sensor signals are transmitted by the card reader to a general purpose computing device such as a PDA, where analytical results are calculated, displayed and transmitted further to the electronic medical record.

View a FlexCard flash movie.

What is a lab-on-a-chip?

'Lab-on-a-chip', as described in the original vision several decades ago, is a completely self contained micro-analytical device. Sample introduction is the only operator step required to use a self-contained lab-on-a-chip, in which case a lab-on-a-chip is also a 'one-step' or a 'sample-to-answer' device. In an accurate, quantitative analytical method, whether it is performed in a conventional laboratory format or its micro counterpart, a lab-on-a-chip, there are three essential functional components

reagents and fluidics — comprising pumps, valves and reactors — which manipulate sample, calibrators and other reagents and move them to a biosensor or an array of biosensors,

a biosensor or an array of biosensors (for transduction of a species specific chemical or physical reaction into a detectable signal),

a quantitative read-out device which accepts a biosensor signal,

Epocal achieves one-step sample-to-answer performance in a self contained lab-on-a-chip by integrating patented biosensor arrays, fluidics and reagents on flex circuits in diagnostic cards.