Microelectrodes Scanning Your Blood

Electrochemical sensors can tell you when to slow down.
Thanks to technology, your heart rate, sweat rate, calories
burned, stride length, and whether you're wearing boxers or
briefs can all be calculated in real time, wirelessly
transmitted to a laptop, and posted to Twitter before you
return home from your weekend jog. Engineers in Germany are
hoping to add blood lactate levels to the abundance of
fitness data using a miniature ear clip containing
an electrochemical sensor.

Lactate levels quantify just how deep into anaerobic hell
an athlete is. As exertion progresses, oxygen levels in the
blood drop, starving tissues of the O2 they crave. At this
point, pyruvic acid starts to be converted into lactic acid,
thereby increasing the blood's lactate level. Once the
accumulation begins, the athlete's performance is likely to
slip. Understanding where and when an athlete reaches this
threshold would be a valuable data point, allowing workouts
to be optimized and focused, to increase endurance or sharpen
a skill. But getting such data currently requires a costly
instrument and a sample of blood from a pin prick. So only
elite athletes undergo such analysis, and only do so in a lab
setting.

Germans dislike a pin prick as much as the next country's
athletes, so researchers at the Fraunhofer Institute for
Microelectronic Circuits and Systems have developed
a prototype sensor to get athletes out of the lab and keep
their fingers unscathed.

The sensor consists of multiple microchips, as shown in the
photo, measuring just 2 by 3 mm. One contains an enzyme gel
that triggers flow from the lactate. Additional chips with
microelectrodes work to quantify the data from first chip.
Apparently the electrode can be coated with various enzymes,
allowing the quantification of other blood properties or
electrolytes. The data can be transmitted from the ear clip
to one's chosen form of mobile data collection.

The researchers suggest it could be three to four years for
commercialization. Till then, assume that burning in your
legs on mile 13 is evidence enough that you've crossed the
dreaded lactate threshold.