Rapid, portable blood ammonia detection device (PAD)

Stanford researchers have built a low cost, portable, simple-to-use device designed to rapidly detect elevated ammonia in a drop of blood. This device could be used to manage the treatment of patients with conditions such as urea cycle defects and liver disease or for individuals being treated with certain chemotherapeutic agents. With easy detection, patients can be treated to prevent cognitive impairment and other effects of hyperammonemia.

The device uses an inexpensive fuel cell component to measure the ammonia released from whole blood upon alkalinization. It can achieve the same sensitivity and accuracy of the traditional laboratory assay, but achieves this with a smaller blood sample that requires no special handling or plasma preparation. Thus, this device could be used for point-of-care analysis at the bedside, or in a patient's home. Its applications include diagnostics, patient monitoring and drug development.

Stage of Research
The inventors have tested a prototype Portable Ammonemia Detector (PAD) using 100 microliters (2 drops) of blood. The results from PAD analysis were highly correlated with conventional plasma ammonia testing (r² = 0.97) from normal to the most extreme ammonia concentrations seen in clinical practice.