Hand-Cranked Device Delivers Rapid Blood Type and Red Cell Levels

Doctors urgently require a patient's blood type for safe transfusions and hematocrit levels to assess blood loss or anemia, especially in emergency situations. Current hospital methods rely on large machines needing electricity and trained staff, which are often unavailable in critical settings like ambulances, disaster zones, or remote clinics.

A team led by Professor Chien-Fu Chen at National Taiwan University has developed a simple, electricity-free alternative. This innovation, published in Biosensors and Bioelectronics, utilizes a small plastic chip spun by a hand-cranked centrifuge. The device operates with only about 3 microliters of finger-prick blood, addressing the need for rapid diagnostics in resource-limited environments.

The mechanism involves turning a crank, which propels the blood through winding channels preloaded with reagents for the A, B, and Rh blood groups. If the blood matches, its red blood cells clump together and are trapped by a gap approximately one-tenth the width of a human hair, forming a visible red band at the channel's end that indicates the blood type. The length of this band simultaneously reveals the hematocrit, readable against scale marks etched onto the chip.

In tests conducted on 21 hospital patient samples, the device's results closely matched those obtained from standard hospital analyzers. Readings remained consistent regardless of how fast the crank was turned, with the entire test completed in about one minute. Professor Chen, a distinguished professor at the Institute of Applied Mechanics at National Taiwan University, stated, "Our goal is to bring two essential blood tests out of the laboratory and into the hands of first responders, with no electricity or specialized training needed."

What to watch: Further development and deployment for emergency and remote medical applications.

Editor's note: Thoroughly captures the study details, mechanical operation, and testing results without padding.