In an open Nature Communications paper published today, researchers from the University of Michigan described a prototype wearable device that could continuously collect bloodborne cancer cells often used as a biomarker for treatment.

Currently, blood draws are required to identify and examine circulating tumor cells (CTCs), and are often limited by inconsistent CTC counts as well as the health impacts of blood removal from a sick patient. The wrist-worn prototype device — which has so far been tested in canines but likely wouldn’t see human trials for another three to five years — screens patients’ blood over the course of a few hours and only draws the CTCs it is seeking.

"Nobody wants to have a biopsy,” Dr. Daniel F. Hayes, a professor at the University of Michigan Rogel Cancer Center and the paper’s senior author, said in a statement. “If we could get enough cancer cells from the blood, we could use them to learn about the tumor biology and direct care for the patients. That's the excitement of why we're doing this.”

According to the paper, the device is comprised of four major components: a micro-controller, a peristaltic pump, a heparin injector and a CTC capture module containing a microfluidic capture chip. This system is housed in a 3D printed casing and controlled wirelessly using a custom-built app.

When worn, whole blood from a patient’s peripheral vein is routed into the device through an indwelling intravenous catheter, and then back into their bloodstream. This approach allows the device to screen a substantially larger volume of the patient’s blood with minimal loss, and in the animal test yielded roughly 3.5 times as many CTCs per milliliter of blood compared to blood draw collection.

"The most challenging parts were integrating all of the components into a single device and then ensuring that the blood would not clot, that the cells would not clog up the chip, and that the entire device is completely sterile," Tae Hyun Kim, a postdoctoral scholar at the California Institute of Technology and the paper’s lead author, said in a statement.

What’s the impact

Thanks to the promise consistent, plentiful CTC draws for tumor analysis, the researchers stressed that a fully-realized version of their system would “significantly reduce errors in determining the disease status” and better allow clinicians to develop personalized therapies specific to each patient’s tumor.

"This is the epitome of precision medicine, which is so exciting in the field of oncology right now,” Hayes said.

What’s the trend

A number of new technologies are playing a key role in the developing field of precision oncology. Chief among these so far are artificial intelligence for patient, treatment, and cancer-linked gene analysis, and new comprehensive diagnostic tests that can inform clinical decision making.