It seems quaint now in a world of instant access and online streaming, but Netflix’s DVD rental service was revolutionary when it launched in 1998. No longer would movie buffs have to head to their local Blockbuster to rent their desired flick. They could instead choose the title they wanted, wait a couple of days and it would arrive in the post without them needing to leave the house.
At the peak of the DVD service’s popularity ten years later, Ben Casavant and Erwin Berthier were working on microfluidics projects at the University of Wisconsin-Madison. They wondered if a similar level of convenience could be applied to medicine.
“I got really interested in the way that microfluidics can miniaturise things and be able to do more powerful diagnostics,” reveals Seattle-based Casavant. “But we saw that the bottleneck to access all of these amazing technologies was blood collection.”
A blood sample can tell health experts a lot about what’s going on in the body, but getting one isn’t without its challenges. Having to arrange for a professional to take your blood can be inconvenient, especially for patients with chronic conditions who will require more frequent trips to the health centre. People in rural areas who can’t easily get to a phlebotomist, meanwhile, can face delays to their care. And, of course, no one enjoys going for blood tests – particularly the around 20% of adults with needle phobia. Casavant calls a blood draw “a terrible experience”.
Collection at the click of a button
Casavant and Berthier imagined a future where heading to the doctor’s office for a venepuncture was as obsolete as a trip to a DVD rental store. They wanted to give patients the tools to safely and painlessly take their own blood sample whenever and wherever was convenient for them. According to the American Clinical Laboratory Association, 4,000 diagnostic tests are run seven billion times a year in the US, so they figured the impact of such as product could be huge. The duo created Hemolink, a wearable, minimally invasive device that lets patients collect blood samples from the comfort of their own homes.
Tasso, the resulting company, was launched in 2011. Tasso makes two devices: Tasso-M20 for dry blood samples and Tasso-SST for liquid blood samples. Testing kits are dispatched directly to the patient. And Casavant says blood collection is as simple as pressing a button. During a video call, he gives a brief demonstration. He peels off the device’s adhesive backing, sticks it on his upper arm and points to the red button on the tool’s surface.
“You press the big red button until you hear a click, and then leave it on for about two to three minutes. Blood is collected passively while it’s just sitting on your arm,” he explains.
Four small lancets are quickly released to puncture the arm. These are automatically retracted and locked in the device for safety as soon as the button is released. A small vacuum is then generated to enhance the blood collection process. Then, microfluidic channels inside the device collect the blood and direct it down a tube. The user removes the Hemolink, seals the tube and posts it off to a laboratory for diagnostic tests.
Casavant says the whole process is practically painless, especially compared to the standard finger-prick devices already available for patients, such as those with diabetes, who need to collect their blood at home. And the patient never has to see a needle, which makes the device an attractive prospect for people with phobias or a tendency to faint during routine blood tests.
“Our partners try to find the people who are most squeamish first before they order more,” reveals Casavant. “And honestly, those are actually some of our biggest proponents.”
Validating a new era of diagnostics
Tasso’s devices are being validated for routine diagnostics, chronic disease monitoring, athletic testing and clinical trials. The team needs to prove that the capillary blood collected with the device is equivalent to that collected when professionals insert a needle into a patient’s vein. Tasso has a submission with the US Food and Drug Administration and is involved in several clinical studies with organisations, such as the Fred Hutchinson Cancer Research Center and Cedars-Sinai to expand the number of diagnostic tests, for which the device can be used to collect blood.
The Tasso-SST is available for investigational use only, while the Tasso M20 is a listed class 1 exempt product and is used by pharmaceutical companies for clinical trials. It means medical research participants don’t have to visit clinical sites so frequently. They can simply collect their blood at home at the required time.
Before the coronavirus pandemic, no one could have foreseen quite how important remote healthcare services would become. Unsurprisingly, Tasso has seen increased demand for its devices in recent months.
Being able to collect blood without having to visit a health setting is clearly advantageous while we’re encouraged to avoid physical contact with others as much as possible. In July 2020, Tasso completed a $17m Series A financing round, which will be used to scale manufacturing and operations for its devices. Telemedicine is here to stay, believes Casavant.
“People don’t want to go into the hospital right now, and I don’t blame them,” he says. “More physicians are doing telemedicine visits and trying to figure out how to access their patients in new and innovative ways. Helping them solve that is critical.”