NEW YORK – Inspired by leeches' method of removing blood from their prey, researchers from ETH Zurich have developed a blood collection device to help people reluctant to have blood draws done with traditional venipuncture.
The product, which was described in a March paper in Advanced Science, uses microneedles attached to a silicon cup to collect capillary blood. The microneedles can increase compliance with laboratory test orders for those patients who are afraid of needles, said Nicole Zoratto, one of the authors of the paper and a professor at the university. The device is also intended to make blood sampling for diagnostic testing more accessible in low- and middle-income countries because it can be used by nonprofessionals and doesn't require additional equipment. The use of microneedles also cuts down on the potential for needle-stick injuries, the researchers noted in the paper.
The idea for the device came from a colleague who was developing a suction cup-based tool to deliver drugs to patients, Zoratto said. The device was inspired by the function and anatomical structure of leeches, which attach to their host's skin and use their muscular structure to create pressure to help them suck blood.
The microneedles in the device, which are placed in a patch hidden within the cup, act similarly to leeches' teeth to puncture the skin. When the cup is pressed to the skin, the microneedles are released, the device is sealed to the skin, and its elastic self-recovery generates negative pressure to suck out the capillary blood. The blood is kept in a fluid storage compartment that can be loaded with an anticoagulant.
In the Advanced Science paper, the researchers applied the device for approximately 10 minutes, but Zoratto noted that the ideal application time for humans would be about five minutes, since coagulation will begin after that time.
The device is intended to be used anywhere, with an emphasis on LMICs that lack blood collection facilities and experts to collect that blood, Zoratto said. The device can be used by the person whose blood is being collected and can be closed and shipped to laboratories or tested on-site using point-of-care or laboratory instruments. The potential combination of the blood collection device with point-of-care systems "can improve healthcare access, especially in low- and middle-income countries," Zoratto said.
The device is not yet ready for use in humans, Zoratto noted, as the materials need to be optimized for clinical use. The silicone needs to be switched to medical-grade silicone, and the safe use of the device needs to be tested with a small group of test subjects — thus far, it has only been tested on piglets. Use of the device for humans will need to be compared to conventional sampling methods to ensure the quality of the blood sample is consistent with conventional sampling, she noted.
The product also needs to be further optimized to ensure it's easy to apply, comfortable, and patient-friendly, Zoratto added, although with instructions and videos to teach patients how to use the device, its use should be relatively straightforward.
The goal, Zoratto said, was to develop something "really cost-effective." Other blood collection devices exist but are complicated to use and have high production costs that make them less accessible to LMICs. The price of the leech-inspired device may fluctuate from the prototype to the final product, but producing the device is "super cheap" because silicon is a "very low-cost material" and the microneedles are made of stainless steel, which is also inexpensive.
There are multiple companies that currently offer micro-sampling blood collection products, such as Taiwanese firm Winnoz, which provides the Haiim device with a lancet and a vacuum component that collects blood directly from the fingertips, and Tasso, which provides the Tasso+ blood sampling system. The researchers noted in their paper that Haiim's device requires a trained specialist to oversee the blood collection, while Tasso's device has a high estimated cost and cannot be directly integrated with current point-of-care devices. The researchers referenced Tasso's OnDemand family of devices, of which only one is still commercially available.
Tasso Chief Technology Officer and Cofounder Erwin Berthier said via email that the firm has "greatly scaled up our manufacturing capabilities to meet increased demand." The scale-up has "enabled lower price points that are now very competitive for digital health and research," he added.
Winnoz did not respond to a request for comment.
The researchers are also trying to address waste management for the device by making it biodegradable, utilizing biodegradable polymers and materials to ensure sustainability.
Zoratto noted that the researchers haven't filed a patent for the device because it is aimed at LMICs, and the team wanted to make everything open-source and accessible. She added that she hopes a charitable foundation or company can manufacture and produce the device to make it even more affordable and available for widespread use.