Needle-compatible miniaturized optoelectronic sensor for pancreatic cancer detection

Pancreatic cancer is one of the deadliest cancers, with a 5-year survival rate of <10%. The current approach to confirming a tissue diagnosis, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), requires a time-consuming, qualitative cytology analysis and may be limited because of sampling error. We designed and engineered a miniaturized optoelectronic sensor to assist in situ, real-time, and objective evaluation of human pancreatic tissues during EUS-FNA. A proof-of-concept prototype sensor, compatible with a 19-gauge hollow-needle commercially available for EUS-FNA, was constructed using microsized optoelectronic chips and microfabrication techniques to perform multisite tissue optical sensing. In our bench-top verification and pilot validation during surgery on freshly excised human pancreatic tissues (four patients), the fabricated sensors showed a comparable performance to our previous fiber-based system. The flexibility in source-detector configuration using microsized chips potentially allows for various light-based sensing techniques inside a confined channel such as a hollow needle or endoscopy.

Fabrication of Stainless Steel Microneedle with Laser-Cut Sharp Tip and its Penetration and Blood Sampling Performance

The demand for minimally invasive injection needles or needle-shaped tools is growing from those who carry out medical practices such as blood or insulin injections. Applying the mosquito biomimetic, we have used a femtosecond laser to fabricate minimally invasive microneedles out of ultrafine hollow SUS304 pipes, 50μm in outer diameter and 20μm in inner diameter. When such a stainless steel needle tip is angled at 15°, it has the lowest penetration resistance, two and a half times lower than that of the finest hollow needle that is commercially available. A blood suction experiment with a newly developed microneedle has demonstrated that 2.8μellof blood can be drawn out in 20 seconds. Such stainless steel microneedles fabricated by femtosecond lasers have great potential as minimally invasive and mass-producible blood sampling needles to be used for diabetic inspections.