Yen-Wen Lu

Trigger finger (stenosing tenosynovitis) reflects abnormal tendon-pulley mechanics, primarily at the A1 pulley; however, objective assessment during functional motion remains limited in routine clinical practice. We evaluated electrical contact resistance (ECR) from a wearable tactile sensor during standardized digit motion and examined its association with symptoms. Nine participants with Green grade II-III trigger finger were prospectively enrolled. An origami-inspired pentagon-knot graphene-paper tactile sensor measured ECR over the A1 and A2 pulleys during repeated flexion-extension cycles. A 4-week intervention program (electrical stimulation plus infrared irradiation; three sessions per week) enabled repeated measurements. ECR and patient-reported outcomes were collected at weekly Tuesday assessments, with ECR recorded immediately before and after the session (ECR_pre and ECR_post). Outcomes included pain (visual analog scale [VAS]) and triggering severity (ST), frequency (FT), and functional impact (FIT). Within-session change was defined as ΔECR_session = ECR_pre - ECR_post. Analyses used linear mixed-effects models, repeated-measures correlation (rmcorr; r_rm coefficient) and week-adjusted fixed-effects regression. Sensor placement and recording were feasible, with no adverse events. Across 27 paired weekly sessions (Weeks 1-4), ECR decreased from pre- to post-session at both pulleys (model-estimated mean ΔECR_session: A1 0.0795; A2 0.0990; both P < 0.001). A1 ECR_pre declined over Weeks 1-4 (r_rm = - 0.672; P = 0.0016). At matched weekly timepoints (N = 6; n = 24), A1 ECR_pre correlated with VAS (r_rm = 0.781; P < 0.001), FT (r_rm = 0.578; P = 0.0095), and ST (r_rm = 0.543; P = 0.0164), but not FIT (r_rm = 0.165; P = 0.50). Larger A1 ΔECR_session values were associated with greater subsequent week-to-week pain improvement (r_rm = 0.625; P = 0.0042). In a fixed-effects model adjusting for week, A1 ECR_pre independently predicted VAS (β = 29.19; P = 0.018). Wearable ECR sensing was safe and feasible in this pilot study and demonstrated consistent within-session responsiveness. Clinically, motion-acquired ECR may serve as an objective adjunct for tracking session-level changes and week-to-week status with symptom scales. Retrospectively registered at ChiCTR (ChiCTR2600120811 approved).

Correction for ‘Pipette-operable microfluidic devices with hydrophobic valves in sequential dispensing with various liquid samples: multiplex disease assay by RT-LAMP’ by Yen-Wei Chang et al., Lab Chip, 2024, 24, 3112–3124, https://doi.org/10.1039/D4LC00209A.

An origami-based tactile sensory ring utilizing multilayered conductive paper substrates presents an innovative approach to wearable health applications. By harnessing paper’s flexibility and employing origami folding, the sensors integrate structural stability and self-packaging without added encapsulation layers. Knot-shaped designs create loop-based systems that secure conductive paper strips and protect sensing layers. Demonstrating a sensitivity of 3.8 kPa⁻¹ at subtle pressures (0–0.05 kPa), the sensors detect both minimal stimuli and high-pressure inputs. Electrical modeling of various origami configurations identifies designs with optimized performance with a pentagon knot offering higher sensitivity to support high-sensitivity needs. Meanwhile a square knot provides greater precision and quicker recovery, balancing sensitivity and stability for real-time feedback devices. The enhanced elastic modulus from folds remains within human skin’s elasticity range, ensuring comfort. Applications include grip strength monitoring and pulse rate detection from the thumb, capturing pulse transit time (PTT), an essential cardiovascular biomarker. This design shows the potential of origami-based tactile sensors in creating versatile, cost-effective wearable health monitoring systems.

Microfluidic dispensing technologies often require additional equipment, posing challenges for their integration into point-of-care testing (POCT) applications. In response to this challenge, we have developed a pipette-operable microfluidic device fabricated using 3D printing technology for precise liquid dispensing. This device features three reaction chambers and three distinct hydrophobic valves to control the flow direction of liquids. Through these valves, the pipette-operable microfluidic device can sequentially dispense and isolate the liquid into the three reaction chambers, allowing for the individual conduction of three distinct reactions. These hydrophobic valves, with optimized flow resistance and burst pressure, can sustain a volumetric flow rate of up to 25 μL s⁻¹, making them compatible with a standard pipette, a syringe, or a dropper operation. Furthermore, the device is successfully used to operate with various liquids, including BSA, DMEM, FBS, plasma, and blood, representing that the device has the potential to be used for various applications. Additionally, distinct RT-LAMP primer sets have been incorporated for diagnosing SARS-CoV-2, influenza A, and influenza B within each chamber through lyophilization. This pipette-operable microfluidic device serves as a versatile tool for diagnosing these three diseases using a single loading process, with results readable by the naked eye or image assay within 30 minutes of incubation. Finally, the design concepts are extended to engineer a microfluidic device with 20 reaction chambers, offering significant potential for multi-disease diagnostics.

Drawing inspiration from origami structures, a pressure sensor was developed with unique interconnection scaling at its creases crafted on a conductive paper substrate, paving the way for advanced wearable technology. Two screen-printed conductive paper substrates were combined face-to-face, and specific folds were introduced to optimize the sensor structure. The Electrical Contact Resistance (ECR) was systematically analyzed across different fold numbers and crease gaps, revealing a notable trade-off: while increasing the number of folds expanded the sensing area, it also influenced the ECR, reaching a performance plateau. Strategic modifications in the sensor's design, including refining interconnections at the crease, enhanced its sensitivity and stability, culminating in a remarkable sensitivity of 3.75 kPa^-1 at subtle pressure levels (0-0.05 kPa). This sensor's real-world applications proved to be transformative, from detecting bruxism and aiding in neck posture correction to remotely sensing trigger finger locking phenomena, highlighting its potential as a pivotal tool in upcoming medical diagnostics and treatments.

Microfluidic device research employs acoustic streaming and bubble dynamics for effective cell separation, mitigating filter fouling and enhancing forensic and biological analysis efficiency.