A microfluidic sucrose gap platform using trilaminar flow with on-chip switching and novel calibration: Challenges and limitations.

Gap junction connectivity is crucial to intercellular communication and plays a key role in many critical processes in developmental biology. However, direct analysis of gap junction connectivity in populations of developing cells has proven difficult due to the limitations of patch clamp and dye diffusion based technologies. We re-examine a microfluidic technique based on the principle of laminar flow, which aims to electrically measure gap junction connectivity.

A microfluidic sucrose gap device for electrical measurement of gap junction connectivity.

A microfluidic device has been designed to electrically measure average intercellular connectivity in a cell monolayer. This proof-of-concept design uses elastomeric microvalves to isolate cells across three microfluidic chambers, creating a direct microscale analog of benchtop sucrose gap physiology rigs. The device operation has been verified for normal rat kidney cells (NRK-49F) using a chemical gap junction blocker, 2-aminoethoxydiphenyl borate (2-APB).

Preschool Vision Screening and Policy: Availability, Awareness and Perceptions of Stakeholders in Selected Locations in Harare and Mashonaland East Provinces.

Background: This study aimed to determine the availability, awareness and perceptions of preschool vision screening (PSVS) and policies among stakeholders in Zimbabwe.

Methods: A descriptive cross-sectional survey was carried out, and a multi-stage sampling was used to select the schools from private and public schools. The study involved stakeholders (parents/guardians, teachers, principals, proprietors/owners and administrators) and data was collected using a validated questionnaire.

Frequency-domain instrument with custom ASIC for dual-slope near-infrared spectroscopy.

Real-time and non-invasive measurements of tissue concentrations of oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) are invaluable for research and clinical use. Frequency-domain near-infrared spectroscopy (FD-NIRS) enables non-invasive measurement of these chromophore concentrations in human tissue. We present a small form factor, dual-wavelength, miniaturized FD-NIRS instrument for absolute optical measurements, built around a custom application-specific integrated circuit and a dual-slope/self-calibrating (DS/SC) probe.

Going beyond the means: Exploring the role of bias from digital determinants of health in technologies.

Background: In light of recent retrospective studies revealing evidence of disparities in access to medical technology and of bias in measurements, this narrative review assesses digital determinants of health (DDoH) in both technologies and medical formulae that demonstrate either evidence of bias or suboptimal performance, identifies potential mechanisms behind such bias, and proposes potential methods or avenues that can guide future efforts to address these disparities.

Approach: Mechanisms are broadly grouped into physical and biological biases (e.g.

Optimization of Oligomer Stamping Technique for Normally Closed Elastomeric Valves on Glass Substrate.

Microscale elastomeric valves are an integral part of many lab-on-chip applications. Normally closed valves require lower actuation pressures to form tight seals, making them ideal for portable devices. However, fabrication of normally closed valves is typically more difficult because the valve structure must be selectively bonded to its substrate.

Development of a Mobile Application Platform for Self-Management of Obesity Using Artificial Intelligence Techniques.

Obesity is a major global health challenge and a risk factor for the leading causes of death, including heart disease, stroke, diabetes, and several types of cancer. Attempts to manage and regulate obesity have led to the implementation of various dietary regulatory initiatives to provide information on the calorie contents of meals. Although knowledge of the calorie content is useful for meal planning, it is not sufficient as other factors, including health status (diabetes, hypertension, etc.

A CMOS-Based Bidirectional Brain Machine Interface System With Integrated fdNIRS and tDCS for Closed-Loop Brain Stimulation.

A CMOS-based bidirectional brain machine interface system with on-chip frequency-domain near infrared spectroscopy (fdNIRS) and transcranial direct-current stimulation (tDCS) is designed to enable noninvasive closed-loop brain stimulation for neural disorders treatment and cognitive performance enhancement. The dual channel fdNIRS can continuously monitor absolute cerebral oxygenation during the entire tDCS process by measuring NIR light's attenuation and phase shift across brain tissue. Each fdNIRS channel provides 120 dBΩ transimpedance gain at 80 MHz with a power consumption of 30 mW while tolerating up to 8 pF input capacitance.

Optical Characterization of Tissue Phantoms Using a Silicon Integrated fdNIRS System on Chip.

An interface circuit with signal processing and digitizing circuits for a high frequency, large area avalanche photodiode (APD) has been integrated in a 130 nm BiCMOS chip. The system enables the absolute oximetry of tissue using frequency domain Near Infrared Spectroscopy (fdNIRS). The system measures the light absorbed and scattered by the tissue by measuring the reduction in the amplitude of signal and phase shift introduced between the light source and detector which are placed a finite distance away from each other.