Microwave imaging for monitoring breast cancer treatment: A pilot study.

BACKGROUND: Microwave imaging has been proposed for medical applications, creating maps related to water content of tissues. Breast imaging has emerged as a key application because the signals can be coupled directly into the breast and experience limited attenuation in fatty tissues. While the literature contains reports of tumor detection with microwave approaches, there is limited exploration of treatment monitoring. PURPOSE: This study aims to detect treatment-related changes in breast tissue with a low-resolution microwave scanner. METHODS: Microwave scans of 15 patients undergoing treatment for early-stage breast cancer are collected at up to 4 time points: after surgery (baseline), 6 weeks after accelerated partial breast radiation, as well as 1 and 2 years post-treatment. Both the treated and untreated breast are scanned at each time point. The microwave scanner consists of planar transmit and receive arrays and uses signals from 0.1 to 10 GHz. The average microwave frequency properties (permittivity) are calculated for each scan to enable quantitative comparison. Baseline and 6-week results are analyzed with a two-way ANOVA with blocking. RESULTS: Consistent properties are observed for the untreated breast over time, similar to a previous study. Comparison of the scans of the treated and untreated breast suggests increased properties related to treatment, particularly at baseline and 6-weeks following radiotherapy. Analysis of the average properties of the scans with ANOVA indicates statistically significant differences ( p < 0.05 $p < 0.05$ ) in the treated and untreated breast at these time points. CONCLUSIONS: Microwave imaging has the potential to track treatment-related changes in breast tissues.

Microwave Hydration Monitoring: System Assessment Using Fasting Volunteers.

Hydration is an important aspect of human health, as water is a critical nutrient used in many physiological processes. However, there is currently no clinical gold standard for non-invasively assessing hydration status. Recent work has suggested that permittivity in the microwave frequency range provides a physiologically meaningful metric for hydration monitoring. Using a simple time of flight technique for estimating permittivity, this study investigates microwave-based hydration assessment using a population of volunteers fasting during Ramadan. Volunteers are measured throughout the day while fasting during Ramadan and while not fasting after Ramadan. Comparing the estimated changes in permittivity to changes in weight and the time s fails to establish a clear relationship between permittivity and hydration. Assessing the subtle changes in hydration found in a population of sedentary, healthy adults proves difficult and more work is required to determine approaches suitable for tracking subtle changes in hydration over time with microwave-based hydration assessment techniques.

µDrop: Multi-analyte portable electrochemical-sensing device for blood-based detection of cleaved tau and neuron filament light in traumatic brain injury patients.

Over 27 million individuals are affected every year worldwide with central nervous system (CNS) injuries. These injuries include but are not limited to traumatic brain injury (TBI) and spinal cord injury (SCI). CNS injuries remain a significant public health concern which demands reliable tools for rapid, on-sight, on-field, and point-of-care diagnostic (POC) solutions. To address these challenges, we developed a low-cost, open-source, hand-held, portable, and POC detection technology, termed as MicroDrop (µDrop), which can simultaneously detect up to eight target biomolecules and display results in both analog and digital formats. The data acquired is stored wirelessly in a cloud server for further investigation and statistical analysis. Multiplexing capability of µDrop and immuno-biosensors detects and quantifies Cleaved-Tau Protein (C-Tau) and Neuron-Filament (NFL) proteins in the blood of TBI patients. Immuno-biosensors rapidly sense the two target proteins in less than 30 min, with µDrop and a conventional potentiostat. C-Tau and NFL were selectively detected with µDrop within the dynamic range of 10 pg/mL - 100 ng/mL and the sensitivity range of 47 µA/pg mm2 - 65 µA/pg mm2. Comparing the biosensing performance with enzyme-linked immunosorbent assays (ELISA) shows that the immuno-biosensors combined with µDrop could successfully differentiate between clinical controls and injured patients.