Rigorous science demands support of transgender scientists.

To build a just, equitable, and diverse academy, scientists and institutions must address systemic barriers that sex and gender minorities face. This Commentary summarizes (1) critical context informing the contemporary oppression of transgender people, (2) how this shapes extant research on sex and gender, and (3) actions to build an inclusive and rigorous academy for all.

Characterization and Correction of Low Frequency Artifacts in Segmental Bioimpedance Measurements.

Bioimpedance analysis can be used for remote monitoring of volume status for various conditions such as congestive heart failure. The measurement is typically performed with four electrodes, two of them driving an alternating current through the tissue and the other two sensing the resulting voltage. Issues with the measurement setup such as stray capacitance or electrode mismatch can cause artifacts that impact Cole parameters used for volume estimation. While previous research has focused on mitigating high frequency artifacts, little research has been done to understand the cause and impact of low frequency artifacts, nor how to mitigate the impact of these artifacts. These artifacts are most prevalent in wearable segmental bioimpedance systems, especially using textile electrodes, so future research in this area is needed for these systems to be viable. The present study uses simulations to identify the potential sources of low frequency artifacts, and explores techniques to minimize the impact of these artifacts on Cole parameters. Theoretical analysis and simulations show that the mismatch of the voltage electrodes causes artifacts at low frequency. These artifacts are highly dependent on the impedance of the negative current injecting electrode. Averaging measurements of the mismatch of both voltage electrodes and limiting high frequency measurements to 200 kHz can reduce errors due to these artifacts from over 137% to less than 3%. The results of this study suggest the impact of low frequency artifacts can be significantly reduced, enabling future development of wearable bioimpedance systems.Clinical relevance- Reducing the impact of low frequency artifacts on Cole parameter estimation enables wearable segmental bioimpedance systems that can be used for remote monitoring of volume status in home environments.

Two researchers share how their cross disciplinary collaboration enables work to guide the future of data science.

In their recent perspective published in Patterns, Maggie Delano and Kendra Albert highlight the limitations of sex and gender data classification in health systems and show how this contributes to the marginalization of trans and non-binary individuals. They provide recommendations to improve incorporating gender data into healthcare algorithms. Here they discuss their collaboration and how it enabled this cross-disciplinary research.

Sex trouble: Sex/gender slippage, sex confusion, and sex obsession in machine learning using electronic health records.

False assumptions that sex and gender are binary, static, and concordant are deeply embedded in the medical system. As machine learning researchers use medical data to build tools to solve novel problems, understanding how existing systems represent sex/gender incorrectly is necessary to avoid perpetuating harm. In this perspective, we identify and discuss three factors to consider when working with sex/gender in research: "sex/gender slippage," the frequent substitution of sex and sex-related terms for gender and vice versa; "sex confusion," the fact that any given sex variable holds many different potential meanings; and "sex obsession," the idea that the relevant variable for most inquiries related to sex/gender is sex assigned at birth. We then explore how these phenomena show up in medical machine learning research using electronic health records, with a specific focus on HIV risk prediction. Finally, we offer recommendations about how machine learning researchers can engage more carefully with questions of sex/gender.

Band Electrodes Reduce Simulated Calf Bioimpedance Measurement Errors Due to Muscle Anisotropy.

Remote monitoring of fluid status via calf bioimpedance measurements could improve the experience of patients with congestive heart failure and reduce readmission rates. Most measurements today use conventional Ag/AgCl electrodes and a short inter-electrode spacing, resulting in current flowing primarily near the electrodes, preventing deeper current penetration and in turn accurate volume estimation. Textile band electrodes may more evenly distribute current throughout the calf. In the present study, simulations were conducted to investigate the impact of inter-electrode spacing/placement and fat tissue on bioimpedance using both Ag/AgCl electrodes and textile band electrodes. Simulation results showed that increasing the inter-electrode spacing can improve current distribution in the tissue, but there are still errors that increase with fat thickness (14.3% error at 10 cm spacing down to 1.7% error at 20 cm spacing for a "nominal" fat thickness, vs. -0.3% and -0.5% error for band electrodes). Band electrodes most closely matched the expected resistance and seem the most suitable regardless of inter-electrode spacing.

Textile band electrodes as an alternative to spot Ag/AgCl electrodes for calf bioimpedance measurements.

OBJECTIVE: To evaluate the performance of five different types of textiles as band electrodes for calf bioimpedance measurements in comparison with conventional spot Ag/AgCl electrodes. APPROACH: Calf bioimpedance measurements were performed in 10 healthy volunteers with five different textile materials cut into bands and Ag/AgCl spot electrodes as a baseline. Collected bioimpedance data were analyzed in terms of precision, fit error and presence of measurement artifacts. Each textile material was also evaluated for participant comfort. MAIN RESULTS: Bioimpedance values for spot electrodes were higher at low frequencies as compared with band electrodes but not at high frequencies. This suggests that spot electrodes have frequency dependent current distributions that adversely impact their use for volume measurements and band electrodes are preferable. The SMP130T-B fabric had the highest precision and the lowest best fit error to the Cole model of the tested textile materials. However, it was the least comfortable textile and most expensive. The Stretch material performed slightly worse than the SMP130T-B fabric, but was half the cost and the most comfortable. SIGNIFICANCE: These results suggest that there are suitable textile materials for use as dry, band electrodes for calf bioimpedance measurements and that these band electrodes enable greater current uniformity. These textiles could be integrated into a compression sock for remote monitoring of diseases such as Congestive Heart Failure.

Evaluating calf bioimpedance measurements for fluid overload management in a controlled environment.

OBJECTIVE: To evaluate the relationship between calf bioimpedance measurements and fluid removal in a controlled environment (hemodialysis) as a first step toward using these measurements for remote congestive heart failure (CHF) monitoring. APPROACH: Calf bioimpedance measurements were recorded in 17 patients undergoing hemodialysis (9/17 (53%) CHF, 5/17 (30%) female). Measurements were performed before and after hemodialysis. Additional parameters related to hemodialysis and patient fluid status such as estimated dry weight were also recorded. MAIN RESULTS: Calf bioimpedance changes depended on calf fluid status as assessed by calf normalized resistivity (CNR). Patients with lower calf fluid overload (as assessed by CNR greater than [Formula: see text] [Formula: see text]m[Formula: see text] kg[Formula: see text]) had larger decreases in calf fluid than patients with higher calf fluid overload. High CNR patients had fluid changes within the calf that depended on the ultrafiltration rate, with patients with lower ultrafiltration rates experiencing fluid shifts from extracellular to intracellular fluid. Additionally, there were correlations between changes in calf extra-, intra- and total- water and the ultrafiltration volume removed for high CNR patients ([Formula: see text], respectively, all p-values [Formula: see text] 0.05). SIGNIFICANCE: These results suggest that while the relationship between calf fluid status and total fluid status is complex, changes in calf volumes comparable to those expected in an ambulatory setting are measurable and relate to changes in total volume. This suggests that calf bioimpedance measurements for CHF remote monitoring warrant future investigation, as remote fluid status management could reduce fluid overload related hospitalizations in CHF patients.

Electrode Placement for Calf Bioimpedance Measurements During Hemodialysis.

Congestive Heart Failure (CHF) is a chronic medical condition that causes reduced exercise tolerance, shortness of breath, and fluid buildup in the lungs, legs, and abdomen. Monitoring patient fluid status using non-invasive techniques such as bioimpedance may help reduce CHF related read- mission rates. Bioimpedance measurements were performed in a controlled environment (hemodialysis) at two locations on the calf (side and back) to determine ideal electrode placement for monitoring changes in fluid status. Changes in calf bioimpedance were heterogeneous. Three out of seven patients had higher changes at the back of the calf compared with the side of the calf for the bioimpedance parameter $R_{0}$ (the resistance measured at low frequency that is related to extracellular water). These data suggest there are differences in resistivity within the calf. Simulations showed that the use of point electrodes weights tissue nearest the electrodes more heavily, but that this dependence can be eliminated through the use of ring electrodes, effectively averaging resistivity around the calf.

A wearable cardiac monitor for long-term data acquisition and analysis.

A low-power wearable ECG monitoring system has been developed entirely from discrete electronic components and a custom PCB. This device removes all loose wires from the system and minimizes the footprint on the user. The monitor consists of five electrodes, which allow a cardiologist to choose from a variety of possible projections. Clinical tests to compare our wearable monitor with a commercial clinical ECG recorder are conducted on ten healthy adults under different ambulatory conditions, with nine of the datasets used for analysis. Data from both monitors were synchronized and annotated with PhysioNet's waveform viewer WAVE (physionet.org) [1]. All gold standard annotations are compared to the results of the WQRS detection algorithm [2] provided by PhysioNet. QRS sensitivity and QRS positive predictability are extracted from both monitors to validate the wearable monitor.