Inkjet printing of surfactant solutions onto thin moving porous media

We have studied the combined imbibition and evaporation of surfactant solutions into thin porous media by means of experiments and numerical simulations. Solutions of anionic and non-ionic surfactants were deposited onto moving sheets of paper by a droplet-on-demand inkjet system. Optical transmission imaging and infrared thermography were used to monitor their lateral transport and evaporation. Moreover, we propose a theoretical model based on a dual-porosity approach that accounts for moisture and surfactant transport in both the pores and the fibers of the paper sheets as well as for surfactant adsorption. The numerical simulations reproduce the experimental data qualitatively well.</p

The Accuracy of Blood Pressure Measurement by Two Cuff-Less Wearable and Portable Health Devices

Introduction: Wearable and portable devices that claim to measure blood pressure without the need of a cuff are becoming increasingly popular among consumers. Given that hypertension is the leading cause for cardiovascular mortality worldwide, a portable technology that allows consumers to easily measure their BP several times a day would be of great value. However, the convenience that portable health technology provides is useless, and even dangerous, if the measurements are inaccurate. Objective: Investigate the accuracy of two popular commercial cuff-less BP device, the Bodimetrics Performance Monitor and Everlast TR10 watch. Methods: A sample of 127 ambulatory patients (\u3e18y) were recruited from the Thomas Jefferson University Hospital Preadmission Testing Center. Following the 2013 ANSI/AAMI/ISO standard protocol for evaluating non-invasive automated sphygmomanometers, four reference and three investigational BP measurements were obtained after a five minute initial rest period. Reference measurements were taken with the validated Cardiocap 5 sphygmomanometer. Results: 85 subjects met inclusion criteria. The average absolute differences (SD) between the Everlast watch and reference were 22.7 (27.4) mmHg for SBP and 6.9 (6.2) mmHg for DBP. The average absolute difference (SD) between the BodiMetrics Performance Monitor and the reference was 5.3 (4.7) mmHg for systolic BP. Discussion: The Everlast fitness watch tested is not accurate enough to be used as BP measurement device. The Bodimetrics device was more accurate, likely due to calibration immediately prior to validation, but even with this advantage the BP device failed to meet accuracy guidelines. Widespread use of this technology likely results in the misclassification of patients’ BP status

The Accuracy of Blood Pressure Measurement by a Smartwatch and a Portable Health Device

Introduction: Hypertension is a leading cause of mortality. Proper blood pressure (BP) control can be achieved by lifestyle modification, pharmacotherapy, and frequent measurements. With the growing popularity of cuffless blood pressure monitors, it is important to independently validate their accuracy. Objective: We evaluated two cuffless blood pressure monitors, The Everlast TR10 fitness watch and the BodiMetrics Performance Monitor, for their accuracy and precision in BP measurements. Methods: Using a protocol derived from the ANSI/AAMI/ISO 2013 standard for evaluating automated sphygmomanometers, we measured the blood pressures of 85 patients recruited from the Thomas Jefferson University Hospital Preadmission Testing Center with two experimental devices and a validated automated sphygmomanometer cuff. We compared the mean absolute differences in measurements between the investigational and reference devices. Comparisons were analyzed with Spearman correlation and T-test, p\u3c0.05. Results: The BodiMetrics Performance Monitor SBP measurements correlated well with the reference SBP measurements (ρ = 0.88, P \u3c 0.01), whereas the Everlast TR10 fitness watch did not (SBP: ρ = -0.19, P \u3c 0.01; DBP: ρ = -0.01, P \u3c 0.01). The BodiMetrics performance monitor reported a hypertensive BP (≥140 mm Hg) for 80% of the hypertensive reference SBP measurements, whereas the Everlast watch measured no hypertensive BP values for any of the hypertensive reference SBP or DBP measurements. Discussion: The Everlast fitness watch and BodiMetrics Performance Monitor are not accurate enough to use for blood pressure monitoring. Use of these devices will likely result in misclassifying patients with hypertension as normotensive, which is a public health concern

Accuracy of Vital Signs Measurements by a Smartwatch and a Portable Health Device: Validation Study.

BACKGROUND: New consumer health devices are being developed to easily monitor multiple physiological parameters on a regular basis. Many of these vital sign measurement devices have yet to be formally studied in a clinical setting but have already spread widely throughout the consumer market. OBJECTIVE: The aim of this study was to investigate the accuracy and precision of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and oxygen saturation (SpO2) measurements of 2 novel all-in-one monitoring devices, the BodiMetrics Performance Monitor and the Everlast smartwatch. METHODS: We enrolled 127 patients (\u3e18 years) from the Thomas Jefferson University Hospital Preadmission Testing Center. SBP and HR were measured by both investigational devices. In addition, the Everlast watch was utilized to measure DBP, and the BodiMetrics Performance Monitor was utilized to measure SpO2. After 5 min of quiet sitting, four hospital-grade standard and three investigational vital sign measurements were taken, with 60 seconds in between each measurement. The reference vital sign measurements were calculated by determining the average of the two standard measurements that bounded each investigational measurement. Using this method, we determined three comparison pairs for each investigational device in each subject. After excluding data from 42 individuals because of excessive variation in sequential standard measurements per prespecified dropping rules, data from 85 subjects were used for final analysis. RESULTS: Of 85 participants, 36 (42%) were women, and the mean age was 53 (SD 21) years. The accuracy guidelines were only met for the HR measurements in both devices. SBP measurements deviated 16.9 (SD 13.5) mm Hg and 5.3 (SD 4.7) mm Hg from the reference values for the Everlast and BodiMetrics devices, respectively. The mean absolute difference in DBP measurements for the Everlast smartwatch was 8.3 (SD 6.1) mm Hg. The mean absolute difference between BodiMetrics and reference SpO2 measurements was 3.02%. CONCLUSIONS: Both devices we investigated met accuracy guidelines for HR measurements, but they failed to meet the predefined accuracy guidelines for other vital sign measurements. Continued sale of consumer physiological monitors without prior validation and approval procedures is a public health concern

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Infrared thermography of sorptive heating of thin porous media: experiments and continuum simulations

We have studied the imbibition of water from a stationary nozzle into thin, moving porous media that are suspended in air, as well as the accompanying evaporation and condensation processes. Due to sorptive heating and the latent heat associated with the phase change processes, the temperature of the porous medium becomes non-uniform. We have measured the temperature distributions using infrared thermography as a function of substrate speed. Moreover, we developed a numerical model coupling Darcy flow and heat transfer in the thin porous medium with gas flow, heat and water vapor transport in the surrounding gas phase. The numerical simulations reproduce the measurements very well and point at an intricate buoyancy-induced gas-phase convection pattern

Chromatographic Effects in Inkjet Printing

We have studied the chromatographic separation of solvents and dyes after deposition of a dye solution on a paper substrate. Due to their larger molecular size, dyes typically exhibit a stronger interaction with the paper constituents. Consequently, the imbibition process of the dye is usually delayed compared to that of the solvent. This impacts the achievable resolution and color homogeneity in inkjet printing. We present experiments and a comprehensive numerical model to illustrate and quantify these effects. The model accounts for the solvent evaporation, heat transfer, multicomponent unsaturated flow, and dye adsorption, as well as the presence of permeable fibers in the paper substrate. We identify the key parameters that can be tuned to optimize the pattern fidelity of the printing process