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Background The evaluation of a patient's pulse rate (PR) plays a key role in emergency triage and is commonly measured in a contact-dependent way. Objective Our aims were to evaluate a camera-based prototype application (CBPA) measuring PR in an emergency department (ED) as an alternative to the current contact-dependent method of pulse oximetry and to determine the correlation between CBPA and pulse oximetry in measuring PR. Methods We simultaneously measured PR with CBPA and pulse oximetry as a reference method on a large group of ED walk-in patients. We then estimated correlation and agreement between the two methods, as well as the corresponding 95% confidence intervals. Results In a convenience sample of 446 patients, the correlation between CBPA and pulse oximetry in measuring PR was 0.939 (95% confidence interval [CI] 0.927–0.949) and the intraclass correlation was 0.939 (95% CI 0.927–0.949). Conclusions Our study found that CBPA seems to be a viable alternative to the current method of measuring PR at triage. ClinicalTrials.gov identifier: NCT03393585.

To prospectively evaluate the clinical feasibility of the magnetic resonance cholangiopancreatography (MRCP) protocol using both contact-free physiological monitoring (CFPM) and compressed sensing (CS) (CS-CFPM-MRCP) and to compare its performance with that of the standard navigator-triggered (NT) CS-NT-MRCP and NT-MRCP.A total of 63 patients (36 males, 27 females, age range: 18-83 years, mean age: 52.30 ± 15.70 years) suspected with duct-related pathologies were prospectively enrolled and performed the three MRCP protocols randomly. The acquisition time was compared. The pancreaticobiliary system was divided into 12 segments and evaluated based on a five-point Likert scale and compared by the Friedman test with a post hoc test. The diagnostic performance of the 3 MRCP was evaluated by the AUC value and compared by Delong's test. The interobserver agreement was evaluated by Kendall's W test.Compared to NT-MRCP, the acquisition time of CS-NT-MRCP and CS-CFPM-MRCP was significantly decreased (both p0.001). There is no significant difference in the overall imaging quality (p0.05) between the NT-MRCP and CS-CFPM-MRCP protocols. CS-CFPM-MRCP depicted pancreatic duct and intrahepatic ducts better than CS-NT-MRCP (all p0.05) and was comparable with that of the NT-MRCP (all p0.05). For identification of abnormalities and diseases associated with MPD anatomy, the mean AUC value for NT-MRCP and CS-CFPM-MRCP were 0.896 (95%CI: 0.834, 0.958) and 0.905 (95%CI: 0.846, 0.964), which were significantly higher when compared to that for CS-NT-MRCP (0.713 [95%CI:0.622, 0.805]) (p = 0.001 and0.001). All evaluations showed good to excellent agreement (0.619-0.897).The combination of CS and CFPM is considered feasible for shortening the scan time of 3D free breath MRCP without impairing the imaging quality and CS-CFPM-MRCP is considered feasible for patients suspected with pancreaticobiliary diseases.

The Covid-19 pandemic has caused many issues, especially in the medical field. One of the groups that are affected by the pandemic the worst is the health workers. The surge of demand for health services, especially for Covid-19 patients, overwhelms health workers, forcing them to work extra hard and eventually experience exhaustion. Due to this condition, the health workers may face difficulties in doing heavy-duty work. This paper proposes a design of a mortuary trolley as a device to ease the health workers in handling the dead bodies of Covid-19 victims. Considering the need for a corpse mobility aid that is contact-free, the design utilizes a combination of a scissor lift structure, a power screw mechanism to elevate and lower the table, and a conveyor system to load and unload the table. To ensure that the device can operate without experiencing unwanted failure, strength analyses are done on the most critical components, such as the scissor arm, pin joint, power screw, and scissor arm connector, to determine the safety factor at maximum load in static and fatigue loading condition. Analysis results show that all those components have a safety factor greater than 1 for both static and fatigue loading conditions, indicating the device will not yield and is predicted to have infinite life. The design and analyses of this device can be a reference for manufacturers of medical devices to design a mortuary trolley to ease the work of health workers.

This work is a collaboration between BioRISC (the Biosecurity Research Initiative at St Catharine’s College, Cambridge), Conservation Evidence based in the Department of Zoology, University of Cambridge and the Centre for the Study of Existential Risk. It was created by documenting our experience of options, consulting guidance, contacting people working in different countries to explore the range of options and crowd-sourcing ideas through social media. We welcome suggestions for options missed (especially those implemented outside of the UK), innovations for novel options or means of improving existing options. Please contact biorisc@caths.cam.ac.uk. You can also view the list of options on the BioRISC website (https://covid-19.biorisc.com/) or customise the list yourself using this app we developed (https://alecchristie888.shinyapps.io/Covid_19_options/).

To evaluate the utility of a contact-free device in screening for obstructive sleep apnea.Three hundred fifty-nine participants (mean age 46 ± 13 years, body mass index 26.1 ± 4.2 kg/m², 67.7% male) underwent overnight monitoring using a contact-free device, the OrbSense, and polysomnography (PSG) in the sleep laboratory simultaneously. The OrbSense recordings were analyzed automatically, and PSG was scored based on recommended guidelines.The respiratory event index from the OrbSense was lower than the apnea-hypopnea index (AHI) from PSG (25.5 ± 20.7 vs 27.0 ± 25.2 events/h; P = .007) and was significantly correlated with AHI (Pearson coefficient, 0.92; P.0001). Bland-Altman analysis showed a mean difference of 1.5 events/h, and the limit of agreement was -18.6 to 21.5 events/h. Use of the OrbSense resulted in larger underestimates of AHI and lower negative predictive values at higher AHI values (especially when AHI ≥ 30 events/h). When we used a PSG diagnostic criterion of AHI5 events/h, the optimal diagnostic cutoff value from the OrbSense was 8 events/h, with a sensitivity of 90.4%, a specificity of 77.6%, a 94.6% positive predictive value, and a 65% negative predictive value. For patients with moderate to severe obstructive sleep apnea whose AHI was15 events/h, the OrbSense cutoff was 16.6 events/h, with a sensitivity of 87.1% and a specificity of 89.7%. Among the 359 participants, 250 patients (69.6%) had the same obstructive sleep apnea severity division classified by both PSG and the OrbSense.The contact-free device OrbSense can detect respiratory events during sleep and has close agreement with in-laboratory PSG in screening for obstructive sleep apnea. Further studies are warranted to test its utility in community-based settings and at home.

Frequency domain spectroscopy (FDS) is widely used in analysis of insulation condition of dielectric material. The traditional contact method is susceptible to the impact of the contact state between the test sample and the electrode, which is also difficult to ensure the accuracy and repeatability of the test results. Using the method of sputtering gold on the surface of the sample is an effective way to avoid this problem though, this processing method is time‐consuming and high‐cost. This paper presents a method based on limit fitting by neural network to realize contact‐free dielectric response measurement, which can eliminate the distortion effect of the air gap introduced by the uneven surface of dielectric material. Cross linked polyethylene (XLPE) is chosen as the test object to verify this method: in the domain of frequency = 1–1000 Hz, comparing with the test results of sample treatment by gold sputtering, the average error of frequency domain spectroscopy data in traditional method is 10%, while the new method is only 1%. Meanwhile, this paper analyses the cause of the errors in each method.

In recent years, the inputs from magnetically assisted strategies have been contributing to the development of more sensitive screening methods and precise means of diagnosis to overcome existing and emerging treatment challenges. The features of magnetic materials enabling in vivo traceability, specific targeting and space- and time-controlled delivery of nanomedicines have highlighted the resourcefulness of the magnetic toolbox for biomedical applications and theranostic strategies. The breakthroughs in magnetically assisted technologies for contact-free control of cell and tissue fate opens new perspectives to improve healing and instruct regeneration reaching a wide range of diseases and disorders. In this review, the contribution of magnetic nanoparticles (MNPs) will be explored as sophisticated and versatile nanotriggers, evidencing their unique cues to probe and control cell function. As cells detect and engage external magnetic features, these approaches will be overviewed considering molecular engineering and cell programming perspectives as well as cell and tissue targeting modalities. The therapeutic relevance of MNPs will be also emphasized as key components of nanostructured systems to control the release of nanomedicines and in the context of new therapy technologies., ERC CoG grant MagTendon (No. 772817), H2020 Twinning project Achilles (No. 810850), FCT Project MagTT PTDC/CTM-CTM/29930/2017 (POCI-01-0145-FEDER29930), and project Norte-01-0145-FEDER-02219015 supported by Norte Portugal Regional Operational Programme (NORTE 2020). Ana F. Almeida is funded by Fundação para a Ciência e Tecnologia (FCT) – Doctoral Grant SFRD/BD/144816/2019

Multiple sensor systems are used to monitor physiological parameters, activities of daily living and behaviour. Digital biomarkers can be extracted and used as indicators for health and disease. Signal acquisition is either by object sensors, wearable sensors, or contact-free sensors including cameras, pressure sensors, non-contact capacitively coupled electrocardiogram (cECG), radar, and passive infrared motion sensors. This review summarizes contemporary knowledge of the use of contact-free sensors for patients with cardiovascular disease and healthy subjects following the PRISMA declaration. Chances and challenges are discussed. Thirty-six publications were rated to be of medium (31) or high (5) relevance. Results are best for monitoring of heart rate and heart rate variability using cardiac vibration, facial camera, or cECG; for respiration using cardiac vibration, cECG, or camera; and for sleep using ballistocardiography. Early results from radar sensors to monitor vital signs are promising. Contact-free sensors are little invasive, well accepted and suitable for long-term monitoring in particular in patient’s homes. A major problem are motion artefacts. Results from long-term use in larger patient cohorts are still lacking, but the technology is about to emerge the market and we can expect to see more clinical results in the near future.

Using silent speech to issue commands has received growing attention, as users can utilize existing command sets from voice-based interfaces without attracting other people's attention. Such interaction maintains privacy and social acceptance from others. However, current solutions for recognizing silent speech mainly rely on camera-based data or attaching sensors to the throat. Camera-based solutions require 5.82 times larger power consumption or have potential privacy issues; attaching sensors to the throat is not practical for commercial-off-the-shell (COTS) devices because additional sensors are required. In this paper, we propose a sensing technique that only needs a microphone and a speaker on COTS devices, which not only consumes little power but also has fewer privacy concerns. By deconstructing the received acoustic signals, a 2D motion profile can be generated. We propose a classifier based on convolutional neural networks (CNN) to identify the corresponding silent command from the 2D motion profiles. The proposed classifier can adapt to users and is robust when tested by environmental factors. Our evaluation shows that the system achieves 92.5% accuracy in classifying 20 commands.

In this paper, the millimeter-wave (mmWave) multiple-input multiple-output (MIMO) array aperture is studied for the capability in estimating human postures in a contact-free manner. A mono-static array with Mills cross topology is utilized for transmitting and receiving the scattered fields from a human body. The 3D image of the human body in the radio 'vision' of the array is thus synthesized using the back projection algorithm. In order to conduct a quantitative evaluation of the estimated target geometry associated to postures, the 3D image moments are calculated as the performance metrics. Furthermore, the influence of circular and linear polarization of antenna arrays on generated images are demonstrated. It is shown that linear polarized antennas can capture details of body in simple postures as in standing, however circular polarized antennas can perform satisfactorily in more complex postures as in the sitting. The investigation in this paper is instructive and transferable to specific hardware use cases in practice.

Respiratory rate is always evaluated as an indispensable physiological parameter to know about the health status of a person. Also, the monitoring of human breathing activity for a long period has numerous foundational applications in medicine. This paper proposes a prototype whose functions are measuring respiration rate and detecting sleep apnea periods with a view to monitoring sleep quality. The main principle of this device is using an infrared sensor to detect respiratory activity based on the movement of the abdomen. The distance between the sensor and the patient is from 20 to 35 cm. The distance permits supervising the breathing activity without any awareness by the subject and any modification of the sleep quality, which is very important for sleep disorders diagnostic applications. The experiments were conducted on three people during about 10 minutes each, one of whom has no sleep apnea syndrome while two others are suffering from such disease. The average accuracy of the proposed system is 95.72%, the average sensitivity is 94.57%, and the average specificity is 96.92% in terms of respiratory measurement. The sleep apnea detection reaches high average parameters which are 100%. Generally speaking, the results obtained are moderately acceptable with high precision. However, the proposed system only performs well if the users sleep stably on their back, and there is no obstacle, such as a thick blanket between them and the sensor. These problems need improving in further research to create an optimal product which offers potential application in home and mobile healthcare.

Study question To design and test an automated microfluidic device to revolutionize the cumulus-oocyte-complex (COC) denudation procedure for intracytoplasmic sperm injection (ICSI) using murine oocytes. Summary answer Oocyte exposure to temperature variation, mechanical stress, and prolonged chemical treatment during denudation was mitigated using our microfluidic device based on surface acoustic waves (SAWs). What is known already COC denudation is a prerequisite for many ART procedures such as ICSI. However, this procedure is based on manual pipetting (MP), which lacks standardization and requires experienced embryologists to perform. Inadequate MP may damage oocytes through prolonged enzymatic treatment or high fluidic stresses and may jeopardize gamete competence. The use of microfluidic devices based on porous membranes or microchannels has been adopted by many laboratories for sperm selection. Of these, microchannel devices may also be adapted for denudation with minimal mechanical stress in a controlled microenvironment. However, oocyte manipulation and extraction have proven difficult to achieve. Study design, size, duration We developed a novel ultrasonic microfluidic device based on a microwell design manufactured with Polydimethylsiloxane (PDMS). The SAWs were generated by 4 interdigitated transducers (IDTs) arranged in an orthogonally symmetric pattern. A non-toxic dosage of ultrasonic waves, similar to those used in gynecology and obstetrics, was applied. COCs were denuded by induced acoustic streaming and acoustic radiation force. Denudation rate, embryo development, and pregnancy outcomes were assessed and compared to control oocytes denuded by MP. Participants/materials, setting, methods For each run, up to 10 individual COCs from super-ovulated B6D2F1 mice were loaded into the microwell alongside diluted hyaluronidase (20 IU/ml) and denuded by 80 or 200 MHz SAWs. Denuded oocytes were fertilized by piezo-actuated ICSI using spermatozoa from the same strain. Pre-implantation embryo development was assessed in a time-lapse incubator for up to 96 h. High-quality blastocysts were transferred to 2.5-dpc pseudo-pregnant CD-1 surrogates. Pregnancy and offspring health were observed. Main results and the role of chance Using alternating frequency sweep in a pulse-repetition mode, we swirled the fluid inside the microwell consistently and tumbled COCs inside the microwell to expose them to acoustic steaming-induced drag forces and acoustic radiation force. Using a high-speed camera and particle-tracking technique, we observed that the drag force generated by the SAWs fulfilled the denudation mechanism. Additionally, due to the small attenuation coefficient in water, thermal absorption heating remains minuscule, preventing any thermal-induced damage. Our device significantly reduced the time and labor of the denudation process. It also yielded proper denudation quality without oocyte loss. To ensure that SAWs do not damage oocytes, 40 oocytes denuded by 80 MHz SAWs, 25 oocytes denuded by 200 MHz SAWs, and 30 oocytes denuded by MP were inseminated by piezo-actuated ICSI. The 80-MHz, 200-MHz, and MP groups yielded comparable post-ICSI survival (82.5% vs. 84.0% vs. 83.3%, respectively), fertilization (80.0% vs. 80.0% vs. 83.3%,respectively), and blastulation rates (72.5% vs. 82.0% vs. 66.7%, respectively). Embryo morphokinetics were also not impacted. After transferring all blastocysts into recipient mice, 8 live births were achieved from the 80-MHz group, while 5 were achieved from the 200-MHz group. Limitations, reasons for caution Although PDMS is a popular material due to its high optical transparency and biocompatibility, adverse effects due to gas permeability and small-molecule adsorption cannot be excluded. Large-scale mouse embryo assays should be performed to assess the teratogenicity of PDMS. Operation parameters must be optimized for human COCs in clinical application. Wider implications of the findings Adopting widely used ultrasound techniques with emerging SAW technology is a major step toward advancing and standardizing oocyte denudation—a laborious yet delicate procedure. We predict it will be further integrated with AI and miniaturized robotics, modules specialized in gamete assessment, ICSI, and embryo evaluation in the near future. Trial registration number ‘not applicable’

We consider suspensions of rigid bodies in a two-dimensional viscous fluid. Even with high-fidelity numerical methods, unphysical contact between particles occurs because of spatial and temporal di ...

Interspecies interactions inside microbial communities bear a tremendous diversity of complex chemical processes that are by far not understood. For the investigation of these interactions, precise analytical tools are often missing. This article presents microfluidic single-cell tools that can be used for dynamic growth analysis of contact-based (here: horizontal gene transfer) and contact free (diffusive) interactions (here: L-lysine exchange) between microbial cells and colonies on single-cell level.

In this paper, we explore the hypothesis that multimodal features as well as demographic information can play an important role in increasing the performance of automatic lie detection. We introduce a large, multimodal deception detection dataset balanced across genders, and we analyze the patterns associated with the thermal, linguistic, and visual responses of liars and truth-tellers. We show that our multimodal noncontact deception detection approach can lead to a performance in the range of 60%–80%, with different modalities, different genders, and different domain settings playing a role in the accuracy of the system.

This research work demonstrates the feasibility of stress quantification in situations where the attention of the user is divided. Psychologically kosher (i.e., unobtrusive) quantification of stress and its correlation to user performance and emotion are of singular importance in man-machine interaction. We have also proved that talking on a cell phone during simulated driving increases the supraorbital skin temperature significantly. This finding clearly demonstrates that concurrent performance of two critical tasks increases user's stress level. Thus, we can safely claim that the proposed system is capable of reflecting the user's stress in divided attention situations. A feedback system can be devlope that alerts the users about their mental status based on the facial thermal signature . The initial experiment with a small dataset shows a lot of promise. More multi-faceted and extensive experiments, however, are necessary to understand the complete picture. The proposed system can be use to monitor physiological behavior during critical multitasking activities. The potential use of our system is to understand the vehicle drivers' emotional states in order to reduce traffic accidents. The major bottelnack of this system is very high cost of the thermal camera, which prevents the system to be a practial applciation. We hope the cost of the thermal camera will reduce in the near future.

Queuing at airport border controls is one of the bottlenecks in the flow of passengers, which results in a poor travel experience and in serious health risks, like COVID19, due to the concentration of people and contact surfaces [3]. To address this problem, biometrics-on-the-move removes physical barriers for passengers, while preserving security at a maximum level. In this paper we describe a prototype, tested at the Lisbon Airport, demonstrating biometrics-on-the-move technology, where airport passengers are authenticated at a distance without having to pass through physical barriers or contact surfaces. This new setting requires a careful design of the flow of passengers and liveness detection biometrics to allow the robust authentication of passengers and, more importantly, detect fraud attempts in the different points of the process.

BackgroundTo increase the consultation rate of potential major depressive disorder (MDD) patients, we developed a contact-type fingertip photoplethysmography-based MDD screening system. With the outbreak of SARS-CoV-2, we developed an alternative to contact-type fingertip photoplethysmography: a novel web camera-based contact-free MDD screening system (WCF-MSS) for non-contact measurement of autonomic transient responses induced by a mental task.MethodsThe WCF-MSS measures time-series interbeat intervals (IBI) by monitoring color tone changes in the facial region of interest induced by arterial pulsation using a web camera (1920 × 1080 pixels, 30 frames/s). Artifacts caused by body movements and head shakes are reduced. The WCF-MSS evaluates autonomic nervous activation from time-series IBI by calculating LF (0.04–0.15 Hz) components of heart rate variability (HRV) corresponding to sympathetic and parasympathetic nervous activity and HF (0.15–0.4 Hz) components equivalent to parasympathetic activities. The clinical test procedure comprises a pre-rest period (Pre-R; 140 s), mental task period (MT; 100 s), and post-rest period (Post-R; 120 s). The WCF-MSS uses logistic regression analysis to discriminate MDD patients from healthy volunteers via an optimal combination of four explanatory variables determined by a minimum redundancy maximum relevance algorithm: HF during MT (HFMT), the percentage change of LF from pre-rest to MT (%ΔLF(Pre–R⇒MT)), the percentage change of HF from pre-rest to MT (%ΔHF(Pre–R⇒MT)), and the percentage change of HF from MT to post-rest (%ΔHF(MT⇒Post–R)). To clinically test the WCF-MSS, 26 MDD patients (16 males and 10 females, 20–58 years) were recruited from BESLI Clinic in Tokyo, and 27 healthy volunteers (15 males and 12 females, 18–60 years) were recruited from Tokyo Metropolitan University and RICOH Company, Ltd. Electrocardiography was used to calculate HRV variables as references.ResultThe WCF-MSS achieved 73% sensitivity and 85% specificity on 5-fold cross-validation. IBI correlated significantly with IBI from reference electrocardiography (r = 0.97, p < 0.0001). Logit scores and subjective self-rating depression scale scores correlated significantly (r = 0.43, p < 0.05).ConclusionThe WCF-MSS seems a promising contact-free MDD screening apparatus. This method enables web camera built-in smartphones to be used as MDD screening systems.

Nocturnal periodic breathing of chronic opioid users has been predominantly documented by the use of polysomnography. No previous studies have assessed the opioid effects of respiratory rhythms throughout the day without the use of physical restraint. We recently developed a contact-free unconstraint vital sign monitoring system with four load cells placed under the bed legs, which allows continuous measurements of respiratory change at the center of gravity on the bed. We aimed to reveal details of the patient's 24-h respiratory status under a monitoring system and to test the hypothesis that respiratory rhythm abnormalities are opioid dose-dependent and worsen during the night time. Continuous 48-h respiratory measurements were successfully performed in 51 patients with advanced cancer (12 opioid-free patients and 39 opioid-receiving patients). Medians of respiratory variables with minimal body movement artifacts were calculated for each 8-h split time period. Compared with opioid-free patients, opioid-receiving patients had slower respiratory rate with higher respiratory rate irregularity without changing tidal centroid shift regardless of the time period. Irregular ataxic breathing was only identified in opioid-receiving patients (33%

There is a growing need for remote monitoring of patients due to a lack of resources and infection control. Current systems use sensors that require constant physical contact with the user, which may result in discomfort or lack of adherence. In the present study, we evaluated the accuracy of a new contact-free system to monitor heart and respiratory rate. Study participants were measured simultaneously using two devices: a contact-free optical system that measures nano-vibrations and movements (investigational device, "Gili Pro BioSensor") and a standard reference bed-side monitor, inclusive of an electrocardiogram and capnograph modules (Mindray

This work aimed to evaluate whether a radar sensor can distinguish sleep from wakefulness in real time. The sensor detects body movements without direct physical contact with the subject and can be embedded in the roof of a hospital room for completely unobtrusive monitoring. We conducted simultaneous recordings with polysomnography, actigraphy, and radar on two groups: healthy young adults (n = 12, four nights per participant) and patients referred to a sleep examination (n = 28, one night per participant). We developed models for sleep/wake classification based on principles commonly used by actigraphy, including real-time models, and tested them on both datasets. We estimated a set of commonly reported sleep parameters from these data, including total-sleep-time, sleep-onset-latency, sleep-efficiency, and wake-after-sleep-onset, and evaluated the inter-method reliability of these estimates. Classification results were on-par with, or exceeding, those often seen for actigraphy. For real-time models in healthy young adults, accuracies were above 92%, sensitivities above 95%, specificities above 83%, and all Cohen's kappa values were above 0.81 compared to polysomnography. For patients referred to a sleep examination, accuracies were above 81%, sensitivities about 89%, specificities above 53%, and Cohen's kappa values above 0.44. Sleep variable estimates showed no significant intermethod bias, but the limits of agreement were quite wide for the group of patients referred to a sleep examination. Our results indicate that the radar has the potential to offer the benefits of contact-free real-time monitoring of sleep, both for in-patients and for ambulatory home monitoring.

We present a concept for a supplementary patient monitoring and emergency alerting system. It renders hot pluggability of sensors possible by taking a modular design as a basis. Specialized sensor modules detect the occurrence of particular emergencies such as excessive increasing or decreasing heart rate. The observers operating the system can receive and easily react to these emergencies using augmented reality headsets without having to interrupt their routine. Means to monitor multiple patients per sensor are discussed in this paper as well.

International audience; Direct contact with devices such as elevator buttons, beepers, telephones, computer mice and keyboards can contribute to spread viral diseases. Here, we report our experience in designing, producing and dispatching three 3D-printed objected intending to lower the risks of COVID-19 contamination by limiting direct contacts: (1) fixed hand-free door openers, (2) door hooks and (3) button pushers. These devices were produced in industrial quantities and made available for free for Greater Paris University Hospitals and various state institutions as part of the 3D COVID project. In this short technical note, we describe the sequential organisation of the design and production and highlight the advantages of additive manufacturing in dealing with specific aspects of sanitary crises.

In this paper we introduce a novel contact-free volumetric haptic feedback device. A symmetric electromagnet is used in combination with a dipole magnet model and a simple control law to deliver dynamically adjustable forces onto a hand-held tool. The tool only requires an embedded permanent magnet and thus can be entirely untethered. The force, however, while contact-free, remains grounded via the spherical electromagnet and relatively large forces (1N at contact) can be felt by the user. The device is capable of rendering both attracting and repulsive forces in a thin shell around the electromagnet. We report findings from a user experiment with 6 participants, characterizing force delivery aspects and perceived precision of our system. We found that users can discern at least 25 locations for repulsive forces., 2020 IEEE Haptics Symposium (HAPTICS), ISBN:978-1-7281-0234-4, ISBN:978-1-7281-0235-1

Evaporative assembly of colloids in tiny contact free droplet is a facile and one step process to realize nanostructured microgranules. In such a process, with relatively fast drying rate a random jamming of the nanoparticles are expected. Here we have shown that even in such a rapid random jamming process, a nice local hexagonal ordering can exist. Although the local volume fraction of the nanoparticles in the granules is not affected in a statistically sense, the intermediate range ordering gets influenced depending on the rapidness of the assembly process.

Contact-free detection of human vital signs like heart rate and respiration rate will improve the patients' comfort and enables long-term monitoring of newborns or bedridden patients. For that, reliable and safe measurement techniques are indispensable. The aim of this work is the development and comparison of novel ultrasonic and capacitive measurement setups, sharing a common hardware platform. Both measurement techniques that are implemented and compared are based on the detection of minor chest wall vibrations in millimeter ranges, due to geometrical thorax changes during respiration and heartbeat activities. After examining the physical measurement conditions and simulating the capacitive sensor, a problem-specific measurement setup is proposed. The system is characterized to be capable of detecting distance changes below 2 {\mu}m via the ultrasonic sensor and below 800 {\mu}m via the capacitive sensor. First subject measurements show that the detection of heart activities is possible under ideal conditions and exclusively with the proposed ultrasonic approach. However, the capacitive sensor works reliably for respiration monitoring, even when the subject is fully-clothed and covered with a blanket. The chosen ultrasonic approach is sensitive regarding minor changes of the reflecting surface and therefore has high uncertainty. In contrast, capacitive respiration detection is very reliable. It is conceivable that improvements in the capacitive sensor circuitry will also enable the detection of heart activities. The proposed ultrasonic approach presents current problems of this technique. In contrast to that, the unusual approach of capacitive sensing demonstrates a high potential regarding vital signs acquisition., Comment: IEEE Access

Synthetic micro-/nanomachines, which are able to mimic the amazing natural system, can convert energy source into movement, and are expected to help humanity complete environmental and biological tasks. Ultrasound, with major advantages of on-demand motion control, long lifetime, noninvasive, contact free, and great biocompatibility, have been one of the most probable potential toward in vivo drug delivery and clinical diagnosis. In present short review, we intent to summarize the progress in using ultrasound to control and propel micro-/nanomachines during the last decade, and discussed the important aspects toward biomedical applications.

Introduction Snoring can disturb the sleep of snorers as well as their bed partners. Recent technological advances allow objective measurement of sleep and snoring in the comfort of the bedroom. This study examined effects of a non-medical contactless snoring solution on snoring and sleep in snorers and their partners. Methods Self-reported snorers (n=29; 72% male; age 25-59 years, avg. 43; BMI Results Objectively-measured average snoring reduced from 10% of the night when not using the product to 9% during the first week of use and 7% during the second week of use (p Conclusion By reducing the amount of snoring, the contactless snoring solution improved objectively-measured sleep in snorers’ bed partners. Also, the perceived sleep of both snorers and their partners improved. Support (if any) Smart Nora

STUDY OBJECTIVES: To evaluate the utility of a contact-free device in screening for obstructive sleep apnea. METHODS: Three hundred fifty-nine participants (mean age 46 ± 13 years, body mass index 26.1 ± 4.2 kg/m(2), 67.7% male) underwent overnight monitoring using a contact-free device, the OrbSense, and polysomnography (PSG) in the sleep laboratory simultaneously. The OrbSense recordings were analyzed automatically, and PSG was scored based on recommended guidelines. RESULTS: The respiratory event index from the OrbSense was lower than the apnea-hypopnea index (AHI) from PSG (25.5 ± 20.7 vs 27.0 ± 25.2 events/h; P = .007) and was significantly correlated with AHI (Pearson coefficient, 0.92; P < .0001). Bland-Altman analysis showed a mean difference of 1.5 events/h, and the limit of agreement was –18.6 to 21.5 events/h. Use of the OrbSense resulted in larger underestimates of AHI and lower negative predictive values at higher AHI values (especially when AHI ≥ 30 events/h). When we used a PSG diagnostic criterion of AHI > 5 events/h, the optimal diagnostic cutoff value from the OrbSense was 8 events/h, with a sensitivity of 90.4%, a specificity of 77.6%, a 94.6% positive predictive value, and a 65% negative predictive value. For patients with moderate to severe obstructive sleep apnea whose AHI was > 15 events/h, the OrbSense cutoff was 16.6 events/h, with a sensitivity of 87.1% and a specificity of 89.7%. Among the 359 participants, 250 patients (69.6%) had the same obstructive sleep apnea severity division classified by both PSG and the OrbSense. CONCLUSIONS: The contact-free device OrbSense can detect respiratory events during sleep and has close agreement with in-laboratory PSG in screening for obstructive sleep apnea. Further studies are warranted to test its utility in community-based settings and at home. CITATION: Zhao R, Xue JB, Dong XS, et al. Screening for obstructive sleep apnea using a contact-free system compared with polysomnography. J Clin Sleep Med. 2021;17(5):1075–1082.

Thrombogenesis (blood clot formation) is a major barrier to the development of biomedical devices that interface with blood. Although state-of-the-art chemically and pharmacologically mediated clot mitigation strategies are effective, some limitations of such approaches include depletion of active agents, or adverse reactions in patients. Increased clotting protein adsorption and platelet adhesion, which occurs when artificial surfaces are exposed to blood, results in enhanced clot formation on artificial surfaces. It is hypothesized that repelling proteins and platelets using dielectrophoresis (DEP), a contact free particle manipulation technique, will reduce clot formation in biomedical devices. In this paper, the effect of DEP on thrombogenesis in a human blood is investigated. Undiluted whole blood from human donors is pumped through microchannels at a physiological shear rate (400 s−1). Experiments are performed by applying 0 V, 0.5 Vrms, 2 Vrms, and 3 Vrms to electrodes in the channel. Clot formation is observed to decrease in experiments in which DEP electrodes are active (average of 6% coverage @ 0V reduced to 0.08% coverage @ 3 Vrms). Repulsion is more effective at higher voltages. DEP causes a quantifiable reduction in microscopic and macroscopic clot formation in PDMS microchannels. This article is protected by copyright. All rights reserved

Recent studies show that the handling of thin wafers in the photovoltaic industry can lead to unacceptable yields due to cell scratching and breaking. This paper presents the concept and design of a novel modular conveyor that is intended for handling planar fragile objects at a high speed without contact. Each element of the conveyor is a square block that is able to generate tilted air jets that lift and push the object in a single direction. Various handling functions can thus be achieved by the assembly of several blocks. To manage the complexity of assembling systems composed of hundreds of blocks, an automatized design methodology is proposed. This process gives the best topology of the conveyor that meets expected specifications such as trajectory, speed, and travel time. The optimization relies on the physical model of the modular system describing the motion of the object pushed by directed air jets. Experimental comparisons show that the simulation predicts accurately the motion of a glass wafer according to the arrangement of the blocks and the volume of air flow. A maximal speed of 0.3 m/s was experimentally observed and, on larger simulated conveyors, the speed of the wafer could theoretically reach 2.9 m/s.

Vascular biometric templates are gaining increasing popularity due to simple and contact free capture and resilience to presentation attacks. We present the state of the art in Biometric Graph Comparison, a technique to register and compare vascular biometric templates by representing them as formal graphs. Such graphs consist of a set of vertices, representing the branch, termination and crossover points in the vascular pattern, and a set of edges. An edge represents the relationship between a pair of feature points that are directly connected by a vessel segment in a vascular biometric image. We summarise how this information has been successfully used over the past 8 years to improve registration and recognition performance for the vasculature under the palm, wrist, hand and retina. The structural properties of biometric graphs from these modalities differ, with retina graphs having the largest number of vertices on average and the most complex structure, and hand graphs having the smallest number of vertices on average and being the least connected. All vascular graphs have similarities to trees, with the ratio of edges to vertices being close to 1. We describe our most recent algorithms for biometric graph registration and comparison, and our performance results. We are interested in the possibility of using biometric graphs in a template protection scheme based on the paradigm of dissimilarity vectors. As a first step, we wish to improve registration. Certain modalities like retina have an intrinsic reference frame that makes registration more straightforward. Other modalities may not have an intrinsic reference frame. To overcome this, we introduce the notion of anchors—subgraphs of a biometric graph, having between 5 and 10 vertices, that occur consistently in samples from the same individual—that would enable the dissimilarity vector scheme to be applied to any vascular modality. Experiments on palm and wrist databases show that all individuals had at least some sets of 6 captures which could be used to identify an anchor, and anchors were identified in \(94\%\) and \(88\%\) for the palm and wrist databases, respectively.

This paper presents a contact-free method for physiological parameter estimation in people with profound intellectual and multiple disabilities (PIMD). We used an existing state-of-the-art algorithm Plane-Orthogonal-to-Skin (POS) in order to obtain an initial remote photoplethysmogram (rPPG) reconstruction from facial videos. We enhanced this signal by applying a long-short-term-memory (LSTM) neural network to the initial PPG reconstruction. Evaluation of our method on a public database DEAP has shown heart rate (HR) error of 8.09 beats-per-minute, suprpassing the state-of-the-art POS algorithm implementation, which had error of 13.36 BPM. More importantly, a good correlation between our predictions and ground-truth HRs has been observed. The method is currently being implemented as part of a system which aims to monitor people with PIMD in real time in order to obtain information about their physiological and psychological state and in turn increase their quality of life.

Most proteins are electrical insulators or poor conductors. We present temperature resolved conductivity measurements on electrically conducting proteins. Temperature-resolved THz spectroscopy was used as a contact free method to measure the conductivity. We measured the conductivity of the wild-type pili as well as for two bioengineered pili.

Background In protein crystals, flexible loops are frequently deformed by crystal contacts, whereas in solution, the large motions result in the poor convergence of such flexible loops in NMR structure determinations. We need an experimental technique to characterize the structural and dynamic properties of intrinsically flexible loops of protein molecules. Methods We designed an intended crystal contact-free space (CCFS) in protein crystals, and arranged the flexible loop of interest in the CCFS. The yeast Tim 21 protein was chosen as the model protein, because one of the loops (loop 2) is distorted by crystal contacts in the conventional crystal. Results Yeast Tim21 was fused to the MBP protein by a rigid α-helical linker. The space created between the two proteins was used as the CCFS. The linker length provides adjustable freedom to arrange loop 2 in the CCFS. We re-determined the NMR structure of yeast Tim21, and conducted MD simulations for comparison. Multidimensional scaling was used to visualize the conformational similarity of loop 2. We found that the crystal contact-free conformation of loop 2 is located close to the center of the ensembles of the loop 2 conformations in the NMR and MD structures. Conclusions Loop 2 of yeast Tim21 in the CCFS adopts a representative, dominant conformation in solution. General significance No single powerful technique is available for the characterization of flexible structures in protein molecules. NMR analyses and MD simulations provide useful, but incomplete information. CCFS crystallography offers a third route to this goal.

Wi-Fi-based in-home health care has attracted much attention over the past years. In this paper, leveraging the complementary amplitude and phase data of Wi-Fi Channel State Information (CSI), we propose a contact-free elderly-focused health monitoring system to simultaneously detect the human presence and monitor the detailed respiration status. By utilizing the Naive Bayes classifier, the proposed system could detect human presence based on the Doppler spectrum. To obtain detailed respiration status, we define the Respiration-to-Noise Ratio (RNR) to select the most sensitive data streams. For detecting and distinguishing abnormal respiratory patterns, we extend the peak detection method and leverage machine learning based classifier in respiration apnea period. We carry out extensive experiments and the results demonstrate the effectiveness of our approach to health monitoring.

Rate of respiration is a fundamental vital sign. Accuracy and precision of respiratory rate measurements with contact-free load cell sensors under the bed legs were assessed by breath-by-breath comparison with the pneumotachography technique during two different dynamic breathing tasks in 16 awake human adults resting on the bed. The subject voluntarily increased and decreased the respiratory rate between 4 and 16 breaths/min ( n = 8) and 10 and 40 breaths/min ( n = 8) at every 2 breaths in 6 different lying postures such as supine, left lateral, right lateral, and 30, 45, and 60° sitting postures. Reciprocal phase changes of the upper and lower load cell signals accorded with the respiratory phases indicating respiratory-related shifts of the centroid along the long axis of the bed. Bland-Altman analyses revealed 0.66 and 1.59 breaths/min standard deviation differences between the techniques (limits of agreement: −1.22 to 1.36 and −2.96 to 3.30) and 0.07 and 0.17 breaths/min fixed bias differences (accuracy) (confidence interval: 0.04 to 0.10 and 0.12 to 0.22) for the mean respiratory rates of 10.5 ± 3.7 and 24.6 ± 8.9 breaths/min, respectively, regardless of the body postures on the bed. Proportional underestimation by this technique was evident for respiratory rates >40 breaths/min. Sample breath increase up to 10 breaths improved the precision from 1.59 to 0.26 breaths/min. Abnormally faster and slower respirations were accurately detected. We conclude that contact-free unconstraint respiratory rate measurements with load cells under the bed legs are accurate and may serve as a new clinical and investigational tool. NEW & NOTEWORTHY Four load cells placed under the bed legs successfully captured a centroid shift during respiration in human subjects lying on a bed. Breath-by-breath comparison of the breaths covering a wide respiratory rate range by pneumotachography confirmed reliability of the contact-free unconstraint respiratory rate measurements by small standard deviations and biases regardless of body postures. Abnormally faster and slower respirations were accurately detected. This technique should be an asset as a new clinical and investigational tool.