A Review of Wearable Multi-wavelength Photoplethysmography

Optical pulse detection photoplethysmography (PPG) provides a means of low cost and unobtrusive physiological monitoring that is popular in many wearable devices. However, the accuracy, robustness and generalizability of single-wavelength PPG sensing are sensitive to biological characteristics as well as sensor configuration and placement; this is significant given the increasing adoption of single-wavelength wrist-worn PPG devices in clinical studies and healthcare. Since different wavelengths interact with the skin to varying degrees, researchers have explored the use of multi-wavelength PPG to improve sensing accuracy, robustness and generalizability. This paper contributes a novel and comprehensive state-of-the-art review of wearable multi-wavelength PPG sensing, encompassing motion artifact reduction and estimation of physiological parameters. The paper also encompasses theoretical details about multi-wavelength PPG sensing and the effects of biological characteristics. The review findings highlight the promising developments in motion artifact reduction using multi-wavelength approaches, the effects of skin temperature on PPG sensing, the need for improved diversity in PPG sensing studies and the lack of studies that investigate the combined effects of factors. Recommendations are made for the standardization and completeness of reporting in terms of study design, sensing technology and participant characteristics

Evaluation of Wearable Electronics for Epilepsy: A Systematic Review

Epilepsy is a neurological disorder that affects 50 million people worldwide. It is characterised by seizures that can vary in presentation, from short absences to protracted convulsions. Wearable electronic devices that detect seizures have the potential to hail timely assistance for individuals, inform their treatment, and assist care and self-management. This systematic review encompasses the literature relevant to the evaluation of wearable electronics for epilepsy. Devices and performance metrics are identified, and the evaluations, both quantitative and qualitative, are presented. Twelve primary studies comprising quantitative evaluations from 510 patients and participants were collated according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Two studies (with 104 patients/participants) comprised both qualitative and quantitative evaluation components. Despite many works in the literature proposing and evaluating novel and incremental approaches to seizure detection, there is a lack of studies evaluating the devices available to consumers and researchers, and there is much scope for more complete evaluation data in quantitative studies. There is also scope for further qualitative evaluations amongst individuals, carers, and healthcare professionals regarding their use, experiences, and opinions of these devices

Art for Computer Scientists: Processing as an open-source art medium for computer science undergraduates

Art undergraduates increasingly engage in the design and coding of digital media and generative art, for example, using the open-source Processing library and Integrated Development Environment (IDE) created for visual artists. An equivalent cross-over, of art and creativity into traditional computer science programmes, is not so evident despite a shortfall of skilled graduates in the digital media sector.This paper considers art for computer scientists and outlines a Keele University Animation and Multimedia module that uses media programmingnot only as a vehicle for first-year undergraduates to practice new Java programming skills, but also as an opportunity for artistic exploration and creative expressio

Poster: Heart Rate Performance of a Medical-Grade Data Streaming Wearable Device

Wrist-worn devices afford convenient and unobtrusive heart rate sensing, however, motion artifacts can lead to unreliable data recordings. This paper evaluates heart rate estimates acquired during treadmill walking and 12 hours of everyday living from a medical-grade Empatica E4 data streaming wristband wearable compared to a Polar H10 chest strap ECG sensor. For treadmill walking, heart rate Mean Absolute Percentage Errors (MAPEs) were between 7.2\% and 29.2\%, and IntraClass Correlations (ICCs) between 0.6 and \nobreakdash-0.5, indicating moderate agreement and strong disagreement, respectively. During 12-hour everyday living acquisitions, heart rate estimate MAPEs were between 5.3\% and 13.5\% and ICCs between 0.7 and 0.1, indicating good to poor agreements

Computational aspects of model acquisition and join geometry for the virtual reconstruction of the atrahasis cuneiform tablet

The epic of Atrahasis is one of the most famous pieces of ancient Mesopotamian literature. The account has survived millennia on sets of clay tablets inscribed with cuneiform script; a sophisticated early writing system comprising signs formed from wedge-shaped impressions. The third tablet belonging to one of the most complete copies of the Atrahasis epic is broken. For over fifty years, one fragment, held in Geneva, was believed to join with another held in London. However, due to their 1000 km separation, the join had never been physically tested. This paper contributes a technological account of the successful virtual joining of the fragments [1]; the first ever longdistance virtual join of its type

Automated Low-Cost Photogrammetric Acquisition of 3D Models from Small Form-Factor Artefacts

The photogrammetric acquisition of 3D object models can be achieved by Structure from Motion (SfM) computation of photographs taken from multiple viewpoints. All-around 3D models of small artefacts with complex geometry can be difficult to acquire photogrammetrically and the precision of the acquired models can be diminished by the generic application of automated photogrammetric workflows. In this paper, we present two versions of a complete rotary photogrammetric system and an automated workflow for all-around, precise, reliable and low-cost acquisitions of large numbers of small artefacts, together with consideration of the visual quality of the model textures. The acquisition systems comprise a turntable and (i) a computer and digital camera or (ii) a smartphone designed to be ultra-low cost (less than $150). Experimental results are presented which demonstrate an acquisition precision of less than 40 μm using a 12.2 Megapixel digital camera and less than 80 μm using an 8 Megapixel smartphone. The novel contribution of this work centres on the design of an automated solution that achieves high-precision, photographically textured 3D acquisitions at a fraction of the cost of currently available systems. This could significantly benefit the digitisation efforts of collectors, curators and archaeologists as well as the wider population

High-Resolution 3D Printing Fabrication of a Microfluidic Platform for Blood Plasma Separation

Additive manufacturing technology is an emerging method for rapid prototyping, which enables the creation of complex geometries by one-step fabrication processes through a layer-by-layer approach. The simplified fabrication achieved with this methodology opens the way towards a more efficient industrial production, with applications in a great number of fields such as biomedical devices. In biomedicine, blood is the gold-standard biofluid for clinical analysis. However, blood cells generate analytical interferences in many test procedures; hence, it is important to separate plasma from blood cells before analytical testing of blood samples. In this research, a custom-made resin formulation combined with a high-resolution 3D printing methodology were used to achieve a methodology for the fast prototype optimization of an operative plasma separation modular device. Through an iterative process, 17 different prototypes were designed and fabricated with printing times ranging from 5 to 12 min. The final device was evaluated through colorimetric analysis, validating this fabrication approach for the qualitative assessment of plasma separation from whole blood. The 3D printing method used here demonstrates the great contribution that this microfluidic technology will bring to the plasma separation biomedical devices market.This research was funded by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 778001 (DNASurf), “Ministerio de Ciencia y Educación de España” under grant PID2020-120313GB-I00/AIE/10.13039/501100011033, the Basque Government (Grant IT1271-19) and the US National Institutes of Health (R01 EB027096 and R15 GM123405-02)

Investigation of wearable health tracker version updates

Background: Wearable fitness trackers are increasingly used in healthcare applications; however, the frequent updating of these devices is at odds with traditional medical device practices. Objective: Our objective was to explore the nature and frequency of wearable tracker updates recorded in device changelogs, to reveal the chronology of updates and to estimate the intervals where algorithm updates could impact device validations. Method: Updates for devices meeting selection criteria (that included their use in clinical trials) were independently labelled by four researchers according to simple function and specificity schema. Results: Device manufacturers have diverse approaches to update reporting and changelog practice. Visual representations of device changelogs reveal the nature and chronology of device iterations. 13% of update items were unspecified and 32% possibly affected validations with as few as 5 days between updates that may affect validation. Conclusion: Manufacturers could aid researchers and health professionals by providing more informative device update changelogs