TY - JOUR AU - Kluge, Felix AU - Brand, E. Yonatan AU - Micó-Amigo, Encarna M. AU - Bertuletti, Stefano AU - D'Ascanio, Ilaria AU - Gazit, Eran AU - Bonci, Tecla AU - Kirk, Cameron AU - Küderle, Arne AU - Palmerini, Luca AU - Paraschiv-Ionescu, Anisoara AU - Salis, Francesca AU - Soltani, Abolfazl AU - Ullrich, Martin AU - Alcock, Lisa AU - Aminian, Kamiar AU - Becker, Clemens AU - Brown, Philip AU - Buekers, Joren AU - Carsin, Anne-Elie AU - Caruso, Marco AU - Caulfield, Brian AU - Cereatti, Andrea AU - Chiari, Lorenzo AU - Echevarria, Carlos AU - Eskofier, Bjoern AU - Evers, Jordi AU - Garcia-Aymerich, Judith AU - Hache, Tilo AU - Hansen, Clint AU - Hausdorff, M. Jeffrey AU - Hiden, Hugo AU - Hume, Emily AU - Keogh, Alison AU - Koch, Sarah AU - Maetzler, Walter AU - Megaritis, Dimitrios AU - Niessen, Martijn AU - Perlman, Or AU - Schwickert, Lars AU - Scott, Kirsty AU - Sharrack, Basil AU - Singleton, David AU - Vereijken, Beatrix AU - Vogiatzis, Ioannis AU - Yarnall, Alison AU - Rochester, Lynn AU - Mazzà, Claudia AU - Del Din, Silvia AU - Mueller, Arne PY - 2024/5/1 TI - Real-World Gait Detection Using a Wrist-Worn Inertial Sensor: Validation Study JO - JMIR Form Res SP - e50035 VL - 8 KW - digital mobility outcomes KW - validation KW - wearable sensor KW - walking KW - digital health KW - inertial measurement unit KW - accelerometer KW - Mobilise-D N2 - Background: Wrist-worn inertial sensors are used in digital health for evaluating mobility in real-world environments. Preceding the estimation of spatiotemporal gait parameters within long-term recordings, gait detection is an important step to identify regions of interest where gait occurs, which requires robust algorithms due to the complexity of arm movements. While algorithms exist for other sensor positions, a comparative validation of algorithms applied to the wrist position on real-world data sets across different disease populations is missing. Furthermore, gait detection performance differences between the wrist and lower back position have not yet been explored but could yield valuable information regarding sensor position choice in clinical studies. Objective: The aim of this study was to validate gait sequence (GS) detection algorithms developed for the wrist position against reference data acquired in a real-world context. In addition, this study aimed to compare the performance of algorithms applied to the wrist position to those applied to lower back?worn inertial sensors. Methods: Participants with Parkinson disease, multiple sclerosis, proximal femoral fracture (hip fracture recovery), chronic obstructive pulmonary disease, and congestive heart failure and healthy older adults (N=83) were monitored for 2.5 hours in the real-world using inertial sensors on the wrist, lower back, and feet including pressure insoles and infrared distance sensors as reference. In total, 10 algorithms for wrist-based gait detection were validated against a multisensor reference system and compared to gait detection performance using lower back?worn inertial sensors. Results: The best-performing GS detection algorithm for the wrist showed a mean (per disease group) sensitivity ranging between 0.55 (SD 0.29) and 0.81 (SD 0.09) and a mean (per disease group) specificity ranging between 0.95 (SD 0.06) and 0.98 (SD 0.02). The mean relative absolute error of estimated walking time ranged between 8.9% (SD 7.1%) and 32.7% (SD 19.2%) per disease group for this algorithm as compared to the reference system. Gait detection performance from the best algorithm applied to the wrist inertial sensors was lower than for the best algorithms applied to the lower back, which yielded mean sensitivity between 0.71 (SD 0.12) and 0.91 (SD 0.04), mean specificity between 0.96 (SD 0.03) and 0.99 (SD 0.01), and a mean relative absolute error of estimated walking time between 6.3% (SD 5.4%) and 23.5% (SD 13%). Performance was lower in disease groups with major gait impairments (eg, patients recovering from hip fracture) and for patients using bilateral walking aids. Conclusions: Algorithms applied to the wrist position can detect GSs with high performance in real-world environments. Those periods of interest in real-world recordings can facilitate gait parameter extraction and allow the quantification of gait duration distribution in everyday life. Our findings allow taking informed decisions on alternative positions for gait recording in clinical studies and public health. Trial Registration: ISRCTN Registry 12246987; https://www.isrctn.com/ISRCTN12246987 International Registered Report Identifier (IRRID): RR2-10.1136/bmjopen-2021-050785 UR - https://formative.jmir.org/2024/1/e50035 UR - http://dx.doi.org/10.2196/50035 UR - http://www.ncbi.nlm.nih.gov/pubmed/38691395 ID - info:doi/10.2196/50035 ER - TY - JOUR AU - Brobbin, Eileen AU - Deluca, Paolo AU - Hemrage, Sofia AU - Drummond, Colin PY - 2022/4/14 TI - Accuracy of Wearable Transdermal Alcohol Sensors: Systematic Review JO - J Med Internet Res SP - e35178 VL - 24 IS - 4 KW - alcohol consumption KW - alcohol detection KW - alcohol monitoring KW - alcohol treatment KW - digital technology KW - ecologic momentary assessment KW - transdermal alcohol sensors KW - wearables KW - mobile phone N2 - Background: There are a range of wearable transdermal alcohol sensors that are available and are being developed. These devices have the potential to monitor alcohol consumption continuously over extended periods in an objective manner, overcoming some of the limitations of other alcohol measurement methods (blood, breath, and urine). Objective: The objective of our systematic review was to assess wearable transdermal alcohol sensor accuracy. Methods: A systematic search of the CINAHL, Embase, Google Scholar, MEDLINE, PsycINFO, PubMed, and Scopus bibliographic databases was conducted in February 2021. In total, 2 team members (EB and SH) independently screened studies for inclusion, extracted data, and assessed the risk of bias. The methodological quality of each study was appraised using the Mixed Methods Appraisal Tool. The primary outcome was transdermal alcohol sensor accuracy. The data were presented as a narrative synthesis. Results: We identified and analyzed 32 studies. Study designs included laboratory, ambulatory, and mixed designs, as well as randomized controlled trials; the length of time for which the device was worn ranged from days to weeks; and the analyzed sample sizes ranged from 1 to 250. The results for transdermal alcohol concentration data from various transdermal alcohol sensors were generally found to positively correlate with breath alcohol concentration, blood alcohol concentration, and self-report (moderate to large correlations). However, there were some discrepancies between study reports; for example, WrisTAS sensitivity ranged from 24% to 85.6%, and specificity ranged from 67.5% to 92.94%. Higher malfunctions were reported with the BACtrack prototype (16%-38%) and WrisTAS (8%) than with SCRAM (2%); however, the former devices also reported a reduced time lag for peak transdermal alcohol concentration values when compared with SCRAM. It was also found that many companies were developing new models of wearable transdermal alcohol sensors. Conclusions: As shown, there is a lack of consistency in the studies on wearable transdermal alcohol sensor accuracy regarding study procedures and analyses of findings, thus making it difficult to draw direct comparisons between them. This needs to be considered in future research, and there needs to be an increase in studies directly comparing different transdermal alcohol sensors. There is also a lack of research investigating the accuracy of transdermal alcohol sensors as a tool for monitoring alcohol consumption in clinical populations and use over extended periods. Although there is some preliminary evidence suggesting the accuracy of these devices, this needs to be further investigated in clinical populations. Trial Registration: PROSPERO CRD42021231027; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=231027 UR - https://www.jmir.org/2022/4/e35178 UR - http://dx.doi.org/10.2196/35178 UR - http://www.ncbi.nlm.nih.gov/pubmed/35436239 ID - info:doi/10.2196/35178 ER - TY - JOUR AU - D´Ancona, Giuseppe AU - Murero, Monica AU - Feickert, Sebastian AU - Kaplan, Hilmi AU - Öner, Alper AU - Ortak, Jasmin AU - Ince, Hueseyin PY - 2021/4/21 TI - Implantation of an Innovative Intracardiac Microcomputer System for Web-Based Real-Time Monitoring of Heart Failure: Usability and Patients? Attitudes JO - JMIR Cardio SP - e21055 VL - 5 IS - 1 KW - heart KW - failure KW - left atrial KW - pressure KW - intracardiac KW - device KW - monitoring KW - implantable KW - wireless KW - transmission KW - web-based N2 - Background: Heart failure (HF) management guided by the measurement of intracardiac and pulmonary pressure values obtained through innovative permanent intracardiac microsensors has been recently proposed as a valid strategy to individualize treatment and anticipate hemodynamic destabilization. These sensors have potential to reduce patient hospitalization rates and optimize quality of life. Objective: The aim of this study was to evaluate the usability and patients? attitudes toward a new permanent intracardiac device implanted to remotely monitor left intra-atrial pressures (V-LAP, Vectorious Medical Technologies, Tel Aviv, Israel) in patients with chronic HF. Methods: The V-LAP system is a miniaturized sensor implanted percutaneously across the interatrial septum. The system communicates wirelessly with a ?companion device? (a wearable belt) that is placed on the patient?s chest at the time of acquisition/transmission of left heart pressure measurements. At first follow-up after implantation, the patients and health care providers were asked to fill out a questionnaire on the usability of the system, ease in performing the various required tasks (data acquisition and transmission), and overall satisfaction. Replies to the questions were mainly given using a 5-point Likert scale (1: very poor, 2: poor, 3: average, 4: good, 5: excellent). Further patient follow-ups were performed at 3, 6, and 12 months. Results: Use and acceptance of the first 14 patients receiving the V-LAP technology worldwide and related health care providers have been analyzed to date. No periprocedural morbidity/mortality was observed. Before discharge, a tailored educational session was performed after device implantation with the patients and their health care providers. At the first follow-up, the mean score for overall comfort in technology use was 3.7 (SD 1.2) with 93% (13/14) of patients succeeding in applying and operating the system independently. For health care providers, the mean score for overall ease and comfort in use of the technology was 4.2 (SD 0.8). No significant differences were found between the patients? and health care providers? replies to the questionnaires. There was a general trend for higher scores in patients? usability reports at later follow-ups, in which the score related to overall comfort with using the technology increased from 3.0 (SD 1.4) to 4.0 (SD 0.7) (P=.40) and comfort with wearing and adjusting the measuring thoracic belt increased from 2.8 (SD 1.0) to 4.2 (SD 0.4) (P=.02). Conclusions: Despite the gravity of their HF pathology and the complexity of their comorbid profile, patients are comfortable in using the V-LAP technology and, in the majority of cases, they can correctly and consistently acquire and transmit hemodynamic data. Although the overall patient/care provider satisfaction with the V-LAP system seems to be acceptable, improvements can be achieved after ameliorating the design of the measuring tools. Trial Registration: ClincalTrials.gov NCT03775161; https://clinicaltrials.gov/ct2/show/NCT03775161 UR - https://cardio.jmir.org/2021/1/e21055 UR - http://dx.doi.org/10.2196/21055 UR - http://www.ncbi.nlm.nih.gov/pubmed/33881400 ID - info:doi/10.2196/21055 ER - TY - JOUR AU - Manzo, Maurizio AU - Cavazos, Omar AU - Huang, Zhenhua AU - Cai, Liping PY - 2021/4/12 TI - Plasmonic and Hybrid Whispering Gallery Mode?Based Biosensors: Literature Review JO - JMIR Biomed Eng SP - e17781 VL - 6 IS - 2 KW - plasmonic KW - whispering gallery mode, microlasers, biomedical KW - sensors N2 - Background: The term ?plasmonic? describes the relationship between electromagnetic fields and metallic nanostructures. Plasmon-based sensors have been used innovatively to accomplish different biomedical tasks, including detection of cancer. Plasmonic sensors also have been used in biochip applications and biosensors and have the potential to be implemented as implantable point-of-care devices. Many devices and methods discussed in the literature are based on surface plasmon resonance (SPR) and localized SPR (LSPR). However, the mathematical background can be overwhelming for researchers at times. Objective: This review article discusses the theory of SPR, simplifying the underlying physics and bypassing many equations of SPR and LSPR. Moreover, we introduce and discuss the hybrid whispering gallery mode (WGM) sensing theory and its applications. Methods: A literature search in ScienceDirect was performed using keywords such as ?surface plasmon resonance,? ?localized plasmon resonance,? and ?whispering gallery mode/plasmonic.? The search results retrieved many articles, among which we selected only those that presented a simple explanation of the SPR phenomena with prominent biomedical examples. Results: SPR, LSPR, tilted fiber Bragg grating, and hybrid WGM phenomena were explained and examples on biosensing applications were provided. Conclusions: This minireview presents an overview of biosensor applications in the field of biomedicine and is intended for researchers interested in starting to work in this field. The review presents the fundamental notions of plasmonic sensors and hybrid WGM sensors, thereby allowing one to get familiar with the terminology and underlying complex formulations of linear and nonlinear optics. UR - https://biomedeng.jmir.org/2021/2/e17781 UR - http://dx.doi.org/10.2196/17781 UR - http://www.ncbi.nlm.nih.gov/pubmed/ ID - info:doi/10.2196/17781 ER - TY - JOUR AU - Nelson, C. Elizabeth AU - Sools, M. Anneke AU - Vollenbroek-Hutten, R. Miriam M. AU - Verhagen, Tibert AU - Noordzij, L. Matthijs PY - 2020/11/3 TI - Embodiment of Wearable Technology: Qualitative Longitudinal Study JO - JMIR Mhealth Uhealth SP - e16973 VL - 8 IS - 11 KW - wearability KW - implantable wearable KW - body extension KW - smart prosthesis KW - implantable devices KW - technology dependence KW - cognitive prosthesis KW - phenomenology KW - embodied self-discrepancy KW - technology addiction KW - longitudinal qualitative design N2 - Background: Current technology innovations, such as wearables, have caused surprising reactions and feelings of deep connection to devices. Some researchers are calling mobile and wearable technologies cognitive prostheses, which are intrinsically connected to individuals as if they are part of the body, similar to a physical prosthesis. Additionally, while several studies have been performed on the phenomenology of receiving and wearing a physical prosthesis, it is unknown whether similar subjective experiences arise with technology. Objective: In one of the first qualitative studies to track wearables in a longitudinal investigation, we explore whether a wearable can be embodied similar to a physical prosthesis. We hoped to gain insights and compare the phases of embodiment (ie, initial adjustment to the prosthesis) and the psychological responses (ie, accept the prosthesis as part of their body) between wearables and limb prostheses. This approach allowed us to find out whether this pattern was part of a cyclical (ie, period of different usage intensity) or asymptotic (ie, abandonment of the technology) pattern. Methods: We adapted a limb prosthesis methodological framework to be applied to wearables and conducted semistructured interviews over a span of several months to assess if, how, and to what extent individuals come to embody wearables similar to prosthetic devices. Twelve individuals wore fitness trackers for 9 months, during which time interviews were conducted in the following three phases: after 3 months, after 6 months, and at the end of the study after 9 months. A deductive thematic analysis based on Murray?s work was combined with an inductive approach in which new themes were discovered. Results: Overall, the individuals experienced technology embodiment similar to limb embodiment in terms of adjustment, wearability, awareness, and body extension. Furthermore, we discovered two additional themes of engagement/reengagement and comparison to another device or person. Interestingly, many participants experienced a rarely reported phenomenon in longitudinal studies where the feedback from the device was counterintuitive to their own beliefs. This created a blurring of self-perception and a dilemma of ?whom? to believe, the machine or one?s self. Conclusions: There are many similarities between the embodiment of a limb prosthesis and a wearable. The large overlap between limb and wearable embodiment would suggest that insights from physical prostheses can be applied to wearables and vice versa. This is especially interesting as we are seeing the traditionally ?dumb? body prosthesis becoming smarter and thus a natural merging of technology and body. Future longitudinal studies could focus on the dilemma people might experience of whether to believe the information of the device over their own thoughts and feelings. These studies might take into account constructs, such as technology reliance, autonomy, and levels of self-awareness. UR - https://mhealth.jmir.org/2020/11/e16973 UR - http://dx.doi.org/10.2196/16973 UR - http://www.ncbi.nlm.nih.gov/pubmed/33141093 ID - info:doi/10.2196/16973 ER -