Background: Numerous multidimensional assessment tools have been developed to measure frailty; however, the clinical feasibility of these tools is limited. We previously developed and validated an upper-extremity function (UEF) assessment method that incorporates wearable motion sensors. The purpose of the current study was to: 1) cross-sectionally validate the UEF method in a larger sample in comparison with the Fried index; 2) develop a UEF frailty index to predict frailty categories including non-frail, pre-frail, and frail based on UEF parameters and demographic information, using the Fried index as the gold standard; and 3) develop a UEF continuous score (points scores for each UEF parameter and a total frailty score) based on UEF parameters and demographic information, using the Fried index as the gold standard. Methods: We performed a cross-sectional validation and index development study within the Banner Medical Center, Tucson, and Banner Sun Health Research Institute, Sun City, Arizona. Community-dwelling and outpatient older adults (>= 60 years; n = 352; 132 non-frail, 175 pre-frail, and 45 frail based on Fried criteria) were recruited. For the UEF test, each participant performed a 20-s elbow flexion, within which they repetitively and rapidly flexed and extended their dominant elbow. Using elbow motion outcomes two UEF indexes were developed (categorical and score). The Fried index was measured as the gold standard. Results: For the categorical index, speed of elbow flexion, elbow range of motion, elbow moment, number of flexion, speed variability and reduction within 20 s, as well as body mass index (BMI) were included as the pre-frailty/frailty predictor parameters. Results from 10-fold cross-validation showed receiver operator characteristic area under the curve of 0.77 +/- 0.07 and 0.80 +/- 0.12 for predicting Fried pre-frailty and frailty, respectively. UEF score (0.1 to 1.0) was developed using similar UEF parameters. Conclusions: We present an objective, sensor-based frailty assessment tool based on physical frailty features including slowness, weakness, exhaustion (muscle fatigue), and flexibility of upper-extremity movements. Within the current study, the method was validated cross-sectionally using the Fried index as the gold standard and the UEF categorical index and UEF frailty score were developed for research purposes and potentially for future clinical use.

abstract: Respiratory behavior provides effective information to characterize lung functionality, including respiratory rate, respiratory profile, and respiratory volume. Current methods have limited capabilities of continuous characterization of respiratory behavior and are primarily targeting the measurement of respiratory rate, which has relatively less value in clinical application. In this dissertation, a wireless wearable sensor on a paper substrate is developed to continuously characterize respiratory behavior and deliver clinically relevant parameters, contributing to asthma control. Based on the anatomical analysis and experimental results, the optimum site for the wireless wearable sensor is on the midway of the xiphoid process and the costal margin, corresponding to the abdomen-apposed rib cage. At the wearing site, the linear strain change during respiration is measured and converted to lung volume by the wireless wearable sensor utilizing a distance-elapsed ultrasound. An on-board low-power Bluetooth module transmits the temporal lung volume change to a smartphone, where a custom-programmed app computes to show the clinically relevant parameters, such as forced vital capacity (FVC) and forced expiratory volume delivered in the first second (FEV1) and the FEV1/FVC ratio. Enhanced by a simple, yet effective machine-learning algorithm, a system consisting of two wireless wearable sensors accurately extracts respiratory features and classifies the respiratory behavior within four postures among different subjects, demonstrating that the respiratory behaviors are individual- and posture-dependent contributing to monitoring the posture-related respiratory diseases. The continuous and accurate monitoring of respiratory behaviors can track the respiratory disorders and diseases' progression for timely and objective approaches for control and management. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

<div>The aim of this study was to compare a newly developed ultrathin wearable surface electromyography (sEMG) sensors patch (patent pending, inventors: Lee & Malandraki) (i.e., experimental sensors) to commercially available and widely-used sEMG sensors (i.e., conventional sensors) in monitoring submental muscle activity during swallowing in healthy older adults. A randomized crossover design was employed to compare the performance of the experimental sensors with the performance of conventional snap-on sensors. Forty healthy older adults participated (24F; age range 53-85). Participants completed the same experimental protocol with both sensor types in a counterbalanced order. Swallow trials completed with both types of sensors included 5 trials of 5ml and 10ml water swallows. Comparisons were made on: a) signal related factors (i.e., signal-to-noise ratio, baseline amplitude, normalized amplitude of the swallow trials, and duration of sEMG burst during swallow trials); and b) safety and preclinical factors (safety/adverse effects, efficiency, and satisfaction/comfort).</div><div><br></div><div><div>In terms of signal related factors (Aim 1), we hypothesized that the signal-to-noise ratio and baseline amplitude values acquired using the experimental sensors will not be inferior to the ones acquired using the conventional sensors. These hypotheses were tested using non-inferiority tests. Moreover, we hypothesized that the normalized amplitude values and the sEMG burst duration during swallow trials will be comparable/equivalent between the two sensor types. These hypotheses were tested using equivalency tests. In terms of safety and pre-clinical factors</div><div>(Aim 2), we predicted that no adverse effects will be reported after using either type of sensors. We also hypothesized that sensor placement will be more efficient, and satisfaction/comfort level will be higher with the experimental sensors. These hypotheses were tested using paired t-tests.</div></div><div><br></div><div><div>Overall, the findings supported our hypotheses for Aim 1. Results showed that the experimental sensors did not perform inferiorly to the conventional sensors based on signal-tonoise ratio (left sensors: t(39) = 3.95, p <0.0002; right sensors: t(39) = 2.66, <i>p <0.0056</i>) and baseline amplitude values (left sensors: t(39) = -7.72, p <<i>0.0001</i>; right sensors: t(39) = -7.43, <i>p</i><<i>0.0001</i>). The normalized amplitude values were deemed equivalent for all swallow trials (5ml left: t_u = 4.25, t_l = -6.22; overall <i>p-value <0.0001</i>; 5ml right: t_u = 2.07, t_l = -4.06; overall <i>p-value <0.0224</i>; 10ml left: t_u = 5.49, t_l = -7.20; overall <i>p-value <0.0001</i>; 10ml right: t_u = 3.36 t_l = -5.28; overall <i>p-value <0.0012</i>).The duration of sEMG burst was also deemed equivalent for all variables (5ml left: t_u = 9.48, t_l = -7.25; overall <i>p-value <0.0001</i>; 5ml right: t_u = 9.03, t_l = -6.35; overall <i>p-value <0.0001</i>; 10ml left: t_u = 6.75, t_l = -6.11; <i>p-value <0.0001</i>; 10ml right: t_u = 6.58, t_l = -6.23; overall <i>p-value < 0.0001</i>).</div></div><div><br></div><div><div>In terms of safety and adverse effects (Aim 2, hypothesis #1), mild redness and itchiness occurred with the conventional sensors in six participants, whereas only one participant reported itchiness with the experimental sensors. No redness or skin irritation was observed or reported by any of the participants after the removal of the experimental sensors. In terms of time efficiency of electrode placement (Aim 2, hypothesis #2), our hypothesis was not proven, as there were no statistically significant differences in the time it took to place both sensor types; (t(39) = 1.87, <i>p= 0.9657</i>). However, as hypothesized (Aim 2, hypothesis #3) satisfaction/comfort level was significantly higher with the experimental sensors than the conventional ones, albeit with a relatively small effect size, t(39) = 1.71, <i>p = 0.0476</i>, <i>d = 0.226</i>.</div></div><div><br></div><div><div>Taken together, these findings indicate that the newly developed ultrathin wearable sEMG sensors obtain comparable signal quality and signal parameters to conventional and widely used sEMG snap-on electrodes; have fewer adverse effects associated with them compared to the conventional sensors, and healthy older adults are highly satisfied and comfortable using them. Future research is warranted to optimize the wearable sEMG sensors, before clinical trials examining the effectiveness of these sensors in the treatment of dysphagia can be initiated.</div></div>

abstract: There are many inconsistencies in the literature regarding how to estimate the Lyapunov Exponent (LyE) for gait. In the last decade, many papers have been published using Lyapunov Exponents to determine differences between young healthy and elderly adults and healthy and frail older adults. However, the differences in methodologies of data collection, input parameters, and algorithms used for the LyE calculation has led to conflicting numerical values for the literature to build upon. Without a unified methodology for calculating the LyE, researchers can only look at the trends found in studies. For instance, LyE is generally lower for young adults compared to elderly adults, but these values cannot be correlated across studies to create a classifier for individuals that are healthy or at-risk of falling. These issues could potentially be solved by standardizing the process of computing the LyE. This dissertation examined several hurdles that must be overcome to create a standardized method of calculating the LyE for gait data when collected with an accelerometer. In each of the following investigations, both the Rosenstein et al. and Wolf et al. algorithms as well as three normalization methods were applied in order to understand the extent at which these factors affect the LyE. First, the a priori parameters of time delay and embedding dimension which are required for phase space reconstruction were investigated. This study found that the time delay can be standardized to a value of 10 and that an embedding dimension of 5 or 7 should be used for the Rosenstein and Wolf algorithm respectively. Next, the effect of data length on the LyE was examined using 30 to 1300 strides of gait data. This analysis found that comparisons across papers are only possible when similar amounts of data are used but comparing across normalization methods is not recommended. And finally, the reliability and minimum required number of strides for each of the 6 algorithm-normalization method combinations in both young healthy and elderly adults was evaluated. This research found that the Rosenstein algorithm was more reliable and required fewer strides for the calculation of the LyE for an accelerometer. / Dissertation/Thesis / Appendix A / Doctoral Dissertation Biomedical Engineering 2019

abstract: As the world population continues to age, the demand for treatment and rehabilitation of long-term age-related ailments will rise. Healthcare technology must keep up with this demand, and existing solutions must become more readily available to the populace. Conditions such as impairment due to stroke currently take months or years of physical therapy to overcome, but rehabilitative exoskeletons can be used to greatly extend a physical therapist’s capabilities. In this thesis, a rehabilitative knee exoskeleton was designed which is significantly lighter, more portable and less costly to manufacture than existing designs. It accomplishes this performance by making use of high-powered and weight-optimized brushless DC (BLDC) electric motors designed for drones, open-source hardware and software solutions for robotic motion control, and rapid prototyping technologies such as 3D printing and laser cutting. The exoskeleton is made from a series of laser cut aluminum plates spaced apart with off-the-shelf standoffs. A drone motor with a torque of 1.32 Nm powers an 18.5:1 reduction two-stage belt drive, giving a maximum torque of 24.4 Nm at the output. The bearings for the belt drive are installed into 3D printed bearing mounts, which act as a snug intermediary between the bearing and the aluminum plate. The system is powered off a 24 volt, 1,500 MAh lithium battery, which can provide power for around an hour of walking activity. The exoskeleton is controlled with an ODrive motor controller connected to a Raspberry Pi. Hip angle data is provided by an IMU, and the knee angle is provided by an encoder on the output shaft. A compact Rotary Series Elastic Actuator (cRSEA) device is mounted on the output shaft as well, to accurately measure the output torque going to the wearer. A Proportional-Derivative (PD) controller with feedforward relates the input current with the output torque. The device was tested on a treadmill and found to have an average backdrive torque of 0.39 Nm, significantly lower than the current state of the art. A gravity compensation controller and impedance controller were implemented to assist during swing and stance phases respectively. The results were compared to the muscular exertion of the knee measured via Electromyography (EMG). / Dissertation/Thesis / Masters Thesis Engineering 2020

Wearable Health Devices (WHDs) are an emerging technology that enables continuous monitoring of vital signs during daily life. Issues with constant and consistent data acquisition have been found while WHD technology has developed. The force of the measurement area and movement of the sensors are key mechanical issues that need to be solved for WHDs to become a viable way to continuously monitor health conditions. This work explores Constant-Force Mechanisms (CFMs) as a solution to problems the current WHD industry faces. Additionally, the relationship between force provided from the mechanism, sensor pressure on the wrist, patient comfort, and sensor readings quality are explored and analyzed. Design requirements for a constant-force wristband were narrowed down to seven critical requirements (mechanism size vs. allowable travel, ability to be used on a curved surface, works well with existing clasps, ease of assembly, direction of travel, material, and force generation). These key requirements need to be considered for a WHD with an integrated CFM to be designed successfully. Two main concepts (buckling beams and tape springs) were prototyped and evaluated against the seven key requirements. The design and testing of a wrist worn sensing band used to gather relationship data among band tension, sensor pressure, patient comfort, and pulsatile signal quality is also presented. Human subject testing (IRB2020-268) was performed on a wristband with an integrated CFM and the wrist worn sensing band that were developed. The band with an integrated CFM compared pressure on the wrist for both a band with and without an integrated CFM for eight different movement activities. On average the band with the integrated CFM had a lower coefficient of variation for all except one of the activities. The data collected from the wrist worn sensing band shows that tension varies linearly with pressure, and that the pressure vs. tension slope increases with increasing wrist width. There also exists a linear relationship between tension and patient pain/comfort, but pressure does not show an effect on the patient discomfort or pain experienced. Signal quality when measured in the range of of 0-4 N and 0-20 kPa does not have a direct correlation to either tension or pressure.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this article, we propose a wireless monitoring solution for gait parameters using low-cost sensors in the physical rehabilitation of patients with gait disorders. This solution consists of infrared speed sensors (IRSS), force-sensing Resistor (FSR) and microcontrollers placed in a walker. These sensors collect the pressure distribution on the walker's handle and the speed of the steps during therapy session. The proposal allows to improve the traditional physiotherapy session times through a mobile application to perform the monitoring controlled by a health specialist in real time. The proposed solution consists of 4 stages: 1. Obtaining gear parameters, 2. Data transmission, 3. Information Storage and 4. Data collection and processing. Solution was tested with 10 patients from a physical rehabilitation center in Lima, Peru. Preliminary results revealed a significant reduction in the rehabilitation session from 25 to 5.2 minutes. / Revisión por pares

Around 2.5% of the world population are affected by allergies. Children and their families are part of that affected group. However, there seems to be lack of research and tools that would help and provide valuable designs for these families. This thesis explored if and how interaction design might contribute to make the everyday life easier for families with allergic children.  A design process was conducted based upon both theoretical and qualitative research. With the help of methods from interaction design, this thesis has analyzed and brainstormed possible concepts. The final result is a wearable called All-gen that helps children to scan and get feedback if their food is safe or not.

, / El presente trabajo ofrece una propuesta de solución tecnológica al problema asociado a la violencia contra la mujer en el Perú. El proyecto realizo un diagnóstico del tiempo promedio de atención, en base a un estudio, de los principales canales de prevención y denuncia existentes. Del estudio realizado se pudo determinar que existen elevados tiempos de atención y asimetrías de información entre los diferentes actores del sistema de prevención y protección a la mujer. La solución propuesta, propone reducir al tiempo mínimo necesario para la atención y detención de un acto de violencia hacia la mujer brindando una reacción inmediata al evento. Complementando el proceso de proceso del proyecto hemos usamos componentes electrónicos de bajo costo y sistemas acordes y existentes en el mercado actual. La solución agrupa componentes tecnológicos propiamente configurados tanto en hardware como en software para realizar el seguimiento de la violencia, el cual se compone principalmente de la siguiente configuración: 1) Un dispositivo ‘wearable’, alertando a un grupo determinado de personas previamente agregadas, familiares, conocidos o personas dispuestas a ayudar, 2) Un sistema de comunicación, la alerta en tiempo real la cual que por medio de señales a una plataforma Cloud son distribuidos a una aplicación móvil y pagina web. La solución fue validada en un CEM ubicada en una comisaría de la policía nacional en la provincia del Callao, Distrito de Ventanilla. El proyecto busca contribuir con la disminución del tiempo de respuesta de ayuda a las mujeres víctimas y la asimetría de información en las organizaciones públicas que se ven involucradas. / This work offers a proposal for a technological solution to the problem associated with violence against women in Peru. The project made a diagnosis of the average attention time, based on a study, of the main existing prevention and reporting channels. From the study carried out, it was possible to determine that there are high attention times and information asymmetries between the different actors in the prevention and protection system for women. The proposed solution proposes to reduce to the minimum time necessary for the attention and arrest of an act of violence against women, providing an immediate reaction to the event. Complementing the process of the project process we have used low-cost electronic components and systems that are consistent and existing in the current market. The solution groups properly configured technological components in both hardware and software to track violence, which mainly consists of the following configuration: 1) A 'wearable' device, alerting a specific group of previously added people, family members , acquaintances or people willing to help, 2) A communication system, the alert in real time which through signals to a Cloud platform are distributed to a mobile application and website. The solution was validated at a CEM located in a national police station in the Callao province, Ventanilla District. The project seeks to contribute to reducing the response time to help women victims and the asymmetry of information in the public organizations that are involved. / Tesis

Work-related musculoskeletal disorders (WSMDs) are an important health concern in the workplace.  Accurately quantifying the level of physical exposures (i.e., kinematics and kinetics) is essential for risk assessments, developing and/or testing interventions, and improving estimates of exposure-response relationships.  Such exposures ideally should be quantified in situ, while workers interact with the actual work environment to complete their tasks.  However, in practice, relatively crude and/or time-consuming methods are often used, including self-reports, observational methods, and simple instrumentation, since directly assessing physical exposures is challenging in the workplace, and typically resource prohibitive. Inertial motion capture (IMC) and in-shoe pressure measurement (IPM) systems are emerging wearable technologies, and they can, respectively, facilitate monitoring of body kinematics and external forces on the body in the workplace.  Thus, this research examined the potential of such technologies in exposure assessments, and evaluated them in comparison to mature laboratory systems (i.e., optical motion capture system and force platform) or direct observation.  Performance of an IMC system was evaluated during several manual material handling (MMH) tasks, in terms of estimated body kinematics and kinetics at selected body parts.  A practical issue, regarding calibrating the IPM system in the field, was addressed by defining an ad hoc global coordinate system using a force platform.  Several regression models were developed for estimating center-of-pressure location and ground reaction forces.  Given that outputs from the IMC and the IPM systems are numerically fine-grained, but generally lack contextual information about a given job, task classification approaches were explored to automatically identify task types and their time proportions in a job. Overall, the outcomes from these studies demonstrated the potential of the IMC and the IPM systems for measuring physical exposures in the workplace.  However, estimation of physical exposures using these systems requires further improvements in some cases.  This research provided groundwork for future rapid and direct assessments of physical exposures in the workplace, and which needs to be expanded and validated in future efforts. / Ph. D.