In our current environment virtually any information, including health-related data, can be readily accessible due to the ubiquity of smart devices and health monitoring smart device accessories, such as activity, sleep, heart rate, pulse, and blood pressure tracking devices. However, currently available self-monitoring devices are restricted to extra-corporeal data, leaving many important physiological parameters such as glucose, hormone, and electrolyte level changes uncharted. Of notable interest in the area of self-monitoring is that of blood glucose levels in the pre-diabetic population. Continuous glucose monitoring (CGM) devices utilised by diabetics are invasive and cost prohibitive for general consumers and therefore uncommonly used pre-diagnosis. These devices are thus unlikely to enable the lifestyle changes and administration of the appropriate adjustments in a timely manner to pre-diabetics, which may prevent the progression to diabetes. This dissertation discusses and demonstrates the development of a minimally invasive wearable device for the continuous sensing of glucose, with Bluetooth wireless connectivity to enable data transfer to a smart device. Three major components of this device are: 1) microneedles, which serve to penetrate the skin to access the underlying dermal interstitial fluid, and to immobilise the glucose sensor; 2) fluorescent glucose sensor, which senses glucose in the dermal interstitial fluid whilst being immobilised to the microneedles; and 3) wearable fluorescence detection system, which interrogates and evaluates the light signal generated by the microneedle sensing platform. The microneedles are unique compared to the previous microneedle sensing devices, in that the sensing moiety can be chemically integrated into the microneedles to allow for continuous fluid sampling and analyte monitoring to take place simultaneously in situ. Glucose sensing is enabled by modular fluorescent sensors, consisting of glucose receptors, a reporting fluorophore, and an immobilisation site. The wearable fluorometer is 5.1 x 3.2 x 1.9 cm in dimension, is battery-powered, has an adjustable dynamic range, and exhibits fluorescence detection capability comparable to that of the gold standard microplate reader device. In vitro and in vivo assessments demonstrate that the microneedle sensing platform and the detector are able to perform their intended functions, and more importantly, can be integrated compatibly into the final envisioned system. Beyond the intended overall application of continuous glucose monitoring, each component and their fabrication methods have the potential to be utilised for the continuous monitoring of other health metrics. When these components are assembled, the end product is a wearable continuous sensing system that is easy to use, almost painless, minimally invasive, and overall, accessible in terms of convenience and cost to the general consumer.

As more data are observed over time, investigating the variation across time has become a vital part of analyzing such data. In this dissertation, we discuss varying-coefficient models and functional data analysis methods for temporally heterogenous data. More specifically, we examine two different types of temporal heterogeneity. The first type of temporal heterogeneity stems from temporal evolution of relational pattern over time. Dynamic networks are commonly used when relational data are observed over time. Unlike static network analysis, dynamic network analysis emphasizes the importance of recognizing temporal evolution of relationship among observations. We propose and investigate a family of dynamic network models, known as varying-coefficient exponential random graph model (VCERGM), that characterize the evolution of network topology through smoothly varying parameters. The VCERGM directly provides an interpretable dynamic network model that enables the inference of temporal heterogeneity in dynamic networks. Furthermore, we introduce a method that analyzes multilevel dynamic networks. If there exist multiple relational data observed at one time point, it is reasonable to additionally consider the variability among the repeated observations at each time point. The proposed method is an extension of stochastic blockmodels with a priori block membership and temporal random effects. It incorporates a variability among multiple relational structures at one time point and provides a richer representation of dependent engagement patterns at each time point. The method is also flexible in analyzing networks with time-varying networks. Its smooth parameters can be interpreted as evolving strength of engagement within and across blocks. The second type of temporal heterogeneity is motivated by temporal shifts in continuously observed data. When multiple curves are obtained and there exists a common curvature shared by all the observed curves, understanding the common curvature may involve a preprocessing step of managing temporal shifts among curves. We explore the properties of continuous in-shoe sensor recordings to understand the source of variability in gait data. Our case study is based on measurements of three healthy subjects. The in-shoe sensor data we explore show both phase and amplitude variabilities; we separate these sources via curve registration. We examine the correlation of temporal shifts across sensors to evaluate the pattern of phase variability shared across sensors. We apply a series of functional data analysis approaches to the registered in-shoe sensor curves to examine their association with current gold-standard gait measurement, so called ground reaction force.

abstract: Wearable assistive devices have been greatly improved thanks to advancements made in soft robotics, even creation soft extra arms for paralyzed patients. Grasping remains an active area of research of soft extra limbs. Soft robotics allow the creation of grippers that due to their inherit compliance making them lightweight, safer for human interactions, more robust in unknown environments and simpler to control than their rigid counterparts. A current problem in soft robotics is the lack of seamless integration of soft grippers into wearable devices, which is in part due to the use of elastomeric materials used for the creation of most of these grippers. This work introduces fabric-reinforced textile actuators (FRTA). The selection of materials, design logic of the fabric reinforcement layer and fabrication method are discussed. The relationship between the fabric reinforcement characteristics and the actuator deformation is studied and experimentally verified. The FRTA are made of a combination of a hyper-elastic fabric material with a stiffer fabric reinforcement on top. In this thesis, the design, fabrication, and evaluation of FRTAs are explored. It is shown that by varying the geometry of the reinforcement layer, a variety of motion can be achieve such as axial extension, radial expansion, bending, and twisting along its central axis. Multi-segmented actuators can be created by tailoring different sections of fabric-reinforcements together in order to generate a combination of motions to perform specific tasks. The applicability of this actuators for soft grippers is demonstrated by designing and providing preliminary evaluation of an anthropomorphic soft robotic hand capable of grasping daily living objects of various size and shapes. / Dissertation/Thesis / Masters Thesis Biomedical Engineering 2019

The use of wearable sensors in consumer health and medicine is a rapidly developing topic of interest. The main purpose of the series of studies in this thesis is to identify novel uses of technology that can provide clinicians and scientists clinically feasible, low cost approaches to obtain meaningful information about functional limb symmetry in patients with knee injuries. In Study 1, individuals undergoing knee surgery were evaluated as they walked and stepped down onto a force platform in a manner similar to how one would step off a curb to cross a street. When subjects stepped onto their uninvolved leg, peak vertical ground reaction force was greater and occurred earlier than when stepping onto their involved leg. Asymmetries were greater in those with higher quadriceps neuromuscular impairment. In Study 2, the reliability and validity of using wearable accelerometer sensors was evaluated for estimating single leg vertical hop height in healthy people and individuals after ACL reconstruction surgery. The reliability and concurrent validity of using accelerometers to estimate single leg hop height were excellent, and were similar for healthy and ACL-reconstructed subjects. Error for this method was low, in particular when the accelerometer was worn at the lower leg. Asymmetry in hop height was greater in those with higher quadriceps neuromuscular impairment. In Study 3, wearable accelerometers were compared to a system of motion capture cameras and force platform as a method to assess functional movement asymmetry in healthy people and individuals after ACL reconstruction. While walking and stepping down, accelerometers worn at the waist were able to detect underlying movement asymmetry when it exists in people after ACL reconstruction. Acceleration at the waist was strongly associated with vertical ground reaction force and moderately associated with knee extension moments. Collectively, these studies provide evidence that functional movement symmetry can be measured with simple, inexpensive methods that can be used in a variety of clinical or field-based settings.

Wearable sensors are at the heart of the digital health revolution. Integral to the use of these sensors for monitoring conditions impacting balance and mobility are accurate estimates of joint angles. To this end a simple and novel method of estimating hip joint angles from small wearable magnetic and inertial sensors is proposed and its performance is established relative to optical motion capture in a sample of human subjects. Improving upon previous work, this approach does not require precise sensor placement or specific calibration motions, thereby easing deployment outside of the research laboratory. Specific innovations include the determination of sensor to segment rotations based on functionally determined joint centers, and the development of a novel filtering algorithm for estimating the relative orientation of adjacent body segments. Hip joint angles and range of motion determined from the proposed approach and an existing method are compared to those from an optical motion capture system during walking at a variety of speeds and tasks designed to exercise the hip through its full range of motion. Results show that the proposed approach estimates flexion/extension angle more accurately (RMSE from 7.08 to 7.29 deg) than the existing method (RMSE from 11.64 deg to 14.33 deg), with similar performance for the other anatomical axes. Agreement of each method with optical motion capture is further characterized by considering correlation and regression analyses. Mean ranges of motion for the proposed method are not largely different from those reported by motion capture, and showed similar values to the existing method. Results indicate that this algorithm provides a promising approach for estimating hip joint angles using wearable inertial sensors, and would allow for use outside of constrained research laboratories.

Wearable video systems (WVSs) are one of the most popular and fastest growing technologies used by law enforcement today. While published WVS literature predominantly focuses on stakeholder perceptions, community interactions, assaults against officers, and use of force, there has diminutive exploration of the impact of WVSs as it related to aspects of police misconduct, especially in the Cruiser Police Department (pseudonym; CPD). The purpose of this mixed methods study was to explore and describe how the use of the use of WVSs by the CPD impact police misconduct, by tracking the changes in complaint type and disposition of a 5-year period, and to examine how CPD officers perceive the impact of the use of WVSs. Deterrence theory and phenomenology provided structure for this research study. The quantitative portion of this study consisted of an interrupted time series analysis of 419 documented complaints against CPD officers between June 2013 and June 2018. The qualitative portion consisted of 67 anonymous, online surveys completed by current CPD officers with WVS experience that were thematically analyzed. Quantitative findings included a 13% overall increase in the number of complaints, a 15% drop in citizen complaints, a 28% increase in chief-initiated complaints, and a 41% increase in sustained complaints. Qualitative findings provided insight into CPD officers' acceptance and value of WVS, along with their strong concern for WVSs implementation creating more discipline of officers. Implications for positive social change include an awareness of unintended consequences of current policies and practices and empirical awareness of trends associated with WVS, specifically regarding discipline, officer acceptance, and police-community interaction.

Wearable video systems (WVSs) are one of the most popular and fastest growing technologies used by law enforcement today. While published WVS literature predominantly focuses on stakeholder perceptions, community interactions, assaults against officers, and use of force, there has diminutive exploration of the impact of WVSs as it related to aspects of police misconduct, especially in the Cruiser Police Department (pseudonym; CPD). The purpose of this mixed methods study was to explore and describe how the use of the use of WVSs by the CPD impact police misconduct, by tracking the changes in complaint type and disposition of a 5-year period, and to examine how CPD officers perceive the impact of the use of WVSs. Deterrence theory and phenomenology provided structure for this research study. The quantitative portion of this study consisted of an interrupted time series analysis of 419 documented complaints against CPD officers between June 2013 and June 2018. The qualitative portion consisted of 67 anonymous, online surveys completed by current CPD officers with WVS experience that were thematically analyzed. Quantitative findings included a 13% overall increase in the number of complaints, a 15% drop in citizen complaints, a 28% increase in chief-initiated complaints, and a 41% increase in sustained complaints. Qualitative findings provided insight into CPD officers' acceptance and value of WVS, along with their strong concern for WVSs implementation creating more discipline of officers. Implications for positive social change include an awareness of unintended consequences of current policies and practices and empirical awareness of trends associated with WVS, specifically regarding discipline, officer acceptance, and police-community interaction.

It was demonstrated in recent studies that Complementary Limb Motion Estimation (CLME) is robust approach for controlling active knee prostheses. A wearable sensor system is then needed to provide inputs to the controller in a real-time platform. In the present work, a wearable sensor system based on magnetic and inertial measurement units (MIMU) together with a simple calibration procedure were proposed. This sensor system was intended to substitute and extend the capabilities of a previous device based on potentiometers and gyroscopes. The proposed sensor system and calibration were validated with an Optical Tracking System (OTS) in a standard gait lab and first results showed that the proposed solution had a performance comparable to similar studies in the literature.

The explosive growth of the biosensors and health-related wearable monitoring devices has accentuated the need for miniaturized, high-efficiency conformal bio-modules that can operate over a wide range of frequencies, while they can be integrated in wearable and lightweight configurations. One of the major issue for the implementation of Wireless Body Area Networks (WBAN) is the very limited range of commonly used metal antennas. Due to the high dielectric constant between the metal antenna material (as well as the metal-based circuitry) and the mostly "ionized-water" human body parts, the near-field gets significantly disturbed, while local reflections due to the dielectric mismatch further shorten the operation range. Even wearable bracelet-like sensing devices have a very low range due to this reason. Thus, there are two major aspects that are going to be addressed in this Thesis: enhanced-range wearable antennas for wireless biosensors and compact "rugged-polarization" wireless sensor readers.

Over the last few years, there have been striking developments in wearable computing. Among all the different forms of wearable devices, Head Mounted Displays (HMDs) are deemed the first seamless solution to enabling workers with real time contextual information and allowing companies to integrate with existing back-end systems. The hands-free feature that come along with the HMDs is also believed a great advantage over many traditional technologies. However, few studies had discussed the impact of different design characteristics of head mounted displays on task performance. This study aimed to find out how different display positions of Head Mounted Displays may affect the performance of workers performing guided repair and maintenance tasks. A set of car maintenance tasks were performed by 20 participants with task guidance presented at four Display Conditions: above-eye HMD, eye-centered HMD, below-eye HMD and the traditional paper manual. Time and errors were measured and discussed, as well as other user experience related measurements.