Collaborative Processing of Wearable and Ambient Sensor System for Blood Pressure Monitoring

This paper describes wireless wearable and ambient sensors that cooperate to monitor a person’s vital signs such as heart rate and blood pressure during daily activities. Each wearable sensor is attached on different parts of the body. The wearable sensors require a high sampling rate and time synchronization to provide a precise analysis of the received signals. The trigger signal for synchronization is provided by the ambient sensors, which detect the user’s presence. The Bluetooth and IEEE 802.15.4 wireless technologies are used for real-time sensing and time synchronization. Thus, this wearable health-monitoring sensor response is closely related to the context in which it is being used. Experimental results indicate that the system simultaneously provides information about the user’s location and vital signs, and the synchronized wearable sensors successfully measures vital signs with a 1 ms resolution

Exploring wearable sensors as an alternative to marker-based motion capture in the pitching delivery

Background Improvements in data processing, increased understanding of the biomechanical background behind kinetics and kinematics, and technological advancements in inertial measurement unit (IMU) sensors have enabled high precision in the measurement of joint angles and acceleration on human subjects. This has resulted in new devices that reportedly measure joint angles, arm speed, and stresses to the pitching arms of baseball players. This study seeks to validate one such sensor, the MotusBASEBALL unit, with a marker-based motion capture laboratory. Hypothesis We hypothesize that the joint angle measurements (“arm slot” and “shoulder rotation”) of the MotusBASEBALL device will hold a statistically significant level of reliability and accuracy, but that the “arm speed” and “stress” metrics will not be accurate due to limitations in IMU technology. Methods A total of 10 healthy subjects threw five to seven fastballs followed by five to seven breaking pitches (slider or curveball) in the motion capture lab. Subjects wore retroreflective markers and the MotusBASEBALL sensor simultaneously. Results It was found that the arm slot (R = 0.975, P < 0.001), shoulder rotation (R = 0.749, P < 0.001), and stress (R = 0.667, P = 0.001 when compared to elbow torque; R = 0.653, P = 0.002 when compared to shoulder torque) measurements were all significantly correlated with the results from the motion capture lab. Arm speed showed significant correlations to shoulder internal rotation speed (R = 0.668, P = 0.001) and shoulder velocity magnitude (R = 0.659, P = 0.002). For the entire sample, arm slot and shoulder rotation measurements were on a similar scale, or within 5–15% in absolute value, of magnitude to measurements from the motion capture test, averaging eight degrees less (12.9% relative differences) and nine degrees (5.4%) less, respectively. Arm speed had a much larger difference, averaging 3,745 deg/s (80.2%) lower than shoulder internal rotation velocity, and 3,891 deg/s (80.8%) less than the shoulder velocity magnitude. The stress metric was found to be 41 Newton meter (Nm; 38.7%) less when compared to elbow torque, and 42 Nm (39.3%) less when compared to shoulder torque. Despite the differences in magnitude, the correlations were extremely strong, indicating that the MotusBASEBALL sensor had high reliability for casual use. Conclusion This study attempts to validate the use of the MotusBASEBALL for future studies that look at the arm slot, shoulder rotation, arm speed, and stress measurements from the MotusBASEBALL sensor. Excepting elbow extension velocity, all metrics from the MotusBASEBALL unit showed significant correlations to their corresponding metrics from motion capture and while some magnitudes differ substantially and therefore fall short in validity, the link between the metrics is strong enough to indicate reliable casual use. Further research should be done to further investigate the validity and reliability of the arm speed metric

Exploring the role of wearable technology in sport kinematics and kinetics: a systematic review

The aim of this review was to understand the use of wearable technology in sport in order to enhance performance and prevent injury. Understanding sports biomechanics is important for injury prevention and performance enhancement and is traditionally assessed using optical motion capture. However, such approaches are limited by capture volume restricting assessment to a laboratory environment, a factor that can be overcome by wearable technology. A systematic search was carried out across seven databases where wearable technology was employed to assess kinetic and kinematic variables in sport. Articles were excluded if they focused on sensor design and did not measure kinetic or kinematic variables or apply the technology on targeted participants. A total of 33 articles were included for full-text analysis where participants took part in a sport and performed dynamic movements relating to performance monitored by wearable technologies. Inertial measurement units, flex sensors and magnetic field and angular rate sensors were among the devices used in over 15 sports to quantify motion. Wearable technology usage is still in an exploratory phase, but there is potential for this technology to positively influence coaching practice and athletes’ technique

Variable Vector Countermeasure Suit (V2Suit) for Space Habitation and Exploration

The Variable Vector Countermeasure Suit (V2Suit) for Space Habitation and Exploration is a visionary system concept that will revolutionize space missions by providing a platform for integrating sensors and actuators with daily astronaut intravehicular activities to improve human health and performance. The V2Suit uses control moment gyroscopes (CMGs) within a miniaturized module placed on body segments to provide a viscous resistance during movements _ a countermeasure to the sensorimotor and musculoskeletal adaptation performance decrements that manifest themselves while living and working in microgravity and during gravitational transitions during long-duration spaceflight, including post-flight recovery and rehabilitation. Through an integrated design, system initialization, and control systems approach the V2Suit is capable of generating this viscous resistance along an arbitrarily specified direction of down. When movements are made, for example, parallel to that down direction a resistance is applied, and when the movement is perpendicular to that direction no resistance is applied. The V2Suit proposes to be a countermeasure to this spaceflight-related adaptation and de-conditioning and the unique sensorimotor characteristics associated with living and working in 0-G, which are critical for future long-duration space missions. This NIAC Phase II project leveraged the study results from Phase I and focused on detailing several aspects of the V2Suit concept, including a wearable CMG architecture, control steering laws, human-system integration evaluations, developing a brassboard prototype unit as a proof-of-concept, as well as evaluating the concept in the context of future space exploration missions. A human mission to Mars, such as that outlined in the Mars Design Reference Architecture 5.0, provides a framework for determining the concept of operations and requirements for the V2Suit system. Mars DRA 5.0 includes approximately 180 day 0-G transits to- and from- Mars, as well as a 500 day stay on the surface (~3/8-G) (Figure 3). Accordingly, there are four gravitational transitions associated with this mission: 1-G to 0-G (Earth launch), 0-G to 3/8-G (Mars landing), 3/8-G to 0-G (Mars launch), and 0-G to 1-G (Earth landing). This reference mission provided the basis for developing high-level operational requirements to guide the subsequent study and design of the key V2Suit components

A comprehensive review of wireless body area network

Recent development and advancement of information and communication technologies facilitate people in different dimensions of life. Most importantly, in the healthcare industry, this has become more and more involved with the information and communication technology-based services. One of the most important services is monitoring of remote patients, that enables the healthcare providers to observe, diagnose and prescribe the patients without being physically present. The advantage of miniaturization of sensor technologies gives the flexibility of installing in, on or off the body of patients, which is capable of forwarding physiological data wirelessly to remote servers. Such technology is named as Wireless Body Area Network (WBAN). In this paper, WBAN architecture, communication technologies for WBAN, challenges and different aspects of WBAN are illustrated. This paper also describes the architectural limitations of existing WBAN communication frameworks. blueFurthermore, implementation requirements are presented based on IEEE 802.15.6 standard. Finally, as a source of motivation towards future development of research incorporating Software Defined Networking (SDN), Energy Harvesting (EH) and Blockchain technology into WBAN are also provided

The Variable Vector Countermeasure Suit (V2Suit) for space habitation and exploration

The “Variable Vector Countermeasure Suit (V2Suit) for Space Habitation and Exploration” is a novel system concept that provides a platform for integrating sensors and actuators with daily astronaut intravehicular activities to improve health and performance, while reducing the mass and volume of the physiologic adaptation countermeasure systems, as well as the required exercise time during long-duration space exploration missions. The V2Suit system leverages wearable kinematic monitoring technology and uses inertial measurement units (IMUs) and control moment gyroscopes (CMGs) within miniaturized modules placed on body segments to provide a “viscous resistance” during movements against a specified direction of “down”—initially as a countermeasure to the sensorimotor adaptation performance decrements that manifest themselves while living and working in microgravity and during gravitational transitions during long-duration spaceflight, including post-flight recovery and rehabilitation. Several aspects of the V2Suit system concept were explored and simulated prior to developing a brassboard prototype for technology demonstration. This included a system architecture for identifying the key components and their interconnects, initial identification of key human-system integration challenges, development of a simulation architecture for CMG selection and parameter sizing, and the detailed mechanical design and fabrication of a module. The brassboard prototype demonstrates closed-loop control from “down” initialization through CMG actuation, and provides a research platform for human performance evaluations to mitigate sensorimotor adaptation, as well as a tool for determining the performance requirements when used as a musculoskeletal deconditioning countermeasure. This type of countermeasure system also has Earth benefits, particularly in gait or movement stabilization and rehabilitation.United States. National Aeronautics and Space Administration (Innovative Advanced Concepts Grant NNX11AR25G)United States. National Aeronautics and Space Administration (Innovative Advanced Concepts Grant NNX12AQ58G

Utility of Novel Rotational Load-velocity Profiling Methods in Collegiate Softball Players

The purposes of this study were to determine the reliability of the bat swing (BS) and rotational medicine ball throw (RMBT) load-velocity profiling (LVP) methods and the relationships between LVP variables and batting performance in NCAA Division I softball players. Current NCAA Division I softball athletes participated in this study. Bat velocity was tracked with a swing sensor during the BS method. An inertial measurement unit (IMU) tracked forearm velocity during the BS and RMBT methods. Two-way intraclass correlation coefficients (ICC) were used for relative reliability and coefficient of variation (CV) was used for absolute reliability. For the BS method with the swing sensor, relationships between the multiple- and two-load models and between LVP variables and batting variables were examined using Pearson\u27s correlation coefficients. During the RMBT method and BS method using the IMU, no LVP variables were reliable (ICC = 0.7; CV = 15%). For the BS method with the swing sensor, all bat loads and V0 had acceptable reliability using peak velocity (PV) and average peak velocity (PVavg) (ICC \u3e 0.7; CV \u3c 15%). All LVP variables were highly related between the multiple- and two-load models when utilizing PV and PVavg (r = 0.915-0.988; p \u3c 0.01). There were significant relationships (r = 0.603-0.671; p \u3c 0.05) between PV using the 0.99 kg bat load and slugging percentage and on-base plus slugging, and between V0 and doubles, runs batted in, and total bases. Neither the RMBT method nor the BS method using the IMU provided reliable LVP variables. All bat velocities were highly reliable during the BS method using the swing sensor, while only V0 provided acceptable reliability. Practitioners may utilize the two-load model when utilizing the BS method using the swing sensor, although further research is needed to examine the relationship between LVP variables and batting performance

Advancing Applications of IMUs in Sports Training and Biomechanics.

Miniature inertial measurement units (IMUs) have become popular in the field of biomechanics as an alternative to expensive and cumbersome video-based motion capture (MOCAP). IMUs provide three-axis sensing of angular velocity and linear acceleration in lieu of position data provided by MOCAP. The research presented herein further explores the use of IMUs in five applications for sports training and clinical biomechanics. The first study focuses on the sports of baseball and softball and yields estimates of the release velocity of a pitched ball within 4.6% of MOCAP measurements. The ball angular velocity further distinguishes and quantifies different types of pitches. The second study enables estimates of angular velocity during free-flight based solely on data from an embedded tri-axial accelerometer. Doing so eliminates angular rate gyros, which are often range limited, yet yields angular velocity estimates accurate to within 2%. We further exploit this technique to reveal the rotational stability of rigid bodies in free-flight. The third study extends the use of IMUs to assess the speed of an athlete estimated from a torso-mounted IMU. The speed estimates remain highly correlated with those obtained by MOCAP (r=0.96, slope=0.99) for motions characteristic of explosive sports (e.g., basketball). Moreover, the accurate speed estimation algorithm (mean RMSE=0.35 m/s) does not require data from GPS or magnetometers rendering it valuable and usable in any environment (indoor or outdoor). The remaining studies advance the use of IMU arrays to estimate joint reactions in multibody systems. The fourth study establishes the accuracy of this method using experiments on an instrumented double pendulum. Estimated reaction forces and moments remain within 5.0% and 5.9% RMS respectively of values measured via load cells. The final study addresses the companion need to measure the location of joint centers. A method employing a single IMU yields the center of rotation (CoR) of a spherical joint to within 3 mm as established by a coordinate measuring machine. The simplicity and accuracy of this method may render it attractive for broad use in field, laboratory or clinical applications requiring non-invasive, rapid estimates of joint CoR.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/97947/1/ryanmcg_1.pd