Ryan Z. Amick

Exercise capacity in an individual with LVAD explantation without heart transplantation.

PURPOSE: Left ventricular assist devices (LVADs) have become a viable treatment alternative to heart transplantation, in some instances providing for a level of improvement of native heart function to allow for device explantation. The aim of this case study was to describe changes in physical work capacity following 9 months of LVAD support. CLINICAL CASE: The patient described here was diagnosed with idiopathic dilated cardiomyopathy and demonstrated worsening heart failure over a 5-year period with a maximum left ventricular end-diastolic diameter of 8.99 cm and an ejection fraction of 15% to 25%. Upon implantation of an LVAD, central hemodynamic function improved and the device was removed after 9 months of support. Left ventricular diastolic and systolic diameter decreased by 39.8% and more than 30%, respectively. The left atrium decreased by 21.7% and ejection fraction was maintained by the LVAD and stabilized at 20%. Four months postexplantation, a cycle ergometry graded cardiopulmonary exercise test was performed. Exercise began at 0 W and increased 25 W per 3-minute stage. RESULTS: The patient showed improvement in peak aerobic capacity when compared to pre-LVAD cardiopulmonary stress tests. Peak oxygen uptake increased from pre-LVAD measures of 11.8 mL · kg−1 · min−1 to 17.0 mL · kg−1 · min−1. Time to maximal exertion increased from 5 minutes 27 seconds to 15 minutes. CONCLUSION: Results of this case study indicate that significant improvements in native heart function leading to an increased ability to perform work is possible following a period of mechanical unloading through LVAD support.

Passive Wearable Skin Patch Sensor Measures Limb Hemodynamics Based on Electromagnetic Resonance

Objective: The objectives of this study were to design and develop an open-circuit electromagnetic resonant skin patch sensor, characterize the fluid volume and resonant frequency relationship, and investigate the sensors ability to measure limb hemodynamics and pulse volume waveform features. Methods: The skin patch was designed from an open-circuit electromagnetic resonant sensor comprised of a single baseline trace of copper configured into a square planar spiral which had a self-resonating response when excited by an external radio frequency sweep. Using a human arm phantom with a realistic vascular network, the sensors performance to measure limb hemodynamics was evaluated. Results: The sensor was able to measure pulsatile blood flow which registered as shifts in the sensors resonant frequencies. The time-varying waveform pattern of the resonant frequency displayed a systolic upstroke, a systolic peak, a dicrotic notch, and a diastolic down stroke. The resonant frequency waveform features and peak systolic time were validated against ultrasound pulse wave Doppler. A statistical correlation analysis revealed a strong correlation (

Wearable Technologies: How Will We Overcome Barriers to Enhance Worker Performance, Health, And Safety?

R^{2}\,= \,0.99

Preliminary Assessment of Ergonomic Injury Risk Factors in the Extravehicular Mobility Unit Spacesuit Glove

) between the resonant sensor peak systolic time and the pulse wave Doppler peak systolic time. Conclusion: The sensor was able to detect pulsatile flow, identify hemodynamic waveform features, and measure heart rate with 98% accuracy. Significance: The open-circuit resonant sensor design leverages the architecture of a thin planar spiral which is passive (does not require batteries), robust and lightweight (does not have electrical components or electrical connections), and may be able to wirelessly monitor cardiovascular health and limb hemodynamics.

Estimation of Low Back Disorder Risk for the ACGIH TLVs

Wearable technologies are changing the way that people interact with the world. Personal physical activity monitors are becoming ubiquitous in our society and are helping to advance user health and performance, yet, many workplaces have not broadly adopted the technologies beyond either low fidelity/complexity pedometer-based applications or, inversely, high fidelity/complexity lab- based evaluations. Considering adoption of wearable technologies in the workplace, some technology-related concerns include; (1) types of data needed to be captured (motion, muscle, temperature, etc.), (2) constraints of sensor design, such as human-sensor system integration (embedded in clothing versus strapped to person), ruggedness, form factor, or weight, and (3) types of data interpretation and feedback applications that exist to translate data into useful information (communication, trend mapping, situational awareness). From the research design perspective, there is difficulty in conducting studies capable of demonstrating a safety or productivity that supports employing wearable technology in the workplace. Difficulties include poor access to workplaces and varied worker populations to conduct research, lack of funding, and the need for extended time periods to demonstrate utility (often longer than the lifecycle of the technology in question). Considering the industry perspective, barriers to adopting wearable technologies include lack of convincing data, cost, and anticipation of reduced productivity, poor usability, and/or information overload. Additionally, employee privacy concerns and public policy implications may provide challenges. Another potential barrier may be that some practitioners, however, believe that innovative technologies may be adopted without rigorous testing. This may have short term success to garner interest but may create a barrier to adoption in the long term if the devices are found to have no near or mid- term efficacy. The overarching goal of the session will be to improve understanding of different perspectives as it relates to the use, barriers, and adoption of wearable technologies and generate discussion for overcoming such barriers to improve the process of research to practice to research (RtPtR). The panelists are from a variety of industry sectors and academia. The session will begin with a 5- minute introductory statement from each panelist; therefore, most of the session will be a discussion between panelists and audience.

Characterization of Joint Resistance and Performance Degradation of the Extravehicular Mobility Unit Spacesuit: A Pilot Study

Injuries to the hands and fingers are commonly reported among astronauts who perform and train for Extravehicular Activities in the Extravehicular Mobility Unit Spacesuit. In an effort to better understand the physical and environmental ergonomic injury risk factors associated with spacesuit glove use, a custom built carrier glove with multiple integrated sensors was developed to be worn within the spacesuit glove with the purpose of measuring the physical and environmental variables acting on the fingers and hand, and the physiological response, within two pressurized glove conditions in a 1G laboratory setting. One male subject performed multiple dynamic and functional tasks in a pressurized EMU. Results indicate that the sensor glove is capable of measuring multiple physical and environmental variables associated the development of finger and hand injuries observed in astronauts.

Comparison of Postural Sway Measures Using a Balance Platform and Mobile Application: 3378 Board #22 May 31, 8

The American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Lifting Value (TLV) lifting assessment method was designed to identify potentially safe lifting weights as a function of location of the lift, duration and frequency, assessed at the origin of the lift. However, there may be scenarios where the destination of the lift may present greater risk than the origin. This study utilized a measure of low back disorder risk to evaluate if the destination of a lift could be assessed in addition to the origin of the lift. Results indicated that the destination of the lift could be evaluated using the ACGIH TLV assessment method. Additionally, the TLVs identified by the ACGIH were consistent with low risk values of the measure of low back disorder risk utilized in this study.

Sensitivity of Tri-Axial Accelerometers within Mobile Consumer Electronic Devices: A Pilot Study

Introduction: The primary objective of this pilot study was to characterize human performance degradations caused by the pressurized Extravehicular Mobility Unit Spacesuit (EMU). Method: This study assessed maximum strength (force) for elbow flexion/extension and shoulder abduction/adduction for three EMU suit conditions. Results: Statistically significant differences were observed between suit conditions during elbow flexion. Differences of practical significant were observed between suit conditions for mean peak elbow flexion and extension, but not for shoulder abduction/adduction. EMU resistance to movement was found to differ based on the direction of movement. Discussion: Characteristics of the EMU spacesuit may reduce performance for some movements and improve performance for others.

Comparison of a Mobile Technology Application with the Balance Error Scoring System

Methods Results Conclusions Introduction Balance training has become common in therapeutic exercise routines for rehab, injury prevention, and fall prevention. Unstable surfaces such as foam pads are commonly used in these to improve balance. While postural sway is often used as a measure of balance ability and to evaluate the efficacy of such programs to improve postural balance, there is little research regarding the measurement of sway while standing on foam pads. Evaluating clinical balance has typically been performed using expensive force platform technology that presents issues of portability, cost and ease of use. The use of smartphones equipped with accelerometers to measure balance is a novel technique for measuring postural sway. The purpose of this study was to compare measures of postural sway on firm and foam surfaces from a clinical balance platform against a mobile application. Participants ▪57 participants (28 male; 29 female) ▪Ages 24.3 + 6.8 yr Protocol ▪ 2 devices were used to obtain postural dynamics of static balance: ▪ a balance platform (Biodex Balance System SD) ▪ a mobile application (SWAY Balance) that utilizes the built-in triaxial accelerometer within an iPod Touch to measure balance. ▪The mobile device was held against the chest so data collection on both devices was performed simultaneously. ▪Each device measured anterior/posterior and medial/lateral stability as the displacement in degrees from level. (Actual Stability Score.) ▪Stances: stable surface feet together with eyes closed, feet together eyes closed on a foam surface, single leg eyes closed on stable surface. and single leg eyes closed on foam surface. There were no significant differences between the two devices as measured on the firm surface. There was a difference (p<0.05) when standing on foam (balance platform = 3.775; mobile application = 5.659) between the two devices. Unilateral stance on foam (9.887) was higher (p<0.05) than unilateral stance on the solid surface (4.862) with only the mobile application. Balance training has become common in therapeutic exercise routines for rehabilitation, injury prevention, and fall prevention. Unstable surfaces such as foam pads are commonly used in these purportedly to improve balance. While postural sway is often used as a measure of balance ability and to evaluate the efficacy of such programs to improve postural balance, there is little research regarding the measurement of sway while standing on foam pads. Purpose: To compare measures of postural sway from a clinical balance platform against a mobile application. Method: Two devices were used to obtain the postural dynamics of static balance for each subject: 1) a balance platform (Biodex Balance System SD) and 2) a mobile application (SWAY Balance) that utilizes the built-in tri-axial accelerometer within an iPhone or iPod Touch to measure balance. The mobile device is held against the chest so data from both devices can be collected simultaneously. 57 participants (28 male; 29 female) aged 24.3 + 6.8 yr completed the study in which they stood bilaterally and then unilaterally on a firm surface and then on foam pads using both devices to evaluate postural sway. Results: There were no significant differences between the two devices as measured on the firm surface. However, there was a difference (p<0.05) when standing on foam (balance platform = 3.775; mobile application = 5.659) between the two devices. Unilateral stance on foam (9.887) was higher (p<0.05) than unilateral stance on the solid surface (4.862) with only the mobile application. Conclusion: Based on these results, the mobile application is a valid and useful clinical tool for the evaluation of balance as results did not differ with the balance platform when measuring balance on the stable surface. However, given that postural sway did not differ between unilateral stance on firm versus foam surfaces with the balance platform, it appears that the balance platform strain gauges do not effectively measure sway while standing on foam. Therefore, this mobile application may be a better tool for quantification of sway while standing on foam. The mobile application is a valid and useful clinical tool for the evaluation of balance as results did not differ with the balance platform when measuring balance on the stable surface. Given that postural sway did not differ between unilateral stance on firm versus foam surfaces with the balance platform, it appears that the balance platform does not effectively measure sway while standing on foam. Therefore, this mobile application may be a better tool for quantification of sway while standing on foam.