Effect of Stress on the Work Ability of Aging American Workers: Mediating Effects of Health

We examined how stress affects the work ability of an aging workforce, how health mediates this relationship, and how the effects of stress on work ability differ in relation to social status. We analyzed data from the Health and Retirement Survey, namely, 2921 observations in 2010, 2289 observations in 2012, and 2276 observations in 2014. Ongoing chronic stress, social status, health status, and associations with individual work ability were assessed with ordinary least squares regression. Stress was significantly inversely associated with work ability. Health may function as a mediator between individual stress and work ability. The effects of stress and health on work ability decreased as social status increased. To cope with the challenges of aging workforces, future policy-makers should consider job resources and social status

A Low-Temperature Poly-Silicon Thin Film Transistor Pixel Circuit for Active-Matrix Simultaneous Neurostimulation

This work reports a novel low-temperature poly-silicon thin-film-transistor-based pixel circuit for active-matrix neurostimulation. The pixel circuit consists of four transistors and one capacitor (4T1C) for programmable current-mode stimulation, which are designed for storing stimulation intensity information, simultaneously stimulating a large number of channels, and discharging stimulation electrodes. Due to the high mobility and low threshold voltages of the devices, the fabricated circuit occupies a pixel area of 200\times 200\,\,\mu \text{m}\,\,^{\mathrm{ 2}} , and delivers a stimulation current of $147 ~\mu \text{A}$ , sufficient to stimulate a neuron. The turn-on resistance of the fabricated transistor is below 6 $\text{k}\Omega$ , sufficient to be used as switches for bioelectronic applications. By employing a discharging switch transistor, the accumulated charges on the stimulation electrodes were released, and the electrode voltage was reduced to 0.08 V, thus mitigating corrosion. We demonstrated that two pixel circuits at different rows and columns can output stimuli simultaneously without a noticeable delay. This pixel circuit shows high potential to scale up as an active-matrix neurostimulation system with a high channel count

Towards active tracking of beating heart motion in the presence of arrhythmia for robotic assisted beating heart surgery.

In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion

Tracking results of 183-s arrhythmia data (only a part of the data is presented) from animal 1 for the generalized predictor.

<p>Reference and PHANToM positions, RMS position error and MPC control effort are shown (A) Axis 1 results. (B) Axis 2 results. (C) Axis 3 results.</p

Experimental setup for the measurement of the heart motion.

<p>Two sonomicrometer crystals that are sutured on the anterior and posterior surfaces of the heart are used for data collection. Pacemaker leads and sonomicrometer base are also visible in the image.</p

A schematic of the heart motion prediction problem.

<p>The circles represent past observations, now in memory, the is the current observation, and the short curve originating from there is the horizon estimate. The predictor takes the past observations and produces the horizon estimate from past observations.</p

Tracking results of 183-s arrhythmia data (only a part of the data is presented) from animal 1 for the PD Controller.

<p>Axis 1 results are shown only.</p