R&D of the device for blind to conceive 2D graphical information

Miniature piezoelectric thimble is described and investigated, based on friction control between PC screen and thimble’s contacting surface. The contours of the image on PC screen switch on and off harmonic or non-harmonic electric signals, connected to the electrodes of bimorph piezoelectric transducer, generating bending deformations, affecting friction coefficient. While scanning the PC screen in two directions, these periodic variations of friction coefficient result in oscillations of the fingertip, related to the color or intensity of the image components on the screen. Another three cases of pin’s oscillations normal to finger contacting surface are described

Simulation of vibrational piezoelectric actuators of the micro-robot using the finite element method

This paper describes a micro-robot with the vibrational piezoelectric actuator that was developed and tested using finite element method. Dependency of the robot motion speed on vibration frequency and coefficient of friction of the actuating elements and bearing surface has been investigated. The principle for motion control of the robot has been described and potential domains for its application have been discusse

Autonomic and muscular responses and recovery to one-hour laboratory mental stress in healthy subjects

<p>Abstract</p> <p>Background</p> <p>Stress is a risk factor for musculoskeletal pain. We wanted to explore stress related physiology in healthy subjects in order to gain insight into mechanisms of pain development which may relate to the pathophysiology of musculoskeletal pain disorders.</p> <p>Methods</p> <p>Continuous blood pressure, heart rate, finger skin blood flow, respiration, surface electromyography together with perception of pain, fatigue and tension were recorded on 35 healthy women and 9 healthy men before, during a 60 minute period with task-related low-grade mental stress, and in the following 30 minute rest period.</p> <p>Results</p> <p>Subjects responded physiologically to the stressful task with an increase in trapezius and frontalis muscle activity, increased blood pressure, respiration frequency and heart rate together with reduced finger skin blood flow. The blood pressure response and the finger skin blood flow response did not recover to baseline values during the 30-minute rest period, whereas respiration frequency, heart rate, and surface electromyography of the trapezius and frontalis muscles recovered to baseline within 10 minutes after the stressful task. Sixty-eight percent responded subjectively with pain development and 64% reported at least 30% increase in pain. Reduced recovery of the blood pressure was weakly correlated to fatigue development during stress, but was not correlated to pain or tension.</p> <p>Conclusion</p> <p>Based on a lack of recovery of the blood pressure and the acral finger skin blood flow response to mental stress we conclude that these responses are more protracted than other physiological stress responses.</p

R&D of the device for blind to conceive 2D graphical information

Miniature piezoelectric thimble is described and investigated, based on friction control between PC screen and thimble’s contacting surface. The contours of the image on PC screen switch on and off harmonic or non-harmonic electric signals, connected to the electrodes of bimorph piezoelectric transducer, generating bending deformations, affecting friction coefficient. While scanning the PC screen in two directions, these periodic variations of friction coefficient result in oscillations of the fingertip, related to the color or intensity of the image components on the screen. Another three cases of pin’s oscillations normal to finger contacting surface are described

R&D of the device for blind to conceive 2D graphical information

Miniature piezoelectric thimble is described and investigated, based on friction control between PC screen and thimble’s contacting surface. The contours of the image on PC screen switch on and off harmonic or non-harmonic electric signals, connected to the electrodes of bimorph piezoelectric transducer, generating bending deformations, affecting friction coefficient. While scanning the PC screen in two directions, these periodic variations of friction coefficient result in oscillations of the fingertip, related to the color or intensity of the image components on the screen. Another three cases of pin’s oscillations normal to finger contacting surface are described

Cardiovascular responses to cognitive stress in patients with migraine and tension-type headache

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to investigate the temporal relationship between autonomic changes and pain activation in migraine and tension-type headache induced by stress in a model relevant for everyday office-work.</p> <p>Methods</p> <p>We measured pain, blood pressure (BP), heart rate (HR) and skin blood flow (BF) during and after controlled low-grade cognitive stress in 22 migraineurs during headache-free periods, 18 patients with tension-type headache (TTH) and 44 healthy controls. The stress lasted for one hour and was followed by 30 minutes of relaxation.</p> <p>Results</p> <p>Cardiovascular responses to cognitive stress in migraine did not differ from those in control subjects. In TTH patients HR was maintained during stress, whereas it decreased for migraineurs and controls. A trend towards a delayed systolic BP response during stress was also observed in TTH. Finger BF recovery was delayed after stress and stress-induced pain was associated with less vasoconstriction in TTH during recovery.</p> <p>Conclusion</p> <p>It is hypothesized that TTH patients have different stress adaptive mechanisms than controls and migraineurs, involving delayed cardiovascular adaptation and reduced pain control system inhibition.</p