A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theorywas introduced inmanyworks, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cyl...

BACKGROUND AND OBJECTIVE The objective of this study was to compare visual acuity outcomes between the following procedures used to treat submacular hemorrhages: pneumatic displacement followed by intravitreal tissue plasminogen activator (tPA) if needed (pneumatic ± tPA) and pars plana vitrectomy (PPV) with subretinal tPA (PPV + tPA). PATIENTS AND METHODS This is a retrospective chart review...

This study aims to develop a X-Y dual-axial intelligent servo pneumatic-piezoelectric hybrid actuator for position control with high response, large stroke (250 mm, 200 mm) and nanometer accuracy (20 nm). In each axis, the rodless pneumatic actuator serves to position in coarse stroke and the piezoelectric actuator compensates in fine stroke. Thus, the overall control systems of the single axis...

2 Abstract Pneumatic actuators have several advantages such as light weight, safety, low cost and high compliance. However, many pneumatic actuators have complicated systems that include a compressor, air tubes, and pneumatic valves with electrical wires. This research proposes a new control method for a multiplex pneumatic transmission constructed with special resonant valves and air tubes wit...

Birds are characterized by pneumatization of their skeletons by epithelial diverticula from larger, air-filled cavities. The diverticula-or ‘air sacs’-that invade the postcranium result from outgrowths of the lungs; postcranial pneumaticity has been very well studied. Much more poorly understood are the air sacs that pneumatize the skull. Study of craniofacial pneumaticity in modern birds (Neor...

This paper presents a comparative study among friction behavior of several double-acting pneumatic actuators available to industrial use. A brief review covering the manner that pneumatic actuator manufacturers and current literature approach friction force and its usual models also is presented. After depicting friction test methodology and test apparatus, the comparison work is carried out th...

This work presents a modeling and control design method for PWM-controlled pneumatic systems. Difficulties associated with servovalves typically used to continuously control pneumatic systems, in addition to a general lack of analytic control design techniques available for PWMcontrolled pneumatic systems, motivate the development> of a modeling and control design technique for PWM pneumatics. ...

Since 1972 the Hyogo Rehabilitation Centre has been developing a variable-resistance-type pneumatic control device, the HRC Adjustable Pneumatic Swing-Phase Control Knee. Successful field tests have been carried out on 20 cases with Model IV since 1973 with only a limited number of mechanical troubles. This paper introduces the HRC adjustable pneumatic swing-phase control knee with follow-up st...

Idiopathic achalasia is a primary esophageal motor disorder characterized by loss of esophageal peristalsis and insufficient lower esophageal sphincter relaxation in response to deglutition. Patients with achalasia commonly complain of dysphagia to solids and liquids, bland regurgitation often unresponsive to an adequate trial of proton pump inhibitor, and chest pain. Weight loss is present in ...

BACKGROUND Dysphagia results from impeded transport of liquids, solids, or both from the pharynx to the stomach. Among the malignant lesions, carcinoma of oesophagus is the commonest cause. Our objective was to find out the frequency of different endoscopic lesions and outcome of the endoscopic therapeutic interventions in patients presenting with dysphagia. METHODS This descriptive study was...