BACKGROUND Treatment of achalasia is focused on decreasing the resting lower esophageal sphincter by either pneumatic dilation or surgical myotomy. When patients symptomatically relapse after one or more pneumatic dilations, then one explanation is to consider the possibility of pseudoachalasia as the diagnosis. CASE REPORT We present a rare case of an elderly patient with a presentation of c...

Novel latching microfluidic valve structures are developed, characterized, and controlled independently using an on-chip pneumatic demultiplexer. These structures are based on pneumatic monolithic membrane valves and depend upon their normally-closed nature. Latching valves consisting of both three- and four-valve circuits are demonstrated. Vacuum or pressure pulses as short as 120 ms are adequ...

BACKGROUND To investigate the incidence of pulmonary embolism and risk factors for this condition after obstetric and gynecologic surgery, as well as the efficacy of intermittent pneumatic compression. METHODS A total of 6,218 patients operated at Keio University Hospital excluding obstetric or infertility-related surgery and uterine cervical conization were evaluated retrospectively to deter...

Perioperative nurses are likely to encounter the use of pneumatic tourniquets in a variety of operative and invasive extremity procedures. Use of a pneumatic tourniquet offers an opportunity to obtain a near-bloodless surgical field; however, the use of tourniquets is not without risk. Unfavorable outcomes include pain, thrombotic events, nerve compression injuries, and disruption of skin integ...

between 1993-1996 seventy-three consecutive patients (33 m, 40 f, mean age 35.4) with newly diagnosed achalasia underwent one or more pneumatic dilatations with the rigiflex balloon using a protocol of graded dilatation with a fixed inflation pressure of 10 psi and constant duration of 30 seconds for all patients without using fluoroscopy. using vantrappen's classification for assessment o...

This paper presents a rigorous analysis and design method for PWM-based control of pneumatic systems. An equivalent analytical model incorporating the effects of a finite PWM switching period is formulated. This equivalent model was motivated by a lack of control design and analysis techniques needed to treat the inherently non-analytical switching models associated with PWM-based systems. The ...

Abstract—The utilization of pneumatic muscles in the actuation of industrial systems is still in its early stages, hence studies on the constructive solutions which include an assessment of their functional performance with a focus on one of the most important characteristics-energy efficiency are required. A quality indicator that adequately reflects the energy efficiency of an actuator is the...

AbstructThis article models a pneumatic system consisting of double-acting or single acting cylinder and a servovalve with the goal of providing an insight into pneumatic design and control requirements for Berkeley Exoskeleton (ht<v://wwu..me. berkeZev.edu/heZ/). The modeling approach uses the thermodynamic principles of energy and mass conservation. We demonstrate that pneumatic systems suffe...

Considering rather severe parametric uncertainties and nonlinear uncertainties exist in the dynamic model of pneumatic muscles driven parallel manipulator, a discontinuous projection-based adaptive robust control strategy (ARC) is adopted to effectively handle the effect of various parameter variations of the system and hard-to-model nonlinearities such as the friction forces of the pneumatic m...