• The aortic incisura and the second heart sound have been considered simultaneous with and caused by aortic valve closure for many years. While Wiggers believed in a noiseless approximation of the semilunar valves and that after-vibrations of the closed valves and aortic blood column caused the second sound, the incisura was related to semilunar valve closure. Thus, subsequent studies relating...

Pediatric patients account for a small portion of the heart valve replacements performed, but a pediatric pulmonary valve replacement with growth potential remains an unmet clinical need. Herein we report the first tubular heart valve made from two decellularized, engineered tissue tubes attached with absorbable sutures, which can meet this need, in principle. Engineered tissue tubes were fabri...

The movement of the anterior leaflet of the mitral valve has been recorded with an ultrasound echo technique. The intrinsic mobility of the valve cusps and the rate of ventricular filling are thought to influence the closure of the valve during diastole. Atrial contraction occurs at the end of ventricular diastole and reopens the valve before the mitral valve returns to the closed position befo...

The large primary-secondary chilled water systems often suffer from the excess flow demand and low chilled water temperature difference, which is known as the low ΔT central plant syndrome, during operation. This paper presents an approach for experimental validation of the possible utility of a check valve (i.e., putting a one-direction check valve in the chilled water by-pass line) to solve t...

Microfluidic characterization plays an outstanding role in the development of glaucoma drainage devices. Here, we describe the optimization of an existing test facility with regard to measurement of small volumetric flow rates in the range of 1 μl/min to 40 μl/min in a minimized testing time. The existing test facility is extended by a flow sensor and validated by microfluidic characterization ...

The precise measurement of the pressure gas enclosed in starting volume a static expansion system is important for achieving low uncertainties. This work focuses on valve closing process and resulting difference. condition flow conservation used to set up model an experimental procedure has been developed investigate change caused by moving plate. Various parameters are evaluated compared with ...

OBJECTIVE To measure the noise produced and related subjective complaints after implantation of four different mechanical heart valve prostheses and to identify further factors related to the patient and prosthesis that influence noise generation and complaints. DESIGN Sound pressure was measured 5 and 10 cm and 1 m from the point of maximal impulse on the body surface by a calibrated meter i...

This work presents a novel vision-force based interface; allowing a local operator to visually specify a path constraint to a remote robot manipulator. By using our interface the operator is able to control a 7-DOF arm with only 2-DOF. Our interface aims to reduce task complexity and operator cognitive load. We illustrate our approach with 2 mock-up examples: 1) Closing a steam valve, 2) Gluing...

As the key control component of water hydraulic systems, proportional valve has a significant influence on performance systems. Due to poor viscosity and lubricity water, spool resistance is large non-linear. In this study, novel fast-response presented. The actuator adopts voice coil motor (VCM), which advantages fast response, high precision small volume. order realize valve, lever amplifier ...