Mitral valve disease is quite variable and can occur as an isolated defect or in association with other complex left sided lesions. These lesions are often best described with detailed pre-operative imaging studies to define the valve anatomy and to access associated left heart disease. Depending on the type of mitral valve disease, various surgical repair techniques have led to improved surviv...

In patients with heart valve disease, echocardiography is the mainstay for diagnosis, assessment and serial surveillance. However, other modalities, notably cardiac MRI and CT, are used if echocardiographic imaging is suboptimal but can also give complementary information to improve assessment of the valve lesion and cardiac compensation to aid the timing of surgery and determine risk. This sta...

Background/Introduction The indications for urgent valve replacement in patients with infective endocarditis (IE) include uncontrolled infection, recurrent emboli, valve dysfunction and cardiac failure. The optimal timing of this surgery when IE is complicated by cerebrovascular events (such as cerebral infarction or haemorrhage) is controversial, largely due to the escalated risk of perioperat...

Systolic pressure in the pulmonary artery was estimated from the interval between pulmonary valve closure and tricuspid valve opening, and the heart rate using a nomogram previously described. The timing of valve movements was recorded by Doppler ultrasound. The estimated pressure correlated well with that obtained at catheterisation in 45 of 48 patients with pulmonary hypertension. Instantaneo...

In Part I of this article, several aspects of valve structure and function and their possible clinical relevance were discussed. We now review the clinical evolution and application for various forms of valve repair and outline some of the factors relating to the timing and choice of particular types of repair or replacement and, whenever appropriate, repair versus replacement. In addition, fut...

This paper reports spreadsheet calculations intended to verify the timing of 6-4 GasP asynchronous Network on Chip (NoC) control circuits. The Logical Effort model used in the spreadsheet estimates the delays of each logic gate in the GasP control. The calculations show how these delays vary in response to differing environmental conditions. The important environmental variable is the physical ...

Hydraulic applications requiring a variation in the speed or torque of actuators have historically used throttling valve control or a variable displacement pump or motor. An alternative method is switch-mode control that uses a high-speed valve to rapidly switch between efficient on and off states, allowing any hydraulic actuator to have virtually variable displacement. An existing barrier to s...

This work presents passive time delay valves for micro channels in two different working modes for microfluidic on chip timing. The delay valve designs are compatible with conventional lamination techniques for microfluidics and allow to pre-program advanced sequential operations independent from the geometries of the microfluidic system. The time delay of the dissolvable valves ranges from 1.2...

In this paper, the influence of the gas exchange process on the diesel engine thermal overload is provided. Main components involved in the gas exchange process are discussed. The ambient conditions, the turbocharger performance, and the valve timing that affect the gas exchange process have been investigated. Experiments were conducted to simulate ambient conditions at different geographical l...

In this paper, a Rankine cycle test system is established to recover exhaust energy from a 2.0 L gasoline engine. Experiments on the system’s performance are carried out under various working conditions. The experimental results indicate that the recovery power of the expander is strongly related to the load and speed of the gasoline engine. It is found that when the output power of the gasolin...