Proper left ventricular assist device (LVAD) insertion will help maximize LVAD flow and may reduce adverse events such as right heart failure and pump thrombosis. Although no standardized insertion technique has been universally accepted, the goals are: unobstructed inflow cannula, unobstructed outflow graft with avoidance of right ventricular compression, and prevention of pump migration. To a...

An adiabatic dry saturated steam compression process with inner evaporative spray cooling in screw compressors for steam heat pump systems is studied. Thermodynamic model and simulation of this variable-mass compression process are devised. Differential equations are formulated and used to calculate the amount of liquid injected and the work to drive the compressor on the basis of simplificatio...

Pressure gradients across and between the head and chest were studied during mechanical cardiopulmonary resuscitation (CPR) in 22 humans. Patients in medical cardiac arrest, managed by ACLS guidelines, underwent placement of aortic arch (Ao), jugular venous bulb (JVB), and right atrial (RA) catheters. Simultaneous pressures were measured, and intercatheter gradients were calculated. The JVB to ...

Vapor compression systems continuously leak a small fraction of their refrigerant charge to the environment, whether during operation or servicing. As a result of the slow leak rate occurring during operation, the refrigerant charge decreases until the system is serviced and recharged. This charge degradation, after a certain limit, begins to have a detrimental effect on system capacity, energy...

The heating capacity and coefficient of performance (COP) of conventional air-source heat pumps decreases towards lower ambient temperatures. Additionally, the heat pump stops running at very low ambient temperatures due to the high discharge temperature at the outlet of the compressor. Oil injected into the compression chamber absorbs the heat generated during the compression process and thus,...

A piston piezoelectric (PZT) pump has many advantages for the use of light actuators. How to deal with contradiction between intermittent oil supplying and position control precision is essential when designing controller. In order accurately output actuator, a backstepping sliding-mode method based on Lyapunov function introduced, controller designed basis establishing mathematical model syste...

Three techniques of intermittent venous occlusion (an oscillotonometer cuff, pneumatic leggings and an automatic arterial pressure monitoring cuff (Sentinel] were applied to one upper limb of seven healthy male volunteers. Fibrinolytic activity was assessed by the measurement of the euglobulin clot lysis time during a control period followed by 1 h of intermittent venous occlusion. Although no ...

the aim of the current study was to design a porous osmotic pump–based drug delivery system for controlling the release of buspirone from the delivery system. the osmotic pump was successfully developed using symmetric membrane coating. the core of the tablets was prepared by direct compression technique and coated using dip-coating technique. drug release from the osmotic system was studied us...

The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded asse...