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This paper presents a robust telerobotic system that consists of a real-time vision-based operator hand tracking system (client) and a slave robot (server) which are interconnected through a LAN. The tracking system: 1) monitors the operator hand motion and 2) determines its position and orientation which are used to control the slave robot. Two digital cameras are used to monitor a four-ball-based feature frame that is held by the operator hand. To determine the three-dimensional (3-D) position a tracking algorithm based on uncalibrated cameras with weak perspective projection model is used. This allows finding 3-D differential position and orientation of the operator hand. The features of the proposed system are: 1) a metric for color matching to discriminate the balls from their background; 2) a uniform and spiral search approach to speed up the detection; 3) tracking in the presence of partial occlusion; 4) consolidate detection by using shape and geometric matching; and 5) dynamic update of the reference colors. The operator can see the effects of the previous motion which enables making the necessary corrections through repetitive operator hand-eye interactions. Evaluation shows that the static and dynamic errors of the tracking algorithm are 0.1% and 0.6% for a centered workspace of [20.sup.3] [in.sup.3] that is 40-60 in away from the cameras. Running the tracking algorithm on two PCs in parallel allowed: 1) a parallel image grabbing delay of 60 ms; 2) a stereo matching delay of 50 ms; and 3) a global refresh rate of 9 Hz. Index Terms--Robotics, stereo vision, telerobotics, three-dimensional (3-D) tracking, 3-D vision.

In today''s world, research on cardiovascular diseases has increased due to the social losses. Diagnosis and treatment of cardiovascular disorders are necessary to understand the biological and mechanical causes of the diseases. In vitro and in vivo experiments are performed to understand the mechanism of the disease. In in vitro experiments physiological blood flow signals are used to simulate the blood flow inside human body. In this study novel closed-loop flow control system has been developed with control technique and flow control devices to simulate the physiological waveform, unlike studies conducted to date. In vitro experimental system consists of centrifugal pump, pump driver card, solenoid valve, valve driver card, data acquisition card (DAQ), flow meters, in vitro model and sample fluid piping system. The control algorithm is written and run using Matlab/Simulink AC pump and solenoid valves were used to simulate the pulsatile flow in femoral and coronary arteries that they have the high and low flow rates of 25 and 3ml/s, respectively. In the human body blood flow velocity and geometry of the measurement location can be recorded and visualized by MR imaging techniques. Images of blood flow signal can be transferred to experimental system by providing equivalence of dynamic simulation. For realization of blood flow, Fourier coefficients were obtained from MR blood flow image using image processing techniques and they were used to create flow velocity profile. Using Fourier coefficients femoral and coronary artery blood flow have been realized on the experimental system. Error performance (EP) criterion was developed during the studies to compare human blood flow signal to in vitro experimental blood flow signal. This study is a pioneer in terms of using close-loop control, two flow control devices and EP criteria in in vitro experimental systems. The algorithm developed in this research will be applied to different regions of cardiovascular system for future studies to better understand the cardiovascular diseases and related treatment. [Copyright &y& Elsevier]