Mechanical circulatory support (MCS) devices, i.e., ventricular assist devices (VADs) and total artificial hearts (TAHs), while effective and vital in restoring hemodynamics in patients with circulatory compromise in advanced heart failure, remain limited by significant adverse thrombotic, embolic and bleeding events. Many of these complications relate to chronic exposure, via these devices, to nonpulsatile flow and the high shear stress created by current methods of blood propulsion or use of prosthetic valves. Here we propose a novel noncompressing single sliding vane MCS device to: 1) dramatically reduce pump operating speed thus potentially lowering the shear stress imparted to blood; 2) eliminate utilization of prosthetic valves thus diminishing potential shear stress generations; 3) allow direct flow rate control to generate physically desired blood flow rate include pulsatile flow; and 4) achieve compactness to fit into the majority of patients. The fundamental working principle and governing design equations are introduced first with multiple design and performance objectives presented. A first prototype was fabricated and experimental tests were conducted to validate the model with a 93.10% match between theoretical and experimental flow rate results. After model validation, the proposed MCS was tested to illustrate the ability of pulsatile flow generation. Finally, it was compared with some representative MCS pumps to discuss its potential of improving current MCS design. The presented work offers a novel MCS design and paves the way for next steps in device hemocompatibility testing.

This work proposes the theory and design of an experimental setup to mimic the dynamic impedance of the human circulatory system for testing the dynamic characteristics of an artificial heart. This platform has the same resistance, compliance, and inertance elements as the well-studied 4-element Windkessel model. As opposed to a circuit analogy model commonly seen in the literature, our platform remains within the same energy domain as the circulatory system. This allows an artificial heart designer to test pump performance and dynamic pressure characteristics under realistic loading. A test platform is designed using a non-hazardous working fluid with the same density and viscosity as blood. The system uses as few custom components as possible and interchangeable parts allow for system tuning.

This paper presents a hardware and software system to implement the task space control of an MR-conditional robot by integrating inductively coupled wireless coil based tracking feedback into the control loop. The main motivation of this work is to increase the accuracy performance and address the system uncertainties in the practical scenarios. We present the MR-conditional robot hardware design, wireless tracking method, and custom-designed communication software for real-time tracking data transfer. Based on these working principles, we fabricate the robot platform and evaluate the complete system with respect to various performance indices, i.e. data communication speed, targeting accuracy, tracking coil resolution, image quality, temperature variation, and task space control accuracy for static and dynamic targeting inside MRI scanner. The in-scanner targeting results show that the MR-conditional robot with wireless tracking coil feedback achieves the targeting error of 0.17 ± 0.08 mm, while the error calculated from the joint space optical encoder feedback is 0.68 ± 0.19 mm.

The complications of identifying radiation effects in electromechanical sensors in the presence of mechanical variation are discussed. A corresponding analysis method is developed to separate radiation degradation effects from expected sensing variation due to mechanical tolerances of test fixtures. This is achieved by statistically characterizing the fixture variation for each sensor before irradiation, and evaluating the statistical significance of any sensitivity changes after irradiation. The method is demonstrated using a contactless Hall-effect rotary encoder IC commonly used in robotic systems. Sensitivity changes in measurements relevant to robotic controller design are isolated and quantified as a maximum positioning error of 0.5 degrees and an angular velocity error of 1.5%. These measurements can be used to improve a commercial off-the-shelf robotic system's tolerance to radiation by designing motion controllers robust to sensitivity changes prior to total device failure.

Machine learning is used to extend performance in robotic systems suffering from TID sensor failure. The method is implemented on a robotic manipulator to demonstrate reconstruction of encoder signals submitted to simulated radiation effects.