No abstract

Two procedures are currently in use for the determination of proton magnetization transfer rate constants between macromolecular tissue components and water. The first method assumes that there are only two spin baths (macromolecular plus solvent) and that during off-resonance irradiation complete saturation of the "immobile" proton spin bath occurs (S. H. Koenig, R. D. Brown, III, R. Ugolini, Magn. Reson. Med. 29, 311 (1993)). This approach neglects the possibility of incomplete saturation and polydispersity, and yields an apparent magnetization transfer rate constant, Kapp. The second approach utilizes a formalism which can account for polydispersity and incomplete saturation of the immobile spin bath (K. Kuwata, D. Brooks, H. Yang, T. Schleich, J. Magn. Reson., in press). In this work magnetization transfer rate constants derived by the use of both methods for two systems, ocular lens tissue and cross-linked bovine serum albumin (BSA) were compared. For both samples Kapp was dependent on B2 off-resonance irradiation frequency and power when the first method was used. The second method provided values of the magnetization transfer rate constant that were similar to the values obtained by the first method, as the limit of complete saturation was approached.

The objective of this research effort is to integrate therapy instruction with child-robot play interaction in order to better assess upper-arm rehabilitation. Using computer vision techniques such as Motion History Imaging (MHI), edge detection, and Random Sample Consensus (RANSAC), movements can be quantified through robot observation. In addition, incorporating prior knowledge regarding exercise data, physical therapeutic metrics, and novel approaches, a mapping to therapist instructions can be created allowing robotic feedback and intelligent interaction. The results are compared with ground truth data retrieved via the Trimble 5606 Robotic Total Station and visual experts for the purpose of assessing the efficiency of this approach. We performed a series of upper-arm exercises with two male subjects, which were captured via a simple webcam. The specific exercises involved adduction and abduction and lateral and medial movements. The analysis shows that our algorithmic results compare closely to the results obtain from the ground truth data, with an average algorithmic error is less than 9% for the range of motion and less than 8% for the peak angular velocity of each subject.

This paper describes our successful implementation of a robot that autonomously and strategically removes multiple blocks from an unstable Jenga tower. We present an integrated strategy for perception, planning and control that achieves repeatable performance in this challenging physical domain. In contrast to previous implementations, we rely only on low-cost, readily available system components and use strategic algorithms to resolve system uncertainty. We present a three-stage planner for block extraction which considers block selection, extraction order, and physics-based simulation that evaluates removability. Existing vision techniques are combined in a novel sequence for the identification and tracking of blocks within the tower. Discussion of our approach is presented following experimental results on a 5-DOF robot manipulator.

This research investigates proper movement correlation as well as the overall perception of human subjects' interaction with a simulated agent and an embodied agent in a physical therapeutic scenario. Using computer vision techniques coupled with the Microsoft Kinect to quantify reaching kinematics, correlation was assessed by aliging movements with a Vicon Motion Capture System as well as determining how well the specific exercises were mimicked. The results indicate that this approach is a viable alternative to Motion Capturing Systems for assessing certain movements during therapy. The results also indicate that there is some dependence on the use of an embodied agent as opposed to a simulated agent when assessing adherence.