Pragathi Praveena

Pragathi Praveena, Guru Subramani, Bilge Mutlu et al.

Human demonstrations are important in a range of robotics applications, and are created with a variety of input methods. However, the design space for these input methods has not been extensively studied. In this paper, focusing on demonstrations of hand-scale object manipulation tasks to robot arms with two-finger grippers, we identify distinct usage paradigms in robotics that utilize human-to-robot demonstrations, extract abstract features that form a design space for input methods, and characterize existing input methods as well as a novel input method that we introduce, the instrumented tongs. We detail the design specifications for our method and present a user study that compares it against three common input methods: free-hand manipulation, kinesthetic guidance, and teleoperation. Study results show that instrumented tongs provide high quality demonstrations and a positive experience for the demonstrator while offering good correspondence to the target robot.

A. P. Prathosh, Pragathi Praveena, Lalit K. Mestha et al.

Non-contact estimation of respiratory pattern (RP) and respiration rate (RR) has multiple applications. Existing methods for RP and RR measurement fall into one of the three categories - (i) estimation through nasal air flow measurement, (ii) estimation from video-based remote photoplethysmography, and (iii) estimation by measurement of motion induced by respiration using motion detectors. These methods, however, require specialized sensors, are computationally expensive and/or critically depend on selection of a region of interest (ROI) for processing. In this paper a general framework is described for estimating a periodic signal driving noisy LTI channels connected in parallel with unknown dynamics. The method is then applied to derive a computationally inexpensive method for estimating RP using 2D cameras that does not critically depend on ROI. Specifically, RP is estimated by imaging the changes in the reflected light caused by respiration-induced motion. Each spatial location in the field of view of the camera is modeled as a noise-corrupted linear time-invariant (LTI) measurement channel with unknown system dynamics, driven by a single generating respiratory signal. Estimation of RP is cast as a blind deconvolution problem and is solved through a method comprising subspace projection and statistical aggregation. Experiments are carried out on 31 healthy human subjects by generating multiple RPs and comparing the proposed estimates with simultaneously acquired ground truth from an impedance pneumograph device. The proposed estimator agrees well with the ground truth device in terms of correlation measures, despite variability in clothing pattern, angle of view and ROI.

Pragathi Praveena, Jobin J Kavalam, Namita Jacob

Simulators, as tools that can clearly bring out the effect of impairment, are invaluable in the design and development process of an assistive device. Simulators are vital in meeting high standards of accessibility. Described is our work on a smartphone-based vision simulator for diabetic retinopathy that is economic, portable, flexible and easy-to-use.