Papers by Mandayam Srinivasan
Also issued as a Ph.D. thesis, Dept. of Electrical Engineering and Computer Science, Massachusett... more Also issued as a Ph.D. thesis, Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology.
ArXiv, 2019
Fast accurate diagnosis of malaria is still a global health challenge for which automated digital... more Fast accurate diagnosis of malaria is still a global health challenge for which automated digital-pathology approaches could provide scalable solutions amenable to be deployed in low-to-middle income countries. Here we address the problem of Extended Depth-of-Field (EDoF) in thick blood film microscopy for rapid automated malaria diagnosis. High magnification oil-objectives (100x) with large numerical aperture are usually preferred to resolve the fine structural details that help separate true parasites from distractors. However, such objectives have a very limited depth-of-field requiring the acquisition of a series of images at different focal planes per field of view (FOV). Current EDoF techniques based on multi-scale decompositions are time consuming and therefore not suited for high-throughput analysis of specimens. To overcome this challenge, we developed a new deep learning method based on Convolutional Neural Networks (EDoF-CNN) that is able to rapidly perform the extended d...
Scientific Reports, 2020
Over 200 million malaria cases globally lead to half-million deaths annually. The development of ... more Over 200 million malaria cases globally lead to half-million deaths annually. The development of malaria prevalence prediction systems to support malaria care pathways has been hindered by lack of data, a tendency towards universal “monolithic” models (one-size-fits-all-regions) and a focus on long lead time predictions. Current systems do not provide short-term local predictions at an accuracy suitable for deployment in clinical practice. Here we show a data-driven approach that reliably produces one-month-ahead prevalence prediction within a densely populated all-year-round malaria metropolis of over 3.5 million inhabitants situated in Nigeria which has one of the largest global burdens of P. falciparum malaria. We estimate one-month-ahead prevalence in a unique 22-years prospective regional dataset of > 9 × 104 participants attending our healthcare services. Our system agrees with both magnitude and direction of the prediction on validation data achieving MAE ≤ 6 × 10–2, MSE ≤...
American Journal of Hematology, 2020
Nature Communications, 2020
Genetic and environmental factors are key drivers regulating organismal lifespan but how these im... more Genetic and environmental factors are key drivers regulating organismal lifespan but how these impact healthspan is less well understood. Techniques capturing biomechanical properties of tissues on a nano-scale level are providing new insights into disease mechanisms. Here, we apply Atomic Force Microscopy (AFM) to quantitatively measure the change in biomechanical properties associated with ageing Caenorhabditis elegans in addition to capturing high-resolution topographical images of cuticle senescence. We show that distinct dietary restriction regimes and genetic pathways that increase lifespan lead to radically different healthspan outcomes. Hence, our data support the view that prolonged lifespan does not always coincide with extended healthspan. Importantly, we identify the insulin signalling pathway in C. elegans and interventions altering bacterial physiology as increasing both lifespan and healthspan. Overall, AFM provides a highly sensitive technique to measure organismal b...
2014 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2014
Touch Lab Report, Cambridge, …, 1996
2016 IEEE 9th Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS), 2016
It is increasingly apparent that the traditional scene graph is not fulfilling the requirements o... more It is increasingly apparent that the traditional scene graph is not fulfilling the requirements of real-time interactive systems. The use of a single graph as a representation of the current state of the world means that display systems, that may operate at very different rates, or may need to predict ahead the state, need to be very tightly integrated with behaviour and semantics. In this position paper, we will propose a type of field called the "ambient field" which represents information proximate to the user's senses, which they could sample over short time periods. These fields might represent audio, video, haptic or other potentially sensed information. A display device can then sample these fields as necessary to construct the best representation possible at its own display rate. The ambient field draws on the concept of the ambient optical array from Gibson, light fields from computer graphics rendering and point-based physics simulations.
1. Introduction The goal of haptic rendering is to enable a user to touch, feel, and manipulate v... more 1. Introduction The goal of haptic rendering is to enable a user to touch, feel, and manipulate virtual objects through a haptic interface. With the introduction of high fidelity haptic devices (ref. **Biggs and Srinivasan Chapter**), it is now possible to simulate the feel of even fine surface textures on rigid complex shapes under dynamic conditions. Starting from the early nineties, significant progress has occurred in our ability to model and simulate haptic interactions with 3D virtual objects in real-time (Salisbury and Srinivasan, 1997; Srinivasan and Basdogan, 1997). The rapid increase in the number workshops, conference sessions, community web pages, and electronic journals on haptic displays and rendering techniques 1 indicates growing interest in this exciting new area of research, which we call computer haptics. Just as computer graphics is concerned with synthesizing and rendering visual images, computer haptics is the art and science of developing software algorithms t...
House in Dedham Massachusetts. Designed as a forum for sharing results and insights, the workshop... more House in Dedham Massachusetts. Designed as a forum for sharing results and insights, the workshop was attended by more than 60 participants from 7 countries. Twenty presentations in diverse areas including rigid and compliant rendering, tool kits, development environments, techniques for scientific data visualization, multi-modal issues and a programming tutorial were enjoyed by all. In addition, numerous hands-on demonstrations were made available and provided concrete evidence of the enormous progress made by the PHANToM users community during the past year. Best presentation awards (and the coveted SensAble leather jackets) were given to John McLaughlin from CISRO (Australia) and Rob Playter from Boston Dynamics (USA). We would like to express our sincere gratitude to all the participants for helping make the workshop a success and look forward to future meetings. We would also like to thank the staff of SensAble Technologies for their generous support and assistance in making th...
Current demonstrations of Brain-Machine Interfaces have shown the possibility of controlling neur... more Current demonstrations of Brain-Machine Interfaces have shown the possibility of controlling neuro-prostheses under pure motion control extremely successfully. For interaction with objects, pure motion control lacks the information required for versatile manipulation. This study investigates the idea of applying impedance control in BMI system. A musculoskeletal arm model based extraction algorithm was developed for this purpose. The new algorithm was tested on cortical recordings from a behaving monkey. The algorithm was able to predict motion parameters to an equivalent level of accuracy to that of a traditional extraction algorithm. Furthermore, it was able to predict interactions with external force fields that previous algorithms would not be able to predict.
It is well known that realistic haptic rendering depends on high update rates. Nevertheless, ther... more It is well known that realistic haptic rendering depends on high update rates. Nevertheless, there are many applications for which haptic interfaces could be useful where haptic data cannot be delivered at these rates. In VR and real-time dynamic simulation of deformable objects, for instance, update rates are limited by the computation time. In distributed systems, as telerobotics or network-based simulators, communication rates are unstable and limited by the network features. In this paper we show how this problem can be minimised using a "buffer model" between the haptic interface and the data source (the system being interfaced). This buffer is intended to be able to deliver data to the haptic device at the required rate and its role is to maximise the information contained in the data flow. The buffer is implemented as a local numerical model of the data source. The buffer model must be simple, generic and easily adaptable. The data flow will be used to continuously ...
Journal of Visual Impairment & Blindness, 2015
Introduction The BlindAid, a virtual system developed for orientation and mobility (O&M) training... more Introduction The BlindAid, a virtual system developed for orientation and mobility (O&M) training of people who are blind or have low vision, allows interaction with different virtual components (structures and objects) via auditory and haptic feedback. This research examined if and how the BlindAid that was integrated within an O&M training program could be of help when teaching those who are blind or visually impaired to develop O&M skills. Methods Using qualitative and quantitative methods, this research focused on 16 participants during their O&M course, and studied virtual environment exploration and orientation tasks in virtual environments. Results The encouraging results of the current study indicate the potential strengths of the BlindAid system as an O&M training device for visually impaired people. Discussion Follow-up research evaluating transference of knowledge from virtual environments to real spaces could contribute to O&M training for people who are visually impaire...
2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016
IEEE transactions on haptics, Jan 11, 2014
Based on recent discoveries of stretch and voltage activated ion-channels present in the receptiv... more Based on recent discoveries of stretch and voltage activated ion-channels present in the receptive area of Pacinian-corpuscle (PC), this paper describes a novel two-stage nonlinear mechanotransduction model of vibrotactile-sensitivitythreshold (VTST), valid over a wide frequency-band of 10 Hz to few kHz. The model is based on the nonlinear and stochastic behaviour of ion-channels represented as dependent-charge-sources loaded with membrane impedance. It accurately simulates the neural-response of PC around threshold considering the morphological and statistical properties of receptor-potential and action-potential with the help of adaptive-relaxation-pulse-frequency-modulator (ARPFM). This model also simulates the plateaus and nonmonotonic saturation of spike-rate characteristics. The stochastic simulation based on additional mechanical and neural noise clearly describes that VTST at higher frequency is more dependent on noise than at lower frequency range. Therefore even SNR=150 im...
It is well known that realistic haptic rendering depends on high update rates. Nevertheless, ther... more It is well known that realistic haptic rendering depends on high update rates. Nevertheless, there are many applications for which haptic interfaces could be useful where haptic data cannot be delivered at these rates. In VR and real-time dynamic simulation of deformable objects, for instance, update rates are limited by the computation time. In distributed systems, as telerobotics or network-based simulators, communication rates are unstable and limited by the network features. In this paper we show how this problem can be minimised using a "buffer model" between the haptic interface and the data source (the system being interfaced). This buffer is intended to be able to deliver data to the haptic device at the required rate and its role is to maximise the information contained in the data flow. The buffer is implemented as a local numerical model of the data source. The buffer model must be simple, generic and easily adaptable. The data flow will be used to continuously update a number of parameters of this model in order to render it locally as close as possible of the data source. We will show also how a buffer model can be useful to easily implement a proxy-based calculation of the haptic forces. We will finish showing how we used this approach to interface a PHANToM with a deformable objects simulator.
Gary Bishop, UNC-Chapel Hill (co-chair) William Bricken, U. of Washington, Seattle Frederick Broo... more Gary Bishop, UNC-Chapel Hill (co-chair) William Bricken, U. of Washington, Seattle Frederick Brooks, Jr., UNC-Chapel Hill Marcus Brown, U. of Alabama, Tuscaloosa Chris Burbeck, UNC-Chapel Hill Nat Durlach, M. I. T. Steve Ellis, NASA-Ames Research Center Henry Fuchs, UNC-Chapel Hill (co-chair) Mark Green, U. of Alberta, Canada James Lackner, Brandeis University Michael McNeill, NCSA Michael Moshell, U. of Central Florida Randy Pausch, U. of Virginia, Charlottesville Warren Robinett, UNC-Chapel Hill Mandayam Srinivasan, M. I. T. Ivan Sutherland, Sun Microsystems Dick Urban, DARPA Elizabeth Wenzel, NASA-Ames Research Center
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Papers by Mandayam Srinivasan