Field Programmable Gate Array Based Embedded System for Non-Invasive Estimation of Hemoglobin in Blood using Photoplethysmography

Abstract In this paper, a Field Programmable Gate Array (FPGA) based embedded system has been proposed for non-invasive detection of hemoglobin in blood using photoplethysmography. Photoplethysmography (PPG) is a non-invasive and low-cost optical technique that can be used to detect blood volume changes in the micro-vascular bed of tissue. Our investigations revealed that volume of water present in blood considerably affects the reading of the concentration of blood hemoglobin. In our current work, the proposed device is developed with monitoring of PPG waves at three wavelengths so as to compensate for the error due to absorption of near infrared radiation (NIR) by water in the blood. The device also has been developed to be robust enough to tolerate distortions in the waveform due to motion of the subject. In order to sense the motion of the subject a 3-axis accelerometer has been used and correction is suitably applied to the sensed waveform. As a result, it is possible to measure the concentration of hemoglobin in blood while the subject is on the move.</jats:p

Comparative Study of Maximum Power Point Tracking using Linear Kalman Filter &amp; Unscented Kalman Filter for Solar Photovoltaic Array on Field Programmable Gate Array

Abstract The paper proposes comparative study of Field Programmable Gate Array implementation of 2 closely related approaches to track maximum power point of a solar photovoltaic array. The current work uses 2 versions of kalman filter viz. linear kalman filter and unscented kalman filter to track maximum power point. Using either of these approach the maximum power point tracking (MPPT) becomes much faster than using the conventional Perturb &amp; Observe approach specifically in case of sudden weather changes. In this paper comparative analysis of both the algorithms being implemented on FPGA is presented. Experiments have been performed under optimal conditions as well as under cloudy conditions i.e. falling irradiance levels. Using the linear kalman filter the maximum power point of a solar PV array has been tracked with an efficiency of 97.11% while using the unscented kalman filter technique the maximum power point of the same solar PV array is tracked with higher efficiency of 98.3%. However, the maximum power point has been tracked at a much faster rate i.e. 4.5 ms using the linear kalman filter approach as compared to the unscented kalman filter approach which tracks maximum power point at 11 ms which is in turn faster than existing generic Perturb and Observe approach which takes 15ms to track the maximum power point. The system has been implemented on Altera EP2C20F484C7 FPGA board.</jats:p

Evaluating the efficacy of haptic feedback, 360{\deg} treadmill-integrated Virtual Reality framework and longitudinal training on decision-making performance in a complex search-and-shoot simulation

Virtual Reality (VR) has made significant strides, offering users a multitude of ways to interact with virtual environments. Each sensory modality in VR provides distinct inputs and interactions, enhancing the user's immersion and presence. However, the potential of additional sensory modalities, such as haptic feedback and 360{\deg} locomotion, to improve decision-making performance has not been thoroughly investigated. This study addresses this gap by evaluating the impact of a haptic feedback, 360{\deg} locomotion-integrated VR framework and longitudinal, heterogeneous training on decision-making performance in a complex search-and-shoot simulation. The study involved 32 participants from a defence simulation base in India, who were randomly divided into two groups: experimental (haptic feedback, 360{\deg} locomotion-integrated VR framework with longitudinal, heterogeneous training) and placebo control (longitudinal, heterogeneous VR training without extrasensory modalities). The experiment lasted 10 days. On Day 1, all subjects executed a search-and-shoot simulation closely replicating the elements/situations in the real world. From Day 2 to Day 9, the subjects underwent heterogeneous training, imparted by the design of various complexity levels in the simulation using changes in behavioral attributes/artificial intelligence of the enemies. On Day 10, they repeated the search-and-shoot simulation executed on Day 1. The results showed that the experimental group experienced a gradual increase in presence, immersion, and engagement compared to the placebo control group. However, there was no significant difference in decision-making performance between the two groups on day 10. We intend to use these findings to design multisensory VR training frameworks that enhance engagement levels and decision-making performance.Comment: 13 pages, 6 figures, 1 Tabl