Piyush Gupta - Academia.edu (original) (raw)
Papers by Piyush Gupta
MEMS-based sensing and algorithm development for fall detection and gait analysis
SPIE Proceedings, 2010
Falls by the elderly are highly detrimental to health, frequently resulting in injury, high medic... more Falls by the elderly are highly detrimental to health, frequently resulting in injury, high medical costs, and even death. Using a MEMS-based sensing system, algorithms are being developed for detecting falls and monitoring the gait of elderly and disabled persons. In ...
Journal of Paediatrics and Child Health, 2005
Objective: To identify whether polymicrobial bacteremia in newborns is associated with any predis... more Objective: To identify whether polymicrobial bacteremia in newborns is associated with any predisposing factors, distinguishing clinical features, or higher mortality. Methods: Results of blood cultures obtained over a period of 1 year from neonates admitted to the paediatric ward and Neonatal Intensive Care Unit of a tertiary care hospital were retrospectively analysed. The study group included all cases with polymicrobial bacteremia (isolation of two or more organisms). Controls (double the number of study cases) were randomly selected from the monomicrobial group. Case records of included cases were retrieved and scrutinized. Results: Of 770 positive cultures during the study period, 52 (6.8%) cultures were positive for more than one organism. Complete case records were retrieved for 40 polymicrobial and 78 monomicrobial cases. The two groups were comparable for maternal and neonatal parameters including: maternal and obstetric complications; period of gestation; mode of delivery; birthweight and perinatal asphyxia; clinical symptomatology; invasive therapeutic interventions; and mortality. Conclusions: Isolation of more than one organism from the blood culture of a suspected septic newborn is not rare. It does not always represent a true invasion by multiple organisms. Polymicrobial isolation per se should not be the criterion for hastily changing the therapeutic decisions.
Indian Pediatrics, 2010
Wheezing in acute respiratory infections is a rule rather than exception. A large proportion of c... more Wheezing in acute respiratory infections is a rule rather than exception. A large proportion of children (up to 75%) having 'pneumonia' or 'severe pneumonia' as per WHO definitions have associated wheezing. The current strategies to diagnose and manage wheeze in the community need to be updated, as audible wheeze is present in only less than one-third of wheezy children, and can not be relied upon solely. A history of previous episodes of respiratory distress has a high sensitivity to diagnose wheezy disorders. In a significant proportion of children, the respiratory rate comes back to normal and the chest indrawing disappear after two to three cycles of inhaled bronchodilator medications. Operational research is needed to evaluate the feasibility of including management of wheezing in the community based ARI management programs.
Indian Pediatrics, 2010
T o rationalize the management of severely malnourished children, World Health Organization (WHO)... more T o rationalize the management of severely malnourished children, World Health Organization (WHO) proposed guidelines which state that a child with complications should be treated in hospital until the weight for length improves above 90%(1,2). However, this is seldom feasible because of bed shortage in hospitals and budgetary constraints. Prolonged hospital stay also carries the risk of nosocomial infections leading INDIAN PEDIATRICS 694 VOLUME 47 __
IEEE Transactions on Information Theory, 2010
We consider the question of determining the scaling of the n 2-dimensional balanced unicast and t... more We consider the question of determining the scaling of the n 2-dimensional balanced unicast and the n2 ndimensional balanced multicast capacity regions of a wireless network with n nodes placed uniformly at random in a square region of area n and communicating over Gaussian fading channels. We identify this scaling of both the balanced unicast and multicast capacity regions in terms of Θ(n), out of 2 n total possible, cuts. These cuts only depend on the geometry of the locations of the source nodes and their destination nodes and the traffic demands between them, and thus can be readily evaluated. Our results are constructive and provide optimal (in the scaling sense) communication schemes. We illustrate the strength of these results by computing the capacity scaling in a number of scenarios with non-uniform traffic patterns for which no such results have been available before.
IEEE Transactions on Information Theory, 2009
In recent work, Özgür, Lévêque, and Tse (2007) obtained a complete scaling characterization of th... more In recent work, Özgür, Lévêque, and Tse (2007) obtained a complete scaling characterization of throughput scaling for random extended wireless networks (i.e., n nodes are placed uniformly at random in a square region of area n). They showed that for small path-loss exponents 2 (2; 3], cooperative communication is order optimal, and for large path-loss exponents > 3, multihop communication is order optimal. However, their results (both the communication scheme and the proof technique) are strongly dependent on the regularity induced with high probability by the random node placement. In this paper, we consider the problem of characterizing the throughput scaling in extended wireless networks with arbitrary node placement. As a main result, we propose a more general novel cooperative communication scheme that works for arbitrarily placed nodes. For small path-loss exponents 2 (2; 3], we show that our scheme is order optimal for all node placements, and achieves exactly the same throughput scaling as in Özgür et al. This shows that the regularity of the node placement does not affect the scaling of the achievable rates for 2 (2; 3]. The situation is, however, markedly different for large path-loss exponents > 3. We show that in this regime the scaling of the achievable per-node rates depends crucially on the regularity of the node placement. We then present a family of schemes that smoothly "interpolate" between multihop and cooperative communication, depending upon the level of regularity in the node placement. We establish order optimality of these schemes under adversarial node placement for > 3.
IEEE Transactions on Biomedical Engineering, 2014
Activity recognition is required in various applica-4 tions such as medical monitoring and rehabi... more Activity recognition is required in various applica-4 tions such as medical monitoring and rehabilitation. Previously 5 developed activity recognition systems utilizing triaxial accelerom-6 eters have provided mixed results, with subject-to-subject variabil-7 ity. This paper presents an accurate activity recognition system 8 utilizing a body worn wireless accelerometer, to be used in the real-9 life application of patient monitoring. The algorithm utilizes data 10 from a single, waist-mounted triaxial accelerometer to classify gait 11 events into six daily living activities and transitional events. The 12 accelerometer can be worn at any location around the circumfer-13 ence of the waist, thereby reducing user training. Feature selection 14 is performed using Relief-F and sequential forward floating search 15 (SFFS) from a range of previously published features, as well as 16 new features, are introduced in this paper. Relevant and robust fea-17 tures that are insensitive to the positioning of accelerometer around 18 the waist are selected. SFFS selected almost half the number of fea-19 tures in comparison to Relief-F and provided higher accuracy than 20 Relief-F. Activity classification is performed using Naïve Bayes and 21 k-nearest neighbor (k-NN) and the results are compared. Activity 22 recognition results on seven subjects with leave-one-person-out er-23 ror estimates show an overall accuracy of about 98% for both the 24 classifiers. Accuracy for each of the individual activity is also more 25 than 95%.
European Journal of Paediatric Neurology, 2002
The objective of the study was to characterize the plantar response at various ages in infancy in... more The objective of the study was to characterize the plantar response at various ages in infancy in Indian children. The subjects were 1281 apparently healthy children born at term and without any history suggestive of neurological disease, enrolled between the ages of 1 and 12 months. The plantar response was elicited in both feet by thumbnail drag method and graded as flexor, extensor and equivocal. The percentage of extensor, flexor and equivocal responses was compared between right and left foot and the average of these two responses was compared between the age categories [1-3 months (n ¼ 389), 3.1-6 months (n ¼ 332), 6.1-9 months (n ¼ 354) and 9.1-12 months (n ¼ 206)]. Frequency (%) of various combinations of bilateral responses was also calculated for different age categories. Results showed that the extensor plantar response was the predominant response till 6 months of age. Bilateral extensor response was seen in 79.4%, 67.8%, 32.5% and 31.1% in the four age categories respectively; bilateral flexor response in the corresponding age groups was 0.3%, 5.1%, 26.6% and 39.3% respectively. The percentage of asymmetrical responses was 20.7%, 25.3%, 40.3%, and 28.7% in different age categories. We concluded that normal plantar response is predominantly extensor in early infancy; the transition to flexor response starts occurring after 6 months of age. A fairly high number of infants continue to have an extensor response even after 6 months; and the transition may be advanced in one foot leading to asymmetrical plantar response.
Archives of Pediatrics & Adolescent Medicine, 2003
To determine the efficacy of a topical anesthetic cream, eutectic mixture of local anesthetics (E... more To determine the efficacy of a topical anesthetic cream, eutectic mixture of local anesthetics (EMLA), in alleviating pain associated with lumbar puncture in newborns. Design: Randomized double-blind placebo-controlled trial. Setting: Neonatal intensive care unit of a university teaching hospital. Patients: Sixty consecutive newborns (gestational age, Ն34 weeks) undergoing diagnostic lumbar puncture. Intervention: Topical application of 1 g of EMLA or placebo 60 to 90 minutes before lumbar puncture. Main Outcome Measures: Heart rate, transcutaneous oxygen saturation level, and total behavioral score recorded on a video camera and graded according to the Neonatal Facial Coding System. Results: Compared with baseline, all newborns experienced pain as evidenced by increased heart rate, decreased oxygen saturation level, and total behavioral score (all within-groups differences were significant using repeated-measures analysis of variance; PϽ.001) during the procedure. Compared with placebo, EMLA significantly attenuated the pain response as shown by a lower mean±SE heart rate (per minute), particularly at needle insertion
Lung function values in healthy children (10–15 years)
The Indian Journal of Pediatrics, 1997
The present study was designed to establish norms for pulmonary functions in urban healthy childr... more The present study was designed to establish norms for pulmonary functions in urban healthy children of Delhi under the age group of 10-15 years. Pulmonary functions were assessed using an electronic lung function spirometer in 222 boys and 188 girls belonging to middle income group families of East Delhi. The pulmonary functions were separated by age and sex. All pulmonary functions showed an increase with advancing age. FEV1 and FVC were more in boys as compared to girls. Values of PEFR, FRC and TLC were similar in both sexes till the age of 13 years after which boys attained higher values. Prediction equations were obtained using height, age and weight as independent variables. Forward selection method was used to choose the best equation for each pulmonary function. Maximum variance in the lung functions was explained with the height. It is felt that norms established in the present study will act as reference standards for various lung functions in well nourished urban Delhi children under the age group of 10-15 years.
MEMS-based sensing and algorithm development for fall detection and gait analysis
SPIE Proceedings, 2010
Falls by the elderly are highly detrimental to health, frequently resulting in injury, high medic... more Falls by the elderly are highly detrimental to health, frequently resulting in injury, high medical costs, and even death. Using a MEMS-based sensing system, algorithms are being developed for detecting falls and monitoring the gait of elderly and disabled persons. In ...
Journal of Paediatrics and Child Health, 2005
Objective: To identify whether polymicrobial bacteremia in newborns is associated with any predis... more Objective: To identify whether polymicrobial bacteremia in newborns is associated with any predisposing factors, distinguishing clinical features, or higher mortality. Methods: Results of blood cultures obtained over a period of 1 year from neonates admitted to the paediatric ward and Neonatal Intensive Care Unit of a tertiary care hospital were retrospectively analysed. The study group included all cases with polymicrobial bacteremia (isolation of two or more organisms). Controls (double the number of study cases) were randomly selected from the monomicrobial group. Case records of included cases were retrieved and scrutinized. Results: Of 770 positive cultures during the study period, 52 (6.8%) cultures were positive for more than one organism. Complete case records were retrieved for 40 polymicrobial and 78 monomicrobial cases. The two groups were comparable for maternal and neonatal parameters including: maternal and obstetric complications; period of gestation; mode of delivery; birthweight and perinatal asphyxia; clinical symptomatology; invasive therapeutic interventions; and mortality. Conclusions: Isolation of more than one organism from the blood culture of a suspected septic newborn is not rare. It does not always represent a true invasion by multiple organisms. Polymicrobial isolation per se should not be the criterion for hastily changing the therapeutic decisions.
Indian Pediatrics, 2010
Wheezing in acute respiratory infections is a rule rather than exception. A large proportion of c... more Wheezing in acute respiratory infections is a rule rather than exception. A large proportion of children (up to 75%) having 'pneumonia' or 'severe pneumonia' as per WHO definitions have associated wheezing. The current strategies to diagnose and manage wheeze in the community need to be updated, as audible wheeze is present in only less than one-third of wheezy children, and can not be relied upon solely. A history of previous episodes of respiratory distress has a high sensitivity to diagnose wheezy disorders. In a significant proportion of children, the respiratory rate comes back to normal and the chest indrawing disappear after two to three cycles of inhaled bronchodilator medications. Operational research is needed to evaluate the feasibility of including management of wheezing in the community based ARI management programs.
Indian Pediatrics, 2010
T o rationalize the management of severely malnourished children, World Health Organization (WHO)... more T o rationalize the management of severely malnourished children, World Health Organization (WHO) proposed guidelines which state that a child with complications should be treated in hospital until the weight for length improves above 90%(1,2). However, this is seldom feasible because of bed shortage in hospitals and budgetary constraints. Prolonged hospital stay also carries the risk of nosocomial infections leading INDIAN PEDIATRICS 694 VOLUME 47 __
IEEE Transactions on Information Theory, 2010
We consider the question of determining the scaling of the n 2-dimensional balanced unicast and t... more We consider the question of determining the scaling of the n 2-dimensional balanced unicast and the n2 ndimensional balanced multicast capacity regions of a wireless network with n nodes placed uniformly at random in a square region of area n and communicating over Gaussian fading channels. We identify this scaling of both the balanced unicast and multicast capacity regions in terms of Θ(n), out of 2 n total possible, cuts. These cuts only depend on the geometry of the locations of the source nodes and their destination nodes and the traffic demands between them, and thus can be readily evaluated. Our results are constructive and provide optimal (in the scaling sense) communication schemes. We illustrate the strength of these results by computing the capacity scaling in a number of scenarios with non-uniform traffic patterns for which no such results have been available before.
IEEE Transactions on Information Theory, 2009
In recent work, Özgür, Lévêque, and Tse (2007) obtained a complete scaling characterization of th... more In recent work, Özgür, Lévêque, and Tse (2007) obtained a complete scaling characterization of throughput scaling for random extended wireless networks (i.e., n nodes are placed uniformly at random in a square region of area n). They showed that for small path-loss exponents 2 (2; 3], cooperative communication is order optimal, and for large path-loss exponents > 3, multihop communication is order optimal. However, their results (both the communication scheme and the proof technique) are strongly dependent on the regularity induced with high probability by the random node placement. In this paper, we consider the problem of characterizing the throughput scaling in extended wireless networks with arbitrary node placement. As a main result, we propose a more general novel cooperative communication scheme that works for arbitrarily placed nodes. For small path-loss exponents 2 (2; 3], we show that our scheme is order optimal for all node placements, and achieves exactly the same throughput scaling as in Özgür et al. This shows that the regularity of the node placement does not affect the scaling of the achievable rates for 2 (2; 3]. The situation is, however, markedly different for large path-loss exponents > 3. We show that in this regime the scaling of the achievable per-node rates depends crucially on the regularity of the node placement. We then present a family of schemes that smoothly "interpolate" between multihop and cooperative communication, depending upon the level of regularity in the node placement. We establish order optimality of these schemes under adversarial node placement for > 3.
IEEE Transactions on Biomedical Engineering, 2014
Activity recognition is required in various applica-4 tions such as medical monitoring and rehabi... more Activity recognition is required in various applica-4 tions such as medical monitoring and rehabilitation. Previously 5 developed activity recognition systems utilizing triaxial accelerom-6 eters have provided mixed results, with subject-to-subject variabil-7 ity. This paper presents an accurate activity recognition system 8 utilizing a body worn wireless accelerometer, to be used in the real-9 life application of patient monitoring. The algorithm utilizes data 10 from a single, waist-mounted triaxial accelerometer to classify gait 11 events into six daily living activities and transitional events. The 12 accelerometer can be worn at any location around the circumfer-13 ence of the waist, thereby reducing user training. Feature selection 14 is performed using Relief-F and sequential forward floating search 15 (SFFS) from a range of previously published features, as well as 16 new features, are introduced in this paper. Relevant and robust fea-17 tures that are insensitive to the positioning of accelerometer around 18 the waist are selected. SFFS selected almost half the number of fea-19 tures in comparison to Relief-F and provided higher accuracy than 20 Relief-F. Activity classification is performed using Naïve Bayes and 21 k-nearest neighbor (k-NN) and the results are compared. Activity 22 recognition results on seven subjects with leave-one-person-out er-23 ror estimates show an overall accuracy of about 98% for both the 24 classifiers. Accuracy for each of the individual activity is also more 25 than 95%.
European Journal of Paediatric Neurology, 2002
The objective of the study was to characterize the plantar response at various ages in infancy in... more The objective of the study was to characterize the plantar response at various ages in infancy in Indian children. The subjects were 1281 apparently healthy children born at term and without any history suggestive of neurological disease, enrolled between the ages of 1 and 12 months. The plantar response was elicited in both feet by thumbnail drag method and graded as flexor, extensor and equivocal. The percentage of extensor, flexor and equivocal responses was compared between right and left foot and the average of these two responses was compared between the age categories [1-3 months (n ¼ 389), 3.1-6 months (n ¼ 332), 6.1-9 months (n ¼ 354) and 9.1-12 months (n ¼ 206)]. Frequency (%) of various combinations of bilateral responses was also calculated for different age categories. Results showed that the extensor plantar response was the predominant response till 6 months of age. Bilateral extensor response was seen in 79.4%, 67.8%, 32.5% and 31.1% in the four age categories respectively; bilateral flexor response in the corresponding age groups was 0.3%, 5.1%, 26.6% and 39.3% respectively. The percentage of asymmetrical responses was 20.7%, 25.3%, 40.3%, and 28.7% in different age categories. We concluded that normal plantar response is predominantly extensor in early infancy; the transition to flexor response starts occurring after 6 months of age. A fairly high number of infants continue to have an extensor response even after 6 months; and the transition may be advanced in one foot leading to asymmetrical plantar response.
Archives of Pediatrics & Adolescent Medicine, 2003
To determine the efficacy of a topical anesthetic cream, eutectic mixture of local anesthetics (E... more To determine the efficacy of a topical anesthetic cream, eutectic mixture of local anesthetics (EMLA), in alleviating pain associated with lumbar puncture in newborns. Design: Randomized double-blind placebo-controlled trial. Setting: Neonatal intensive care unit of a university teaching hospital. Patients: Sixty consecutive newborns (gestational age, Ն34 weeks) undergoing diagnostic lumbar puncture. Intervention: Topical application of 1 g of EMLA or placebo 60 to 90 minutes before lumbar puncture. Main Outcome Measures: Heart rate, transcutaneous oxygen saturation level, and total behavioral score recorded on a video camera and graded according to the Neonatal Facial Coding System. Results: Compared with baseline, all newborns experienced pain as evidenced by increased heart rate, decreased oxygen saturation level, and total behavioral score (all within-groups differences were significant using repeated-measures analysis of variance; PϽ.001) during the procedure. Compared with placebo, EMLA significantly attenuated the pain response as shown by a lower mean±SE heart rate (per minute), particularly at needle insertion
Lung function values in healthy children (10–15 years)
The Indian Journal of Pediatrics, 1997
The present study was designed to establish norms for pulmonary functions in urban healthy childr... more The present study was designed to establish norms for pulmonary functions in urban healthy children of Delhi under the age group of 10-15 years. Pulmonary functions were assessed using an electronic lung function spirometer in 222 boys and 188 girls belonging to middle income group families of East Delhi. The pulmonary functions were separated by age and sex. All pulmonary functions showed an increase with advancing age. FEV1 and FVC were more in boys as compared to girls. Values of PEFR, FRC and TLC were similar in both sexes till the age of 13 years after which boys attained higher values. Prediction equations were obtained using height, age and weight as independent variables. Forward selection method was used to choose the best equation for each pulmonary function. Maximum variance in the lung functions was explained with the height. It is felt that norms established in the present study will act as reference standards for various lung functions in well nourished urban Delhi children under the age group of 10-15 years.