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Biomedical subjects

R S Patil

Publications and source records attributed to R S Patil.

At least 19 recordsLinked to original sources
PubMed2004

A statistical analysis of particulate data sets for Jawaharlal Nehru Port and surrounding harbour region in India.

The concentrations of total suspended particulate matter (TSP) and particulate matter less than 10 microns (PM10) were measured at various locations in a Jawaharlal Nehru port and surrounding harbour region. Meteorological data was also collected to establish the correlation with air pollutant concentration. The results are analysed from the standpoint of monthly and seasonal variations, annual trends as well as meteorological effects. The monthly mean concentration of TSP was in the range of 88.2 to 199.3 microg m(-3). The maximum and minimum-recorded value of PM10 was 135.8 and 20.3 microg m(-3), respectively. The annual average concentration of PM10 was 66.1 microg m(-3). There are clear associations between TSP and PM10 data set at all the measured three sites with a correlation coefficient of 0.89, 0.69 and 0.81, respectively. PM10 data appears to be a constant fraction of the TSP data throughout the year, indicating common influences of meteorology and sources. Particle size analysis showed PM10 to be 47% of the total TSP concentration, which is lower than reported for industrial area and traffic junctions in Mumbai. Anthropogenic sources contribute significantly to the PM10 fraction in an industrial region, while contributions from natural sources are more in a port and harbour area. Statistical analysis of air quality data shows that TSP is strongly correlated with wind speed but weakly correlated with temperature. There appears to be a simple inverse relationship between TSP and wind speed data, indicating the dilution and transport by winds.

Air Pollutants↗
PubMed2004

Size distribution of aerosols (PM10) and lead (Pb) near traffic intersections in Mumbai (India).

The size distribution of aerosols was measured near traffic intersections of Marol link road in air quality control region (AQCR1), which is a moderately industrial area and Dadar Khodad circle in AQCR2, which is a heavily commercial core of the Mumbai City. The reason behind selecting the two unidentical regions was to study the contribution from vehicles to the size separated PM10 and that of Pb. It is recognised that particulates in urban air are responsible for serious health effects. As very small particles are assumed to be important for the adverse health effects, the particle size distribution is thus an important factor that needs to be addressed whenever the particulates pollution is concerned. The size measurements were done with a cascade impactor of eight stages with a back-up filter. It effectively separates the particulate matter into nine-sizes ranging from 0.0-0.4 to 9.0-10.0 microm. Samples were analysed in nine-particle size fractions with special reference to a toxic metal - lead (Pb) by atomic absorption spectrophotometry (AAS). It was found that PM10 and Pb at both the intersections could easily be classified by the size distribution. The fractions of the PM10 and that of Pb showing a tendency of trimodal distributions with the first peak at coarse mode approximately 9.0-10.0 microm, second at approximately 5.8 microm and the third at coarse mode approximately1.1 microm. The significant percentage of Pb was found in the range below 2.5 microm at both the intersections. However, Pb in AQCR1 is found in the coarser range as well, which could probably be the influence of various industrial activities in the area. PM10 concentration values in the coarser range in AQCR2 are associated with the resuspension of dust particles and mechanical erosions.

Aerosols↗
PubMed2004

Modelling the size separated particulate matter (SSPM10) from vehicular exhaust at traffic intersections in Mumbai.

The study was carried out to predict the size separated particulate matter below 10 microm size (SSPM10) from vehicular exhausts at traffic intersections using modified general finite line source model (GFLSM). Two air quality control regions (AQCRs) were selected in Mumbai City for this study. One was industrial area (AQCR1) containing the busy intersection, i.e. Marol link road, with the heavy inflow of two-three wheelers. And, the other was commercial busy district area (AQCR2) containing the busy intersection, i.e. Dadar circle, with a heavy traffic flow especially cars. The model was applied at both the traffic intersections. The data were collected for modelling study for three winter months in 1995 using cascade impactor of nine size ranges. The prediction results revealed that modified GFLSM underpredicted the SSPM10 concentrations for all the size ranges. However, showed considerable correlation between observed and predicted values for the size range below 4.7 microm at both the intersections. The relative high concentrations observed in the coarser range of 10-4.7 microm are attributed to the resuspension of the roadside particulate matter. Hence, the amount of underprediction was more for this range, which was due to the characteristics of model that does not take into account the factor for resuspension of roadside particulate matter caused by traffic movements. The model was also applied to predict the total particulate matter for downwind distances from the road intersection. The statistical evaluation of model was done, which indicated that the model's performance was good for the finer range of particles (below 4.7 microm) with r-square values of 0.49 and 0.57 found at both the intersections in AQCR1 and AQCR2, respectively. However, it is not unusual that the model uncertainty is likely to exist due to data input errors and stochastic fluctuations irrespective of the models accurateness. The statistical distribution model was therefore identified using Kolmogorov-Smirnov test. At both the intersections, SSPM10 concentration data were found lognormally distributed.

Air Pollutants↗
PubMed2003

Exposure of infants to outdoor and indoor air pollution in low-income urban areas - a case study of Delhi.

Indoor air pollution is potentially a very serious environmental and public health problem in India. In poor communities, with the continuing trend in biofuel combustion coupled with deteriorating housing conditions, the problem will remain for some time to come. While to some extent the problem has been studied in rural areas, there is a dearth of reliable data and knowledge about the situation in urban slum areas. The microenvironmental model was used for assessing daily-integrated exposure of infants and women to respirable suspended particulates (RSP) in two slums of Delhi - one in an area of high outdoor pollution and the other in a less polluted area. The study confirmed that indoor concentrations of RSP during cooking in kerosene-using houses are lesser than that in wood-using houses. However, the exposure due to cooking was not significantly different across the two groups. This was because, perhaps due to socioeconomic reasons, kerosene-using women were found to cook for longer durations, cook inside more often, and that infants in such houses stayed in the kitchen for longer durations. It was observed that indoor background levels during the day and at nighttime can be exceedingly high. We speculate that this may have been due to resuspension of dust, infiltration, unknown sources, or a combination of these factors. The outdoor RSP levels measured just outside the houses (near ambient) were not correlated with indoor background levels and were higher than those reported by the ambient air quality monitoring network at the corresponding stations. More importantly, the outdoor levels measured in this study not only underestimated the daily-integrated exposure, but were also poorly correlated with it.

Adult↗
PubMed2003

Cluster analysis of Delhi's ambient air quality data.

The purpose of this study was to study the spatial patterns of ambient air quality in Delhi in the absence of extensive datasets needed for space-time modeling. A spatial classification was attempted on the basis of ambient air quality data of nine years (1998 is latest year for which published data were available) for three criteria pollutants--nitrogen dioxide, sulfur dioxide, and suspended particulate matter. Monitoring stations take 24-hour samples twice a week. Published monthly average concentration data were used in this study. A hierarchical agglomerative algorithm using the average linkage between groups method and the Euclidean distance metric was used. Cluster analysis indicated that till 1998, by and large, two distinct classes existed. The results of cluster analysis prompted an investigation of systematic biases in the monitored data. No statistically significant differences in the mean concentration of all pollutants were observed between stations belonging to different land-use types (residential and industrial). This fact would be useful, if and when the authorities consider modifying the network or expanding it in Delhi. The results also support the recommendation that Delhi have a uniform standard across all areas. This study has provided a methodology for Indian researchers and practitioners to do an exploratory study of spatial patterns of air pollution and data quality issues in Indian cities using the National Ambient Air Quality Monitoring System data.

Air Pollutants↗
PubMed2002

Emissions of gaseous and particulate pollutants in a port and harbour region in India.

Ports can generate large quantity of pollutants in the atmosphere due to various activities like loading and unloading, transportation, and construction operations. Determination of the character and quantity of emissions from individual sources is an essential step in any project to control and minimize the emissions. In this study a detailed emission inventory of total suspended particulate matter (TSP), particulate matter less than 10 microm (PM10), sulfur dioxide (SO2) and nitrogen oxides (NOx) for a port and harbour project near Mumbai is compiled. Results show that the total annual average contributions of TSP and PM10 from all the port activities were 872 and 221 t yr(-1), respectively. Annual average emissions of gaseous pollutants SO2 and NOx were 56 and 397 t yr(-1), respectively, calculated by using emission factors for different port activities. The maximum TSP emission (419 t yr(-1)) was from paved roads, while the least (0.4 t yr(-1)) was from bulk handling activity. The maximum PM10 emission (123 t yr(-1)) was from unpaved roads and minimum (0.2 t yr(-1)) from bulk handling operations. Similarly the ratio of TSP and PM10 emission was highest (5.18) from paved roads and least (2.17) from bulk handling operations. Regression relation was derived from existing emission data of TSP and PM10 from various port activities. Good correlation was observed between TSP and PM10 having regression coefficient >0.8.

Air Pollutants↗
PubMed2001

Monitoring of atmospheric behaviour of NOx from vehicular traffic.

In recent years the concern about the behaviour of oxides of nitrogen (NOx: NO, NO2) in atmosphere has increased considerably. NOx undergoes various complex atmospheric reactions to generate secondary pollutants which are known to cause severe adverse effects on human health. This work focuses on the study of physical and chemical fate of NOx released in the atmosphere from vehicles, which are the main sources of atmospheric NOx. Keeping the objective and standard guidelines for monitoring in view, two typical sites near the road with high vehicular density were chosen for the study. One site was a relatively cleaner area with only vehicles as major source of pollution, and the second site was a traffic junction in an industrial region, where pollution levels are amongst the highest in Mumbai. Ambient monitoring of NOx was done for 24 hr continuously using chemiluminescent NOx analyser. The data was used to analyse temporal and spatial variation of NO, NO2 and NOx and their atmospheric chemical reactions. The monitoring results show that at larger distance from the road the level of NO decreases but the concentration of NO2 which is very harmful remains the same. Statistical analysis is conducted to establish the relationship between likely change in NO2 concentration as a result of NOx emission changes.

Air Pollutants↗
PubMed1998

Antispermatogenic and androgenic activities of Momordica charantia (Karela) in albino rats.

Petroleum ether, benzene and alcohol extracts of the seeds of Momordica charantia tested in rats at the dose level of 25 mg/100 g body weight for 35 days showed antispermatogenic activity as the number of spermatocytes, spermatids and spermatozoa was decreased. Increase in cholesterol level and Sudanophilic lipid accumulation indicates inhibition in the steroidogenesis. At the same time the weight of epididymis, prostate gland, seminal vesicle and levator ani was increased which showed its androgenic property. Out of the three extracts, the alcohol extract was more potent in its antispermatogenic, antisteroidogenic and androgenic activities.

Alkanes↗
PubMed1998

Multicenter study of noninvasive monitoring systems as alternatives to invasive monitoring of acutely ill emergency patients.

BACKGROUND: Recent reports showed lack of effectiveness of pulmonary artery catheterization in critically ill medical patients and relatively late-stage surgical patients with organ failure. Since invasive monitoring requires critical care environments, the early hemodynamic patterns may have been missed. Ideally, early noninvasive hemodynamic monitoring systems, if reliable, could be used as the "front end" of invasive monitoring to supply more complete descriptions of circulatory pathophysiology. OBJECTIVES: To evaluate the accuracy and reliability of noninvasive hemodynamic monitoring consisting of a new bioimpedance method for estimating cardiac output combined with arterial BP, pulse oximetry, and transcutaneous PO2 and PCO2; we compared this system of noninvasive monitoring with simultaneous invasive measurements to evaluate circulatory deficiencies in acutely ill patients shortly after hospital admission where invasive monitoring was not readily available. We also preliminarily explored early differences in temporal hemodynamic patterns of survivors and nonsurvivors. DESIGN AND SETTING: Prospective comparison of simultaneous invasive and noninvasive measurements of circulatory function with retrospective analysis of data in university-run county hospitals, university hospitals and affiliated teaching hospitals, and a community private hospital. PATIENTS: We studied 680 patients, including 139 severely injured or hemorrhaging patients in the emergency department (ED), 129 medical (nontrauma) patients on admission to the ED, 274 high-risk surgical patients intraoperatively, and 138 patients recently admitted to the ICU. RESULTS: A new noninvasive impedance device provided cardiac output estimations under conditions in which invasive thermodilution measurements were not usually applied. There were 2,192 simultaneous bioimpedance and thermodilution cardiac index measurements; the correlation coefficient, r = 0.85, r2 = 0.73, p < 0.001. The precision and bias was -0.124+/-0.75 L/min/m2. Both invasive and noninvasive monitoring systems provide similar information and identified episodes of hypotension, low cardiac index, arterial hemoglobin desaturation, low transcutaneous O2, high transcutaneous CO2, and low oxygen consumption before and during initial resuscitation. The limitations of noninvasive systems were described. CONCLUSIONS: Noninvasive monitoring systems gave continuous displays of physiologic data that provided information allowing early recognition of low flow and poor tissue perfusion that were more pronounced in the nonsurvivors. Noninvasive systems may be acceptable alternatives where invasive monitoring is not available.

Adult↗
PubMed1996

Noninvasive physiologic monitoring of high-risk surgical patients.

OBJECTIVES: To study the feasibility of multicomponent noninvasive monitoring, consisting of a new bioimpedance method for estimating cardiac output together with routine pulse oximetry and transcutaneous oximetry, and to compare physiologic data obtained noninvasively with hemodynamic and oxygen transport data obtained by standard invasive pulmonary artery thermodilution catheter to evaluate circulatory function in high-risk surgical patients. DESIGN: Prospective descriptive analysis of the time course of physiologic patterns in surgical patients. SETTING: University-run county hospital. PATIENTS: Seventy-one consecutively monitored, high-risk critically ill surgical patients in their perioperative period. OUTCOME MEASURES: Simultaneous measurements by invasive and noninvasive methods to describe and compare the temporal physiologic patterns of survivors and nonsurvivors. RESULTS: The new impedance cardiac output estimations closely approximated those of the thermodilution method (r = 0.82, P < .001). Episodes of hypotension, tachycardia, low cardiac index, arterial hemoglobin desaturation, low transcutaneous oximetry, reduced oxygen delivery, and low oxygen consumption occurred with both groups but were more pronounced in the nonsurvivors than in the survivors. Noninvasive monitoring provided information similar to that of the thermodilution method. Both approaches indicated low flow and poor tissue perfusion (oxygenation) that was worse in the nonsurvivors. CONCLUSIONS: The multicomponent noninvasive monitoring provides continuous online, real-time displays of physiologic data that allow immediate recognition of circulatory dysfunction as well as the means to titrate therapy to appropriate predetermined therapeutic goals. The noninvasive systems are easy to apply, safe, inexpensive, reasonably accurate, and cost-effective.

Adult↗
PubMed1996

Noninvasive hemodynamic monitoring of critical patients in the emergency department.

OBJECTIVE: To evaluate the feasibility of multicomponent noninvasive hemodynamic monitoring in critical emergency patients and to compare this technique with simultaneous invasive monitoring by the pulmonary artery thermodilution catheter. METHODS: A prospective observational study was done comparing invasive monitoring and noninvasive monitoring in 60 critically ill or injured patients who required hemodynamic monitoring shortly after entering the ED of a university-affiliated country hospital. Cardiac output (CO) values measured by the standard thermo-dilution pulmonary artery catheter technique were compared with simultaneously obtained measurements using a noninvasive bioimpedance method. Concurrent measurements were made of pulse oximetry to screen pulmonary function and transcutaneous oximetry to assess tissue perfusion. RESULTS: The impedance CO values closely approximated those for the thermodilution method; r 0.81, p < 0.001. Significant circulatory abnormalities, including hypotension, reduced cardiac index, arterial hemoglobin desaturation, tissue hypoxia, reduced O2 delivery, and consumption, were found in 54 of the 60 (90%) patients. The cardiac index decreased in 44% of the patients, the transcutaneous O2 decreased in 39%, and the O2 saturation by pulse oximetry fell in 22% during the observation period in the ED (commonly lasting 2-8 hours). CONCLUSIONS: Noninvasive monitoring can provide hemodynamic and perfusion information previously available only by invasive thermodilution catheters. Such noninvasive monitoring can display continuous on-line real-time data, allowing immediate recognition of circulatory abnormalities and providing a means to titrate therapy to appropriate therapeutic goals.

Adult↗
PubMed1996

Early physiologic patterns in acute illness and accidents: toward a concept of circulatory dysfunction and shock based on invasive and noninvasive hemodynamic monitoring.

The aim of the present study was to explore methods, concepts, and techniques that provide recognition of circulatory deficiencies at the earliest possible time in the patient's illness. We used both the standard invasive pulmonary artery thermodilution catheter and noninvasive hemodynamic monitoring systems consisting of a new bioimpedance cardiac output device, pulse oximetry, transcutaneous oxygen (PtCO2) and carbon dioxide tensions as well as the transcutaneous oxygen tension/fraction of inspired oxygen ratio (PtCO2/FIO2). These three noninvasive systems were used to evaluate cardiac function, pulmonary function, and tissue perfusion, respectively. This approach to early noninvasive monitoring is based on recent evidence suggesting that poor tissue perfusion and oxygenation initiate circulatory dysfunction that leads to shock and organ failure. We studied 303 acute episodes of circulatory dysfunction and shock in 261 patients in a university-run county hospital; 75 were acute traumatic injuries and 109 acute nontrauma medical emergencies on admission to the emergency department, and 77 ICU patients with an acute illness or exacerbation of their current illness. The study was a prospective, descriptive study to identify early abnormal circulatory patterns reflecting the cardiac, pulmonary, and perfusion functions associated with death and with survival. We described noninvasively monitored patterns in individual illustrative cases, in common etiologic groups, and in physiologic categories representing various abnormal functional patterns. We found that hypotensive shock usually was preceded by episodes of high flow followed by low flow and inadequate tissue perfusion indicated by reduced PtCO2; this frequent pattern was modified by associated co-morbid conditions, especially hypovolemia, limited cardiac reserve capacity, age, hypertensive states, and increased body metabolism from infection, trauma, stress, exercise, temperature, and endocrine disorders. Reduced pulmonary function occurred in 18% of emergency patients; these were usually patients with thoracic trauma, severe hypovolemia, head injuries, chronic obstructive pulmonary disease, asthma, drug overdose, and central nervous system failure (massive stroke and coma). We concluded that noninvasive measurements identify early circulatory problems reliably and provide objective criteria for physiologic analysis as well as for definition of therapeutic goals and titration of therapy.

Adult↗
PubMed1996

Application of an artificial intelligence program to therapy of high-risk surgical patients.

We developed an artificial intelligence program from a large computerized database of hemodynamic and oxygen transport measurements together with prior studies defining survivors' values, outcome predictors, and a branched-chain decision tree. The artificial intelligence program was then tested on the data of 100 survivors and 100 nonsurvivors not used for the development of the program or other analyses. Using the predictor as a surrogate outcome measure, the therapy recommended by the program improved the predicted outcome 3.16% per therapeutic intervention while the actual therapy given increased outcome 1.86% in surviving patients; the artificial intelligence-recommended therapy improved outcome 7.9% in nonsurvivors, while the actual therapy given increased predicted outcome -0.29% in nonsurvivors (p < .05). There were fewer patients whose predicted outcome decreased after recommended treatment (14%) than after the actual therapy given (37%). Review of therapy recommended by the program did not reveal instances of inappropriate or potentially harmful recommendations.

Artificial Intelligence↗
PubMed1994

An architecture for a health care provider's workstation.

This paper presents an architecture for a health care provider's workstation designed to assist health care providers in performing their daily activities. The design is based on the concept of a clinician's associate which acts as an intelligent intermediary between the provider and a diverse collection of clinical, administrative, and educational information sources. The architecture is designed to be hardware platform independent, to work across different I/O capabilities, and to be open, allowing specialized applications to be easily integrated with the system and their functionality delivered through a common user environment.

Computer Communication Networks↗
PubMed1994

Multicenter trial of a new thoracic electrical bioimpedance device for cardiac output estimation.

OBJECTIVE: To evaluate the capacity of a new thoracic electric bioimpedance system to estimate cardiac output compared with the conventional thermodilution method. DESIGN: Prospective, multicenter study. SETTING: A university-run county hospital, a university-run U.S. Veterans Affairs hospital, and a university-affiliated U.S. military hospital. PATIENTS: A series of 68 critically ill patients whose conditions required pulmonary artery catheter insertion. MEASUREMENTS AND MAIN RESULTS: A total of 842 simultaneous pairs of cardiac output estimations by conventional thermodilution and a new thoracic electric bioimpedance system that uses an improved signal processing technique based on an all-integer-coefficient filtering technology, using a time-frequency distribution that provides a high signal/noise ratio were evaluated. The r value was .86, r2 = .74, and p < .001 by regression analysis; the mean difference between the two methods relative to their average value was 16.6 +/- 12.9 (SD) %; the precision was 1.4 L/min or 0.8 L/min/m2; the bias was -0.013 L/min. The mean difference between successive pairs of thermodilution measurements was 8.6 +/- 0.6 (SD) %, which was about half the difference between simultaneous pairs of measurement by the two methods. The changes in impedance estimations were close to simultaneously measured changes in thermodilution estimates of cardiac output. CONCLUSIONS: The new bioimpedance system satisfactorily estimated cardiac output as measured by the thermodilution technique. The difference between the two estimations is more than made up for by the continuous noninvasive capability of the impedance system.

Adult↗
PubMed1988

Artificial intelligence in medical diagnosis.

In an attempt to overcome limitations inherent in conventional computer-aided diagnosis, investigators have created programs that simulate expert human reasoning. Hopes that such a strategy would lead to clinically useful programs have not been fulfilled, but many of the problems impeding creation of effective artificial intelligence programs have been solved. Strategies have been developed to limit the number of hypotheses that a program must consider and to incorporate pathophysiologic reasoning. The latter innovation permits a program to analyze cases in which one disorder influences the presentation of another. Prototypes embodying such reasoning can explain their conclusions in medical terms that can be reviewed by the user. Despite these advances, further major research and developmental efforts will be necessary before expert performance by the computer becomes a reality.

Artificial Intelligence↗