The purpose of this study was to validate a single bioelectrical impedance analysis (BIA) equation in healthy Indian subjects aged 22-59 years with a body mass index (BMI) between 16.8 and 47.3 kg m⁻². Healthy subjects (34 men and 30 women) were measured by two methods: bone mineral content (BMC) was measured by a commercial body composition analyser and bioelectrical impedance at various frequencies was measured by a newly developed bioelectrical impedance measurement system. As correlations were high and prediction error was low, a single equation was developed using all subjects as follows: BMC = -3.5268 + (0.0279  x  h) + (0.0145  x  w) + (184  x  (h²/Z(body50)))-(1.08  x  (w x  h²/Z(body6.25)))-(0.0032  x  (age))-(0.103  x  (sex); men = 1, women = 0). BMC measured from commercial instrument InBody720 was 2.552 ± 0.457 kg. BMC predicted by equation was 2.554 ± 0.447 kg (R = 0.976, adjusted R² = 0.948, standard error of estimate = 0.104 kg, total error = 0.09987 kg). The results of this study show that the newly developed multi-frequency bioelectrical impedance measurement system with the single prediction BIA equation can be used in screening the subjects suspected with osteoporosis and for follow-up study of the patient under the therapy for osteoporosis. For validation of commercial instrument InBody720, BMC of 22 healthy subjects was measured by InBody720 and dual-energy X-ray absorptiometry. High correlation (R = 0.9531) and low error (total error = 0.0913 kg) was found between these two methods.

No abstract

Measuring oxygen saturation of blood (SpO2) clinically plays a vital role in patient’s health monitoring. In fact, monitoring oxygen level is necessary for people having respiratory problems (pulmonary hypertension) and in other critical conditions. The primary motivation of this work is to develop a low cost computer-based oxygen saturation monitoring system using an embedded system along with lab windows CVI platform. The process of calculating the level of oxygen saturation in the blood using non-invasive method is also called as pulse oximetry, which consists of LED and photo detectors, using MSP430FG4618 microcontroller. The MSP430 employed in designing the microcontroller firmware program for digitization and transmission of the data from sensor to the computer. NI-based Lab windows/CVI Platform was developed as a part of this project to receive, plot, save data and determine the accuracy of SpO2 value. In this proposed system, we have achieved the maximum accuracy of 99.49% which is better than the previously developed methods. The proposed system is also designed with the low cost and low power consuming modules.

Photoplethysmography (PPG), introduced in 1937, is routinely used for monitoring heart rate, blood perfusion and oxygen saturation of the blood in the intensive care units for the past several decades. It is also being used for the assessment of peripheral blood flow and venous filling time in noninvasive vascular laboratories. It works on the principle of light/infrared absorption in the body segment and detection and processing of transmitted light/infrared radiation.In the past few decades, there has been more emphasis on the pulse morphology. Analysis of higher harmonic components and derivation of cardiovascular indices have emerged as powerful tools for the assessment of arterial aging, endothelial function, and vascular compliance. The ease of operating and extreme low cost of PPG system has made it ideal for objective assessment of autonomic nervous system (ANS). This technique is presently being explored for the personal monitoring of blood glucose noninvasively.

No abstract