Abstract—In this paper, we report the development of the device for diagnostics of cardiovascular system state and associated automated workstation for large-scale medical measurement data collection and analysis. It was shown that optimal design for the monitoring device is wristband as it represents engineering trade-off between accuracy and usability. Monitoring device is based on the infrared reflective photoplethysmographic sensor, which allows collecting multiple physiological parameters, such as heart rate and pulsing wave characteristics. Developed device uses BLE interface for medical and supplementary data transmission to the coupled mobile phone, which processes it and send it to the doctor's automated workstation. Results of this experimental model approbation confirmed the applicability of the proposed approach. Keywords—Cardiovascular diseases, health monitoring systems, photoplethysmography, pulse wave, remote diagnostics. I. INTRODUCTION HE rapid development of biological sciences and technologies makes health care system more streamlined and efficient. There is a steady trend to shift from the conventional clinic-based diagnosis to adoption of various individual health monitoring systems [1]. This trend will likely increase over time due to global population aging. Consequently, broad-scale utilization of affordable and easy to use remote medical testing and electronics diagnosis solutions will decrease load of the public health system and promote the popularity of the periodic health self-checks. Portable device for individual ambulatory monitoring can be used to provide timely support for patients with cardiovascular disease, which is the most common chronic disease among the population. At present time, the standard procedure for the cardiovascular disease diagnosis is electrocardiography. Regular electrocardiogram acquisition is relatively laborious process and cannot be used for long-term monitoring without significant interference with everyday life. According to the recent research results, photoplethysmography (PPG) technology is a promising approach for individual cardiovascular monitoring systems design [2], [3]. The main advantages of PPG over electrocardiography are single sensor scheme and the lack of the necessity of electrodes with gel. PPG is a noninvasive S. Botman, D. Borchevkin and V. Petrov are with the Institute of Physics and Technology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia (e-mail: stepan.botman@gmail.com, dmitriyladaniy@mail.ru, vitaliypetrov@mail.ru). E. Bogdanov, M. Patrushev and N. Shusharina are with the Institute of Chemistry and Biology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia (e-mail: eubogdanov@gmail.com, maxpatrushev@gmail.com, nnshusharina@gmail.com). optical technology that detects changes in blood volume in the blood vessels and allows estimating state of cardiac function by measuring the heart rate variability. Generally, PPG-based medical devices for long-term monitoring are easy to place and allow monitoring of multiple physiological parameters, such as heart rate, pulse wave characteristics, blood oxygen level, etc. II. RESULTS AND DISCUSSION The main goal of this work was to create a system which makes cardiovascular state monitoring process more efficient and comfortable for both patient and physician. For this purpose we designed PPG-based portable monitoring device and doctor's automated workstation. Fig. 1 shows a general operation concept of designed system. Portable monitoring device collect data concerning cardiovascular state (heart rate, pulse wave parameters) and supplementary data (temperature, movements). Collected data is transmitted via BLE to the coupled mobile phone, which reduces it and sends to the doctor's automated workstation. Essentially, workstation is hardware independent piece of software, which can be cloud or local hosted. It provides archival storage of medical data for all patients, statistical tools for data analysis and cardiovascular disease prediction and web interface for physician. PPG is cardiac parameters estimation technique based on the intensity measurements of light which passes through the biological tissues. Light source wavelength is chosen in such a way that blood absorbs more infrared light than surrounding tissues. Thus, decrease of blood volume is detected as an increase in intensity of the detected light and vice versa. The highest possible blood volume changes occur in arteries and arterioles. Fig. 2 shows a schematic representation of PPG signal origin. Signal consists of a constant component and variable component. Constant component is defined by the tissues structure, average volume of the arterial and venous blood and varies slowly with the breath. Variable component indicates the blood volume changes between the systolic and diastolic phases of the cardiac cycle. Basic frequency of variable component depends on heart rate. The peak of the pulse wave corresponds to the maximum blood volume, and the bottom corresponds to the smallest blood volume in the examined tissue site. The pulse waveform is dependent on the vascular walls elasticity, the pulse rate, the width of the vessel flow area. It is commonly supposed that the frequency, shape and duration of the pulse wave is dependent on the heart properties, and therefore the state of the cardiovascular system Photoplethysmography-Based Device Designing for Cardiovascular System Diagnostics S. Botman, D. Borchevkin, V. Petrov, E. Bogdanov, M. Patrushev, N. Shusharina T World Academy of Science, Engineering and Technology International Journal of Biomedical and Biological Engineering Vol:9, No:9, 2015 689 International Scholarly and Scientific Research & Innovation 9(9) 2015 scholar.waset.org/1307-6892/10002239 International Science Index, Biomedical and Biological Engineering Vol:9, No:9, 2015 waset.org/Publication/10002239