Visual display system of changes in physiological states for patients with chronic disorders and data transmission via optical wireless communication

Abstract

A visual display system of changes in the physiological state of patients and their data transmission via optical wireless communication is presented. Existing methods such as bedside monitors do not provide the possibility of visual display of information near the object in conditions of high workload of personnel and allow transmitting data via an electric cable or remotely in the radio frequency range. Such disadvantages reduce the responsiveness of personnel and lead to numerous errors in the transmitted data. A remote operational monitoring system is more effective, providing data collection from sensors, display with minimal delay time and data transmission over an interference-free communication channel in the optical range. A simple and visual way of displaying information allows to quickly and accurately recognize critical situations. The proposed system has two channels. The first channel provides a visual representation of changes in the physiological state on the visual display device in the form of a bracelet. The second channel allows transmitting data about the deviation in the patient’s condition via optical wireless communication in the infrared range of the spectrum for detailed display on a computer. The visual representation of changes in the physiological state is based on programmable change in the color of the LED indicators and on change in their operation modes. The block diagram and design of the visual display and data transmission system are presented. As part of the evaluation of the system operability, the heating of the visual display device in the COMSOL Multiphysics was evaluated. It is shown, that the average heating temperature of the indicator part in contact with human skin does not exceed 24 °C and is safe for the patient. The optical scheme of the receiving unit and the transmitting module is presented. The optical model of the module is presented in the Zemax program. It is shown, that the required average optical power of the working spectral region is 235 μW for the four infrared LEDs and four photodiodes located at a distance of 1 meter. A description of the working layout of a visual display and data transmission device is presented, including a digital pulse sensor and blood oxygen level, a color control and data processing unit, a visual display device, and a data transmission unit. The LEDs operation modes and its compliance with the deviation of the controlled parameters were checked by a special microcontroller program of practical significance. The implementation of the developed system is relevant when monitoring the condition of the object of observation in cases where the use of the radio frequency range is limited and the stability of the data transmission channel to electromagnetic interference plays an important role.

Keywords

• visual display system
• optical wireless communication