RSSI (received signal strength indicator) technique based hospital patient positioning method

Abstract

The invention relates to an RSSI (received signal strength indicator) technique based hospital patient positioning method. The method includes: firstly, adopting a theoretical logarithm- normal distribution model as a ranging model, arranging certain positioning nodes and an unknown node, measuring to obtain N (PL(di), di), using a least square method fitting curve to determine a path loss index eta and an environmental factor, and establishing relation between RSSI and the distance; secondly, selecting the three nodes nearest to the unknown node to form a positioning unit, determining coordinates of the unknown nodes with the three-point positioning method, determining corresponding center-of-gravity weight and distance weight, and combining center-of-gravity weight and distance weight of the positioning unit to obtain a final weight Wj; finally, performing positioning for M times circularly, subjecting M coordinates and corresponding weights thereof to weighted fusion, and calculating to obtain final coordinates of a tag. Compared with a common trilateration algorithm, the method has the advantages of high positioning accuracy, strong stability and the like and has important application value.

Description

technical field [0001] The invention relates to an RSSI node positioning method for hospital patient positioning. Background technique [0002] With the development of the economy, the improvement of people's living standards and the improvement of medical and health conditions, it is obvious that the hospital still monitors and treats patients in the traditional way, which obviously cannot meet people's requirements. At present, in some large and medium-sized hospitals at home and abroad, the monitoring of patients generally adopts a central monitoring system, and one or more central monitoring stations are connected to the bedside monitors of each bed. This kind of bedside monitors only monitor but not The function of positioning, once the patient is not in the ward, it is difficult to solve the accident. Therefore, the hospital will usher in a far-reaching information technology revolution. The hospital will become a patient-centered, diagnosis, examination, nursing and o...

AI Technical Summary

Problems solved by technology

TOA requires precise time synchronization between sensor nodes in wireless sensor network positioning, which has high requirements for hardware; TDOA technology has small ranging errors and high accuracy, but it has high requirements for hardware, cost and energy consumption. It is also high, which is a challenge for low-energy sensor network systems; AOA positioning needs to provide node orientation information, so additional hardware equipment is required, which increases hardware costs, and AOA ranging is easily affected by the external environment. Applicable to large-scale sensor networks; RSSI ranging is relatively simple, and there are many practical applications. The positioning mechanism is to know the strength of the transmitted signal of the transmitting node, and the receiving node calculates the transmission loss of the signal according to the received signal strength. Using theoretical models or experience The model converts the signal transmission loss into a distance, and then calculates the position coordinates of the nodes through the existing positioning algorithm. Since the sensor nodes themselves have wireless communication capabilities, the RSSI positioning technology has lower hardware requirements for the sensor nodes, but the propagation of wireless signals is easy. Affected by the environment, the positioning accuracy is relatively low

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