Study Of The Detecting Module For Three-wavelength Oxygen Saturation Based On Zigbee

Blood oxygen saturation is the percentage of oxygen in the blood, is an important indicator whether is normal about the supply of the body. As photoelectric detection technology can be a noninvasive, continuous real-time monitoring of human arterial oxygen saturation, it is widely used in surgery, anesthesia and intensive care and so on. At present, the dual wavelength pulse oxygen saturation monitor can be more applyed in clinic, it must have relatively quiet environment, but also the precision is higher when the oxygen saturation is high, and to the low oxygen saturation, the accuracy is not high enough. To more accurately measure the oxygen saturation of low oxygen fetus, infants, and intensive care patients, we learn how to select ideal optical wavelength of low oxygen saturation from the foreign researchers. When the change of two-photon path length caused by the disturbance of blood and tissue is same and the average penetration depth of two wavelengths has a good match, can reduce the impact of the heterogeneous components in organization, so the accuracy is high and steady. While if the wavelength of light used in excess, can cause equipment bulky, complex, too expensive, and easily damaged. This article uses three-way that is different wavelength 595nm, 735nm and 890nm to compensate for the shortcomings of conventional oximeter.In addition, the devices with wires, ambulatory care, bring a great deal of inconvenience to patients, are increasingly unable to meet modern diverse, information technology and personalized medical care needs. Given the situation described above, this paper introduces Zigbee communication technology, it is a new short-range, low-rate wireless communication technologies, mainly for short-range wireless connections, is ideal for the field of health and medical testing.This article chooses Chipcon's CC2430 as the control core of data acquisition, preprocessing, and wireless transmission of physiological parameters. CC2430 single chip integrated ZigBee radio frequency (RF) front, memory and microcontroller, systems include the hardware design of oxygen probes, microprocessors, peripheral circuits, signal conditioning circuit and the software design of Zigbee communication, signal collection and processing. At the same time, we use Visual C++as a development platform, Access 2003 database as a back support to achieve real-time display of physiological parameters.Also, in order to achieve the small design, some traditional hardware filter circuit have been replaced with software processing, using a simple low-pass filter on the whole coefficient to pretreat pulse wave; using differential threshold method to dedect the characteristic points of pulse wave; wavelet multi-resolution to reduces baseline drift and high frequency noise, through simulation and calculation, it desires the demand of objectives.