Design and implementation of a continuous wave near infrared spectroscopy system for bedside and home monitoring

Near infrared spectroscopy (NIRS) technology is widely used in non-invasive biomedical monitoring and has a significant importance in neurophysiopathology research. This paper shows the design and development of a multichannel, continuous wave near infrared spectroscopy system. The main characteristics of this system are that it is small, multi-channel, reconfigurable, portable, low cost and can be applied to cerebral monitoring. This system consists of a NIR optode, a signal conditioning and control unit and a graphical user interface (GUI). NIR signals are acquired real-time and transferred via USB (Universal Serial Bus) to a laptop, post-processed and visualized with an embedded stand-alone Matlab GUI. The USB connection also powers the system, without the need for external power sources. This new system, called NIR§HARD is designed to be fully integrated with a processing system (called NIR§SOFT) which we previously developed and it can perform time, frequency, and time-frequency analyses