Submit Manuscript | http://medcraveonline.com Abbreviations: BMI, brain machine interface; SI, somatosensory cortices; MFB, medial forebrain Bundle Introduction Robots have been applied to the tasks which are not appropriate for human; for examples dangerous, tough, dirty tasks or the tasks which require high accuracy, good repeatability, quick motion. Nowadays, rescue robots are applied to explore unknown areas or even to rescue victims after disasters because of their several superior performances over human. Due to fexibility and intelligent limitation of robots, they cannot be applied effciently in complicated situations; such as search and rescue of survivals in collapsed structures after big disasters. Hence, the concept of animal robot was proposed by scientists and researchers to overcome limitations of the traditional robots. Recently, results of the researches on robo-animals which are controlled by stimulating of certain brain sites are successful. Shimoyama et al., 1 from the University of Tokyo developed a remote-control cockroach. 1 Research on Robo-rat was accomplished by Talwar et al., 3 from New York University. 2,3 Hirotaka et al., 4 could control the wings and related behaviors of beetles by implanting electrical electrodes on the beetles’ brains and muscles. 4 It is widely known that brain machine interface (BMI) has a variety of advantages. There are large number of BMI applications; such as in medical services and in neuroscience researches. Basically, electrodes are used for electrical stimulating by connecting cables between the stimulators and the electrodes that are implanted to animal brain. The tethered stimulation does not only restrict the freedom of animal movement but also distract its attention. In order to solve the problem, tele-stimulation systems was employed to transmit stimulation signal via wireless communication. 3 The tele- stimulation system should be small and light to avoid distraction of animal movement. In this paper, the brain computer interface on Robo-rat is proposed. Methodology Rat surgery A male Sprague-Dawley rat with the weight of 400-500 grams is operated to implant electrodes into three locations of its brains; one electrode at Medial Forebrain Bundle (MFB), two electrodes at left and right Somatosensory cortices (SI). The rat skull at the marked points of MFB and Si are tenderly punctured using handheld screwdriver. In addition, extra holes are punctured for attaching tiny screw poles to support plug body of the three implanted electrodes with dental fller material. After the dental fller material has dried up, the skull with the implanted electrodes are covered up with a suture. The rat with the implanted electrodes is healed up to full health in two weeks after the operation. The rat is then introduced to some exercise programs in order to build up its muscles for walking. Electrical circuit Photo and block diagram of the backpack circuit of Robo-rat is shown in Figure 1. The main circuit consists of two parts. The frst part is a miniature X-Bee receiver. The receiver is used to receive the stimulation commands from X-Bee transmitter. The second part is a microcontroller module used to receive and translate commands from the X-Bee receiver and generate square-wave signal to stimulate the rat brain at the implanted electrode areas. A miniature X-Bee transmitter Int J Biosen Bioelectron. 2018;4(3):104‒108. 104 © 2018 Naijit et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Brain-computer-interface based automatic control of robo-rat using a-star Volume 4 Issue 3 - 2018 Anantachai Naijit, 1 Manukid Parnichkun, 1 Chailerd Pichitpornchai 2 1 Asian Institute of Technology, Thailand 2 Department of Physiology, Mahidol University, Thailand Correspondence: Manukid Parnichkun, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand, Email manukid@ait.asia Received: March 23, 2018 | Published: May 25 2018 Abstract Robots have been applied to the tasks which are not appropriate for human; for examples dangerous, tough, dirty tasks or the tasks which require high accuracy, good repeatability, quick motion. Nowadays, rescue robots are applied to explore unknown areas or even to rescue victims after disasters because of their several superior performances over human. An operator controls every single motion of the rescue robot remotely using information from onboard sensors and cameras. However, in an extreme situation after disaster where the area is messy with many broken objects and obstacles, area exploration and victim rescue are very diffcult and time consuming. This situation requires a rescuer who at least can make simple decision and execute the actions. Robo-rat fts very well with this situation. Robo-rat is a rat whose brain is implanted by electrodes and trained to follow commands in the form of brain stimulation using electrical square-wave signals. Three commands are trained to Robo-rat; go straight, turn left and turn right. The electrode at Medial Forebrain Bundle (MFB) is stimulated for go straight command. The electrode at left Somatosensory Cortex is stimulated for turn left command. The electrode at right Somatosensory Cortex is stimulated for turn right command. After manual control of Robo-rat, automatic control is implemented using A-star optimization technique. A camera takes the top view image of the maze. Image processing is conducted to identify Robo-rat position. Based on the map of the maze and the current position, A-star is used to determine the shortest path to the goal position. A PC determines and stimulates electrical pulses at the proper electrodes automatically. The experimental results reveal the feasibility of using Robo-rat for rescue purpose. Keywords: robo-rat, brain machine interface, a-star International Journal of Biosensors & Bioelectronics Research Article Open Access