Fraunhofer Institute for Computer Architecture and Software Technology FIRST located in Berlin, Germany, has developed a prosthetic robot arm to provide more independence for paralyzed people. The arm’s movements can be intentionally directed through a Brain-Computer Interface (BCI), which is combined with an eye-tracker. The institute will present the robot arm at the Medica 2007, which takes place from November 14th to 17th, 2007, in Duesseldorf, Germany,
If an accident or serious illness causes irreversible paralysis in a patient, the news can be devastating. It oftentimes means a lifetime depends on the help of others. Depending on the degree of the paralysis, sometimes even the most mundane tasks cannot be performed anymore by the patient, resulting on complete reliance on others. The Brain2Robot prosthetic computer arm is a huge step towards providing these patients with a degree of independence that would otherwise be denied to them.
The eye-tracker is used to determine the direction of the arm movement. For this purpose the patient is wearing a specially designed pair of glasses with two cameras. These cameras monitor the patient’s gaze. To start the system, these cameras record the position of the patient’s pupils. A head-tracker determines how the patient’s head is positioned. The robot arm’s software combines and analyzes the data. If the patient moves the eyes to an object and looks at it, the intended direction for the movement of the robot arm is established. To have the robot arm grab the object, the patient has to imagine moving his or her arm.
The robot arm movement itself is initiated by a signal from the BCI. The BCI uses a traditional electroencephalogram (EEG). Thus, electrodes are attached to the patient’s head to measure the brain’s electrical signals, which are sent to the computer for analysis. Through this analysis the visualization of the arm movement by the patient is captured by detection of changes in the brain activity. Particular changes in neural impulses indicate certain visualized movements. An astonishing accomplishment considering there are millions of neural impulses. Based on the result of the analysis, the computer directs the robot arm movement.
Traditional BCI programs require the user to find out the brain signals recognized by the computer. In the case of the Fraunhofer FIRST robot arm, the computer does the learning. Therefore, a patient can learn to operate the computer within a short period of time, usually about thirty minutes.
The Brain2Robot is primarily designed as an aid in a medical environment, particularly to aid paralyzed patients. However, other application areas might be found like for example as a computer game control.