The control architecture consists of two units. The first one measures the electromyogram (EMG) signals on the wearer's muscles; these are the signals that command the muscles to contract and generate force, and are used by the robot to move in a similar way. The second unit tunes the motion of the device so that the robot moves smoothly together with the wearer. The first time the user wears the exoskeleton, the gait, which is different from person to person, is monitored, recorded and then stored. In future uses, HAL-5 then recognizes the movement and regenerates the adjusted pattern.
Robots in the operating theatre
While robots may not be performing the surgical operations, they are certainly finding their way into the operating rooms of our hospitals. Robotic surgery today is used as an assistance to the surgeon in expanding the surgeon's capabilities – the advantages are those of amazing precision and the ability to work on an incredibly miniaturised level. The most well known system is the da Vinci Surgical System, consisting of three components: a surgeon's console, a patient-side robotic cart with robotic arms and a high-definition 3D vision system. This sophisticated robotic platform has four arms, which are introduced into the body through small incisions. Here the first advantage shows up.Traditional surgery requires large cuts to plainly observe and manipulate the surgical field which in turn increases the risk of infections and also extends recovery times. On three of the arms the instruments are mounted and the fourth arm contains the high-definition 3D vision system.
The surgeon sits away from the patient on a console and sees a magnified, high-resolution 3D image of the surgical area with a real-time progression of the instruments as he operates. The patient and surgeon need not even be in the same room; in fact some thousands of kilometres can be between them. This has led to interest from the American army who have imagined a scenario where a doctor is sitting safely away in a remote location while also able to provide immediate medical care to an injured soldier. Unfortunately, the robot cannot currently be programmed to make its own decisions so the surgeon has to manipulate handles to control the device. These movements are scaled into micro-movements of the instruments and hand tremor is filtered out, while the third arm can be used for additional tasks.
While the device is being operated, several safety checks are performed and regions of the body can be selected where the robot cannot enter so as to protect vital parts; this includes preventing the surgeon from accidentally slipping. A wide range of instruments can be attached to the three arms, such as scissors, graspers, scalpels and other specialised instruments. The system's dexterity is modelled after the human wrist, but with a greater degree of movement, and the handles also provide force feedback from the instruments so the surgeon receives tactile sensation if he is cutting through soft tissue or hard bones. Using the robotic devices, surgeons can perform even the most complex and delicate procedures with unmatched precision. This robot is currently used globally, but the very high price tag prohibits its wide adoption at present.
Researchers are clearly developing very intriguing robots and all of the current medical robots have a direct focus on helping people perform actions. While most of the robots are still in the prototype stages, we are set to see a much larger collaboration of intimate robotic use for serving the needs of humans. As a consequence of such intimate use, safety is of course a primary concern. Regardless, it's clear that medical robotics is a rapidly emerging technology and that the robots we will soon see around us will be used to enhance human mobility, strength and precision.
