Special Issue on Biomechatronics
We are now entering the 21st century. With the aging society having a life expectancy of 80, various problems have emerged. If we can live until 80 without any physical trouble, we will be the happiest. Who take care of the elderly? The children or a spouse? The answer is neither. Everyone will have to be responsible for himself or herself. However, this will be impossible if their physical problems are involved. Then who ? Robots will do the job. It is necessary to develop warmhearted robots that are similar to grandchildren or other loved ones. At present, robots play a significant and remarkable role in the human society. They are roughly classified into two types: one based on a longing for creatures with a good ability that we do not have, such as a giant force or ability of flying in the air or diving underwater or under ground, and the other based on a desire that we want to own an artificial creature, such as a servant performing undersirable tasks for us or accepting all of our orders. The former should be called a tool such as a construction machine, airplane, or submarine rather than a robot. This is derived from the concept that an ability not owned by us is implemented or supplemented through a machine and is added to us, not the concept of “instead of us.” The latter is derived from the concept that makes machines replace what we have done, and its typical examples include industrial or robots working under extreme conditions. No matter how much robots have progressed, human intervention is always required because human hands have an ability that cannot be implemented in current robots. This ability is the flexibility of human hands that can undertake anything to some extent even with less precision. If it cannot be realized, a robot such as a servant will be unable to be implemented. It is no exaggeration to say that this implementation is the final goal of robotics. To analyze a human arm (hand), the following methods are available: direct measuring method using sensors or other devices mounted on the arm and indirect measuring method using the electromyogram (EMG) that is generated by moving muscles. The direct method is capable of measuring fine motion and is applied mainly to industrial robots. The indirect method is considered powerful in the medical field, particularly as the control signal of power-driven artificial arm. When the upper arm or forearm is voluntarily moved, an active potential remains on the remaining muscles at the edge of a person who was operated to cut his or her arm in the same way as an ordinary person. If this active potential is used as the control signal source, the artificial arm will be controlled according to the mechanism approximate to the voluntary movement of an ordinary person. This special issue spotlights the organisms with these good features. I sincerely thank the authors for their cooperation.