# Upper Limb Bionic Orthoses: General Overview and Forecasting Changes
## 1 Introduction  
The current state-of-the-art in bionic orthoses has its beginning in classical antiquity. The first known works related to this topic were created by [PERSON] from Tarentum in 350 BC. He invented several mechanical devices, such as a flying bird powered by steam [1]. His works gave rise to modern robotics. In the Middle Ages it was common to construct devices, which now can be named androids, for entertainment. They were given roles to welcome guests at the entrance, play instruments, open the door, or do other simple activities. To power the androids, former constructors used gravity, energy stored in a spring, or flowing water. The word \"robot\"--describing a mechanical machine--was used for the first time in the science fiction play \"Rossumoui Univerzalni Roboti\" by Czech writer [PERSON] in 1920 [2; 3; 4]. The following decades brought dynamic development in robotics due to intense research and numerous projects being worked on all over the world--simple robots have been expanded to currently used, sophisticated and complex devices. An example of a medical device which design shares similarities with robotic devices is an orthosis. The word orthosis comes from Greek \"ortho\" and means \"to straighten\" [5], thus the purpose of the orthosis is to stabilise joints and groups of muscles that have suffered an injury. The creator of the first known orthosis was French surgeon [PERSON] in the middle of XVI century [6] whose metallic brace was introduced for correction of scoliosis. Although it did not exploit any movement, since then, orthosis devices have been constantly improved. US military efforts in increasing endurance and force of human muscles have led to the idea of a bionic orthosis. The first attempt to construct human muscles amplifier was made by General Electric company in 1965 [7]. The project was called Hardiman (Figure 1a) and was expected to increase human lifting capability up to 650 kg. Unfortunately, it generated a raising force of only 340 kg and the orthosis was enormous. After several attempts of improving, the Hardiman project was abandoned. In subsequentdecades many constructors tried to overcome limitations of contemporary materials. Finally, in the early 1990s, the technology was sufficiently advanced to build a compact version of Hardiman. One of the first patented exoskeletons was the \"Three axis mechanical joint for a power assist device\" created in 1994 [8]. Its main objective was to amplify a human muscle force. While assistive devices for primarily healthy soldiers were developed, it was 1970 when robotic solutions finally found way to be applicated in a health purpose. That year an orthopedic surgeon from Toronto, [PERSON], investigated regeneration and healing possibilities of articular tissues coming from continous passive motion (CPM) observed on rabbits. This research was the key which promoted healing joint cartilage by appropriate motor treatment [9]. Now, we observe more tries to implement the idea of exoskeletons in biomedical engineering, especially in engineering of rehabilitation systems [10; 11; 12; 13; 14; 15]. We can divide bionic orthoses into two groups: the first group is intended to restore muscles to their original efficiency (Figure 1b), while the second (Figure 1c) is supposed to improve daily life of people having paresis [16]. The purpose of this article is to review the latest technology used in constructing a bionic orthosis meant for rehabilitation, as well as to indicate the direction of its future development. As a bionic orthosis we mean a rehabilitation device which, by means of dedicated software, automatically determines the state of the rehabilitation process and, if necessary, supports it. The element \"bionic\" suggests using biological factors for purpose of control strategy. It must be noted that this article will not deal with the question of neurological aspects, because of its complex nature, which is described more fully by [PERSON] et al. [17].