Evaluation of Three Different Phalangeal Motion Measurement Systems and Determination of the Functional Range of Motion

The main contribution of this paper is the introduction of three different devices for measuring the flexion of phalangeal articulations. The devices described in the study are suitable for the determination of the active and the functional range of motion (ROM) of finger joints. In the paper, multiple measurements are reported in order to determine the maximum and minimum values of the active and the functional range of motion of phalangeal articulations and to validate the proper operation of the measurement devices. The first measurement method was based on the post factum image processing of video recordings, while the second and the third method used devices that were attached to the finger and equipped with analogue and digital sensors, which is similar to a miniature goniometer with a computer interface. The results showed that people only use 79-82% of the active range of motion of phalangeal articulations. Additionally, there was a 6% difference between the current measurement results and the data available from previously reported measurements. The current study also aims at finding the cause of this anomaly. Comparative analysis of the measurement results provides a basis for the future development of an actuator that would be used in a multiple finger gripper mechanism suitable for rehabilitation purposes

Ordering in spatial evolutionary games for pairwise collective strategy updates

Evolutionary $2 \times 2$ games are studied with players located on a square lattice. During the evolution the randomly chosen neighboring players try to maximize their collective income by adopting a random strategy pair with a probability dependent on the difference of their summed payoffs between the final and initial state assuming quenched strategies in their neighborhood. In the case of the anti-coordination game this system behaves alike an anti-ferromagnetic kinetic Ising model. Within a wide region of social dilemmas this dynamical rule supports the formation of similar spatial arrangement of the cooperators and defectors ensuring the optimum total payoff if the temptation to choose defection exceeds a threshold value dependent on the sucker's payoff. The comparison of the results with those achieved for pairwise imitation and myopic strategy updates has indicated the relevant advantage of pairwise collective strategy update in the maintenance of cooperation.Comment: 9 pages, 6 figures; accepted for publication in Physical Review