Entropy of balance--some recent results.

Abstract Background Entropy when applied to biological signals is expected to reflect the state of the biological system. However the physiological interpretation of the entropy is not always straightforward. When should high entropy be interpreted as a healthy sign, and when as marker of deteriorating health? We address this question for the particular case of human standing balance and the Center of Pressure data. Methods We have measured and analyzed balance data of 136 participants (young, n = 45; elderly, n = 91) comprising in all 1085 trials, and calculated the Sample Entropy (SampEn) for medio-lateral (M/L) and anterior-posterior (A/P) Center of Pressure (COP) together with the Hurst…

Aktivoi-hanke : projektijulkaisu

409 Using rai-hc assessment instrument to classify home care clients in Finland based on fire emergency evacuation capacity

Background When an uncontrollable fire is detected in a building there may be a 2–3 minutes window for the occupants to move to safety. Poor physical function and cognition may become critical factors in an evacuation situation. In this study a novel functional scale measuring emergency evacuation capacity of home care clients is presented. Methods A fire security expert visited about 250 home care clients assessing their evacuation capacities. For the evacuation capacity three categories were used: 1) is able to evacuate; 2) may be able; 3) unable to evacuate. This data was linked to comprehensive assessments of clients functional and health status performed by home care nurses using the i…

Analyzing gastrocnemius EMG-activity and sway data from quiet and perturbed standing.

In an experiment, we combined force plate measurements and surface EMG in studying quiet and perturbed standing, involving MS (Multiple sclerosis) and controls. The aim of this paper is to report the results thus obtained on the relation between filtered gastrocnemius (GA) EMG and the anterior-posterior center-of-pressure (A/P COP) coordinate. The main finding is the good correspondence between A/P COP and the filtered GA EMG in the low frequency range. The EMG envelope was calculated using a zero-lag filter. Combining this with time shifts around 250-350 ms produced a high correlation (85.5+/-8.4%) between the GA-EMG envelope and the A/P COP. This EMG-COP relation was closest when using a …