Arm position during daily activity
ABSTRACT A new method of evaluation for functional assessment of the shoulder during daily activity is presented. An ambulatory system using inertial sensors attached on the humerus was used to detect the ability to work at a specific position of the shoulder. Nine arm positions were defined based on humerus elevation. The method was tested on 31 healthy volunteer subjects. First, we estimated the ability of the system to detect the different elevation angles and arm positions of each subject. Following that, we evaluated their arm positions during approximately 8h of daily activities. Each arm position was recognized with a good sensitivity (range 80-100%) and specificity (range 96-99%). During daily activity, we estimated the frequency (number/h) that the humerus reached each arm position during the periods of 0-1s (period P1), 1-5s (period P2) and 5-30s (period P3). Our data showed that all subjects had 96% of their arm position reached under the 5th level (100-120 degrees ). No significant difference was observed between dominant and non-dominant sides for the frequency and duration of arm positions (p>0.3). Our evaluation was in accordance with the clinical questionnaire (the Constant score) for the P1 duration, but differed for longer periods P2 and P3. By quantifying the arm positions and their durations for both shoulders, we proposed a new score to evaluate the ability to work at a specific level based on the symmetry index of the arms activity. Using this score, we obtained, on average, good symmetry for healthy subjects. This score can be useful in evaluating the asymmetry in arm function in patients with a shoulder disease. The proposed technique could be used in a number of shoulder diseases where problems in performing daily activities should be expressed in terms of objective measure of arm position.
- SourceAvailable from: Gabriel Baud-Bovy
- "The lifestyle module collects data on the patient daily activity through a body sensor network. From these data the activity can be profiled . The data can be used, along with environmental and physiological data, to tune the rehabilitation exercise level, assess potential risks, and advice clinicians on the therapy. "
Conference Paper: Self-adaptive games for rehabilitation at home[Show abstract] [Hide abstract]
ABSTRACT: Computer games are a promising tool to support rehabilitation at home. It is widely recognized that rehabilitation games should (i) be nicely integrated in general-purpose rehabilitation stations, (ii) adhere to the constraints posed by the clinical protocols, (iii) involve movements that are functional to reach the rehabilitation goal, and (iv) adapt to the patients' current status and progress. However, the vast majority of existing rehabilitation games are stand-alone applications (not integrated in a patient station), that rarely adapt to the patients' condition. In this paper, we present the first prototype of the patient rehabilitation station we developed that integrates video games for rehabilitation with methods of computational intelligence both for on-line monitoring the movements' execution during the games and for adapting the gameplay to the patients' status. The station employs a fuzzy system to monitor the exercises execution, on-line, according to the clinical constraints defined by the therapist at configuration time, and to provide direct feedback to the patients. At the same time, it applies real-time adaptation (using the Quest Bayesian adaptive approach) to modify the gameplay according both (i) to the patient current performance and progress and (ii) to the exercise plan specified by the therapist. Finally, we present one of the games available in our patient stations (designed in tight cooperation with therapists) that integrates monitoring functionalities with in-game self-adaptation to provide the best support possible to patients during their routine.Computational Intelligence and Games (CIG), 2012 IEEE Conference on; 01/2012
[Show abstract] [Hide abstract]
- "for each of the arm elevations at 0 • , 30 • , 60 • and 90 • , respectively. These values were estimated using records of the arm position during daily activity (Coley et al. 2008). For the first arm position, the weighting factor (W 1 ) considered all the occurrences (i.e. "
ABSTRACT: Post-operative change in the mechanical loading of bone may trigger its (mechanically induced) adaptation and hamper the mechanical stability of prostheses. This is especially important in cementless components, where the final fixation is achieved by the bone itself. The aim of this study is, first, to gain insight into the bone remodelling process around a cementless glenoid component, and second, to compare the possible bone adaptation when the implant is assumed to be fully bonded (best case scenario) or completely loose (worst case scenario). 3D finite element models of a scapula with and without a cementless glenoid component were created. 3D geometry of the scapula, material properties, and several physiological loading conditions were acquired from or estimated for a specific cadaver. Update of the bone density after implantation was done according to a node-based bone remodelling scheme. Strain energy density for different loading conditions was evaluated, weighted according to their frequencies in activities of daily life and used as a mechanical stimulus for bone adaptation. The average bone density in the glenoid increased after implantation. However, local bone resorption was significant in some regions next to the bone-implant interface, regardless of the interface condition (bonded or loose). The amount of bone resorption was determined by the condition imposed to the interface, being slightly larger when the interface was loose. An ideal screw, e.g. in which material fatigue was not considered, was enough to keep the interface micromotions small and constant during the entire bone adaptation simulation.Biomechanics and Modeling in Mechanobiology 11/2011; 11(6):903-13. DOI:10.1007/s10237-011-0360-9 · 3.25 Impact Factor
Article: Quality undersupply and oversupply[Show abstract] [Hide abstract]
ABSTRACT: I analyze a market in which a price-taking buyer buys a variable-quality good from a population of sellers, contrasting the case where quality is a seller's private information to that where it is public information. Average quality traded under private information can be either higher (quality oversupply) or lower (quality undersupply) than under public information, depending on sellers’ preferences. We are likely to see quality undersupply if (i) sellers’ preferences exhibit substitutability between the variable-quality good and the numéraire good, and/or (ii) sellers view the numéraire good as a luxury good relative to the variable-quality good. Reverse arguments hold for quality oversupply.Journal of Economic Theory 02/2003; DOI:10.1016/S0022-0531(02)00019-4 · 1.24 Impact Factor