Skeleton data pre-processing for human pose recognition using Neural Network.

Automatic monitoring of daily living activities can greatly improve the possibility of living autonomously for frail individuals. Pose recognition based on skeleton tracking data is promising for identifying dangerous situations and trigger external intervention or other alarms, while avoiding privacy issues and the need for patient compliance. Here we present the benefits of pre-processing Kinect-recorded skeleton data to limit the several errors produced by the system when the subject is not in ideal tracking conditions. The accuracy of our two hidden layers MLP classifier improved from about 82% to over 92% in recognizing actors in four different poses: standing, sitting, lying and dangerous sitting.

Use of surface EMG for evaluation of upper limb spasticity during botulinum toxin therapy in stroke patients.

The clinical assessment of spasticity in stroke patients generally includes descriptive scales, such as the Modified Ashworth Scale (MAS) and the Global Pain Scale (GPS), however these may not be sufficiently sensitive to accurately detect improvements, especially at upper limb level; electromyography (EMG) may be the answer to this clinical requirement. The aim of this study was to quantify the effects of botulinum toxin type A (BTX) in treating upper extremity spasticity in stroke patients, using clinical evaluation (MAS and GPS) and EMG. Ten patients were assessed before, 30 days and 180 days after BTX injection using clinical evaluations and EMG. At 30 days all clinical measures improved significantly. Whereas MAS scores, after recording an improvement at the first evaluation session, were worse at the second assessment, GPS scores improved over time, both at the first and at the second evaluation session. A reduction of EMG activity was found 30 days after injections, in particular at baseline and during passive flexion movement. Our results demonstrated that measurement of EMG activity may be an effective means of detecting functional improvements and of monitoring the effects of treatment in post-stroke patients.

Towards objective evaluation of balance in the elderly: validity and reliability of a measurement instrument applied to the Tinetti test.

The aim of the present study was the validation of an instrument for evaluating balance, applied to the Tinetti test. Trunk inclination was measured by inclinometers during the Tinetti test in 163 healthy participants scoring 28/28 in the Tinetti scale (controls: 92 women, 71 men; age 19-85 years), and 111 residents in old people's homes, able to autonomously perform the test, but scoring less than 28/28 (test group: 78 women, 33 men; age 55-96 years). Trunk inclination was quantified by 20 parameters, whose standardized values were summed and provided an overall performance index (PTOT). PTOT reliability was evaluated by Cronbach's alpha, and its validity by item scale correlation, discriminant validity and concurrent validity. Influence of age and sex was assessed by a logistic regression model. Repeatable and consistent measurements were obtained (Cronbach's alpha=0.88). Parameter distribution was significantly different in controls and patients (P<0.001). Optimal PTOT threshold for discriminating between normal and abnormal performance (153.9/200) corresponded to sensitivity of 88.3%, specificity of 84.7% and area under the receiver operating characteristics curve of 0.93. PTOT correlated with the Tinetti scale score, its partial, balance-related score and Barthel's Index, but not with the Mini Mental State score. PTOT correlated with age and level of performance but not with sex; correlation with age did not prevent the possibility of discriminating between different levels of performance and between normal and abnormal performance. The instrument provided objective discrimination between different performance levels, in particular, between normal and altered performance.

Towards objective quantification of the Tinetti test.

The Tinetti test is a widespread test for assessing motor control in the elderly, which could also be usefully applied in neurology. At present it uses a qualitative measurement scale. As a first step towards its objective quantification, trunk inclination was measured during the test by two inclinometers and quantified by descriptive parameters. The 95th or 5th percentiles of parameter distributions in normal subjects (no.=150) were taken as limits of normality, and parameters computed on 130 institutionalised elderly people were compared to these limits, to test the parameters' discriminatory power. The distributions of many parameters were statistically different in normal subjects and patients. These results suggest that this approach is a promising tool for objective evaluation of the Tinetti test.