A novel functional calibration method for real-time elbow joint angles estimation with magnetic-inertial sensors.

Magnetic-inertial measurement units (MIMUs) are often used to measure the joint angles between two body segments. To obtain anatomically meaningful joint angles, each MIMU must be computationally aligned (i.e., calibrated) with the anatomical rotation axes. In this paper, a novel four-step functional calibration method is presented for the elbow joint, which relies on a two-degrees-of-freedom elbow model. In each step, subjects are asked to perform a simple task involving either one-dimensional motions around some anatomical axes or a static posture. The proposed method was implemented on a fully portable wearable system, which, after calibration, was capable of estimating the elbow joint angles in real time. Fifteen subjects participated in a multi-session experiment that was designed to assess accuracy, repeatability and robustness of the proposed method. When compared against an optical motion capture system (OMCS), the proposed wearable system showed an accuracy of about 4° along each degree of freedom. The proposed calibration method was tested against different MIMU mountings, multiple repetitions and non-strict observance of the calibration protocol and proved to be robust against these factors. Compared to previous works, the proposed method does not require the wearer to maintain specific arm postures while performing the calibration motions, and therefore it is more robust and better suited for real-world applications.

Development and validation of equations to predict the metabolizable energy value of corn for pigs.

Three experiments were conducted with the aim of developing and validating an equation to predict the ME of corn for pigs from its chemical composition, physical characteristics and particle size. Exp. 1: Eight lots of corn were ground in a hammer mill, using 5 sieves with different screen opening sizes, generating 40 batches of ground corn. The chemical composition (DM, CP, ether extract, crude fiber, ADF, NDF, and ash) and physical characteristics (bulk density- BD and 1,000-kernel weight- TKW) were determined in the 8 lots and geometric mean diameter (GMD) and N-corrected ME (AMEn) were determined in the 40 batches of corn. The AMEn values were determined in 16 metabolism assays with pigs. Mathematical models were adjusted by regression analysis, based on the Akaike Information Criterion. Based on statistical parameters ( = 0.76 and prediction error = 1.05%), number of predictor variables, and easiness of measurements, an equation with 2 segments was chosen: y = 2845.41 + 0.9385 × BD - 20.8784 × CP, if GMD ≤ 522.98 and y = 3105.75 - 0.4978 × GMD + 0.9385 × BD - 20.8784 × CP, if GMD > 522.98. Exp. 2 and 3: Sixty four gilts (Exp. 1; 29.5 ± 3.8 kg) and 64 barrows (Exp. 2; 29.3 ± 3.6 kg), 1 lot of corn, and 3 particle sizes (GMD = 483, 632, and 904 µm) were used in a 3 × 2 factorial arrangement with 2 methods of diet formulation, differing in ME value of corn: "FIX" (value from nutrient composition table) vs. "ESTIMATED" (estimated for each particle size using the equation developed in Exp. 1). In Exp. 2, ADFI was greater ( < 0.05) and feed efficiency was lower ( < 0.05) in the diet with GMD of 904 µm compared to the diets with GMD of 632 or 483 µm, but only for diet formulation by the FIX method. In the treatments with GMD of 483 µm, gilts fed with the diet formulated by the ESTIMATED method had greater ( < 0.10) ADFI, backfat, fat area, and fat:meat ratio than gilts fed the diet formulated by the FIX method. In Exp. 3, particle size and formulation method did not affect ( > 0.10) growth performance and carcass traits of barrows. The equation developed was effective to adjust the ME value of corn, considering particle size variation. However, improvement to the proposed equation is necessary to achieve greater precision for predicting corn ME. Validation of the equation with more lots of corn of different chemical compositions and densities appears necessary to assess the efficacy of the equation regarding the variation of the other predicting variables.

Reducing muscle effort in walking through powered exoskeletons.

This paper presents a novel assistive control for lower limb exoskeletons. The controller provides the user with a scaled version of the Winter's nominal torque profile, which is adapted online to the specific gait features of the user. The proposed assistive controller is implemented on the ALEX II exoskeleton and tested on two healthy subjects. Experimental results show that when assisted by the exoskeleton users can reduce the muscle effort compared to free walking.

F8 gene mutation profile and ITT response in a cohort of Italian haemophilia A patients with inhibitors.

Anti factor VIII (FVIII) antibodies represent the main complication of replacement therapy in severe cases of haemophilia and most patients with inhibitor have gross gene rearrangements or point mutations that hamper the production of normal circulating FVIII. In this study we have investigated 82 haemophilia A patients with inhibitors. Seventy six were severe, three were moderate and three were mild. We screened the patients for the causative mutations using long range PCR for the recurrent intron 22 inversion (invint22), multiplex PCR for intron 1 inversion (invint1) and conformation sensitive gel electrophoresis followed by DNA sequencing for all other mutation types in the F8 gene. Diverse genetic defects were detected in the severe cases (with a predominance of severe molecular defects): F8 gene inversions, large deletions and non-sense mutations account for 71% of the mutations. Only missense and splicing mutations were identified in the non-severe patients and we confirmed that the presence of inhibitors correlates well with the presence of severe mutations, but a proportion of severe patients develops inhibitors despite the presence of diverse less severe mutations. When we have analysed the subgroup of patients who underwent immunetolerance, we have found that F8 gene large deletions are likely to be a high risk factor also for immunetolerance therapy unresponsiveness, while no clear evidence has been demonstrated for other mutation types.

[Edematous decompensation of the cornea after silicon implant of the posterior chamber in phakic eyes in myopia]. / Décompensation oedémateuse de la cornée après implant de chambre postérieure en silicone chez le myope phake.

The authors report a case of a girl operated with a silicon IOL in the posterior chamber for the correction of myopia in phakic eye. One year after surgery there was a total bilateral corneal decompensation which required corneal transplantation. The possible hypothesis of the damage are discussed.