When an unfortunate event affects the motor capacity of a person, it is necessary to use devices like wheelchairs that offer a means o displacement for patients with motors problems of the lower limbs. Some patients that cannot manipulate the wheelchair with their arms due to a lack of force or psychomotor problems in the superior members, request electric wheelchairs, frequently manipulated with joysticks; however the joystick manipulation is even not practical and frequently it must be handle with the mouth. The present article presents the partial results in the development of a wheelchair controlled by an intuitive interface, where the instructions are given by hand gesture instructions. The advances are presented in the realization of the control software using a Webcam and some distances and presence sensors controlled by a PIC microcontroller that establishes the communication with a program developed in Labview.

There are different schemes based on observers to detect and isolate faults in dynamic processes. In the case of fault diagnosis in instruments (FDI) there are different diagnosis schemes based on the number of observers: the Simplified Observer Scheme (SOS) only requires one observer, uses all the inputs and only one output, detecting faults in one detector; the Dedicated Observer Scheme (DOS), which again uses all the inputs and just one output, but this time there is a bank of observers capable of locating multiple faults in sensors, and the Generalized Observer Scheme (GOS) which involves a reduced bank of observers, where each observer uses all the inputs and m-1 outputs, and allows the localization of unique faults. This work proposes a new scheme named Simplified Interval Observer SIOS-FDI, which does not requires the measurement of any input and just with just one output allows the detection of unique faults in sensors and because it does not require any input, it simplifies in an important way the diagnosis of faults in processes in which it is difficult to measure all the inputs, as in the case of biologic reactors.

Many users with motor disabilities, such as quadriplegics are unable to handle a power wheelchair securely, without causing harm to others, to themselves or their surroundings. Smart wheelchairs usually have been instrumented with a collection of sensors and computers using systems and algorithms that have been designed to provide safe navigation assistance through collision avoidance. This paper proposes a real-time obstacle avoidance embedded system adapted to work with a multimodal navigation interface. 26 Ultrasonic sensors (Sonars) were used to provide feedback of the distance between the wheelchair and the obstacles.

The high liquid content in fruit and vegetable wastes makes it convenient to mechanically separate these wastes into mostly liquid and solid fractions by means of pretreatment. Then, the liquid fraction can be treated using a high-rate anaerobic biofilm reactor to produce biogas, simultaneously reducing the amount of solids that must be landfilled. In this work, the specific composition of municipal solid waste (MSW) in a public market was determined; then, the sorted organic fraction of municipal solid waste was treated mechanically to separate and characterize the mostly liquid and solid fractions. Then, the mesophilic anaerobic digestion for biogas production of the first fraction was evaluated. The anaerobic digestion resulted in a reduced hydraulic retention time of two days with high removal of chemical oxygen demand, that is, 88% on average, with the additional benefit of reducing the mass of the solids that had to be landfilled by about 80%.