No abstract

An augmentative and alternative communication (AAC) device for people with speech disabilities is presented. This AAC system exhibits the advantages of two currently used systems: 1) usability of the communication boards and 2) natural oral communication of the electronic communicators. To improve comfort in use, robustness and versatility, the system is designed as two separate blocks linked by wireless communication via a wireless network of communication board sheets. The communication sheets, which are the interface with the user, are economical, simple to use, and scalable to adaptation of the number of symbols and the vocabulary of the individuals who use the system. The digital system (record/player system) controls the net, identifies the active sheets and the pushed symbols, and plays and records all sounds. This digital system can be easily replaced by other digital interfaces, such as computers, smartphones, or tablets, and can increase the function of the AAC with the possibility of using the Internet communication (emails and Skype, among others). The prototype has been evaluated in two special education schools, which are attended by children with severe motor disabilities with or without associated disorders and multi-deficiencies. Positive reviews from individuals who use the AAC system open the possibility of the system's use in both home and educational environments.

A bioimpedance system for the continuous measurement of non-invasive physiological parameters in lower-limb amputees is presented. The aim of the system is to monitor as many physiological parameters as possible from a single bioimpedance electrode configuration. In this way, a simple, low-cost and low-size autonomous system is developed that is able to continuously monitor the amputee in different environments (home, work, etc). The system measures both electrical impedance myography and electrical impedance plethysmography in the stump with electrodes placed in the inside face of a silicone interface. Such a system allows for the monitoring of a patient's muscle activity, and heart and breath rate, thus enabling the study and continuous monitoring of prosthesis adaptation and improvement of patient's gait to reduce physiological stress. Additionally, it can prevent cardiovascular problems due to the effort involved in the use of prostheses, which can decrease the life expectancy of amputees with previous vascular diseases. Experimental results obtained from different amputees' test validate the purpose of the system.

Foliar wetness plays an essential role in plant disease cycles and epidemic development yet no cost-effective leaf wetness sensors (LWSs) are available that could be deployed within large areas to better understand that role. Electronic LWSs comprise an artificial leaf and the electronic circuitry able to measure electrical impedance changes due to water film or drops on the leaf surface. We propose a simple, compact and low-cost electronic interface circuit (EIC) for artificial leaves based on capacitance changes. The circuit relies on the charge-transfer capacitive sensing method and it is implemented by a microcontroller unit (MCU), which offers computation and communication capabilities currently missing in commercial LWSs, This EIC can be used in custom and commercial artificial leaves hence suits studies that require a close emulation of particular plant leaves.

A simple method for designing instrumentation fully-differential (FD) circuits based on standard single-ended (SE) operational amplifiers (OAs) is presented. It departs from a SE prototype that verifies the desired differential-mode transfer function, thereby leading to FD versions of the circuit. These circuits have a high common mode rejection ratio (CMRR), independent of component imbalances, and a unity common-mode gain. The proposed method does not allow the design of common-mode response, but it does verify common-mode stability, thus ensuring stable FD circuits. It is intended for instrumentation applications in which high CMRRs are required. The proposed approach makes it possible to design and implement inverter and non-inverter topologies as well. Design examples and experimental data are presented. Using general-purpose OAs and 5%-tolerance components, the CMRR of these circuits easily exceeds 90 to 100 dB. 104E.M. Spinelli et al.