6 documents found, page 1 of 1
Software Based Sigma-Delta Converter with Auto-Calibration Capabilities
Pereira, José Miguel Costa Dias; Viegas, Vítor; Postolache, Octavian; Girão, P. S.This paper presents a software based sigma-delta converter. The proposed A/D converter represents a lowcost and flexible digitalization solution that can be used in a large number of applications. The proposed discrete A/D converter tasks, that are performed by a microcontroller, include: digital filtering, oversampling, noise shaping and decimation. A simple implementation of the digital filtering is easily im...
A Dual Measurement and Stimulating System to Monitor and Promote NNS
Pereira, José Miguel Costa Dias; Viegas, Vítor; Postolache, Octavian; Girão, P. S.The present paper presents a dual system that can be used to measure and to generate non-nutritive sucking (NNS) signals. The NNS measurement is based on a pressure sensor that is pneumatically connected to a silicone pacifier. By its turn, the NNS stimulator is based on a miniature pump and a miniature electro-valve that are operated by opposite phased signals to produce the pulsed pressure signal that is pneu...
Monitoring walker assistive devices: a novel approach based on load cells and o...
Viegas, V.; Pereira, J. M. D.; Postolache, O.; Girão, P. S.This paper presents a measurement system intended to monitor the usage of walker assistive devices. The goal is to guide the user in the correct use of the device in order to prevent risky situations and maximize comfort. Two risk indicators are defined: one related to force unbalance and the other related to motor incoordination. Force unbalance is measured by load cells attached to the walker legs, while moto...
Serious game for physical rehabilitation: measuring the effectiveness of virtua...
Postolache, O.; Lourenço, F.; Dias Pereira, J. M.; Girão, P. S.Recent advances in low-cost natural user interfaces such as Microsoft Kinect and Leap Motion controller allow the Virtual Reality implementation of 3D serious games for, posture, upper limb and lower limb rehabilitation purposes. However, it is very important to compare the results obtained by the users that train in virtual and real environments. This paper presents a virtual reality serious game for upper lim...
Combining distance and force measurements to monitor the usage of walker assist...
Dias Pereira, J. M.; Viegas, V.; Postolache, O.; Girão, P. S.This paper presents a measurement system that can be used to monitor the usage of walker assistive devices. The forces applied on the legs of the walker device are measured using low cost force sensing resistors and a light detection and ranging device is used to evaluate several gait kinematic parameters, such as, walking speed and walking stride length. To evaluate the right usage of the walker device two wal...
Tactile sensors for robotic applications
Girão, P. S.; Ramos, P. M. P.; Postolache, O. A.; Pereira, J. M. D.In this paper, the authors look at the domain of tactile sensing in the context of Robotics. After a short introduction to support the interest of providing robots with touch, the basic aspects related with tactile sensors, including transduction techniques are revisited. The brief analysis of the state-of-the-art of tactile sensing techniques that follows provides indicators to conclude on the future of tactil...