Portable Acquisition System Research Articles

Pinch Grip per SE Is Not an Occupational Risk Factor for the Musculoskeletal System: An Experimental Study on Field

Introduction: Some ergonomic evaluation methods define pinch grip as a risk factor independent of the exerted force. The present experimental study was performed with the main aim of objectively measuring the muscle engagement during the execution of pinch grip. Methods: the participants of the study were healthy workers occupationally involved in a high-intensity repetitive job related to the sorting of letters and small packages. Surface electromyography (sEMG) was used to study the activity of the abductor pollicis brevis and first dorsal interosseous fibers related to the execution of the required working tasks, while the force exerted during voluntary muscle contraction for pinch grip was measured by a portable acquisition system. The subjects were specifically asked to exert the maximum voluntary isometric contraction (MVIC) and further voluntary isometric contractions with a spontaneous force (SF) equal to 10%,20% and 50% of the MVIC; finally, the workers were asked to hold in pinch grip two types of envelopes, weighing 100 g and 500 g, respectively. Results: The force required to pinch 100 and 500 g envelopes by the fifteen subjects of the study corresponded to 4 and 5% MVIC, respectively. The corresponding sEMG average rectified values (ARV) were approximately 6% of that at MVIC for first dorsal interosseus (FDI) fibers and approximately 20–25% of MVIC for abductor pollicis brevis (ABP) fibers. Bivariate correlation analysis showed significant relationships between force at MVIC and FDI ARV at MCV. Conclusions: The obtained results demonstrate that muscle recruitment during pinch grip varies as a function of the SF: not only the position but also the exerted force should be considered when assessing the pinch grip as risk factor for biomechanical overload of the upper limb.

3d Printed Bio-potential Dry Electrodes.

The most commonly used bio-potential electrodes are silver/silver chlorides gel-electrodes (Ag/AgCl electrodes). However, wet electrodes are not suited for daily usage and long-term monitoring. Dry electrodes are the best choice for long-term measurements. Dry electrodes can be fabricated using various methods and materials; one of these methods is three dimensional (3d) printing. 3d printing is a cost-effective method and can be easily used in mass production. This paper will present 3d printed bio-potential dry electrodes using five different commercially available fused deposition modeling (FDM) electrically conductive filaments. Then, these printed electrodes will be tested and validated using electrocardiogram (ECG) portable acquisition system. Three out of five filaments were printed successfully. Collected ECG data from these electrodes showed acceptable quality with Signal to Noise Ratios (SNRs) ranging around 20 dB when compared with wet electrodes collected raw data as a reference. In conclusion, this study designed and printed a 100% 3d printed electrodes from three different FDM filaments which could be used efficiently for ECG signal monitoring in resting position.

Identification and Authentication of Copper Canisters for Spent Nuclear Fuel by a Portable Ultrasonic System.

The long-term storage of nuclear-spent fuel in geological repositories has introduced the need to develop new technologies for safeguarding the fuel. Continuity of knowledge about the fuel's location must be maintained during transport of the copper canisters that contain the fuel from the encapsulation plant to the final repository. Among the possible different containment and surveillance measures are the identification and authentication of each canister. The authors propose an innovative solution for this purpose, which is based on the ultrasonic acquisition of two fingerprints: an artificial code realized by chamfers machined in the inner surface of the copper lid (identification) and a natural signature due to the weld between the lid and the tube (authentication). Several prototypes of ultrasonic acquisition devices have been developed and tested on real copper samples to validate the identification and authentication concepts. This article describes the design of a new, optimized version of the ultrasonic acquisition device. The aim of this new design is to provide a solution for the identification and authentication of copper canisters using a portable device that is cost-effective and easy to use, which does not require the presence of an inspector in the field. The mechanical design of the reader has been upgraded with the introduction of a stepper motor and a new probe holder that includes a beam splitter to acquire two fingerprints simultaneously. The new device has been tested on copper samples, both with and without chamfers, and the results are reported in this article. The implementation of the seal fingerprint acquisition device (SFAD) within the new portable acquisition system is discussed at the end of this article with the goal of improving the electronic performance of the acquisition device in the field.

Portable cost-effective EEG data acquisition system

Neuro-cognitive dysfunctions are common clinical abnormalities found in society. They require objective analysis by various instruments; an important technique involves monitoring electroencephalogram (EEG) signals. To date, EEG machines have been robust, costly and require patients to come to a hospital for test. Therefore, we have constructed a simple, cheap and portable EEG instrument for wider patient use. It consists of two active digital EEG probes with two channels each, making it a four-channel portable acquisition system. It is further connected through a two-wire serial bus to the acquisition unit, which comprises an analogue to digital converter (ADC) and an ARM board processor with 2 GB memory and USB interface. The whole system is placed in a small box making it highly portable for wider use in clinical settings.

A Portable Acquisition System Based on USB Standard for the Medipix2 X-Ray Detector

We describe a portable readout system for an X-ray hybrid detector based on the Medipix2 pixel readout chip. The Medipix2 chip (256times256 square pixels with 55 mum pitch) is bump-bonded with a pixellated Silicon sensor 300-micron thick. The readout system consists of a simple small size electronic card based on a single powerful microcontroller and can be connected to a PC through the widespread Universal Serial Bus (USB) interface. The reduced size of the final card (3.8 cmtimes4.8 cm) makes it suitable for special applications like dental radiology

Data acquisition system for measurements in free moving subjects and its applications

A low-cost, portable acquisition system for monitoring and processing human biomechanical parameters is presented. It is equipped with 16 input channels, each one linked to an external transducer by a suitable connector. Input signals from sensors are converted into a digital form by a 12-bit analog-to-digital converter and stored in a removable memory (memory card) respecting the PCMCIA standard interface, allowing the download of acquired data toward the host computer. The acquisition operating mode is programmable by a host PC, writing proper values into the memory card; then, the instrument acquires the defined number of channels at the selected sampling rate. The instrument is battery powered; then, it can be used in all those applications, like rehabilitation and sports medicine, where the freedom for subject movement is a constraint for the test. In fact, this instrument does not require an arranged environment for measurements, and it is not connected to a PC. Three sample applications are presented in which the instrument is used to evaluate human motor capability, physical parameters in amputees, and motor performance in athletes.