The Evaluation of Potentiostats: Electrochemical Detection Devices

This study evaluated the performance of three types of potentiostats; EmStat, CheapStat and UTMStat. EmStat is the smallest potentiostat available in the market. CheapStat is an open-source potentiostat suitable for educational applications. In addition, UTMStat is the extension of CheapStat, which was designed to overcome few weaknesses of CheapStat such as the input controller/ switch and data storage handling of the cyclic voltammogram. The cyclic voltammetry and amperometry measurements of ions ferrocyanide ([Fe(CN)6]4−) and chloride (Cl-) were carried out for each potentiostat. EmStat potentiostat is not only able to detect but also to measure ferrocyanide and chloride ions. However, CheapStat and UTMStat are only able to detect and measure ferrocyanide ions. The experiment is unable to be conducted due to limitation of waveform selection on both devices. Nevertheless, CheapStat and UTMStat could provide a reliable measurement to realize miniaturized lab-on-chip applications as shown in this study

SWCNT-Based Biosensor Modelling for pH Detection

Different forms of CNT delivery have been discovered with several biomedical functions during past decades. The mechanisms of the cellular uptake of CNTs are mainly maintained due to the chemical nature, the cell type, and the features of the molecules, which are used to functionalize the nanotube exterior. Since single-wall carbon Nanotube (SWCNT) has unique chemical and physical properties, it is a great applicant for pH sensing. In addition, ion sensitive FET (ISFET) base on nanostructured SWCNT have covered a new method to help genetic investigators restructure metabolic pathways in cells, recognize the progression of disease, and expand diagnostics and therapeutics. Particularly, because PH sensing is very crucial for the constancy of enzymes, it is essential to extend the cost efficient types of this sensing. In this research, the conductance changes of the CNT-based ISFET device with different pH values can be modelled by ion concentration of the solution. In addition, the electrical current of channel is imagined as a function of pH levels, which can be controlled by a control factor (α). Thus, ISFET based nanostructured SWCNT is proposed focusing on the area of electrical detection of hydrogen ions of the electrolyte membrane. Besides, electrical detection of hydrogen ion applications is suggested to be used by modelling the delivery of SWCNT sheets. In the end, after comparing the proposed model and experimental data, it has been reported that there is a good compatibility between them

Flexible ECG circuit fabrication and application using vinyl cutting technique

The aim of this study is to prove the capability of vinyl cutting technique to cut the conductive traces of electronic circuit layout which used a copper tape (Copper tape 1181 from 3M) on flexible substrate to replace the method of using nano-scale particle material. A wireless electrocardiography (ECG) circuit was integrated and fabricated on flexible substrate, namely a polyethylene terephthalate (PET) substrate by using vinyl cutting method to produce the conductive line traces. After that, the fabricated circuit is used for acquiring ECG signals from a patient simulator and human subjects to measure the performance differences and compatibility as a wearable device. In the data processing stage, ECG data were denoised using sym20 from Wavelet Transform tool provided by MATLAB. Then, Signal-to-noise-ratio (SNR) was calculated and used as the signal quality indicator. At the end of the study, flexible circuit performance was compared to MIT-BIH Arrhythmia database and it shows that there is no significance difference between both. In conclusion, vinyl cutting method shows a promising fabrication output on PET substrate as the performance of both flexible ECG circuit is comparable with rigid ECG circuit by a previous study

Miniaturized and Wearable Electrocardiogram (ECG) Device with Wireless Transmission

ECG Holter is a device used to acquire and monitor the user heart rhythm. However, it is available only in a major healthcare facility as it is very costly. The objective of this work is to develop a portable ECG monitoring device with wireless transmission for early arrhythmia detection and personal monitoring. The heart of the device is based on Atmel ATmega328p processor, which acquires user ECG data through Analog Devices AD8232 ECG analog front-end chip. Data captured is stored offline in memory card before it is transmitted wirelessly to a cloud server for analysis purpose. Experiments indicate that the device able to sample the ECG data up to 1000 samples per second and Wi-Fi based transmission serves the best for data transfer to the cloud server. User and physician can easily access the data for viewing and analysis, eliminating the needs for users to travel to the hospital for ECG acquisition

Mimicking the biological olfactory system : a Portable electronic Mucosa

In this study the authors report on the development of a new type of electronic nose (e-nose) instrument, which the authors refer to as the Portable electronic Mucosa (PeM) as a continuation of previous research. It is designed to mimic the human nose by taking significant biological features and replicating them electronically. The term electronic mucosa or simply e-mucosa was used because our e-nose emulates the nasal chromatographic effect discovered in the olfactory epithelium, located within the upper turbinate. The e-mucosa generates spatio-temporal information that the authors believe could lead to improved odour discrimination. The PeM comprises three large sensor arrays each containing a total of 576 sensors, with 24 different coatings, to increase the odour selectivity. The nasal chromatographic effect provides temporal information in the human olfactory system, and is mimicked here using two-coated retentive channels. These channels are coated with polar and non-polar compounds to enhance the selectivity of the instrument. Thus, for an unknown sample, the authors have both the spatial information (as with a traditional e-nose) and the temporal information. The authors believe that this PeM may offer a way forward in developing a new range of low-cost e-noses with superior odour specificity

The evaluation of potentiostats: electrochemical detection devices

This study evaluated the performance of three types of potentiostats; EmStat, CheapStat and UTMStat. EmStat is the smallest potentiostat available in the market. CheapStat is an open-source potentiostat suitable for educational applications. In addition, UTMStat is the extension of CheapStat, which was designed to overcome few weaknesses of CheapStat such as the input controller/ switch and data storage handling of the cyclic voltammogram. The cyclic voltammetry and amperometry measurements of ions ferrocyanide ([Fe(CN)6]4−) and chloride (Cl-) were carried out for each potentiostat. EmStat potentiostat is not only able to detect but also to measure ferrocyanide and chloride ions. However, CheapStat and UTMStat are only able to detect and measure ferrocyanide ions. The experiment is unable to be conducted due to limitation of waveform selection on both devices. Nevertheless, CheapStat and UTMStat could provide a reliable measurement to realize miniaturized lab-on-chip applications as shown in this study

Research and development of IMU sensors-based approach for sign language gesture recognition

This paper discusses a few Inertial Measurement Unit (IMU) sensor-based approaches for sign language gesture recognition. Generally, there are three main research areas for the IMU sensor-based approach which consist of the device structure, sensors fusion algorithm and calibration method, and finally gesture recognition and classification method. The device structure includes the number and placement of the sensors to cover the degrees of freedom. Sensors fusion algorithms, such as complementary filter, Kalman filter, and EKF are implemented to combine a variety of sensors used for data acquisition. Several gesture classification and recognition methods are also reviewed in this paper. Some of the limitations related to sensor-based technique such as device structure and classification technique are discussed as a research gap for future references

Miniaturized and wearable electrocardiogram (ECG) device with wireless transmission

ECG Holter is a device used to acquire and monitor the user heart rhythm. However, it is available only in a major healthcare facility as it is very costly. The objective of this work is to develop a portable ECG monitoring device with wireless transmission for early arrhythmia detection and personal monitoring. The heart of the device is based on Atmel ATmega328p processor, which acquires user ECG data through Analog Devices AD8232 ECG analog front-end chip. Data captured is stored offline in memory card before it is transmitted wirelessly to a cloud server for analysis purpose. Experiments indicate that the device able to sample the ECG data up to 1000 samples per second and Wi-Fi based transmission serves the best for data transfer to the cloud server. User and physician can easily access the data for viewing and analysis, eliminating the needs for users to travel to the hospital for ECG acquisition

Applying convolution-based processing methods to a dual-channel, large array, artificial olfactory mucosa

Our understanding of the human olfactory system, particularly with respect to the phenomenon of nasal chromatography, has led us to develop a new generation of novel odour-sensitive instruments (or electronic noses). This novel instrument is in need of new approaches to data processing so that the information rich signals can be fully exploited; here, we apply a novel time-series based technique for processing such data. The dual-channel, large array artificial olfactory mucosa consists of 3 arrays of 300 sensors each. The sensors are divided into 24 groups, with each group made from a particular type of polymer. The first array is connected to the other two arrays by a pair of retentive columns. One channel is coated with Carbowax 20M, and the other with OV-1. This configuration partly mimics the nasal chromatography effect, and partly augments it by utilizing not only polar (mucus layer) but also non-polar (artificial) coatings. Such a device presents several challenges to multi-variate data processing: a large, redundant dataset, spatio-temporal output, and small sample space. By applying a novel convolution approach to this problem, it has been demonstrated that these problems can be overcome. The artificial mucosa signals have been classified using a probabilistic neural network and gave an accuracy of 85%, Even better results should be possible through the selection of other sensors with lower correlation