CardioGuard: A Brassiere-based Reliable ECG Monitoring Sensor System for Supporting Daily Smartphone Healthcare Applications

We propose CardioGuard, a brassiere-based reliable electrocardiogram (ECG) monitoring sensor system, for supporting daily smartphone healthcare applications. It is designed to satisfy two key requirements for user-unobtrusive daily ECG monitoring: reliability of ECG sensing and usability of the sensor. The system is validated through extensive evaluations. The evaluation results showed that the CardioGuard sensor reliably measure the ECG during 12 representative daily activities including diverse movement levels; 89.53% of QRS peaks were detected on average. The questionnaire-based user study with 15 participants showed that the CardioGuard sensor was comfortable and unobtrusive. Additionally, the signal-to-noise ratio test and the washing durability test were conducted to show the high-quality sensing of the proposed sensor and its physical durability in practical use, respectively

Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System

In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG) monitoring system, Sinabro, which monitors a user’s ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR) and heart rate variability (HRV), to support the pervasive healthcare apps for smartphones based on the user’s high-level contexts, such as stress and affective state levels. In this study, we have extended the Sinabro system by: (1) upgrading the sensor device; (2) improving the feature extraction process; and (3) evaluating extensions of the system. We evaluated these extensions with a good set of algorithm parameters that were suggested based on empirical analyses. The results showed that the system could capture ECG reliably and extract highly accurate ECG-derived features with a reasonable rate of data drop during the user’s daily smartphone use

Pneumatic frequency selection filter in the prior stage of the air pressure transducer

To use frequency selection filter with electrical components, the signal from the transducer should have the detailed information with enough signal-to-noise ratio. In the measurement of air pressure, if the small variation is added to the big amplitude of slowly varying signal, there needs to eliminate the low frequency component in front of the transducer to avoid saturation. To achieve that, the concept of balancing tube was suggested and analyzed as pneumatic high pass filter. The simple method to adjust and find the cutoff frequency of the high pass filter is shown and validated, One application of this measurement technique in physiological monitoring using air mattress and balancing tube is summarized. (C) 2008 Elsevier Ltd. All rights reserved.This study was supported by a grant from the Advanced Biometric Research Center (ABRC) and Korea Science and Engineering Foundation (KOSEF).Chee Y, 2005, PHYSIOL MEAS, V26, P413, DOI 10.1088/0967-3334/26/4/007Watanabe T, 2004, IEEE T BIO-MED ENG, V51, P1735, DOI 10.1109/TBME.2004.828037MIN N, 2003, SENSOR ELECTOGATA M, 1978, SYSTEM DYNAMICS

Low-Power Unobtrusive ECG Sensor System for Wireless Power Transfer

Electrocardiogram (ECG) is one of the most widely used physiological signal that provides fundamental health information. Conventional ECG uses gel-type ECG electrodes, however, the gel-type ECG electrode is inconvenient for long-term or daily-life ECG monitoring. Capacitive ECG sensor was implemented to overcome the shortcoming of gel-type ECG electrodes. The wireless power transfer (WPT) technology can improve ubiquitous healthcare, but the power consumption is an important factor of the system based on WPT. Previous study did not consider the power consumption of the system. In this study, we implemented a low-power capacitive ECG monitoring system. The supply power of the system was 5V, and Bluetooth low energy (BLE) module was applied to decrease the power consumption in wireless data transmission. The total power consumption of the system was 16.4 mW.N

Classification of glucose concentration in diluted urine using the low-resolution Raman spectroscopy and kernel optimization methods

In order to detect minute amounts of glucose in diluted urine, we applied the Raman spectroscopy method. To simulate abnormal diluted urine in a toilet bowl, we diluted normal urine ten-fold with water and added glucose up to 8 mg dl(-1). Data were collected using a low-resolution Raman spectrometer that was preprocessed with the optimizing kernel method. We also applied the neural network algorithm to classify abnormal and normal urine samples according to their glucose concentrations. The kernel optimizing method was very effective in the classification of the tested subjects as it increased the accuracy of classification by 92%. This method suggests the possibility of caring for patients by daily monitoring their urine components in a manner non-invasive to ordinary life

An Instant Donning Multi-Channel EEG Headset (with Comb-Shaped Dry Electrodes) and BCI Applications

We developed a new type of electroencephalogram (EEG) headset system with comb-shaped electrodes that enables the wearer to quickly don and utilize it in daily life. Two models that can measure EEG signals using up to eight channels have been implemented. The electrodes implemented in the headsets are similar to a comb and are placed quickly by wiping the hair (as done with a comb) using the headset. To verify this headset system, donning time was measured and three brain computer interface (BCI) application experiments were conducted. Alpha rhythm-based, steady-state visual evoked potential (SSVEP)-based, and auditory steady state response (ASSR)-based BCI systems were adopted for the validation experiments. Four subjects participated and ten trials were repeated in the donning experiment. The results of the validation experiments show that reliable EEG signal measurement is possible immediately after donning the headsets without any preparation. It took approximately 10 s for healthy subjects to don the headsets, including an earclip with reference and ground electrodes. The results of alpha rhythm-based BCI showed 100% accuracy. Furthermore, the results of SSVEP-based and ASSR-based BCI experiments indicate that performance is sufficient for BCI applications; 95.7% and 76.0% accuracies were obtained, respectively. The results of BCI paradigm experiments indicate that the new headset type is feasible for various BCI applications

Effect of Iron Content on Corrosion Properties of Pure Titanium as Grain Refiner

Microstructures and corrosion properties of pure titanium were characterized when iron was used as a grain refiner. The added Fe element acted as a strong grain refiner for pure titanium by forming β Ti phase at grain boundaries, and 0.15 wt% Fe was revealed to be a sufficient amount to make the grain size of pure titanium below 20 μm, which was the requirement for the desired titanium cathode. However, corrosion resistance was decreased with the Fe amount added. From the open circuit potential (OCP) results, it was obvious that the TiO2 stability against the reducing acid environment was deteriorated with the Fe amount, which seemed to be the main reason for the decreased corrosion resistance. Electrochemical impedance spectroscopy (EIS) results showed that both the decrease in the compact oxide film’s resistance (Rb) and the appearance of the outer porous film occurred as a result of the dissolution of the TiO2 layer, whose phenomena became more apparent as more Fe was added

Effects of Supplementary Blood Meal on the Content of Carnosine and Anserine in Broiler Meat

The objective of this research was to evaluate the effects of dietary supplementation of blood meal (BM) on carnosine (L-Car) and anserine (L-Ans) content in the chicken breast muscle (CBM). In Experiment 1,384 Ross® broiler chicks of 1d old were assigned to 3 dietary treatments: 100% basal diet (BM-0), 95% basal diet+5% BM (BM-5), and 90% basal diet+10% BM (BM-10). In Experiment 2, 144 Ross® broiler chicks of 1 d old were fed BM-treated diets, including 0% BM (BMI-0), 5% BM (BMI-5), and 10% BM (BMI-10), with isocalorie and isonitrogen adjustment. Broilers were reared in stainless steel cages for 5wk in both experiments. In Experiment 1, the content of L-Car and L-Arg increased as the birds aged. The increase was quadratic in L-Car and linear in L-Ans. The content of L-Car linearly (P<0.01) increased as the level of BM increased at wk 4 and 5, but there was no significant difference between BM-5 and BM-10 treatment. Conversely, the content of L-Ans linearly (P<0.01) decreased as the level of BM increased at wk 1, 3, 4, and 5. In Experiment 2, the content of L-Car and L-Arg showed quadratic increase as the birds aged. The content of L-Car showed a significant (P<0.01) negative quadratic response as the level of BM increased at wk 1, 3, and 5. The content of L-Ans showed a significant (P<0.05) positive quadratic response as the level of BM increased at wk 3 and 5. The growth performances were not significantly affected by treatments in Experiment 1; in Experiment 2, however, a linear decrease (P<0.01) in feed intake and weight gain, and a linear increase (P<0.01) in feed conversion ratio were observed as the BM was increased. In conclusion, addition of 5% BM in broiler diet increases the L-Car but not L-Ans in CBM

Optimal Lead Position in Patch-Type Monitoring Sensors for Reconstructing 12-Lead ECG Signals with Universal Transformation Coefficient

The aim of this study was to reconstruct a 12-lead electrocardiograph (ECG) with a universal transformation coefficient and find the appropriate electrode position and shape for designing a patch-type ECG sensor. A 35-channel ECG monitoring system was developed, and 14 subjects were recruited for the experiment. A feedforward neural network with one hidden layer was applied to train the transformation coefficient. Three electrode shapes (5 cm × 5 cm square, 10 cm × 10 cm square, and right-angled triangle) were considered for the patch-type ECG sensor. The mean correlation coefficient (CC) and minimum CC methods were applied to evaluate the reconstruction performance. The average CCs between the standard 12-lead ECG and reconstructed 12-lead ECG were 0.860, 0.893, and 0.893 for a 5 cm × 5 cm square, 10 cm × 10 cm square, and right-angled triangle shape. The right-angled triangle showed the highest performance among the considered shapes. The results also suggested that the bottom of the central area of the chest was the most suitable position for attaching the patch-type ECG sensor