Novel design of smart sleep-lighting system for improving the sleep environment of children.

BACKGROUND: Children struggle to fall asleep by themselves because of their physiological characteristics. Therefore, research has been carried on various devices (such as a smartphone) to assist in improving the sleep quality of children. However, all such devices need to be controlled by parents and do not have functions for monitoring the sleep environment. OBJECTIVE: In this paper, a smart sleep-lighting system that includes a sleep-lighting device and a smartphone dongle is developed to improve the sleep environment of children. METHODS: The temperature, humidity, and luminance of the sleep environment are monitored and analyzed by the sleep-lighting device to control multi-color light and audio components. The colored light emitted by the multi-color light can be adjusted to improve the sleep atmosphere. Also, the audio component can play white noise to induce sleep. In addition, parents can use a smartphone dongle with a multi-channel wireless communication method to monitor and control one or more lighting devices in different locations in real time. RESULTS: For environmental monitoring, average difference between proposed device and commercial sensor from chamber setting temperature 15∘C to 35∘C was 0.588∘C ± 0.10∘C, and average error value of the humidity measurement was 0.74% at 40% ∼ 60% RH. Also, the manufactured sleep-lighting device shows good performance in multi-color light emission, and playing of white noise. As result, the smartphone connected to the proposed smartphone dongle enables monitoring and control of the proposed lighting device in a wireless well. CONCLUSIONS: The manufactured sleep-lighting device has a high-precision temperature and humidity sensor and a luminance sensor that can accurately monitor the sleeping environment. The lighting device can play white noise to induce sleep in children. Also, a multi-color LED light is operated via a smartphone application to improve the sleep atmosphere. The measured data will be sent to the lighting device and processed together with sleep environment data in order to improve the sleep quality. Additionally, the final system will be tested for real end-users with clinical experiments by sleep research center of a university hospital.

Development of a Wireless Health Monitoring System for Measuring Core Body Temperature from the Back of the Body.

In this paper, a user-friendly and low-cost wireless health monitoring system that measures skin temperature from the back of the body for monitoring the core body temperature is proposed. To measure skin temperature accurately, a semiconductor-based microtemperature sensor with a maximum accuracy of ±0.3°C was chosen and controlled by a high-performance/low-power consumption Acorn-Reduced Instruction Set Computing Machine (ARM) architecture microcontroller to build the temperature measuring device. Relying on a 2.4 GHz multichannel Gaussian frequency shift keying (GFSK) RF communication technology, up to 100 proposed temperature measuring devices can transmit the data to one receiver at the same time. The shell of the proposed wireless temperature-measuring device was manufactured via a 3D printer, and the device was assembled to conduct the performance tests and in vivo experiments. The performance test was conducted with a K-type temperature sensor in a temperature chamber to observe temperature measurement performance. The results showed an error value between two devices was less than 0.1°C from 25 to 40°C. For the in vivo experiments, the device was attached on the back of 10 younger male subjects to measure skin temperature to investigate the relationship with ear temperature. According to the experimental results, an algorithm based on the curve-fitting method was implemented in the proposed device to estimate the core body temperature by the measured skin temperature value. The algorithm was established as a linear model and set as a quadratic formula with an interpolant and with each coefficient for the equation set with 95% confidence bounds. For evaluating the goodness of fit, the sum of squares due to error (SSE), R-square, adjusted R-square, and root mean square error (RMSE) values were 33.0874, 0.0212, 0.0117, and 0.3998, respectively. As the experimental results have shown, the mean value for an error between ear temperature and estimated core body temperature is about ±0.19°C, and the mean bias is 0.05 ± 0.14°C when the subjects are in steady status.

Implementation of automatic external defibrillator using real time ventricular fibrillation detecting algorithm based on time domain analysis.

The increase in mortality associated with arrhythmia is an inevitable problem of modern society such as westernized eating habits and an increase in stress due to industrialization, and the related social costs are increasing. In this regard, the supply of automatic external defibrillator (AED) used outside hospitals is increasing mainly in public institutions, and AED is a medical practice performed by non-medical personnel. Therefore, studies on arrhythmia detection algorithm to make accurate clinical judgment for proper use are increasing. In this paper, we propose a time domain analysis method to detect arrhythmia in real time and implement AED by porting it to programmable gate array and digital signal processor. The analysis of the phase domain improves the detection rate of R-peak using the differentiated electrocardiogram (ECG) waveform rather than the existing ECG waveform and makes it easy to distinguish the normal ECG from the arrhythmia signal in the phase domain. The proposed algorithm was verified by simulation using Labview and ModelSim, and it was verified that the proposed algorithm works effectively by performing animal experiments using the implemented AED.

Development of visible and NIR imaging equipment for small animals with smart pad.

The portable visible and near-infrared (NIR) imaging equipment for a pre-clinical test with small animals was designed and developed in this paper. The developed equipment is composed of a CCD camera, a focusing lens, an objective lens, a NIR band pass filter and a NIR filter driving motor. An NIR ray is mainly used for imaging equipment because it has high light penetration depth in biological tissue. Therefore, NIR fluorescent agents are available for chemical conjugation to targeting molecules in vivo. This equipment can provide a visible image, NIR image and merged image simultaneously. A communication system was specifically established to check obtained images through a smart pad in real time. It is less dependent on space and time than the conventional system.

Implemented a wireless communication system for VGA capsule endoscope.

Recently, several medical devices that use wireless communication are under development. In this paper, the small size frequency shift keying (FSK) transmitter and a monofilar antenna for the capsule endoscope, enabling the medical device to transmit VGA-size images of the intestine. To verify the functionality of the proposed wireless communication system, computer simulations and animal experiments were performed with the implemented capsule endoscope that includes the proposed wireless communication system. Several fundamental experiments are carried out using the implemented transmitter and antenna, and animal in-vivo experiments were performed to verify VGA image transmission.

Enzyme nanoparticle fabrication: magnetic nanoparticle synthesis and enzyme immobilization.

Immobilized enzymes are drawing significant attention for potential commercial applications as biocatalysts by reducing operational expenses and by increasing process utilization of the enzymes. Typically, immobilized enzymes have greater thermal and operational stability at various pH values, ionic strengths and are more resistant to denaturation that the soluble native form of the enzyme. Also, immobilized enzymes can be recycled by utilizing the physical or chemical properties of the supporting material. Magnetic nanoparticles provide advantages as the supporting material for immobilized enzymes over competing materials such as: higher surface area that allows for greater enzyme loading, lower mass transfer resistance, less fouling effect, and selective, nonchemical separation from the reaction mixture by an applied a magnetic field. Various surface modifications of magnetic nanoparticles, such as silanization, carbodiimide activation, and PEG or PVA spacing, aid in the binding of single or multienzyme systems to the particles, while cross-linking using glutaraldehyde can also stabilize the attached enzymes.

Synthesis and characterization of enzyme-magnetic nanoparticle complexes: effect of size on activity and recovery.

The influence of particle size on the activity and recycling capabilities of enzyme conjugated magnetic nanoparticles was studied. Co-precipitation and oxidation of Fe(OH)(2) methods were used to fabricate three different sizes of magnetic nanoparticles (5 nm, 26 nm and 51 nm). Glucose oxidase was covalently bound to the magnetic nanoparticles by modifying the surfaces with 3-(aminopropyl)triethoxysilane (APTES) and a common protein crosslinking agent, glutaraldehyde. Analysis by Transmission Electron Microscopy (TEM) showed that the morphology of the magnetic nanoparticles to be spherical and sizes agreed with results of the Brunauer, Emmett, and Teller (BET) method. Magnetic strength of the nanoparticles was analyzed by magnetometry and found to be 49 emu g(-1) (5 nm), 73 emu g(-1) (26 nm), and 85 emu g(-1) (51 nm). X-ray photoelectron spectroscopy (XPS) confirmed each step of the magnetic nanoparticle surface modification and successful glucose oxidase binding. The immobilized enzymes retained 15-23% of the native GOx activity. Recycling stability studies showed approximately 20% of activity loss for the large (51 nm) and medium (26 nm) size glucose oxidase-magnetic nanoparticle (GOx-MNP) bioconjugate and about 96% activity loss for the smallest GOx-MNP bioconjugate (5 nm) after ten cycles. The bioconjugates demonstrated equivalent total product conversions as a single reaction of an equivalent amount of the native enzyme after the 5th cycle for the 26 nm nanoparticles and the 7th cycle for the 51 nm nanoparticles.

Surface-enhanced Raman scattering detection of DNA derived from the west nile virus genome using magnetic capture of Raman-active gold nanoparticles.

A model paramagnetic nanoparticle (MNP) assay is demonstrated for surface-enhanced Raman scattering (SERS) detection of DNA oligonucleotides derived from the West Nile virus (WNV) genome. Detection is based on the capture of WNV target sequences by hybridization with complementary oligonucleotide probes covalently linked to fabricated MNPs and Raman reporter tag-conjugated gold nanoparticles (GNPs) and the subsequent removal of GNP-WNV target sequence-MNP hybridization complexes from solution by an externally applied magnetic source. Laser excitation of the pelleted material provided a signature SERS spectrum which is diagnostic for the reporter, 5,5'-dithiobis(succinimidy-2-nitrobenzoate) (DSNB), and restricted to hybridization reactions containing WNV target sequences. Hybridizations containing dilutions of the target oligonucleotide were characterized by a reduction in the intensification of the spectral peaks accorded to the SERS signaling of DSNB, and the limit of detection for target sequence in buffer was 10 pM. Due to the short hybridization times required to conduct the assay and ease with which reproducible Raman spectra can be acquired, the assay is amenable to adaptation within a portable, user-friendly Raman detection platform for nucleic acids.

Combination of uric acid and NT-ProBNP: a more useful prognostic marker for short-term clinical outcomes in patients with acute heart failure.

BACKGROUND/AIMS: In patients with heart failure (HF), N-terminal prohormone brain natriuretic peptide (NT-ProBNP) is a standard prognostic indicator. In addition, uric acid (UA) was recently established as a prognostic marker for poor outcome in chronic HF. The aim of this study was to determine the combined role of UA and NT-ProBNP as prognostic markers for short-term outcomes of acute heart failure (AHF). METHODS: The levels of UA and NT-ProBNP were determined in 193 patients (age, 69 ± 13 years; 76 males) admitted with AHF. Patients were followed for 3 months and evaluated for cardiovascular events, defined as cardiac death and/or readmission for HF. RESULTS: Of the 193 patients, 23 (11.9%) died and 20 (10.4%) were readmitted for HF during the 3-month follow-up period. Based on univariate analysis, possible predictors of short-term cardiovascular events were high levels of UA and NT-ProBNP, low creatinine clearance, no angiotensin converting enzyme inhibitors or angiotensin receptor blockers, and old age. Multivariate Cox hazard analysis showed that UA levels were independently associated with increased incidence of cardiovascular events (hazard ratio, 1.115; 95% confidence interval, 1.006 to 1.235; p = 0.037). Kaplan-Meier survival analysis revealed that patients with UA levels > 8.0 mg/dL and NT-ProBNP levels > 4,210 pg/mL were at highest risk for cardiac events (p = 0.01). CONCLUSIONS: The combination of UA and NT-ProBNP levels appears to be more useful than either marker alone as an independent predictor for short-term outcomes in patients with AHF.

Diagnostic analysis of patients with essential hypertension using association rule mining.

OBJECTIVES: The purpose of this study was to analyze the records of patients diagnosed with essential hypertension using association rule mining (ARM). METHODS: Patients with essential hypertension (ICD code, I10) were extracted from a hospital's data warehouse and a data mart constructed for analysis. Apriori modeling of the ARM method and web node in the Clementine 12.0 program were used to analyze patient data. RESULTS: Patients diagnosed with essential hypertension totaled 5,022 and the diagnostic data extracted from those patients numbered 53,994. As a result of the web node, essential hypertension, non-insulin dependent diabetes mellitus (NIDDM), and cerebral infarction were shown to be associated. Based on the results of ARM, NIDDM (support, 35.15%; confidence, 100%) and cerebral infarction (support, 21.21%; confidence, 100%) were determined to be important diseases associated with essential hypertension. CONCLUSIONS: Essential hypertension was strongly associated with NIDDM and cerebral infarction. This study demonstrated the practicality of ARM in co-morbidity studies using a large clinic database.

A new method for non-invasive measurement of skin in the low frequency range.

OBJECTIVES: The purpose of our study was to estimate skin structure and conductivity distribution in a cross section of local tissue using non-invasive measurement of impedance data. The present study was designed to evaluate the efficiency of skin depth information through computer simulations. The multilayer tissue model was composed of epidermis, dermis tissues, and subcutaneous. METHODS: In this study, electrical characteristics of skin models were used for conductivity of 0.13 S/m, 0.26 S/m, 0.52 S/m, permittivity of 94,000 F/m, and a frequency of 200 Hz. The effect of the new method was assessed by computer simulations using three-electrode methods. A non-invasive electrical impedance method has been developed for analysis using computer simulation and a skin electrical model with low frequency range. Using the three-electrode method differences through the potentials between measurement electrodes and reference electrodes can be easily detected. The Cole electrical impedance model, which is better suited for skin was used in this study. RESULTS: In this study, experiments using three-electrode methods were described by computer simulation based on a simple model. This electrical impedance model was fitted and developed in comparison with our model for measurement of skin impedance. CONCLUSIONS: The proposed electrical model for skin is suitable for use in interpretation of changes in impedance characterization of the skin. Using the computer simulation method, information on skin impedance depth can be more accurately developed and predicted.

Support Vector Regression-based Model to Analyze Prognosis of Infants with Congenital Muscular Torticollis.

OBJECTIVES: Congenital muscular torticollis, a common disorder that refers to the shortening of the sternocleidomastoid in infants, is sensitive to correction through physical therapy when treated early. If physical therapy is unsuccessful, surgery is required. In this study, we developed a support vector regression model for congenital muscular torticollis to investigate the prognosis of the physical therapy treatent in infants. METHODS: Fifty-nine infants with congenital muscular torticollis received physical therapy until the degree of neck tilt was less than 5°. After treatment, the mass diameter was reevaluated. Based on the data, a support vector regression model was applied to predict the prognoses. RESULTS: 10-, 20-, and 50-fold cross-tabulation analyses for the proposed model were conducted based on support vector regression and conventional multi-regression method based on least squares. The proposed methodbased on support vector regression was robust and enabled the effective analysis of even a small amount of data containing outliers. CONCLUSIONS: The developed support vector regression model is an effective prognostic tool for infants with congenital muscular torticollis who receive physical therapy.

Implementation of Chest X-ray Observation Report Entry System.

OBJECTIVES: X-rays are widely used in medical examinations. In particular, chest X-rays are the most frequent imaging test. However, observations are usually recorded in a free-text format. Therefore, it is difficult to standardize the information provided to construct a database for the sharing of clinical data. Here, we describe a simple X-ray observation entry system that can interlock with an electronic medical record system. METHODS: We investigated common diagnosis indices. Based on the indices, we have designed an entry system which consists of 5 parts: 1) patient lists, 2) image selection, 3) diagnosis result entry, 4) image view, and 5) main menu. The X-ray observation results can be extracted in an Excel format. RESULTS: The usefulness of the proposed system was assessed in a study using over 500 patients' chest X-ray images. The data was readily extracted in a format that allowed convenient assessment. CONCLUSIONS: We proposed the chest X-ray observation entry system. The proposed X-ray observation system, which can be linked with an electronic medical record system, allows easy extraction of standardized clinical information to construct a database. However, the proposed entry system is limited to chest X-rays and it is impossible to interpret the semantic information. Therefore, further research into domains using other interpretation methods is required.

Comparison of long-term outcomes following sirolimus-eluting stent vs paclitaxel-eluting stent implantation in patients with long calcified coronary lesions.

BACKGROUND: Although previously reported studies on coronary calcification mainly focused on its presence or absence in discrete focal target lesions, calcified coronary lesions (CCL) angiographically present as diffuse long lesions in some patients. The aim of our study was to evaluate the long-term efficacy of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) on long CCL. METHODS: A total of 122 patients with 134 lesions (77 patients with 88 lesions for SES and 45 patients with 46 lesions for PES) were enrolled from 3 centers. Long CCL was defined visually as a culprit lesion with type B or C that was mainly due to coronary calcification with > 20 mm in total length by coronary angiography. Clinical follow-up was performed at 1 year and angiographic follow-up at 6 to 9 months after procedure. Major adverse coronary events (MACE) were defined as all-cause death, myocardial infarction (MI), and repeat target-lesion revascularization (TLR). RESULTS: There were no statistically significant differences in baseline, procedural, or angiographic characteristics and in 1-year rates of all-cause death, MI, and TLR between the 2 groups (all P = NS [not significant]). Likewise, the cumulative incidence of MACE at 1 year was similar between the 2 groups (7.8% of patients in the SES group vs 4.4% of patients in the PES group, respectively, P = NS). In patients who underwent follow-up angiography, the angiographic binary restenosis rate was 6.2% in the SES group vs 12.1% in the PES group, respectively (P = NS). CONCLUSION: In patients with long CCL, both SES and PES were comparably effective in either angiographic or clinical long-term outcomes.