Han-Chang Wu

Infrared spectrometry based 13C-octanoic acid breath test in measuring human solid gastric emptying

Background and Aims: Because of the convenience of non‐dispersive infrared spectrometry (NDIRS), we attempted to validate the usefulness of NDIRS compared with scintigraphy in human solid gastric emptying (GE) measurement, and tried to establish the normal range of solid GE based on NDIRS.

Psychosocial distress is associated with abnormal gastric myoelectrical activity in patients with functional dyspepsia

Objective. Functional dyspepsia (FD) is a heterogeneous and loosely defined clinical syndrome that is characterized by persistent or recurrent abdominal pain or discomfort centered in the upper abdomen without any identifiable structural or biochemical basis. Gastric myoelectrical activity in functional dyspepsia patients with gastric reddish streaks as a subgroup has not previously been investigated and the potential role of psychosocial distress in the genesis of gastric dysrhythmia in patients with FD is unclear. Material and methods. Electrogastrography was performed in 45 patients with FD and 35 healthy controls for 30 min in the fasting state and 30 min postprandially. Psychological distress and the number and severity of stressful life events were measured using self-rating questionnaires. Results. FD patients had a higher percentage of pre- and postprandial dysrhythmia, lower dominant frequency, and a higher instability coefficient as compared to healthy controls. In FD patients, severity of stressful life events was positively correlated with the percentage of tachygastria in the fasting state (r=0.43, p=0.005) and marginally positively correlated with the percentage of postprandial tachygastria (r=0.253, p=0.098) and instability coefficient of the dominant frequency (r=0.256, p=0.093). Total number of stressful life events was marginally positively correlated with fasting tachygastria (r=0.25, p=0.098) and instability coefficient of the postprandial dominant frequency (r=0.287, p=0.056). Interpersonal sensitivity was found to be negatively correlated with fasting dominant frequency in FD patients (r= − 0.311, p<0.05). Conclusions. FD patients with gastric reddish streaks have abnormal fasting and postprandial gastric myoelectrical activity. Perceived severity of stressful life events and interpersonal sensitivity are associated with disturbance of gastric myoelectrical activity.

A portable monitor for fetal heart rate and uterine contraction

The authors describe a low-power lightweight device for long-term ambulatory monitoring of high-risk pregnancies. The portable instrument was developed to monitor fetal heart rate (FHR) and uterine contraction (UC) continuously. It can record the abnormal FHR and UC, and it alerts pregnant women when to go to the hospital to see a physician. The abnormal FHR and UC recorded by the monitor can be analyzed by the associated system, which provides valuable data for the physician as an aid to diagnosis and treatment. The monitor is miniaturized for ambulatory monitoring and is powered by a commercial alkaline 9 V battery.

Real-time display of the stomach slow wave and its parameters in a newly designed electrogastrographic system

Abstract: We designed a new three-channel electrogastrographic (EGG) system, which was easily operated on the Windows 95 platform and could automatically provide slow wave parameters. The purpose of the present study was to test its reliability and accuracy in clinical recording. The system included a signal acquisition device assembled on a printed circuit board. Recorded myoelectrical signals were filtered, amplified, digitized, and transmitted via this device into a notebook personal computer (PC). Based on the short-term Fourier transform the software could transfer the time domain of the signal into the frequency domain. Real-time displayed slow wave parameters, including dominant frequency/power, percent of normal frequency (2–4 cpm), instability coefficient in frequency/power, and power ratio, were automatically renewed every 64 s. Twenty healthy subjects (M/F, 12/8; age, 23–51 years) were enrolled to measure both fast and postprandial myoelectrical activities for each 30-min recording. Our results indicated that meal ingestion significantly increased dominant frequency (3.15 ± 0.20 vs 3.23 ± 0.23 cpm; P < 0.05) and power (26.1 ± 3.8 vs 28.4 ± 3.9 dB; P < 0.05). The power ratio of the meal effect was 2.02 ± 2.07. Other parameters, including instability coefficient and percent of normal frequency, remained similar despite food ingestion. This newly designed EGG system is acceptable for clinically measuring gastric myoelectrical activity; the real-time display of many EGG parameters is an advantage with this new system.

A mobile system for real-time patient-monitoring with integrated physiological signal processing

Telemedicine is a rapidly growing area and recently there are studies devoted to prehospital care of patients in emergency cases. Here we present a GSM-network-based, function-integrated telemonitoring system to give first aid before reaching the hospital.

A low-cost architecture of audiometer based on direct digital synthesizer

The authors propose a new architecture for audiometers. By utilizing a direct digital synthesizer (DDS), pure tone testing signals could be generated more precisely than by other existing techniques. A microcontroller was used to receive the stimulating commands from a PC and then send appropriate control signals to the DDS and the log attenuator. All components were assembled with compact size and low cost.

Electrogastrographic characteristics in subjects with stomach remnant

Background and Aims:  Slow wave (SW) is an essential component in mediating stomach motility. The purpose of the present study was to investigate the SW characteristics in subjects with stomach remnant.

Areca nut extracts suppress the differentiation and functionality of human monocyte‐derived dendritic cells

BACKGROUND AND OBJECTIVE Areca quid chewing, a major risk factor contributing to the occurrence of oral cancer and precancer, has been reported to be associated with the severity and high prevalence of periodontal diseases in areca quid chewers. As dendritic cells are critically involved in the regulation of innate and adaptive immunity in oral mucosa, the objective of the present study was to investigate the effect of areca nut extracts (ANE) on the differentiation and reactivity of dendritic cells derived from monocytes. MATERIAL AND METHODS Human peripheral blood monocytes were cultured in the presence of granulocyte-monocyte colony-stimulating factor and interleukin-4 for 7 d to generate dendritic cells. To examine the effect of ANE on the generation of dendritic cells, the monocytes were exposed to ANE throughout the 7 d culture period. In addition, the effect of ANE on the maturation of monocyte-derived dendritic cells induced by lipopolysaccharide (LPS) was examined. RESULTS Monocytes cultured in granulocyte-monocyte colony-stimulating factor and interleukin-4 exhibited a typical phenotype of dendritic cells, as evidenced by the heightened expression of human leukocyte antigen (HLA)-DR, CD11c and the co-stimulatory molecules CD40, CD80 and CD86. Exposure of the monocytes to ANE did not influence the expression of HLA-DR and CD11c, but markedly attenuated the proportion of CD40-positive cells and the mean fluorescence intensity of CD86. The expression of co-stimulatory molecules in LPS-activated dendritic cells was not affected, whereas the mRNA expression of interleukin-12 induced by LPS was markedly suppressed by ANE treatment in a concentration-dependent manner. CONCLUSION These results suggest that ANE exposure interfered with the differentiation of dendritic cells from monocytes. Moreover, the functionality of mature monocyte-derived dendritic cells was attenuated in the presence of ANE.

Monitoring long-term uterine contractions

The proposed system for long-term uterine contraction monitoring includes a pressure sensor and a portable monitor. The pressure sensor converts uterine activities into frequency variations from 1 to 2 MHz. The portable monitor is a microcontroller-based embedded system. We chose the 89c52 microcontroller because of its intelligence and functionality. A CMOS counter serves as a frequency down-converter for scaling down the frequency variation from 50 to 100 kHz.

Power distribution analysis of cutaneous electrogastrography using discrete wavelet transform

The electrogastrography (EGG) is considered more and more important due to its noninvasive measurement. Some parameters have been used to assess the EGG signals and the short term Fourier transform was the most commonly used tool to evaluate these parameters. However FFT is used to analyze stationary signals, while non-stationary signals such as EGG may be distorted. A new method based on discrete wavelet transform was achieved to analyze the power distribution of the EGG signals.