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Abstract Introduction Impairment of sleep quality directly increases the risk of heart attack, obesity, and stroke, among other conditions, which makes polysomnography (PSG) an important public health tool. However, the inherent problems with PSG render the correct diagnosis of sleep diseases a difficult task. As a novel alternative to the class II PSG system, this work presents a distributed system composed of three modules, which together are capable of the simultaneous monitoring of environmental variables and patient signals. This system could reduce the distress of a PSG exam in certain cases, dismiss the need for an overnight sleep in a healthcare/sleep centre, and facilitate self-setup and internet-based diagnosis. Methods Hardware and software capable of synchronously monitoring, processing and logging into a µSD card environmental parameters (temperature, humidity, visible light intensity and audible noise level) and directly measured patient signals (electrocardiogram, electrooculogram, and body and limb posture) were designed and implemented. Results A novel alternative to the class III PSG system was demonstrated with independent boards capable of operating for more than 16 hours powered by a 750 mAh/3.7 V battery with 0.003% data loss during preliminary PSG exams. Additionally, a computer-based library capable of reading, decoding, estimating respiration through ECG, and calculating the heart rate was developed and described. Conclusion This article contributes to PSG research through the development of a new PSG system and the improvement of patient comfort. All software and hardware developed are fully open source and available on GitHub.
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Objective To investigate EBT3 and EDR2 film responses to different linear energy transfers ( LETs) and doses from carbon ion beams. Methods EBT3 and EDR2 films were calibrated by two methods. In the first method, films were placed at the same depth within a phantom and irradiated by beams with different parameters such as beam energy. In the second method, films were separately placed at different depths in a phantom and irradiated by the same beams. These methods were used to irradiate films with ions of different LETs. Results For EBT3 film, the dose calibration curves correlated with different LETs appeared to be typical hyperbolic curves with a maximum difference between the curves of ± 17％ (1σ). Meanwhile, the shape of the dose calibration curves for EDR2 film appeared to be linear. The values along all these curves were within ± 27.4％ (1σ) of the value for the average curve. The dose responses of both films were inversely proportional to LETs. The sensitivity of EBT3 film was inversely proportional to the dose, while the sensitivity of EDR2 film showed no relationship with the dose. Conclusions Influenced by the dual factor of LET and dose, the application of EBT3 film was limited in carbon ion. However, without no dose dependence, EDR2 film could be used to measure dose distributions created by single LET carbon ion beam.
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Water shortage has now become a global issue. Reclamation of the effluent from municipal wastewater treatment plant is feasible for supplying the quick growth of water requirement. The objective of this study was to conduct both the cost analysis and environmental impact evaluation of two reclamation processes: sand filter – ultrafiltration - reverse osmosis (SF-UF-RO) and sand filter - electrodialysis reversal (SF-EDR). The results will serve as a reference for selecting the process in the scale-up construction works. Two processes were installed in a reclamation pilot plant in Futian Water Resource Recycling Center (Taichung City, Taiwan) and operated in parallel to evaluate their stability and product quality. The cost analysis was conducted to estimate the capital requirement of building large-scale plant for reclaiming the effluent. The cost of land construction, mechanical with electronic equipment and operation with maintenance were all considered in the analysis. On the other hand, the environmental assessment of these processes has been realized by Life Cycle Assessment (LCA). The software Sima Pro 7.3 was used as the LCA analysis tool. Four different evaluation methods, including Ecoindicator 99, Ecopoints 97, Impact 2002+ and CML 2 baseline 2000, were applied. The results show that the water quality of SF-EDR has similar potential in reclaiming the effluent from municipal water resource recycling center as SF-UF-RO. The cost of SFEDR is lower than that of SF-UF-RO. In the environmental analysis, the LCA demonstrates that SF-EDR may create more impacts on the environment due to more consumption on electricity and chemicals than SF-UF-RO. Using SF-UF-RO as the effluent reclamation process may be an option causing less impacts on climate change.
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This work presents the development of an ECG-Derived Respiration (EDR) methodology based on the amplitude modulation approach. It allows to redefine actual methodologies in order to obtain a continuous EDR signals with high correlations and small delay between EDR and respiration activity. Two algorithms are implemented: one of them using the amplitude modulation of the R-peak (EDRAM) and another one applying a band-pass filter in the bandwidth of respiration. Unlike other techniques in literature, conventional low order filters are applied without sacrifice of correlation factor (0.76 and 0.67) and a minimum delay of 0.27s (with EDRAM) in a ∼6s cycle. A robustness test was performed, and it shows a noise tolerance of up to 20% of the maximum value before its correlation factor drops considerably. The application into a wearable sensor was successfully implemented. The two methodologies proposed show advantages like real-time processing and robustness under certain noises. The proposed AM perspective supports the use of both algorithms for typical applications with high efficiency, low computational cost and ease of implementation. These characteristics result on a technique that facilitates the development of wearable systems, and to increase the information of actual databases.
Este trabajo presenta una metodología para la extracción de la actividad respiratoria derivada de un ECG (EDR, por sus siglas en ingles), basado en el enfoque de amplitud modulada (AM). Esto permite redefinir las metodologías actuales para obtener una señal EDR más continua, con altos factores de correlación y un retraso menor entre la EDR y la actividad respiratoria. Se implementaron dos algoritmos: uno utilizando la modulación de la amplitud del pico R (EDRAM) y el otro aplicando un filtro paso-banda en el espectro de frecuencia de la respiración. A diferencia de otros trabajos en la literatura, se utilizan filtros convencionales de bajo orden pero sin sacrificar el factor de correlación (0.76 y 0.67) y manteniendo un retardo de ∼0.27s (con EDRAM) en un ciclo de ∼6s. Se realizó una prueba de robustez, donde se muestra una tolerancia a ruido blanco de hasta un 20% del valor máximo antes de que el factor de correlación bajara considerablemente. El algoritmo EDRAM se aplicó con éxito en un prototipo de sistema portable. Las dos metodologías propuestas muestran ventajas como el procesamiento en tiempo real y robustez bajo ciertos ruidos. La perspectiva de AM propuesta soporta el uso de ambos algoritmos para aplicaciones típicas con alta eficiencia, bajo costo computacional y facilidad de implementación. Estas características hacen que esta técnica facilite el desarrollo de sistemas portátiles, así como para incrementar la información de las bases de datos actuales.
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PURPOSE: To compare the accuracy and efficacy of EDR2 film, a 2D ionization chamber array (MatriXX) and an amorphous silicon electronic portal imaging device (EPID) in the pre-treatment QA of IMRT. MATERIALS AND METHODS: Fluence patterns, shaped as a wedge with 10 steps (segments) by a multi-leaf collimator (MLC), of reference and test IMRT fields were measured using EDR2 film, the MatriXX, and EPID. Test fields were designed to simulate leaf positioning errors. The absolute dose at a point in each step of the reference fields was measured in a water phantom with an ionization chamber and was compared to the dose obtained with the use of EDR2 film, the MatriXX and EPID. For qualitative analysis, all measured fluence patterns of both reference and test fields were compared with calculated dose maps from a radiation treatment planning system (Pinnacle, Philips, USA) using profiles and gamma evaluation with 3%/3 mm and 2%/2 mm criteria. By measurement of the time to perform QA, we compared the workload of EDR2 film, the MatriXX and EPID. RESULTS: The percent absolute dose difference between the measured and ionization chamber dose was within 1% for the EPID, 2% for the MatriXX and 3% for EDR2 film. The percentage of pixels with gamma%>1 for the 3%/3 mm and 2%/2 mm criteria was within 2% for use of both EDR2 film and the EPID. However, differences for the use of the MatriXX were seen with a maximum difference as great as 5.94% with the 2%/2 mm criteria. For the test fields, EDR2 film and EPID could detect leaf-positioning errors on the order of -3 mm and -2 mm, respectively. However it was difficult to differentiate leaf-positioning errors with the MatriXX due to its poor resolution. The approximate time to perform QA was 110 minutes for the use of EDR2 film, 80 minutes for the use of the MatriXX and approximately 55 minutes for the use of the EPID. CONCLUSION: This study has evaluated the accuracy and efficacy of EDR2 film, the MatriXX and EPID in the pre-treatment verification of IMRT. EDR2 film and the EPID showed better performance for accuracy, while the use of the MatriXX significantly reduced measurement and analysis times. We propose practical and useful methods to establish an effective QA system in a clinical environment.
Subject(s)
Electronics , Electrons , Silicon , WaterABSTRACT
Lysophosphatidylcholine (LPC), which accumulates in atherosclerotic arteries, has been reported to inhibit endothelium-dependent relaxation (EDR) in many different species. However, the underlying mechanism of LPC-induced inhibition of EDR is still uncertain. In the present study, we measured simultaneously both isometric tension and cytosolic free Ca2+ ([Ca2+]i) in rabbit carotid strips, and examined the effect of LPC on tension and [Ca2+]i. In carotid strips with intact-endothelium, high K+ (70 mM) increased both tension and [Ca2+]i, and cumulative addition of acetylcholine (ACh) from 0.1 to 10microM induced dose dependent increase of [Ca2+]i with concomitant relaxation. In the presence of L-NAME (0.1 mM), ACh increased [Ca2+]i without affecting the amplitude of high K+-induced tension. These ACh-induced change of [Ca2+]i and tension was abolished by removal of endothelium or 10 nM 4-DAMP (muscarinic receptor antagonist) pretreatment. Pretreatment of LPC (10microM) inhibited ACh (10microM)-induced change of tension and [Ca2+]i in endothelium-intact carotid artery. On the other hand, LPC had no effect on ACh-induced change of tension and [Ca2+]i in endothelium denuded artery. In Ca2+-free external solution, ACh transiently increased [Ca2+]i, and pretreatment of LPC significantly inhibited ACh-induced transient [Ca2+]i change. Based on the above results, it may be concluded that LPC inhibits the ACh-induced [Ca2+]i change through inhibition of Ca2+ mobilization in vascular endothelial cells, resulting in decreased production of NO and concomitant inhibition of endothelium-dependent vascular relaxation.
Subject(s)
Acetylcholine , Arteries , Carotid Arteries , Cytosol , Endothelial Cells , Endothelium , Endothelium, Vascular , Hand , Lysophosphatidylcholines , NG-Nitroarginine Methyl Ester , RelaxationABSTRACT
OBJECTIVE: The purpose of this study was to identify chemoresistance and prognosis differences between recurrent micropapillary serous ovarian carcinoma (MPSC) and serous ovarian carcinoma. METHODS: The Extreme drug resistance (EDR) assay was performed in 13 recurrent micropapillary serous ovarian carcinoma and 56 recurrent serous ovarian carcinoma. RESULTS: Mean age of MPSC and Serous ovarian cancer were 41.1 and 58.0 respectively (p<0.05). Etoposide and Doxil were the two least resistance chemotherapeutic agents to recurrent MPSC but the most resistance agents to recurrent serous ovarian cancer. Taxol and cisplatin were the two most resistance agents to MPSC. The mean follow up was 42 months (range 1-173) The five-year overall survival rate of MPSC and serous ovarian carcinoma were 71.6% and 33.9% respectively. The mean survival were 136 months in MPSC compared with 72 months in serous ovarian carcinoma (p<0.035). CONCLUSION: In this retrospective analysis, MPSC showed very different in EDR results and favorable prognosis compare to serous ovarian carcinoma.
Subject(s)
Cisplatin , Drug Resistance , Etoposide , Follow-Up Studies , Ovarian Neoplasms , Paclitaxel , Prognosis , Retrospective Studies , Survival RateABSTRACT
OBJECTIVES AND METHODS: To directly examine the function of the endothelial cell(EC) and smooth muscle cell in umbilical arteries acquired from preeclampsia patients between June 1998 to November 1999, using a conventional tension measurement and bioassay experiment. RESULTS: Relaxation responses to EC-dependent relaxing agents including bradykinin and A23187 in human umbilical artery rings were significantly decreased in preeclampsia(p<0.01). Relaxation responses to EC-independent agents(SNP and SNAP) were also inhibited in umbilical artery rings acquired from preeclampsia patients(p<0.01). To test the change of endothelial cell function in preeclampsia without involvement of smooth muscle dysfunction, we used human umbilical artery and rabbit femoral artery as a donor and detector, respectively, in bioassay experiment. Relaxation responses to EC-dependent agents(A23187 and bradykinin) showed similar results to conventional tension measurement (p<0.01). Relaxation responses to 8-bromo-cGMP in human umbilical artery rings were also significantly decreased in preeclampsia(p<0.01). CONCLUSIONS: It can be concluded that increased vascular resistance in preeclampsia is not only due to the disturbance of endothelial function, but also to smooth muscle dysfunction.