Browsing by Author "Wang, Jhi-Joung"

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Brain tissue oxygen evaluation by wireless near-infrared spectroscopy
(2016-02-01)
Wang, Che-Chuan
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Kuo, Jinn-Rung
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Chen, Yu-Chih
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Chio, Chung-Ching
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Wang, Jhi-Joung
Background: Monitoring the partial pressure of oxygen in brain tissue (PbtO(2)) is an important tool for traumatic brain injury (TBI) but is invasive and inconvenient for real time monitoring. Near-infrared spectroscopy (NIRS), which can monitor hemoglobin parameters in the brain tissue, has been used widely as a noninvasive tool for assessing cerebral ischemia and hypoxia. Therefore, it may have the potential as a noninvasive tool for estimating the change of PbtO(2). In this study, a novel wireless NIRS system was designed to monitor hemoglobin parameters of rat brains under different impact strengths and was used to estimate the change of PbtO(2) noninvasively in TBI. Materials and methods: The proposed wireless NIRS system and a PbtO(2) monitoring system were used to monitor the oxygenation of rat brains under different impact strengths. Rats were randomly assigned to four different impact strength groups (sham, 1.6 atm, 2.0 atm, and 2.4 atm; n = 6 per group), and the relationships of concentration changes in oxyhemoglobin (HbO(2)), deoxyhemoglobin (HbR), and total hemoglobin (HbT), and PbtO(2) during and after TBI with different impact strengths were investigated. Triphenyltetrazolium chloride (TTC) staining was also used to evaluate infarction volume. Results: Concentration changes in HbO(2), HbR, and HbT dropped immediately after the impact, increased gradually, and then became stable. Changes in PbtO(2) had a similar tendency with the hemoglobin parameters. There was significant correlation between changes in PbtO(2) and HbO(2) (correlation = 0.76) but not with changes in HbR (correlation = 0.06). In triphenyltetrazolium chloride staining, the infarction volume was highly but negatively associated with oxygen-related parameters like PbtO(2) and HbO(2). Conclusions: Changes in HbO(2) under TBI was highly and positively correlated with changes in PbtO(2). By using the relative changes in HbO(2) as a reference parameter, the proposed
Deep brain light stimulation effects on glutamate and dopamine concentration
(2015-01-01)
Kuo, Jinn-Rung
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Lin, Shih-Shian
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Liu, Janelle
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Chen, Shih-How
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Chio, Chung-Chin
Compared to deep brain electrical stimulation, which has been applied to treating pathological brain diseases, little work has been done on the effect of deep brain light stimulation. A fiber-coupled laser stimulator at 840 nm wavelength and 130 Hz pulse repetition rate is developed in this work for deep brain light stimulation in a rat model. Concentration changes in glutamate and dopamine in the striatum are observed using a microdialysis probe when the subthalamic nucleus (STN) is stimulated at various optical power levels. Experimental results show that light stimulation causes the concentration of glutamate to decrease while that of dopamine is increased. This suggests that deep brain light stimulation of the STN is a promising therapeutic strategy for dopamine-related diseases such as Parkinson's disease. The stimulator developed for this work is useful for deep brain light stimulation in biomedical research. (C) 2014 Optical Society of America
Design of a bi-directional illumination system for a dual view capsule endoscope
(2019-02-06)
Sheu, Ming-Jen
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Liu, Ying-Lan
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Wang, Jhi-Joung
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Pan, Jui-Wen
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光電系統研究所
The capsule endoscope is an important tool for the intestinal examination. But the main disadvantage of the traditional capsule endoscope is the limited field of view. In order to solve this problem, the dual view capsule endoscope (DVCE) was developed. In this work, a dual view illumination system is designed for a DVCE. The dual view illumination system is divided into two sub-systems with a front view illumination lens and a back view illumination lens. The Bezier curves for the front view and back view illumination lenses are used for optimization, based on which we change the radiation pattern of the LED so that the dual view illumination design can support energy for the front view and back view simultaneously while achieving low power consumption and high efficiency. Moreover, a non-uniform illumination process is used to compensate for the problem of uniformity and relative illumination for the DVCE lens. Through this design, we can obtain a uniformity of 91% and an efficiency of 25.2% for front view illumination and uniformity of 91% and an efficiency of 23.5% for back view illumination. Finally, tolerance analysis can also be completed for mass production.
Design of wearable and wireless electrical impedance tomography system
(2016-01-01)
Huang, Ji-Jer
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Hung, Yi-Hsuan
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Wang, Jhi-Joung
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Lin, Bor-Shyh
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影像與生醫光電研究所
Electrical impedance tomography (EIT) is a non-invasive approach to reconstruct the cross-section impedance image of the body. Many EIT systems and impedance image reconstruction algorithms have been proposed in previous studies. However, most of these EIT systems are bulky to cause the limitation of applications. In this study, a wearable and wireless EIT system is proposed to reconstruct impedance images non-invasively and wirelessly. By microminiaturizing the conventional EIT system, the proposed system can provide the advantages of small volume and wireless transmission to reduce the application limitation of conventional EIT systems. Finally, the phantom experiment is tested to validate the performance of the proposed EIT system. The experimental results show the average BR value of the reconstructed image obtained by the proposed system being 1.3 +/- 0.2 and the averaged location error ratio being about 6.27 +/- 3.14%. Therefore, the proposed wearable and wireless EIT system can be viewed as a good system prototype and may be applied to more clinical applications in the future. (C) 2015 Elsevier Ltd. All rights reserved.
Development of Novel Hearing Aids by Using Image Recognition Technology
(2019-05-01)
Lin, Bor-Shing
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Liu, Ching-Feng
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Cheng, Chih-Jen
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Wang, Jhi-Joung
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Liu, Chengyu
Speech is easily affected by different background noise in real environment to reduce the speech intelligibility, in particular, for hearing impaired listeners. In order to improve the above issue, several hearing aids have been developed to enhance the speech signal in noisy environment. Most of current hearing aids were designed to enhance the component of speech and suppress the component of noise. However, it is difficult to separate other speech sources. Adaptive signal enhancement with the beamforming technique might improve the above issue. However, how to distinguish the location of the desired speaker effectively is still a difficult challenge for adaptive beamforming method. A novel concept of hearing aid was proposed in this study. Different from the beamforming-based hearing aids, which use the cross-correlation-coefficient method to estimate time difference of arrival (TDOA), an image recognition technology was used to estimate the location of the desired speaker to obtain the more precise TDOA. An adaptive signal enhancement was also used to enhance the noisy speech sound. From the experimental results, the proposed system could provide a smaller absolute error of TDOA less than 1.25 x 10(-4) ms, and a clear speech sound from the target speaker who the user wants to listen to.
Dual view capsule endoscopic lens design
(2015-04-06)
Sheu, Ming-Jen
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Chiang, Che-Wen
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Sun, Wen-Shing
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Wang, Jhi-Joung
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Pan, Jui-Wen
A dual view capsule endoscopic (DVCE) lens is proposed with front view and back view functions. This is a hybrid lens with a catadioptric mirror and an aspherical surface to support both view functions. The field of view (FOV) for the front view function is 90 degrees. The FOV for the back view function is 260 to 290 degrees. The TV distortion for the front view and back view function is under 30% and 25%. The corner relative illuminations for the two view functions are above 0.53. The Modulation Transfer Function (MTF) performance at the Nyquist Frequency for the two view functions can be kept above 0.35, even under tolerance they can remain above 0.2. Moreover, the telecentric conditions at the image plane of the DVCE system can support constant magnification through focusing. This condition can reduce the measurement error by slightly defocusing of the lens. Thus, the two view functions can offer physicians a wide viewing angle to deal with lesions over the fold. (C)2014 Optical Society of America
Estimation on the effect of local brain cooling after head injury by wireless near infrared spectroscopy
(2017-02)
Wang, Che-Chuan
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Wang, Yao-Chin
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Liao, Yi-Chien
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Wang, Jhi-Joung
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Chan, Ming-Che
Local brain cooling is a way to treat traumatic brain injury and prevent secondary brain injury. The aim of this study is to explore the change of hemoglobin during local brain cooling after traumatic brain injury, and assess the treatment effect by using the wireless near infrared spectroscopy (NIRS) system. Assign all male Sprague Dawley rats to three groups randomly: sham, fluid percussion injury (FPI), FPI + cooling. After executing fluid percussion injury, a cold water bag (5-6 degrees C) was used locally for 30 min. The wireless NIRS system which we developed was used to monitor the concentration change of HbO(2), HbR and HbT. And other physiological parameters, ICP and CPP, were also monitored during the experiment. According to previous results, local brain cooling could reduce infarction volume while traumatic brain injury occurs. Similarly, our results show that local brain cooling caused oxy-hemoglobin, the tissue oxygen saturation and CPP increase and ICP decreased. From the results, the hemoglobin parameters, ICP and MAP were affected by temperature. And local cooling after FPI might have clinical benefits in the future. In addition, the wireless NIRS system might be an instrument to assess the effect of hypothermia. (C) 2016 Elsevier Ltd. All rights reserved.
Increased risk of deep neck infection among HIV-infected patients in the era of highly active antiretroviral therapy-a population-based follow-up study
(2013-04-22)
Liu, Ching-Feng
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Weng, Shih-Feng
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Lin, Yung-Song
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Lin, Chih-Sheng
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Lien, Ching-Feng
Background: Deep neck infections (DNIs) in HIV-infected patients often produce severe complications, even death. Data on the incidence rates and risks of DNI among HIV-infected patients are scarce, particularly with the widespread use of highly active antiretroviral therapy (HAART). We evaluated the incidence rates and risks for DNI among HIV-infected patients and observed the long-term trends. Methods: A total of 9888 new HIV-infected patients diagnosed in 2001-2007 were included and matched with 49440 randomly selected subjects. The HIV-infected subjects were offered free access to HAART. All subjects were traced until December 2009. A Kaplan-Meier analysis generated the cumulative DNI incidence rate. The adjusted hazard ratio was computed using Cox proportional hazard regressions. Results: From the HIV-infected and comparison cohorts, 222 individuals (57.01 cases per 10000 person-years) and 735 individuals (35.54 cases per 10000 person-years) developed DNI, respectively. The log rank test indicated that patients with HIV had a significantly higher 8-year incidence rate of DNI than the control group (P < 0.0001). The adjusted hazard ratio for developing DNI after an HIV attack during the mean 3.94 years follow-up period was 1.59. The incidence rate and relative risk of DNI were 74.58 (per 10000 person-years) and 2.05 (P < 0.0001). Both figures were highest in the first follow-up year and decreased year-by-year thereafter. Conclusion: The risk of developing DNI is significantly elevated among HIV-infected patients, even with free access to HAART. Additional research is needed to examine the role of HAART in reducing the risk.
The impact of comorbidity on survival after hemorrhagic stroke among dialysis patients: a nationwide population-based study
(2014-11-27)
Lin, Chun-Yu
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Chien, Chih-Chiang
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Chen, Hung-An
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Su, Fu-Mei
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Wang, Jhi-Joung
Background: This study was aimed at determining the outcome and examining the association between comorbidities and mortality after intracerebral hemorrhage in chronic dialysis patients. Methods: We used the Taiwan National Health Insurance Research Database and enrolled patients who underwent maintenance dialysis between 2000 and 2007. Annual incidence of intracerebral hemorrhage in patients receiving dialysis from 2000 to 2007 was determined. To identify predictors of hemorrhagic stroke, we used logistic regression model to estimate the relative ratio of factors for intracerebral hemorrhage in the most recent cohort (2007). The cumulative survival rate and comorbid conditions associated with mortality after intracerebral hemorrhage among all dialysis patients between 2000 and 2007 was calculated using the Kaplan-Meier method and Cox regression analysis. Results: We identified 57,261 patients on maintenance dialysis in the cohort of 2007, and 340 patients had history of intracerebral hemorrhage among them. Hypertension was the most common comorbidity of dialysis patients. The incidence rate of intracerebral hemorrhage among dialysis patients was about 0.6%. Adjusted logistic regression model showed that male gender, middle age (45-64 years), hypertension, and previous history of stroke were the independent predictors for the occurrence of intracerebral hemorrhage among chronic dialysis patients. 1,939 dialysis patients with development of intracerebral hemorrhage in the analysis period from 2000 to 2007 were identified. In-hospital mortality was high (36.15%) following intracerebral hemorrhage. They were followed up after intracerebral hemorrhage for a mean time of 41.56 months. Adjusted Cox regression analyses demonstrated that the factors independently associated with mortality after intracerebral hemorrhage among dialysis patients included diabetes mellitus, malignancy and a history of prior stroke. Conclusions: Dialysis patients who have history of prior stroke, diabetes and malignancy have worse survival than patients without these comorbidities. Attention must focus on providing optimal medical care after hemorrhagic stroke for these target groups to reduce mortality.
The use of surface electromyography in dysphagia evaluation
(2017-01-01)
Wang, Yao-Chin
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Chou, Willy
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Lin, Bor-Shing
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Wang, Jhi-Joung
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Lin, Bor-Shyh
Dysphagic patients usually have a variety of clinical problems such as malnutrition, significant weight loss, and aspiration pneumonia. Dysphagia is a complication commonly caused by strokes, and surface electromyography (sEMG) provides a simple, non-radioactive, and non-invasive method to measure the patterns of muscle activity during swallowing, allowing clinicians to describe the physiology of swallowing behavior. Most previous studies have described swallowing behavior in terms of amplitude and duration. However, there is no objective and precise approach available for the evaluation of swallowing coordination. In order to evaluate swallowing coordination more precisely, a wireless and wearable monitoring device for dysphagia evaluation was designed for the present study in order to measure four muscle groups simultaneously during swallowing. In this context, the variations of the cross-correlation coefficients were defined as the discoordination index, a metric which can effectively reflect the differences between the surface EMG patterns of the bilateral muscle groups. The experimental results of this study show that the discoordination indices for dysphagic patients are significantly larger than those for healthy subjects and that these discoordination indices can be used as an effective means of evaluating the coordination between bilateral swallowing muscles.
Wireless near-infrared spectroscopy system for determining brain hemoglobin levels in laboratory animals
(2013-04-15)
Kuo, Jinn-Rung
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Chang, Ming-Hsien
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Wang, Che-Chuan
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Chio, Chung-Ching
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Wang, Jhi-Joung
Traumatic brain injury (TBI) is usually caused by brain shaking or impact. It can affect normal brain function and may even lead to disability or death. However, there are very few studies on the associated physiologic changes in humans or animals. In this study, a non-invasive, wireless multi-channel near-infrared spectroscopy (NIRS) was developed to continuously monitor the concentration change of oxyhemoglobin (HbO(2)), deoxyhemoglobin (HbR), and total hemoglobin (HbT) to elucidate changes in the physiological state of the brain during and after different strength impaction. The triphenyltetrazolium chloride (TTC) staining was also used to monitor changes of infarction volume after different strength impaction. The results indicated that the concentration changes of HbO(2) and HbT, and the changes of infarction volumes were significantly related to the impact strength. In conclusion, the status of TBI can be clinically evaluated by detecting HbO(2) and HbT changes. The system proposed here is stable, accurate, non-invasive, and mostly important wireless which can easily be used for TBI study. (C) 2013 Elsevier B.V. All rights reserved.