Kuo Sheng Cheng

Detecting ineffective triggering in the expiratory phase in mechanically ventilated patients based on airway flow and pressure deflection: Feasibility of using a computer algorithm

Objective: Ineffective triggering (IT) is the most common manifestation of patient–ventilator asynchrony in mechanically ventilated patients. IT in the expiratory phase (ITE) accounts for the majority of IT and is associated with characteristic features of flow and airway pressure deflection, caused by ineffective effort from the patient. The purpose of this study was to quantify the characteristics of flow and airway pressure deflections of ITE and, using a computerized algorithm, to evaluate their usefulness in the detection of ITEs. Design: Prospective, clinical study. Setting: Medical intensive care unit in a 1,000-bed university hospital. Patients: A total of 14 mechanically ventilated adult patients with patient–ventilator asynchrony. Interventions: None. Measurements and Main Results: We analyzed 5,899 breaths and found that 1,831 were ITEs. The average values for maximum flow deflection (Fdef) and maximum airway pressure deflection (Pdef) in ITEs were 13.94 ± 8.0 L/min and 1.91 ± 0.97 cm H2O. With a starting value of 0.1 L/min for Fdef and 0.01 cm H2O for Pdef, the area under the receiver operating characteristics curve of Fdef and Pdef for the detection of ITEs was 0.98 and 0.97, respectively. Sensitivity and specificity for the detection of ITEs were 91.5% and 96.2% for Fdef, respectively, for a cutoff value of 5.45 L/min, and 93.3% and 92.9% for Pdef, for a cutoff value of 0.45 cm H2O. Conclusion: We conclude that accurately detecting and quantifying ITEs is feasible using a computerized algorithm based on Fdef and Pdef. Such a computerized estimation of patient–ventilator interaction might be helpful for adjusting ventilator settings in an intensive care unit.

Advances in Multimedia Information Processing - PCM 2008

This book constitutes the refereed proceedings of the 9th Pacific Rim Conference on Multimedia, PCM 2008, held in Tainan, Taiwan, in December 2008. The 79 revised full papers and 39 revised poster presented were carefully reviewed and selected from 210 submissions. The papers are organized in topical sections on next generation video coding techniques, audio processing and classification, interactive multimedia systems, advances in H.264/AVC, multimedia networking techniques, advanced image processing techniques, video analysis and its applications, image detection and classification, visual and spatial analyses, multimedia human computer interfaces, multimedia security and DRM, advanced image and video processing, multimedia database and retrieval, multimedia management and authoring, multimedia personalization, multimedia for e-learning, multimedia networking techniques, multimedia systems and applications, advanced multimedia techniques, as well as multimedia processing and analyses.

Characterization of the Major Histopathological Components of Thyroid Nodules Using Sonographic Textural Features for Clinical Diagnosis and Management

In this study, the characteristic sonographic textural feature that represents the major histopathologic components of the thyroid nodules was objectively quantified to facilitate clinical diagnosis and management. A total of 157 regions-of-interest thyroid ultrasound image was recruited in the study. The sonographic system used was the GE LOGIQ 700), (General Electric Healthcare, Chalfant St. Giles, UK). The parameters affecting image acquisition were kept in the same condition for all lesions. Commonly used texture analysis methods were applied to characterize thyroid ultrasound images. Image features were classified according to the corresponding pathologic findings. To estimate their relevance and performance to classification, ReliefF was used as a feature selector. Among the various textural features, the sum average value derived from co-occurrence matrix can well reflect echogenicity and can effectively differentiate between follicles and fibrosis base thyroid nodules. Fibrosis shows lowest echogenicity and lowest difference sum average value. Enlarged follicles show highest echogenicity and difference sum average values. Papillary cancer or follicular tumors show the difference sum average values and echogenicity between. The rule of thumb for the echogenicity is that the more follicles are mixed in, the higher the echo of the follicular tumor and papillary cancer will be and vice versa for fibrosis mixed. Areas with intermediate and lower echo should address the possibility of follicular or papillary neoplasm mixed with either follicles or fibrosis. These areas provide more cellular information for ultrasound guided aspiration

Physiological signal analysis for patients with depression

Depression is a common and serious mental disorder. About 1.9 million people in Taiwan are identified as having depression. There is a trend of increase of the prevalence of depression, three times more depressed persons within the past six years. A few patients with depression were in treatment. Therefore, an available algorithm will be build to measure the neurophysiology of depression. In this study, the physiological signals from depressed patients will be compared with those from normal people. This experiment use different pictures expresses happiness, sadness fear, and disgust to cause the emotion of subjects. The physiological signals of the patient is measured at the same time. The preliminary results show that the galvanic skin response, heart rate variability, and blood volume pulse of patients with depression is lower than the normal people does. More subjects will be evaluated in the project for investing the clinical significance.

Feature subimage extraction for cephalogram landmarking

The significant features corresponding to skull structures on cephalograms are clinically useful for cephalometric diagnosis and superimposition. Accordingly the specific anatomical landmarks need to be firstly located for cephalometric measurements. In this paper, a novel method combining the multilayer perceptron and genetic algorithm is proposed to extract the specific feature areas. Thus, the useful landmarks may then be easily found from these feature areas instead of the whole image. The multilayer perceptron is used to approximate a fitness function for the genetic algorithm. In each iteration, eighty randomly selected subimages are grouped as the population for a GA search. Based on the feature characteristics, the selected subimages with the best fitness will survive to the last. From the experimental results, it is shown that the proposed algorithm does work better than our previous method of correlation.

An improved bidimensional empirical mode decomposition: A mean approach for fast decomposition

In this paper, a mean approach is proposed to accelerate bidimensional empirical mode decomposition (BEMD). In the envelope generation process, the proposed method uses a modified mean filter to approximate the interpolated envelope of the conventional BEMD, and utilizes a convolution algorithm based on singular value decomposition (SVD) to further reduce the computation time. Order statistics filter width determination, originally used in fast and adaptive bidimensional empirical mode decomposition (FABEMD), is applied to adaptively formulate an envelope. Considering the computation efficiency, the proposed method improves the algorithm for calculating distances among extrema by using Delaunay triangulation (DT). The experimental results show that the mean approach can produce intrinsic mode functions faster than FABEMD, while retaining acceptable quality.

A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects

BackgroundThe electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects.MethodsForty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0.ResultsIn the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.ConclusionsThis study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

Quantitatively Characterizing the Textural Features of Sonographic Images for Breast Cancer With Histopathologic Correlation

In this study, quantitative characterization of sonographic image texture and its correlation with histopathologic findings was developed for facilitating clinical diagnosis. A statistical feature matrix was applied to quantify the texture difference (ie, the dissimilarity) of the sonographic images for malignant and benign breast tumors.

Electrical impedance image reconstruction using the genetic algorithm

In this paper, a genetic based reconstruction algorithm (GA) is proposed for producing the electrical impedance image. This method has the potential in parallelized hardware implementation. The impedance image reconstruction is cast as a minimization problem. The cost function is defined as the errors between the measured and estimated boundary voltages in least square sense. The image is considered as the bit strings. From the results, it is demonstrated to be feasible for producing the dynamic image. In order to reduce the number of degrees of freedom of this proposed method, a guided technique based upon the voltage measurements is also designed. In addition, the noise effect of the voltage measurement is also investigated. From the simulation results, the proposed algorithm has the some extent of the noise immunity.

Electrical Impedance Spectroscopy as Electrical Biopsy for Monitoring Radiation Sequelae of Intestine in Rats

Electrical impedance is one of the most frequently used parameters for characterizing material properties. The resistive and capacitive characteristics of tissue may be revealed by electrical impedance spectroscopy (EIS) as electrical biopsy. This technique could be used to monitor the sequelae after irradiation. In this study, rat intestinal tissues after irradiation were assessed by EIS system based on commercially available integrated circuits. The EIS results were fitted to a resistor-capacitor circuit model to determine the electrical properties of the tissue. The variations in the electrical characteristics of the tissue were compared to radiation injury score (RIS) by morphological and histological findings. The electrical properties, based on receiver operation curve (ROC) analysis, strongly reflected the histological changes with excellent diagnosis performance. The results of this study suggest that electrical biopsy reflects histological changes after irradiation. This approach may significantly augment the evaluation of tissue after irradiation. It could provide rapid results for decision making in monitoring radiation sequelae prospectively.