Woei-Chyn Chu

Measuring the long-term SNRs of static and adaptive compression amplification techniques for speech in noise.

BACKGROUND Multichannel wide-dynamic-range compression (WDRC) is a widely adopted amplification scheme in modern digital hearing aids. It attempts to provide individuals with loudness recruitment with superior speech intelligibility and greater listening comfort over a wider range of input levels. However, recent surveys have shown that compression processing (operating in the nonlinear regime) usually reduces the long-term signal-to-noise ratio (SNR). PURPOSE The purpose of this study was to determine the long-term SNR in an adaptive compression-ratio (CR) amplification scheme called adaptive wide-dynamic-range compression (AWDRC), and to determine whether this concept is better than static WDRC amplification at improving the long-term SNR for speech in noise. DESIGN AND STUDY SAMPLE AWDRC uses the input short-term dynamic range to adjust the CR to maximize audibility and comfort. Various methods for evaluating the long-term SNR were used to observe the relationship between the CR and output SNR performance in AWDRC for seven typical audiograms, and to compare the results with those for static WDRC amplification. RESULTS The results showed that the variation of the CR in AWDRC amplification can maintain the comfort and audibility of the output sound. In addition, the average long-term SNR improved by 0.1-5.5 dB for a flat hearing loss, by 0.2-3.4 dB for a reverse sloping hearing loss, by 1.4-4.8 dB for a high-frequency hearing loss, and by 0.3-5.7 dB for a mild-to-moderate-sloping high-frequency hearing loss relative to static WDRC amplification. The output long-term SNR differed significantly (p < .001) between static WDRC and AWDRC amplification. CONCLUSIONS The results of this study show that AWDRC, which uses the characteristics of the input signal to adaptively adjust the CR, provides better long-term SNR performance than static WDRC amplification.

Applying artificial intelligence technology to support decision-making in nursing: A case study in Taiwan:

This study applied artificial intelligence to help nurses address problems and receive instructions through information technology. Nurses make diagnoses according to professional knowledge, clinical experience, and even instinct. Without comprehensive knowledge and thinking, diagnostic accuracy can be compromised and decisions may be delayed. We used a back-propagation neural network and other tools for data mining and statistical analysis. We further compared the prediction accuracy of the previous methods with an adaptive-network-based fuzzy inference system and the back-propagation neural network, identifying differences in the questions and in nurse satisfaction levels before and after using the nursing information system. This study investigated the use of artificial intelligence to generate nursing diagnoses. The percentage of agreement between diagnoses suggested by the information system and those made by nurses was as much as 87 percent. When patients are hospitalized, we can calculate the probability of various nursing diagnoses based on certain characteristics.

Decompressed percutaneous vertebroplasty: A secured bone cement delivery procedure for vertebral augmentation in osteoporotic compression fractures

UNLABELLED The purpose of this study was to assess the efficacy of a new assistive procedure for injecting cement in percutaneous vertebroplasty (PV). Percutaneous vertebroplasty is frequently used for treating patients with osteoporotic vertebral compression fractures. However, the leakage of bone cement during PV may lead to serious complications, such as spinal cord compression or pulmonary embolism. Herein we present a secure procedure designed to safely and effectively deliver the bone cement into the vertebral column. MATERIALS AND METHODS Thirty-five patients with a total of 50 levels of osteoporotic compression fracture were consecutively recruited for the study. During a routine PV operation, acrylic cement was injected with a simultaneous application of a continuous negative pressure to the contralateral side of the vertebral body. This negative pressure exerts a pulling force that attracts the bone cement to flow within the vertebral body. RESULTS With the proposed decompressed PV procedure, cross-filling of the vertebrographies was achieved for all 50 fracture levels, with no paravertebral venous plexus leakage. Three of the 50 levels (6%) exhibited contrast-medium leakage into the intradisc or cortical defect regions. After decompressed cement injection, excellent cross-filling of bone cement deposition was achieved in 38 of the 50 levels (76%; cement cross-filling region >75%), good cross-filling deposition was achieved in 7 levels (14%; cement cross-filling region >50%), deposition was poor in 3 levels (6%; cement cross-filling region <50%), and deposition failed in 2 levels (4%; fixed cement with no sign of cross-filling). Routine postoperative reviews revealed that six fracture levels (12%) had minimal cement leakage, with two leaking into the disc and four into paravertebral cortical defect regions. CONCLUSIONS Compared to the reported 20-88% cement leakage rate for the conventional PV procedure, the proposed decompressed PV procedure offers a more secure and effective way to perform cement injection, and reduces the likelihood of cement leakage.

The Binaural Masking-Level Difference of Mandarin Tone Detection and the Binaural Intelligibility-Level Difference of Mandarin Tone Recognition in the Presence of Speech-Spectrum Noise

Binaural hearing involves using information relating to the differences between the signals that arrive at the two ears, and it can make it easier to detect and recognize signals in a noisy environment. This phenomenon of binaural hearing is quantified in laboratory studies as the binaural masking-level difference (BMLD). Mandarin is one of the most commonly used languages, but there are no publication values of BMLD or BILD based on Mandarin tones. Therefore, this study investigated the BMLD and BILD of Mandarin tones. The BMLDs of Mandarin tone detection were measured based on the detection threshold differences for the four tones of the voiced vowels /i/ (i.e., /i1/, /i2/, /i3/, and /i4/) and /u/ (i.e., /u1/, /u2/, /u3/, and /u4/) in the presence of speech-spectrum noise when presented interaurally in phase (S0N0) and interaurally in antiphase (SπN0). The BILDs of Mandarin tone recognition in speech-spectrum noise were determined as the differences in the target-to-masker ratio (TMR) required for 50% correct tone recognitions between the S0N0 and SπN0 conditions. The detection thresholds for the four tones of /i/ and /u/ differed significantly (p<0.001) between the S0N0 and SπN0 conditions. The average detection thresholds of Mandarin tones were all lower in the SπN0 condition than in the S0N0 condition, and the BMLDs ranged from 7.3 to 11.5 dB. The TMR for 50% correct Mandarin tone recognitions differed significantly (p<0.001) between the S0N0 and SπN0 conditions, at –13.4 and –18.0 dB, respectively, with a mean BILD of 4.6 dB. The study showed that the thresholds of Mandarin tone detection and recognition in the presence of speech-spectrum noise are improved when phase inversion is applied to the target speech. The average BILDs of Mandarin tones are smaller than the average BMLDs of Mandarin tones.

Evaluation of the mining techniques in constructing a traditional Chinese-language nursing recording system.

In 2009, the Department of Health, part of Taiwan’s Executive Yuan, announced the advent of electronic medical records to reduce medical expenses and facilitatethe international exchange of medical recordinformation. An information technology platform for nursing records in medical institutions was then quickly established, which improved nursing information systems and electronic databases. The purpose of the present study was to explore the usability of the data mining techniques to enhance completeness and ensure consistency of nursing records in the database system.First, the study used a Chinese word-segmenting system on common and special terms often used by the nursing staff. We also used text-mining techniques to collect keywords and create a keyword lexicon. We then used an association rule and artificial neural network to measure the correlation and forecasting capability for keywords. Finally, nursing staff members were provided with an on-screen pop-up menu to use when establishing nursing records. Our study found that by using miningtechniques we were able to create a powerful keyword lexicon and establish a forecasting model for nursing diagnoses, ensuring the consistency of nursing terminology and improving the nursing staff’s work efficiency and productivity.

A RAPID AND CONVENIENT METHOD FOR DETERMINING LIMB COMPARTMENT PRESSURE

Compartment syndrome (CS) is the pressure increasing within a confined anatomic space, which results in ischemia to the encompassed tissues and then leads to cells death. If left untreated, CS results in irreversible cell damage, further permanently postischemic scarring and contracture. The intracompartmental pressure is a major diagnostic consideration. Various methods of compartment pressure (CP) measurement have been developed since the late 1800s. They can be classified into invasive and noninvasive categories. Invasive methods are accurate but painful; whereas noninvasive approaches are more comfortable but less accurate. Both methods provide reproducible outcomes but also require specific CP measurement instrument to be performed. This research proposes a rapid and convenient method via examining ultrasonographic fascia wall displacement. For the viscoelastic nature of the compartment fascia, our experiment results have shown the ultrasonographic fascia displacement accurately reflects even small changes of the compartment diameter. There is a strong correlation between compartment pressure and fascia displacement ratio. It also recommends that the ratio of 1.4 could be chosen as the critical value for determining acute compartment syndrome. These results suggest that ultrasonography may serve as an adequate noninvasive tool to monitor CP variations.