ABSTRACT
In this paper, a new method, which is based on reconstructing the original intensity distribution of a laser with images captured by a charge-coupled device (CCD) in two orthogonal directions, is proposed for suppressing the influence of CCD vertical blooming on the measurement of the laser beam quality factor (M2). A simplified theoretical model for the distribution of CCD blooming is also proposed. With the proposed method and model, the influence of CCD vertical blooming on the measurement of M2 is simulated. The experimental results demonstrate that the new method can be an effective means to measure the M2 of a near-infrared laser with a silicon CCD camera. The proposed method can be applied to a beam quality analyzer in order to suppress the influence of blooming on the measurement of M2.
ABSTRACT
OBJECTIVE: This study identifies factors affecting sleep patterns among thoracic surgery patients in the intensive care unit (ICU) and compares the perceptions of sleep-disturbing factors between nurses and patients. METHODS: One hundred and fifty-two patients and 40 nurses were surveyed using the Pittsburgh Sleep Quality Index (PSQI) and self-designed questionnaires (for patients and nurses). All statistical analyses were carried out by SPSS, and the following statistical methods were used to evaluate the data: chi-squared test and logistic regression. RESULTS: Of 152 patients, 46.1 % reported poor sleep quality during their hospitalization; their PSQI total score was 6.95 ± 3.713. Of these, 69.1 % indicated that their sleep quality was poorer than before; 50.0 % of them changed their sleep patterns. Significant discrepancies exist between nurses and patients in the perceptions of sleep-disturbing factors of patients. CONCLUSION: Thoracic surgical patients' perceptions of their sleep in the ICU indicate poor sleep quality, which is decided by a variety of disturbing factors. Perceptions of these factors varied greatly between surveyed patients and nurses.
