Showing papers by "Arnon D. Cohen published in 2006"

GMM-based target classification for ground surveillance Doppler radar

Abstract: An automatic target recognition (ATR) algorithm, based on greedy learning of Gaussian mixture model (GMM) is developed. The GMMs were obtained for a wide range of ground surveillance radar targets such as walking person(s), tracked or wheeled vehicles, animals, and clutter. Maximum-likelihood (ML) and majority-voting decision schemes were applied to these models for target classification. The corresponding classifiers were trained and tested using distinct databases of target echoes, recorded by ground surveillance radar. ML and majority-voting classifiers obtained classification rates of 88% and 96%, correspondingly. Both classifiers outperform trained human operators.

Depression in dermatological patients identified by the Mini International Neuropsychiatric Interview questionnaire.

Abstract: Background Early diagnosis and treatment of depression are of vital importance in dermatological patients. Objective Our purpose was to evaluate the prevalence of depression among patients visiting a dermatology clinic in southern Israel. Methods Patients who visited the dermatology clinic were interviewed using the Mini International Neuropsychiatric Interview screening tool. Results The study included 384 patients. The screening questionnaire identified 37 patients (9.6%) with major depression, 3 patients (0.8%) with minor depression, and 74 patients (19.3%) with depressive symptoms. Higher prevalence of depression was found among widowers, among divorced or separated patients, and in unemployed patients. Depression was significantly associated with the perception of severity and suffering induced by the skin diseases. Limitations The study was conducted in a cross-sectional design. To confirm causality, a longitudinal study should be conducted. Conclusion Depression should be a consideration by dermatologists in the effective management of skin diseases.

Acoustic monitoring of double-lumen ventilated lungs for the detection of selective unilateral lung ventilation.

Abstract: One-lung intubation (OLI) is among the most common complications of endotracheal intubation. None of the monitoring tools now available has proved effective for its early detection. In this study we investigated the efficacy of acoustic analysis for the detection of OLI. We collected lung sounds from 11 patients undergoing thoracic surgery requiring the placement of a double-lumen tube. Recordings of separate lung ventilation were performed after induction and confirmation of adequate tube positioning, before surgery. Samples of lung sounds were collected by three piezoelectric microphones, one on each side of the chest and one on the right forearm, for background noise sampling. The samples were filtered, the signals' energy envelopes were calculated, and segmentation to breath and rest periods was performed. Each respiration was classified into one of the three categories: bilateral ventilation, selective right-lung ventilation, or selective left-lung ventilation, on the basis of the ratio between the energy signals of each lung. OLI was accurately identified in 10 of the 11 patients during right OLI and in all 11 patients during left OLI. This study suggests that acoustic monitoring is effective for the detection of selective lung ventilation and may be useful for early diagnosis of OLI.

Non-attendance in adult dermatological patients.

Abstract: 377 Letters to the Editor Sir, Non-attendance (failure to attend clinic appointments) is a common problem in dermatology clinics. Non-attendance proportions range from 15% to 25% and lead to inefficient use of space and personnel and increased costs (1–7). To improve the management of dermatological clinics, factors that determine non-attendance should be identified and addressed. In the past, only a few studies were performed on non-attendance in general dermatology clinics. The factors that determine non-attendance in adult dermatology clinics include the payer type, inadequate communication between the hospital and patients, patients forgetting their appointment date or illness, and problems related to appointments (8–11). In paediatric dermatolo-gical patients, non-attendance was associated with male gender and referrals from emergency department as opposed to referrals from private physicians (12). In this study we investigated factors that determine non-attendance in adults visiting an ambulatory dermatology clinic. The study was conducted in the southern district of Clalit Health Services. Clalit Health Services is the largest organization of managed care in Israel. In the southern district of Israel, Clalit Health Services serves a population of 470,000 enrollees. The dermatology service in this district includes 17 active dermatologists , working in 23 clinics, accounting for approximately 110,000 patient–physician encounters annually. The central ambulatory clinic resides in the district town Beer-Sheva. Visits to district central ambulatory clinic were obtained from a computer-generated listing of scheduled appointments from January 1 to December 31, 2003. The list contained the patient's age, gender, visit date and time, waiting time for an appointment and the treating dermatologist for all new appointments in the clinic. In this clinic, patients were not required to pre-authorize the appointment and did not receive a reminder of the scheduled appointment. Statistical analysis Results of continuous variables are shown as means. Results of categorical variables are described as frequencies. Chi-square tests were used to analyse statistically significant differences of categorical variables. Logistic regression was used for multivariate analyses. p-values ≤ 0.05 were considered statistically significant. reSUlTS A total of 7580 visits were included in the study during a 12-month period. There were 4509 female (59.5%) and 3071 male (40.5%) patients. The mean age was 45.9 years (range 18–100 years). The overall proportion of non-attendance at the dermatology clinic was 26.1%. Non-attendance was 27.2% in female and 24.5% in male patients (p = 0.009). Non-attendance was 30.1% in patients below 50 years, 21.4% in patients in the age range …

Dermatitis artefacta in soldiers.

Abstract: Background: Dermatitis artifacta is not an uncommon disease in military settings. Soldiers may intentionally produce skin lesions to achieve sick leave from military duties. The aim of this work was to describe a series of soldiers with dermatitis artifacta. Methods: A prospective study was conducted among soldiers of the Israel Defense Force. Results: Fourteen soldiers from the Israel Defense Force were included in the study. There were 13 men and one woman. The ages of the patients ranged between 19 and 26 years. For all patients, dermatitis artifacta was characterized by the acute appearance of a pruritic rash located on readily accessible areas of the limbs and abdomen. The rash was associated with systemic symptoms for 12 (85.7%) of 14 patients. None of the patients admitted to intentionally inflicting the skin lesions. The rash consisted of erythematous patches with numerous papules and pustules arranged in a linear pattern. All patients were treated with topical corticosteroids, four patie...

The Lombard Effect's Influence on Automatic Speaker Verification Systems and Methods for its Compensation

Abstract: Speaker identification/verification applications have progressed significantly during the last few years. Performance levels of between 70% - 99% success in speaker recognition systems are normal, depending on the type of application and quality of the signal. Several techniques for robust speaker recognition have been developed. Until now, however, the problem posed by variations in speech characteristics due to acoustical noise has not been thoroughly investigated in the context of speaker recognition. The change a noisy acoustic environment can produce in speech signal parameters is known as the "Lombard Effect." In this paper the Lombard Effect's influence on speaker verification system performance is investigated and several compensation methods are proposed. The verification system is based on a 24 Gaussian Mixture Model (GMM) and speech feature orders of 12 to 60. It was found that, based on the mean Equal Error Rate (EER), verification performance deteriorated by 10.1% (from 3.8% to 13.9%) relative to speech veriflcation in a normal environment due to the Lombard Effect. Two types of Lombard Effect compensation methods are proposed. The first is based on robust speech features that are resistant to the Lombard Effect. The second is based on studying how the Lombard Effect changes speech feature and then transforming the Lombard affected speech back to normal speech. The proposed methods significantly reduce speaker veriflcation system error rates. An improvement in the EER of up to 5.4% (from 13.5% to 8.5%) was achieved.

Marketing of a new non-sedating antihistamine (fexofenadine) puts an additional burden on healthcare system resources in Israel.

Abstract: Current expert opinion on non-sedating antihistamines (NSAH) states that cetrizine, fexofenadine, and loratadine have similar clinical profiles in the treatment of diseases such as allergic rhinitis or urticaria (1 6). Although single studies demonstrated some differences in efficacy and safety between currently available NSAH (7 16), it is commonly conceived by physicians that individual drugs of the NSAH therapeutic category have marginal advantages over one another (2 5). Since the cost of prescribed drugs, including NSAH, continues to increase each year, decision makers are examining ways to control the escalating costs (17 22). In the last few years, three new NSAH have been introduced onto the market in Israel (cetrizine, fexofenadine, and mizolastine). The introduction of fexofenadine (as a new brand drug) onto the Israeli healthcare market was associated with an extensive marketing campaign. In the current study, we describe trends in the market share of NSAH in Israel. Our goal was to investigate the influence of a fexofenadine marketing campaign on NSAH market share within the Israeli healthcare system.