Biomedical subjects

Stefan Schulte

Publications and source records attributed to Stefan Schulte.

6 recordsLinked to original sources

PubMed2006

A fuzzy impulse noise detection and reduction method.

Removing or reducing impulse noise is a very active research area in image processing. In this paper we describe a new algorithm that is especially developed for reducing all kinds of impulse noise: fuzzy impulse noise detection and reduction method (FIDRM). It can also be applied to images having a mixture of impulse noise and other types of noise. The result is an image quasi without (or with very little) impulse noise so that other filters can be used afterwards. This nonlinear filtering technique contains two separated steps: an impulse noise detection step and a reduction step that preserves edge sharpness. Based on the concept of fuzzy gradient values, our detection method constructs a fuzzy set impulse noise. This fuzzy set is represented by a membership function that will be used by the filtering method, which is a fuzzy averaging of neighboring pixels. Experimental results show that FIDRM provides a significant improvement on other existing filters. FIDRM is not only very fast, but also very effective for reducing little as well as very high impulse noise.

Algorithms↗

PubMed2006

Fuzzy two-step filter for impulse noise reduction from color images.

A new framework for reducing impulse noise from digital color images is presented, in which a fuzzy detection phase is followed by an iterative fuzzy filtering technique. We call this filter the fuzzy two-step color filter. The fuzzy detection method is mainly based on the calculation of fuzzy gradient values and on fuzzy reasoning. This phase determines three separate membership functions that are passed to the filtering step. These membership functions will be used as a representation of the fuzzy set impulse noise (one function for each color component). Our proposed new fuzzy method is especially developed for reducing impulse noise from color images while preserving details and texture. Experiments show that the proposed filter can be used for efficient removal of impulse noise from color images without distorting the useful information in the image.

Algorithms↗

PubMed2005

Octyl methoxycinnamate: two generation reproduction toxicity in Wistar rats by dietary administration.

Wistar rats continuously received octyl methoxycinnamate (OMC) in the diet through two successive generations at nominal doses of 0, 150, 450 or 1000 mg/kg bw/day. OMC had no adverse effects on estrous cycles, mating behavior, conception, parturition, lactation and weaning, sperm and follicle parameters, macropathology and histopathology of the sexual organs. 1000 mg/kg bw/day reduced parental food consumption and body weight (-14% to -16% in males, -4% to -5% females), increased liver weight, produced hepatic cytoplasmic eosinophilia and erosion/ulceration of glandular stomach mucosa. and led to a slightly decreased implantation rate in the top dose F0 and F1 dams. The high dose F1 and F2 pups had reduced lactation weight gain and organ weights and delayed sexual maturation landmarks. There was no evidence of a selective influence of the test compound on pups' sexual landmarks. The NOAEL (no observed adverse effect level) is 450 mg/kg bw/day for fertility and reproductive performance, for systemic parental and developmental toxicity.

Animals↗

PubMed2005

The role of epidural spinal cord stimulation in the treatment of Buerger's disease.

PURPOSE: This clinical, retrospective study is evaluated the effect of epidural spinal cord stimulation (SCS) in the treatment of Buerger's disease. METHODS: The clinical criteria of Shionoya were used to diagnose 29 patients (22 men, 7 women; mean age 33.7 years) with Buerger's disease. The patients underwent SCS. Complete physical examination and vascular laboratory data were available and recorded for all patients. Questions regarding the improvement of symptoms, in lifestyle, and in physical activities were asked direct interview or by telephone during mean follow-up of 4 years. RESULTS: The regional perfusion index (RPI), the ratio between the foot and chest transcutaneous oxygen pressure at baseline (before SCS treatment) was 0.27 +/- 0.25. Three months after SCS implantation the RPI increased to 0.41 +/- 0.22. During the follow-up period, a sustained improvement in microcirculation was recorded: the RPI at 1-year follow-up was 0.49 +/- 0.34 and at 3-year follow-up was 0.52 +/- 0.21. The most pronounced improvement in the RPI values was found in the subgroup of 13 patients with trophic lesions. In this group, the RPI increased significantly from 0.17 +/- 0.21 to 0.4 +/- 0.18 (P < .023) after a mean follow-up of 5.7 years. Two patients underwent major amputation of the lower target limb. The limb survival rate was 93.1%. During the follow-up period of 4 years, 21 of the 29 patients continued to smoke, and only five patients stopped nicotine exposure. CONCLUSIONS: We recorded a significant benefit in the microcirculation, a good limb survival rate, and the absence of new trophic lesions. During the follow-up period, no severe complications related to the implanted devices occurred. Because of the diffuse, distal, segmental nature of the disease, SCS should be considered as an alternative treatment modality in patients with Buerger's disease.

Adolescent↗

PubMed2003

Developmental (embryo-fetal toxicity/teratogenicity) toxicity studies of synthetic crystalline lycopene in rats and rabbits.

Synthetic crystalline lycopene is a nutritional supplement to increase dietary intake of lycopene, an antioxidant carotenoid. Its potential oral developmental toxicity was studied in rats and rabbits. Each study included 3 control groups (water and matrix for Lycopene 10 CWD or LycoVit 10%), 3 Lycopene 10 CWD groups [500, 1500 and 3000 (rats)/2000 (rabbits) mg/kg/day] and 1 LycoVit 10% group [3000 mg/kg/day (rats)/2000 (rabbits)]. The high dosages were at maximum achievable concentrations and dosage volumes (15 and 10 ml/kg for rats and rabbits, respectively) of the highly viscous test material suspensions. Dosages were administered on gestation days (GDs) 6 through 19 (rats) or GDs 6 through 28 (rabbits). Endpoints evaluated included viability, body weight, feed consumption, necropsy observations [GD 20 (rats)/GD 29 (rabbits)], uterine contents and fetal viability, gender, body weight and morphology (skeletons double-stained). Feed consumption and weight gain were essentially unaffected in rats and rabbits, despite intubation problems in both species and reduced gastrointestinal motility and mortality in rabbits attributable to the physical properties of the gels. Neither Lycopene 10 CWD nor LycoVit 10% caused direct maternal or developmental toxicity in rats or rabbits at dosages as high as 3000 or 2000 mg/kg/day, respectively.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Spinal cord stimulation in the treatment of peripheral vascular disease: results of a single-center study of 258 patients.

This report is of a retrospective study of data from 258 patients who received spinal cord stimulation (SCS) for the treatment of peripheral vascular disease as a result of arteriosclerosis. The patients' clinical outcomes were monitored over a period of 18 months. In patients with a low baseline transcutaneous oxygen pressure (TcPO(2)) value of <10 mm Hg, limb survival at 18 months of follow-up (estimated by use of Kaplan-Meier survival analysis) was 77.8%, and this was even higher, at 89.5%, in patients with a medium baseline TcPO(2) value of 10-30 mm Hg. This successful treatment was accompanied by a sustained increase in TcPO(2) values to approximately 30 mm Hg in both of these groups. In looking at diabetic and nondiabetic patients, there is no difference in limb survival as a result of the treatment. It is concluded that SCS is an effective therapy in improving limb survival in patients with peripheral vascular disease. In addition, TcPO(2) values at baseline may be a useful predictor of treatment outcome.

Aged↗