Parkinson's disease patients with long-term L-dopa syndrome may benefit from an implanted cerebral stimulation device. When advanced life support demands cardioversion or defibrillation in these ...patients, undesired effects of monophasic electroshocks might occur in brain tissue adjacent to the stimulation electrodes (e.g., thermal injury), but also in the stimulation device itself. Thus, in this animal study (n = 6 pigs), we investigated the effects of repeated defibrillation (2 x 200 J n = 1 and 2 x 360 J n = 5) at the implantation site of cerebral stimulation electrodes and on stimulation device function. Repeated external cardiac defibrillation did not cause acute histopathologic changes typical of thermal injury to brain tissue adjacent to the cerebral stimulation electrodes. Functionality of the stimulator device after defibrillation, however, ranged from normal to total loss of function. Therefore, when defibrillation is performed, the greatest possible distance between the defibrillation site and the stimulator device implantation site should be considered. Subsequent testing of the stimulator device's function is mandatory.
Repeated cardiac defibrillation did not cause histopathologic changes typical of thermal injury at the implantation site of cerebral stimulation electrodes. The function of the stimulator device after defibrillation, however, ranged from normal to total loss of function.
In this paper it is proposed that spectrally sparse radar signals are providing significant advantages for the range estimation performance in terms of multiple target resolution capability as well ...as distance accuracy. It is shown that using multicarrier signals with a structured arrangement of frequency steps on a uniform spectral grid, minimizing equal differential frequency lags, yields the same amount of information as obtained with a common radar signal spanning the whole spectrum. The minimum redundant waveforms do not only allow a considerable reduction of the utilized effective bandwidth without a loss in ranging performance, but also provide detection and parameter estimation capability for more targets compared to traditional radar signals consisting of the same number of equally spaced frequency steps. In order to account for the missing elements in the covariance matrix, a data processing method is described that can handle the sparsity of the measurements and obtain the same amount of information as would be available when using signals occupying the complete spectrum. The effectiveness of the augmentation method, as well as the improvements in the distance estimation are demonstrated based on Monte Carlo simulations.
In this paper an algorithm for time of arrival estimation is proposed, which allows processing of spectrally sparse channel observations in order to provide highly accurate range estimations with a ...maximized resolution capability. The use of sparse waveforms in combination with the presented algorithm provides increased spectral efficiency with lower computational complexity due to reduced size of the observation matrices. Additionally, the ability of the algorithm to efficiently process spectral fragmentary data also gives the capability to efficiently cope with missing data caused by frequency selective fading or interferences.
Imaging RFID system at 24 GHz for object localization Kaleja, M.M.; Herb, A.J.; Rasshofer, R.H. ...
1999 IEEE MTT-S International Microwave Symposium Digest (Cat. No.99CH36282),
1999, Letnik:
4
Conference Proceeding, Journal Article
A new RFID system for the ISM band at 24 GHz employing quasi-optical beam forming is presented. Active integrated antennas are used as transmitters resulting in exceptionally small size of the ...ID-tags. Identification codes are transmitted via a spread-spectrum modulated subcarrier that allows for very simple free running microwave oscillators as well as simple but highly selective receiver concepts. A dielectric lens and a 5/spl times/5 rectenna array comprise an imaging receiver that not only identifies but also localizes the tags with an angular resolution better than 3/spl deg/ at a distance up to 14 meters.
Denial of pregnancy: obstetrical aspects Brezinka, C.; Biebl, W.; Kinzl, J.
Journal of psychosomatic obstetrics and gynaecology,
1994, Letnik:
15, Številka:
1
Journal Article
Recenzirano
Between 1987 and 1990 27 women were observed who professed they did not know they were pregnant until term or until premature contractions set in. The aim of this study was to evaluate obstetric ...history and pregnancy outcomes and assess defence mechanisms and coping strategies which contribute to negation of pregnancy. In 11 women pregnancy was denied until delivery, five of these had breech presentations. In nine women denial ended between 27 and 36 weeks and in seven women between 21 and 26 weeks of gestation. Three of the four fetal deaths that occurred and two of the three cases of prematurity occurred in the last group. There was no infanticide but one woman delivered her infant alone and concealed. Most women reported irregular, sometimes menstruation-like bleedings during pregnancy, three women had taken oral contraceptives during pregnancy. Few women reported actual symptoms of pregnancy, such as nausea and weight gain. Denial of pregnancy is a heterogeneous condition with different meanings and different psychiatric diagnoses in different women. Stressors (e.g. separation from partner, interpersonal problems etc.) do play an important role as precipitating factors for the development of an adjustment disorder with maladaptive denial of pregnancy. There is a fluid transition between conscious coping strategies and unconscious defence mechanisms.
An integrated transmitter at 80 GHz is presented. This device finds many applications in civil sensor and communication systems, and is employed in automotive applications. The device consists of an ...IMPATT diode and a slotted patch resonator. The resonator acts simultaneously as an antenna. The resonator impedance seen by the IMPATT diode is calculated by means of a full wave analysis and the matching of the IMPATT diode is investigated using a large signal analysis. The transmitter devices have been fabricated employing a SIMMWIC (silicon millimeter wave integrated circuit) fabrication process and deliver a radiated power of up to 1 mW at 79 GHz. An excellent carrier-to-noise ratio of 81.7 dBc/Hz at an offset of 100 kHz has been achieved. The deviation of the measured values from the theoretically predicted values of frequency and power is -5.9% and -1.5 dB, respectively.< >
This paper presents a Synthetic Aperture Radar (SAR) algorithm for automotive applications to increase azimuth resolution for radar sensors. The image representation can be used as an amplitude map ...for autonomous maneuvers. The algorithm's emphasis lies on continuous calculation so that current images become immediately available. Thus, the algorithm is described together with a two-grid approach for calculation and storage. In addition, measurements are presented to clarify the SAR procedure. An outlook on a real-time calculation for continuous driving concludes the work.
Chronic mesenteric ischemia (CMI) can be treated with surgical revascularization or with angioplasty and stenting. As experience has been gained, endovascular treatment appears safe and effective in ...selected patients. Currently, surgical revascularization has better success and patency rates but also a higher short- and midterm mortality and morbidity, especially in patients at high surgical risk. A 72-year-old female with severe respiratory dysfunction presented with CMI resulting in profound malnutrition. Serial percutaneous interventions averted urgent surgery and reversed the mesenteric ischemia. Nine months later, after repeated angioplasty and stenting had failed, elective uncomplicated iliomesenteric bypass, in a medically optimized patient, resolved the ischemia. At an 18-month follow-up, the graft remained widely patent and the patient asymptomatic with a body weight corresponding to her ideal body weight. Compared to surgical revascularization, reocclusion or restenosis occurs more frequently after endovascular treatment of CMI, and reintervention may be necessary. Nevertheless, percutaneous intervention effectively provides relief from mesenteric ischemia and has lower perioperative complication rates compared to surgery in patients at high surgical risk. After initial relief of the CMI, the patient's condition may improve, allowing for more definitive secondary surgical revascularization, if needed.
Endovascular stent graft repair of traumatic vessel injuries is gaining worldwide acceptance as a minimally invasive alternative to open surgical repair. However, effective endovascular repair fails ...if the aneurysm is not completely excluded. Conversion to open surgery may be unavoidable in such cases. Herein we describe the case of a 45-year-old man who was referred to our hospital with a pseudoaneurysm of the proximal brachiocephalic artery caused by biopsy during diagnostic medianoscopy. The pseudoaneurysm was primarily treated by stent-graft implantation into the proximal brachiocephalic artery. As a result of the unfavorable location of the lesion exclusion of the aneurysm failed and the initial therapy had to be extended to open reconstruction of the brachiocephalic artery. A bypass procedure from the aortic arch to the right common carotid artery was performed with reinsertion of the right subclavian artery to exclude the pseudoaneurysm.
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