Direct Measurement of Optical Constants of Metals from a KrF Excimer Using Polarization Methods

A simple null modulation-polarization method of measuring optical constants of metals has been adapted for operation with a KrF 248nm excimer laser. The approach requires only 3 optical components to extract the real and imaginary parts of the index of refraction (n,k). Experimental results will show good agreement to reference values for several metals (Cr, Au, Al) and Si

Phase-Shift Mask Issues for 193 nm Lithography

As feature sizes below 0.25 micron are pursued, it becomes apparent that there will be few lithographic technologies capable of such resolution. Of these, deep-UV lithography at 193 urn is being investigated, which may prevail over X-ray lithography in terms of manufacturability. Furthermore, through the use of image enhancement techniques such as phase-shift masking, 193 rim lithography may dominate for feature resolution below 0.20 micron. This paper presents results from investigations into phase-shift mask issues for 193 nm excimer laser lithography. A small field refractive projection system for operation at the 193 .3 nm wavelength of a spectrally narrowed ArF excimer laser has been constructed for lithographic research. The small field, 20X system operates with a variable objective lens numerical aperture from 0.30 to 0.60, variable partial coherence, and control over illumination fill. Through the use of attenuated and alternating phase-shifting techniques resolution can be pushed to the 0.2 micron range with depth of focus as large as 2 microns. Problems do arise, though, as these techniques are applied to such short wavelengths of an excimer laser. Sensitivities to shifter deviations and resist interaction increase. Shifter etch influences on fused silica surface characteristics need to be addressed. Transmission effects of attenuating materials becomes increasingly important. Resist imaging and simulation results presented will shed some light on the potential of phase-shift masking for 193 nm lithography, along with inherent difficulties

Single Incision Laparoscopic Cholecystectomy by Using a 2 mm Atraumatic Grasper without Trocar

Purpose. We present our experience in single incision laparoscopic cholecystectomy by using a grasper directly without using a trocar in five patients. Methods and Results. The technique involves the use of Karl Storz 27290F grasper in order to perform gallbladder retraction in single port cholecystectomy. The grasper was introduced directly into the skin through abdominal wall without using any trocar and used to mobilize gallbladder whenever needed during surgery without causing any perforation or leakage of the gallbladder. There were no intraoperative and postoperative complications in 5 patients with the advantages of shorter operation time and almost invisible postoperative skin scar formation. Conclusion. We claim that the use of this instrument in SILS surgery might be advantageous than the conventional placement of sutures for the gallbladder mobilization

Evaluation of the anatomical and electrical axis of the heart after pneumonectomy

Aim: To investigate the position of the heart after pneumonectomy and, also to find out how the changes in the electrical axis of the heart contribute for the possible electrocardiographic and echocardiographic changes. Methods: Ninety-eight patients with pneumonectomy were included to this observational study. To calculate the rotation of the heart and angle measurement two perpendicular lines, one septal and another atrioventricular, were drawn on the images acquired from thoracic computed tomography. Thoracic CT were taken at every 3 months for the first two years. On electrocardiograms net QRS vectors, amplitudes of p waves, findings of right and left ventricular hypertrophy, and other possible changes were recorded. Results: The mean age of all patients was 55.51 ± 8.9. Right pneumectomy was performed in 40 (57%) and left pneumonectomy in 30 cases (43%) cases. There was no significant change regarding both the angle of rotation and the amount of pleural effusion between the findings of the second and first year after the operation. The QRS shift was significantly more pronounced in patients with left pneumonectomies than right pneumonectomies. On echocardiography these cases showed right ventricular hypertrophy and increased pulmonary artery pressures in the second year when compared to the preoperative period. Conclusions: The current study showed that many significant changes occurred in the electrocardiographic and echocardiographic parameters of the heart after pneumonectomy

New advantageous tool in single incision laparoscopic cholecystectomy: the needle grasper

Introduction: During single-incision laparoscopic cholecystectomy (SILC), the gallbladder is suspended with stitches, resulting in perforation risk and difficulty in exploration. Aim: We used the needle grasper in SILC to hang and manipulate the gallbladder. Material and methods : Sixty-five patients (43 female, 22 male) who underwent SILC between December 2013 and December 2014 were analyzed retrospectively for patient demographics, duration of operation, laparotomy or conventional laparoscopy necessity, drain use, complications, and hospital stay periods. To place the SILC port (Covidien, Inc.), the needle grasper was inserted at the right upper abdominal quadrant without an incision to hang and manipulate the gall-bladder. Results : The mean age was 47.9 ±13.068 years; the mean body mass index (BMI) was 26.94 ±3.913 kg/m2. ASA scores were 1, 2, and 3. Two patients with high BMI with additional trocar use were excluded. The operations were completed without any additional trocar in 59 patients. The mean operation time was 89 ±22.41 min. Eighteen patients required a drain; all were discharged after drain removal. One patient needed re-hospitalization and percutaneous drainage and was discharged on the 9th day. Fifty-three patients were discharged on the 1st post-operative day. Eleven patients with drains were discharged on the 2nd day, and 1 was discharged on the 7th day. The mean hospital stay period was 1.26 ±0.815 days. Conclusions : The main difficulty of SILC is to manipulate hand tools because the triangulation principle of laparoscopy use is not possible in SILC. Inserting a needle grasper into the abdominal cavity at the right subcostal area to manipulate the gallbladder helps and does not leave a visible scar