camera in laparoscope

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  • 1. Bozzinis LichtleiterThe Lichtleiter was made from analuminum tube. The tube was illuminatedby a wax candle and had mirrors fitted toit in order to reflect the images.Bozzini published his invention in 1806 inthe Hufelands Journal of PracticalMedicine, Volume 24, under the titleLight Conductor, An Invention for theViewing of Internal Parts and Diseaseswith Illustration.Incidentally, Bozzini was censured forundue curiosity by the Medical Facultyof Vienna for this invention. (Courtesy ofOlympus Austria,

2. Antoine Jean DesormeauxAntoine Jean Desormeaux (18151894), a FrenchSurgeon, was the first to introduce the BozzinisLichtleiter into a patient. In 1853, he furtherdeveloped the Lichtleiter and termed his devicethe Endoscope. It was the first time this termwas used in history.Desormeaux presented the endoscope in 1865 tothe Academy in Paris. He even used his endoscopeto examine the stomach; but due to an insufficientlight source he was not quite successful.(Copyright Verger-Kuhnke AB. The life of PhilippBozzini (1773-1809), an idealist of endoscopy. ActasUrol Esp. 2007;31:437-444) 3. Desormeauxs EndoscopeDesormeauxs endoscope used as a light source akerosene lamp Berning alcohol and turpentine,with a chimney to enhance the flame and a lens tocondense the beam to a narrower area to achieve abrighter spot.He used this instrument to examine the urethraand bladder.As might have been expected, burns were themajor complication of these procedures.Interestingly, he thought of using electricity butfelt it unsafe.(Courtesy of Olympus Austria, Vienna, Austria) 4. Johannes Freiherrsurgeon of Polish-Lithuanian descent born inBukowina, Romania, constructed the first rigidendoscope in 1880 and was the first to useEdisons light bulb for his gastroscope inpractice.He modified the instrument so that it could beangled by 30 near to its lower third toachieve better visualization.He added a separate channel for airinsufflation. In one of the first interventionalendoscopic procedures, he pushed a largeswallowed bone from the esophagus into thestomach, thus avoiding surgery. (Copyright:surgeon in the evolution of flexible endoscopy.SurgEndosc 2007: 21; 838-853 Springer Verlag) 5. Georg Kelling (18661945), a Germanphysicianfrom Dresden, was introduced toendoscopy and gastrointestinal surgerywhen he worked with Professor Mikulicz-Radecki at the Royal Surgical Clinic inBreslau, Germany. In with the help ofNitzes cystoscope, and coined thislaparoscopic examination celioscopy.He used air filtered through sterile cottonto create pneumoperitoneum in dogs. Forinsufflation he used a trocar Developed byAlfred Fiedler, an internist from Dresden.(Copyright: Hatzinger M: Georg Kelling(18661945) Der Erfinder der modernenLaparoskopie. Urologe A 2006; 45 (7):868-71Springer Verlag) 6. Harold Horace HopkinsHopkins (19181994) obtained a degree in physics andmathematics at Leicester University in 1939. After the war,in 1947, Hopkins became a research fellow at ImperialCollege, London, UK.Hopkins invented the rigid rod-lens system for scopes,which allows double light transmission, requires short andthin spacer tubes, and gives a larger and clearer aperture.He filed a patent for the rod-lens system in 1959.However, the English and American companies to whom heoffered the system displayed little interest.The situation changed however in 1965 when ProfessorGeorge Berci, who recognized the potential of thisinvention, introduced Hopkins to Karl Storz to manufacturethe scopes. (Courtesy of William P. Didusch Center forUrologic History, American Urological Association, MD,USA) 7. Kurt Karl Stephan SemmKurt Karl Stephan Semm (19272003) was born in Munich,Germany, where he also studied medicine at the Ludwigs-Maximillian University. In 1958, he wrote his medicalthesis under the guidance of Nobelmlaureate AdolfButenandt. Semm began his career in gynecology underProfessor Fikentscher in Munich. In 1970s, as the Head ofGynecology in Kiel, introduced an;1- Automatic insufflation device capable of monitoringintra-abdominal pressures,2- Endoscopic loop sutures,3-Extra- and intracorporeal suturing techniques.4-Created the pelvi- trainer. He performed the firstlaparoscopic appendectomyin 1982. (Courtesy of Monika Bals-Pratsch MD,Zentrum fur Gyn.kologie, Universit.t Regensburg,Germany) 8. Anatomy of a Rigid Scope 9. Central to the instrumentation is the scope. Itsbackbone is the rod lens system designed byHopkins. The shaft of scopes houses both light fibers and viewing optics. The viewing optic consist of three distinctparts:o The objective lens,o Rod lenses,o ocular lens. 10. Field of ViewThe field of view (also field of vision)is the angular extent of theobservable area that is seen at anygiven moment. The field of view inscopes for endoscopic surgery canvary from 600 to 820 depending upon the type of instrument. Widerangles of view provide a greaterdepth of field in the image withbetter utilization of illumination. Asmaller field of view allows thescope to be farther from the tissue,for the same to be observed. 11. Angle of ViewThe angle of view in scopes can vary withrespect to the central axis view aredesignated as 00 and provide a straightview of the structure in question. Scopesare also available with a 50, 250, 300, 450,and even 700 angle of view, allowingutilization of the scopes much as aperiscope. The off-axis scopes enable oneto observedown into the gutters and up the anteriorabdominal wall as well as sideways. Off-axisscopes are difficult to work with; however,they provide an excellent means ofobtaining close inspection of tissuesat difficult angles and positions. 12. Scope Size and Screen ImageThe decrease in the size of scopes was an importantfactor in the advancement of minimally invasivesurgery in the pediatric age group. Although scopesare available in sizes from 1.9 mm to 12 mm indiameter, the majority of the procedures areperformed using 5- or 10-mm scopes.When compared to the reduced view obtained in theprevious generation of scopes (left), modern5-mm,full-screen scopes provide a bright, distortion- free,full-screen image (right). In addition, the image sizein modern 5-mm scope is equivalent to that obtainedby the previous-generation10-mm scope. (Courtesy of Richard Wolf, Knittlingen,Germany) 13. Charge Coupled Device (CCD)Video Cameras Scope cameras are available in eithersingle-chipthree-chip versions (one chip offers 300,000 pixels/cm2).In single-chip CCD cameras, all the three primary colors (red,blue and green) are sensed by a single chip. In three-chip CCDcameras, there are three chips for separate capture andprocessing of the primary colors.Single-chip CCD cameras produce images of 450 lines/inchresolution and are ideal for outpatient surgery. On the otherhand, three-chip CCD cameras have high fidelity withunprecedented color reproduction to produce images of 750lines/ inch resolution that can be viewed optimally on flat-panelscreens and are best suited for endoscopic surgery.(Courtesy of RichardWolf, Knittlingen , Germany)Light source:Light-Source Generators and Transmission Pathways Thereare two commonly utilized light sources: halogen and xenon.A schematic overview of light transmission is outlined12 14. The Concept of White BalancingWhite balancing should be performed beforeinserting the camera inside the abdominal cavity. Thisis necessary before commencing surgery to diminishthe added impurities of color that may be introduceddue to a variety of reasons such as:(1) voltage difference,(2) staining of the tip by cleaners,(3) scratches and wear of the eyepiece.White balancing is achieved by keeping a whiteobject in front of the scope and activating theappropriate button on the video system or camera.The camera senses the white object as its referenceto adjust all of the primary colors (red, blueandgreen). (Courtesy of Richard Wolf, Knittlingen,Germany) 15. A three-CCD camera is a camera whoseimaging system uses three separate charge-coupleddevices (CCDs),each one taking a separate measurement ofthe primary colors, red, green, or blue light.Light coming into the lens is split by atrichroic prism assembly, which directs theappropriate wavelength ranges of light totheir respective CCDs.The system is employed by still cameras,telecine systems, professional video camerasand some prosumer video cameras. 16. Rods and ConesThe retina contains two types of photoreceptors,Rodscones.The rods are more numerous, some 120 million, and are more sensitive than theconesthey are not sensitive to color. The 6 to 7 million cones provide the eye's colorsensitivity and they are much more concentrated in the central yellow spot known asthe macula. In the center of that region is the " fovea centralis ", a 0.3 mm diameterrod-free area with very thin, densely packed cones.The experimental evidence suggests that among the cones there are three differenttypes of color reception. Response curves for the three types of cones have beendetermined. Since the perception of color depends on the firing of these three typesof nerve cells, it follows that visible color can be mapped in terms of threenumbers called tristimulus values.Color perception has been successfully modeled in terms of tristimulus values andmapped on the CIE chromaticity diagram. 17. Rods Do Not See Red!The light response of the rods peaks sharply in the blue; they respond very littleto red light. This leads to some interesting phenomena:Red rose at twilight: In bright light, the color-sensitive cones are predominantand we see a brilliant red rose with somewhat more subdued green leaves. Butat twilight, the less-sensitive cones begin to shut down for the night, and mostof the vision comes from the rods. The rods pick up the green from the leavesmuch more strongly than the red from the petals, so the green leaves becomebrighter than the red petals!The ship captain has red instrument lights. Since the rods do not respond to red,the captain can gain full dark-adapted