Optics in urology
- 1. OPTICS IN UROLOGY Dept of Urology Govt Royapettah Hospital and Kilpauk Medical College Chennai
- 2. Moderators: Professors: • Prof. Dr. G. Sivasankar, M.S., M.Ch., • Prof. Dr. A. Senthilvel, M.S., M.Ch., Asst Professors: • Dr. J. Sivabalan, M.S., M.Ch., • Dr. R. Bhargavi, M.S., M.Ch., • Dr. S. Raju, M.S., M.Ch., • Dr. K. Muthurathinam, M.S., M.Ch., • Dr. D. Tamilselvan, M.S., M.Ch., • Dr. K. Senthilkumar, M.S., M.Ch. Dept of Urology, GRH and KMC, Chennai. 2
- 3. ENDOSCOPES IN UROLOGY 1.Rigid endoscopes 2.Flexible endoscopes 3.Composite scopes 4.Digital endoscopes 3 Dept of Urology, GRH and KMC, Chennai.
- 4. RIGID ENDOSCOPES HISTORY: 1806 – Bozzini’s Lichtleiter–direct vision urethral tube --candle light is used 1879 –Nitze&leiter – simple lens system into theviewing tube -- version of modern cystoscope 1900 – heated platinum wires & light bulbs used 1960 – modern fiberoptic lighting introduced - rigid endoscopy 4 Dept of Urology, GRH and KMC, Chennai.
- 5. 20th century: Hopkins rod-lens system -- replacing the thin relay lenses within the shaft of the telescope with long, contoured glasses -- 9 fold increase in light transmission --improved refractive index --increased viewing angle --decreased profile of telescope shaft 5 Dept of Urology, GRH and KMC, Chennai.
- 6. THANK YOU 6 Dept of Urology, GRH and KMC, Chennai.
- 7. OPTICS Rigid endoscopes -- use a telescope that consist of a series of lenses along the shaft --to relay a single optical image from the imaging lens at the distal tip of the endoscope back to the eye of the urologist In early days -- image was transmitted through the hollow tube via thin relay and field lenses placed at precise distance within the air filled assembly tube 7 Dept of Urology, GRH and KMC, Chennai.
- 8. ROD LENS SYSTEM In late1950’s Hopkin introduced this system --air spaces are reduced with long rods of glasses ground,contoured and polished at both ends --images can be magnified at the ocular lens --degree of magnification depend on diameter of viewing lens -- size of magnified image through a small caliber (ureteroscope) is smaller than large bore caliber (cystoscope) --addition of video cameras & monitor based endoscopes has eliminated the discrepancy in image size --binocular view 8 Dept of Urology, GRH and KMC, Chennai.
- 9. --objective lenses with angles ranging from 0-120 degree --cystoscopes –interchangeable lenses 0-5 degree– direct vision internal urethertomy for urethral stricture 12-30degree– transurethral prostate surgery 30-70degree—bladder For rigid ureteroscopes & nephroscopes: -direct vision lens is used -rarely necessary to exchange lens -available only on larger ureteroscope & nephroscope - seldom used 9 Dept of Urology, GRH and KMC, Chennai.
- 10. CONSTRUCTION Cystoscopes mostly uses straight viewing telescopes --access to instrumentation channel is via angled ports inferior to telescope --accessories such as stone graspers or forceps introduction is difficult Rigid ureteroscope & Nephroscope --right angled or offset oblique ocular configuration --direct access to accessories will be easy --with the use of video cameras this is becoming less an issue 10 Dept of Urology, GRH and KMC, Chennai.
- 11. 11 Dept of Urology, GRH and KMC, Chennai.
- 12. 12 Dept of Urology, GRH and KMC, Chennai.
- 13. 13 Dept of Urology, GRH and KMC, Chennai.
- 14. FLEXIBLE ENDOSCOPES --costlier --complex of construction --shaft consist of 3 fiberoptic bundles : Light bundle: 2 noncoherent bundles of fiber that transmit light Imaging bundle: single coherent bundle of glass fibers constitute the imaging bundle Images : -- images obtained is not a single image --composite matrix of each fiber within the bundle -- image is analogous to a newspaper photograph 14 Dept of Urology, GRH and KMC, Chennai.
- 15. 15 Dept of Urology, GRH and KMC, Chennai.
- 16. HONEYCOMB effect *composed of multiple dots merging into a single reconstructed image . --Each optical fiber diameter is 8 micrometer --Each fiber is composed of glass possessing higher refractive index than the cladding that surrounds it --this composition allows excellent light & image preservation over long distance 16 Dept of Urology, GRH and KMC, Chennai.
- 17. 17 Dept of Urology, GRH and KMC, Chennai.
- 18. The coherent bundle consist of thousand of individual fibers with identical arrangement *Each image of each fiber is transmitted along the entire bundle to the ocular lens at eyepiece *Even though optical fibers are flexible they may be damaged by - excessive flexion - force - Pressure on the shaft of the scope 18 Dept of Urology, GRH and KMC, Chennai.
- 19. * If individual fiber is damaged the image will be a black dot *many broken fibers leads to indeterminate image 19 Dept of Urology, GRH and KMC, Chennai.
- 20. Most flexible endoscopes possesses capabilty of active deflection In two directions --either up and down -- side to side *the action is accomplished via a series of interlocking hinges within the distal shaft of the scope which are connected to the deflecting lever in the handle via thin rods and pulleys that run the length of the shaft *the direction of angle of flexion can be changed by rotating the shaft of the scope 20 Dept of Urology, GRH and KMC, Chennai.
- 21. 21 Dept of Urology, GRH and KMC, Chennai.
- 22. *new scopes have passively flex on contact with tissue *this allows retroflexion used to view the bladder neck with cystoscope *ureteroscope passively deflect off of the renal pelvis and enter lower and middle calyxes 22 Dept of Urology, GRH and KMC, Chennai.
- 23. COMPOSITE SCOPES Merger of rigid shaft with flexible optics *resulting scope is called miniscopes *consist of small profile, rigid shaft and a fiberoptic imaging bundle with 1or 2 ports for Instruments Advantages: smaller shaft diameter eleminates optical distortion Disadvantages: loss in resolution of endoscopic image 23 Dept of Urology, GRH and KMC, Chennai.
- 24. DIGITAL ENDOSCOPE Digital and electronic imaging *no lens component *replaced by charge coupled device(CCD) chips *small enough to be mounted at the distal end of shaft *CCD chip will relay digitalized information via a single fiber back to a distal processor which will reconstruct and enhance the image electronically on a television monitor 24 Dept of Urology, GRH and KMC, Chennai.
- 25. • Advantages: 1.superior quality image 2.To know generational distortion 3.Space saved 4.Light weight 5.Larger instrumental channels 6.Larger working elements used 7.No need for additional light source and camera setup 8.Smaller size 9.Increased flexibility 10.Improved durability 25 Dept of Urology, GRH and KMC, Chennai.
- 26. FUTURE TRENDS *three dimensional imaging options *using 2CCD chips to create stereoscopic images with depth perception *wireless image technique *reduced caliber pediatric ureteroscopy using the latest techniques 26 Dept of Urology, GRH and KMC, Chennai.
- 27. THANK YOU 27 Dept of Urology, GRH and KMC, Chennai.