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Optics & Cameras. Mohan St. John’s Medical College Bangalore. Properties of light. Travels in a straight line Cannot bend Loses intensity over distance Prone to colour changes Parallax Refraction Burnout. Refraction in media. Colour distortion. Endoscopy – desirable.
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Optics & Cameras Mohan St. John’s Medical College Bangalore KUA Masterclass 2013
Properties of light • Travels in a straight line • Cannot bend • Loses intensity over distance • Prone to colour changes • Parallax • Refraction • Burnout KUA Masterclass 2013
Refraction in media KUA Masterclass 2013
Colour distortion KUA Masterclass 2013
Endoscopy – desirable • Ease of instrumentation • Sturdy instrumentation • Good optical quality – magnification if needed • Good colour rendering • Feasibility of instrumentation • Ability to demonstrate or view KUA Masterclass 2013
Enablers • Understanding of optics • Ability to construct instruments • Availability of superior material • Developments in electronics • Brave, innovative pioneers KUA Masterclass 2013
Total Internal Reflection KUA Masterclass 2013
Bow to the GuruHarold Horace Hopkins, FRS1918 -1994 KUA Masterclass 2013
He also invented the “ZOOM” lens for the BBC KUA Masterclass 2013
Construction of Endoscope KUA Masterclass 2013
Rod-lens system KUA Masterclass 2013
Distortion due to alignment KUA Masterclass 2013
The Rod-lens system KUA Masterclass 2013
Object vs. Image KUA Masterclass 2013
The desire to see – and show… KUA Masterclass 2013
Teaching attachment KUA Masterclass 2013
Lecturescope KUA Masterclass 2013
Beam-splitting KUA Masterclass 2013
Beam splitter KUA Masterclass 2013
Single-chip camera: CMOS KUA Masterclass 2013
Single-chip Control unit KUA Masterclass 2013
Drawbacks of CMOS chip • Light transmitted as it was • Loss of clarity over distance • Colour distortion • Poor depth perception compared to eye • Not good for video streaming KUA Masterclass 2013
What was seen… KUA Masterclass 2013
What was seen… KUA Masterclass 2013
What was seen… KUA Masterclass 2013
What was seen… KUA Masterclass 2013
Splitting of white light KUA Masterclass 2013
3 – chip Camera & control unit KUA Masterclass 2013
The 3 - Chip • Charge-coupled device • Broke light to 3 primary colours – R,G,B • Converted light to electronic signals • Signals reprocessed by computer • Processed image transferred to Monitor • Good video quality • Optical experience improved KUA Masterclass 2013
What we wanted to see… KUA Masterclass 2013
Now, yehdil mange more… KUA Masterclass 2013
Non-coherent transmission KUA Masterclass 2013
Fibreoptic endoscopes KUA Masterclass 2013
Optics of Fibreoptics KUA Masterclass 2013
Flexible working endoscope KUA Masterclass 2013
Flexible Scope – Construction KUA Masterclass 2013
Flexible endoscopes • Could “bend” light • Could be used in various hollow structures • With improvements, instruments possible • Less traumatic for diagnostics • Better visualisation • More ergonomic KUA Masterclass 2013
But yehdilmaange even more… KUA Masterclass 2013
A “Chip on tip” KUA Masterclass 2013
The chip-on-tip • No camera coupling unit • Processor & electronics at the tip • Fully digitised signal directly to monitor • True Hi-definition possible • Outstanding video quality Diameter < 5mm not possible – yet KUA Masterclass 2013
Chip-on-tip assembly KUA Masterclass 2013
We now see better… KUA Masterclass 2013
We also see more… KUA Masterclass 2013