Paul Musto. Endoscopes and their construction

Transcription

1 Paul Musto Endoscopes and their construction

2 Types of Endoscopes Flexible instruments Rigid instruments Fibre optic imaging systems CCD imaging systems Medical Endoscopes Industrial Endoscopes

3 History The first endoscope was invented by a German doctor, Kassmaul, at the turn of the twentieth century, but being non-flexible, was not much use. A flexible device was made by another German, Rudolf Schindler, but it was still not very flexible unless the patient was contorted to suit the instrument. The endoscope became a much more practical instrument in the 1960's with the invention of the optical fibre.

4 Latest generation all singing and dancing scopes at the tip Very efficient fibre optic light transmission systems Improved mechanics with variable stiffness & scope guide systems

5 Durability of an Endoscope

6 Durability of an Endoscope Use on Patient / manual handling Pre cleaning / manual handling Manual cleaning, brushing & flushing Decontamination process in an AER Storage Decontamination Storage Cleaning 94

7 Flexible Endoscope Construction Light Transmission System Image Transmission System Mechanical Construction

8 Flexible Endoscope Construction Light Transmission System Image Transmission System Mechanical Construction

9 Light Transmission System

10 Light Transmission System

11 Flexible Endoscope Construction Light Transmission System Image Transmission System Mechanical Construction

12 Light Transmission System Coherent Fibre Bundle

13 Image Transmission System Charge Coupled Device

14 Image Transmission System Charge Coupled Device All colours, especially green, carry luminance information that the human visual system uses to discern and define image detail. Recognizing the importance of green light, manufacturers of colour CCDs dedicate 50% of the CCD to capturing green light

15 Image Transmission System RGB Filter RGB SEQUENTIAL, MONOCHROME White Light Light source Video processor Monitor High resolution monochrome CCD

16 Image Transmission System Object Light source White Light Video processor Monitor Color chip CCD

17 Image Transmission System Incident Light Pixels Micro-lens Dead Space

18 Image Transmission System Charge coupled device HDTV LINES

19 Flexible Endoscope Construction NBI (Narrow Band Imaging) AFI (Auto Fluorescence Imaging)

20 What is the advantage of narrow band imaging? Surface disease can be treated but it can be difficult to spot NBI changes the contrast so diseased tissue stands out Need to change the contrast Blood = red Tissue = pink Contrast = poor! NBI How can we improve the contrast without loss of image detail? We need natural wave lengths of light to interact with human tissue Blue and green light interact with tissue in slightly different ways, they penetrate to different depths Blue penetrates slightly deeper than green Red light is completely reflected by haemoglobin which the CCD is picking up from blood

21 Principles of Narrow Band Imaging Normal white light consists of colour overlapping each other and reproduces a natural colour image Conventional nm NBI B = FWHM30nm G = FWHM20nm nm

22 Narrow Band Imaging Conventional Imaging Narrow Band Imaging

23 AFI (Auto Fluorescence Imaging) Substances in the body give of fluorescence (glow in the dark) when excited by blue light Collagen fluoresces and anything that is in the way of the signal being returned (e.g. cancer) will be displayed in a different colour due to weakening of fluorescence coming back Normal tissue bright green Diseased tissue magenta in colour

24 AFI (Auto Fluorescence Imaging) Conventional AFI

25 AFI (Auto Fluorescence Imaging) AFI CCD Standard CCD Lens cleaning jets Instrument channel Light guides

26 Flexible Endoscope Construction Light Transmission System Image Transmission System Mechanical Construction

27 Scope Eyepiece (Fiberscope)

28 Control body/piston chambers

29 Air/Water & Aspiration Channel system Suction Valve Air/Water Valve Biopsy Valve Insertion Tube Nozzle Water Bottle Tube Universal Cord Water Bottle Connection Light Source Connector LIGHT SOURCE Biopsy/Suction Channel Air Channel Water Channel Suction Connection Air Pump WATER BOTTLE

30 Manual flushing of air/water & suction channel system/connections

31 Proximal end of patient tube

32 Distal end of patient tube

33 Proximal end of light guide tube

34 Typical Damage to distal tip

35 Poor Packaging