A fast penetration contributed to a swift gathering of valuable early adopters’ feedback. The experience from specialised respiratory centres proved to be a solid basis for advice on how to further enhance the bronchoscope. In the following years, bronchoscopes were already available in a variation of different models (see Fig. 2.1), targeting different applications.

The first bronchoscopes were based on fundamental technology available for gastroenterologists for examination of the GI tract (see Fig. 2.2). The major technical challenge was the required thinner flexible shaft of the bronchoscope. It had to accommodate a sufficient number of glass fibres to transport the light into the lumen, a high precision fibre bundle to transport the image from the distal end of the scope to the eyepiece. Via the ocular piece at the proximal end, the physician can observe the area of interest. The proximal tip of the bronchoscope can be angulated by a lever which is located at the control section – the central part of the scope the user is holding and manoeuvring the scope with. Different to GI scopes which usually allow deflection of the distal tip in all four directions (up/down, left/right), the bronchoscope can be bent only in two directions 180°and 130°, respectively. A measure to safe space, as such a strategy requires only two wires to run inside the shaft. By clockwise or counterclockwise shaft rotation, the bronchoscope tip can reach all areas of interest. A working channel, sometimes called instrument channel, provides aspiration possibilities and guides thin long instruments, so-called endotherapy devices, to, e.g. acquire specimen during the procedure, allowing subsequent histopathological examination.

Over decades, a wide range of fibre bronchoscopes have been in use in daily routine. The continuous advances in endoscopy design and especially the introduction of video technology – a key breakthrough and a quantum leap for the image quality – influenced the bronchoscope evolution (see Fig. 2.5). The core component needed is the CCD chip (charged ­coupled device) which delivers as a light-sensitive analogue device the image as a electrical signal and is mounted at the distal tip just behind a lens system (see Fig. 2.6).

The major technical challenge was the miniaturisation of the CCD chip enough that the human anatomy can accommodate the outer shaft dimension of such a video bronchoscope. In comparison to a fibre scope, the image glass fibre bundle requires less space compared to the CCD sensor. The eyepiece though is no longer necessary. Wires deliver the electrical video signal to the light guide connector (see Fig. 2.7).

In addition to the light source, a video processing unit is now mandatory. After looping the signal through a connection to the video processor with relevant signal processing measures, the user observes the endoluminal image on a monitor linked to the video processor (see Fig. 2.8).

Since the very first design concepts of video bronchoscopes, there existed two different principles of image acquisition by video signal. The key difference is the way how the CCD sensor at the distal tip of the endoscope is working and acquiring the image contents information in detail.