Figure 1: Endoscope functional block diagram
Leja 2014). However, roughly 80% of persons with
Because light is required for endoscope
H. pylori infections do not develop gastric cancer. imaging, something must introduce light into the
(Ibid).
patient's body so the endoscope's camera sensor can
The first diagnostic device typically used see. The light source is typically too bulky to be
While the exact
when gastric cancer is suspected is an endoscope, a inside the endoscope itself.
device for looking inside a patient's body for medical configuration varies with model, the light source
purposes. Depending on the region of interest, an could be inside the endoscope’s hand control or
appropriate type of endoscope will be introduced elsewhere outside the patient and its light is carried
into the patient's body to view the interior of body through the endoscope by optical fibers.
spaces or hollow organs. See Figure 2, a generic
functional block diagram of an endoscope.
In this case, the measurand is the patient's
internal tissues, and the primary sensor element is a
digital camera. The digital camera contains a circuit
which typically acts as both a color light sensor and
analog-digital converter.
The camera signal
processor then sends the digital image data to the
endoscope output processor, where it is delivered to
the endoscope’s live display and potentially also to a
computer for further image analysis and/or for
storage.
A diagnostic endoscope is also equipped with Figure 2: Left: Normal stomach body, Right:
a biopsy instrument to harvest small quantities of Normal pylorus. From Martin & Lyons (2014)
suspect tissue for further examination. The tissue
samples gathered this way can then be delivered to a
pathology lab for thorough analysis. While using
completely different methods, both of these devices
can be said to act on the same measurand.