What could an abnormal pupillary reflex indicate?

Pupillary light reflex is used to assess the brain stem function. Abnormal pupillary light reflex can be found in optic nerve injury, oculomotor nerve damage, brain stem lesions, such as tumors, and medications like barbiturates.

What is a infrared beam?

Infrared beam sensors detect the motion of objects both in light and dark with equal reliability. The infrared sensors do not need any contact with the object to be detected. The Infrared beam sensors are small in size.

What nerve controls the pupil dilation?

Oculomotor nerve (III) is responsible for the control of the pupil (constriction) via parasympathetic fibres (this is opposed by dilator tone controlled by sympathetic pathways).

What changes in pupils would be considered abnormal?

The pupil is abnormal if it fails to dilate to the dark or fails to constrict to light or accommodation.

What are the main signs for pupillary response?

Performing the Exam for Pupillary Responses

  • Observe the pupil size and shape at rest, looking for anisocoria (one pupil larger than the other)
  • Observe the direct response (constriction of the illuminated pupil)
  • Observe the consensual response (constriction of the opposite pupil)
  • Repeat with the opposite pupil.

How does a beam detector work?

Optical beam smoke detectors work on the principle of light obscuration, where the presence of smoke blocks some of the light from the beam,typically through either absorbance or light scattering. Once a certain percentage of the transmitted light has been blocked by the smoke, a fire is signalled.

What is a photoelectric beam sensor?

A photoelectric sensor emits a light beam (visible or infrared) from its light-emitting element. A reflective-type photoelectric sensor is used to detect the light beam reflected from the target. A thrubeam type sensor is used to measure the change in light quantity caused by the target crossing the optical axis.

How do security beams work?

Strip beams consist of four strips of receivers and transmitters that generate an invisible, pulsed infrared light. If movement is detected due to the pulse being ‘broken’ by an intruder reaching through the beam, an alarm signal is immediately sent.

What happens if cranial nerve 3 is damaged?

The oculomotor (third) cranial nerve plays an important role in the efferent visual system by controlling ipsilateral eye movements, pupil constriction, and upper eyelid elevation. Accordingly, damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis.