Fantastic Voyage (1966)

In Richard Fleischer's classic science-fiction adventure film (the most expensive of its time) - and the Oscar winner for Best Visual Effects:

• the film's basic 'fantastic' premise - in the year 1995, a nearly-dead, injured defecting Communist Czech scientist Dr. Jan Benes (Jean Del Val), whose life was threatened by a blood clot in his brain (after an assassination attempt leaving the airport during his escape); he was to be saved within one hour's time by a miniaturized team of five specialists (four males and a female) engaged in a microscopic mission to his brain (after being injected into the arterial bloodstream of Benes' body) - who were themselves inside a micro-sized, high-tech nuclear-powered submarine, the USS Proteus (full-sized in actuality)
• the reason to revive or cure the scientist was to learn his newly-discovered secret - to prolong the miniaturization process indefinitely, beyond 60 minutes
• the sequence of the miniaturization of the submarine vessel to "about the size of a microbe" - before it was injected in the body; a POV shot from inside the vessel looked out to illustrate its shrinkage; and then the vessel was injected into the arterial bloodstream (via the carotid artery) - seen from various perspectives - in order to travel through the patient's arteries to the brain, to dissolve the clot with a laser beam

The Miniaturized USS Proteus Injected Into Benes' Bloodstream
Full-Sized Proteus

• in terms of special effects, the interior of the scientist's body was created by using large, highly-detailed sets of various body parts (i.e., the brain, the heart). Through various techniques, the explorers were seen 'scuba-diving' (swimming) through the body (the actors were suspended on wires).
• the giant life-sized model of the interior circulatory system of the comatose patient was viewed, while he was being monitored to precisely pinpoint the location of the submarine's 'fantastic voyage' inside of him; the mission was to travel via the carotid artery to the location of the damage (the blood clot) - an attempt to dissolve the clot would be accomplished with a laser beam
  

The USS Proteus Mission Inside the Patient's Body		The Life-Sized Model

• after becoming trapped in the venous system, the group decided to take a short cut through the heart, but needed to induce cardiac arrest for no more than 60 seconds to allow the submarine to detour through it - risking killing the patient; they had to stop the heart momentarily in order to prevent the sub from being crushed by thumping heartbeats
• then in order to replenish the sub's oxygen supply, American secret agent Charles Grant (Stephen Boyd) and the crew exited the sub and used a snorkel tube attached to the patient's lungs to force oxygen into the sub's tanks
• the crew discovered that the surgical laser that was to be used to perform the blood-clot procedure was damaged - it was not strapped down and become dislodged during turbulence - evidence of a enemy saboteur in the group that had tampered with it; it needed repair to its damaged transistor

Discovery of Surgical Laser Damaged

In the Lung to Replenish the Sub's Oxygen - Swimming Outside the Sub

Clearing 'Sea-weed' Like Antibodies from Sub's Vents

• it was determined that the best way to proceed was to pass through the inner ear, it was imperative that exterior sounds be kept to a minimum
• to clear the sub's clogged vents from seaweed-like antibodies in order to prevent the sub's overheating, another 'scuba-diving' trip was required to remove them
• however, a destructive shock wave of vibrations was produced (during the vent-clearing mission) when one of the nurses accidentally dropped a pair of surgical scissors in the operating room - and the ship and all of its crew were violently jostled
• in a memorable scene, curvaceous, 'scuba-diving' technical assistant Cora Peterson (Raquel Welch in her first major screen role) was thrown into some fibers due to the shock waves - causing damage and prompting antibodies to attack her body; Dr. Michaels warned: "If the antibodies reach her, they'll attack as if she were bacteria"; as she screamed: ("They're tightening up - Please, I can't breathe"), she was brought back into the ship where the crew rescued her by pulling the seaweed-like antibodies from her body as they crystallized

The Attack of White Blood Cells - and The Rescue of Cora

• with only six minutes left to perform the blood clot operation with the laser before de-miniaturization began, the crew was under tremendous pressure; once the operation was completed by crew member brain surgeon Dr. Peter Duval (Arthur Kennedy), the mission was sabotaged by twitchy crew member - medical consultant Dr. Michaels (Donald Pleasence), who attempted to crash the submarine into the clot area to kill the patient and ruin the entire mission
• the remaining crew members were saved by heroic Commander Grant, who shot the sub with the laser and incapacitated it; white corpuscles enveloped and digested both the submarine and Dr. Michaels inside

Extraction: Saved Crew Swam Along Optic Nerve and Were Ejected from Patient's Tear Duct in Eye, Before De-Miniaturizing

• the four surviving crew swam along the optic nerve and emerged from the tear duct at the corner of the patient's eye to be rescued - they reverted back to normal size almost immediately afterwards