Original subtitles

Narrator: AROUND THE WORLD,

THE RACE TO WIN WARS AND EXPLORE THE UNIVERSE

HAVE CREATED SOME OF THE MOST

INCREDIBLE PRODUCTS EVER DESIGNED.

AND WE USE THEM EVERY DAY,

UNAWARE OF THEIR AMAZING ORIGINS.

ON "INCREDIBLE INVENTIONS,"

THE WRISTWATCH -- HOW DOES WORLD WAR I

FIT INTO ITS POPULARITY TODAY?

THE DIGITAL CAMERA --

WHAT IS THE LINK BETWEEN SPY SATELLITES AND THE SELFIE?

THE PROSTHETIC LEG --

THE AMAZING EVOLUTION OF THIS HIGH-TECH WONDER.

WE REVEAL THE AMAZING HISTORY

AND ENGINEERING BEHIND THESE INCREDIBLE INVENTIONS.

-- Captions by VITAC -- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

THE MODERN WRISTWATCH HAS MANY ROLES,

AN EXPENSIVE PIECE OF JEWELRY,

A HIGH-TECH WRIST-WORN COMPUTER,

EVEN A DEVICE TO TELL THE TIME.

BUT DO YOU KNOW THAT WARFARE IS THE REASON

FOR ITS POPULARITY TODAY?

PERSONAL WATCHES CAN TRACE

THEIR ORIGINS BACK TO 16th CENTURY EUROPE

WITH TIME PIECES WORN BY MEN

AS PENDANTS AROUND THEIR NECK.

WATCHES WERE A VERY EXPENSIVE ITEM,

AND THE WRISTWATCH WAS USED EXCLUSIVELY

AS A FEMALE ACCESSORY,

TYPIFIED BY ROBERT DUDLEY

PRESENTING A WRISTWATCH TO THE ENGLISH QUEEN,

ELIZABETH THE FIRST, IN 1571.

Ellis: WRISTWATCHES WERE MAINLY RESERVED FOR WOMEN

AND WERE KNOWN THEN AS WRISTLETS.

AND IT WAS CERTAINLY VERY EFFEMINATE

FOR A MAN TO WEAR A WRISTWATCH.

Narrator: IT WAS IN WORLD WAR I, THOUGH, THAT GOOD TIMEKEEPING

BECAME AS IMPORTANT AS THE BULLETS

IN A SOLDIER'S GUN OR THE BOOTS ON HIS FEET.

WE COME TO THE FIRST WORLD WAR.

WE HAVE THE FAMOUS -- OR THE INFAMOUS --

BATTLE OF THE SOMME THE 1st OF JULY, 1916.

7:30 IN THE MORNING,

YOU'VE GOT TO KNOW EXACTLY WHAT TIME YOU'RE GOING OVER.

IF YOU'RE HOLDING A POCKET WATCH,

HOW ARE YOU THEN GOING TO HOLD YOUR WEAPON?

Narrator: THE ONLY WAY THE SOLDIERS COULD SAFELY ADVANCE

WAS IF A CREEPING BARRAGE BY THEIR OWN ARTILLERY

SCREENED THEIR ADVANCE

LIKE A HUGE EXPLODING CURTAIN FALLING JUST AHEAD OF THEM.

AS THEY MOVED FORWARD, SO DID THE COVERING FIRE,

KILLING THE ENEMY BUT GOING OVER THE HEADS OF THEIR OWN SIDE.

TO PROTECT THE GLASS FACE FROM THE MUD, BLOOD, AND BULLETS,

THE WATCHES WERE FITTED WITH SHOCK-PROOF FACES.

AND LUMINOUS DIALS WERE DEVELOPED

TO GIVE AN ACCURATE TIME CHECK IN THE DARK OF A TRENCH

WHERE A SNIPER'S BULLET WOULD FIND ITS TARGET

IF A LIGHT WAS TURNED ON.

WITH THE MEMORY OF THEIR PRACTICALITY

IN WORLD WAR I FRESH IN THEIR MINDS

AND THE AVAILABILITY OF CHEAP PARTS

AND MASS PRODUCTION,

EVEN THE ORDINARY MAN CAN NOW AFFORD ONE.

BUT JUST HOW IS A WRISTWATCH MANUFACTURED?

THE SCHOFIELD WATCH COMPANY

HAS BEEN CREATING LUXURY WRISTWATCHES SINCE 2011.

THE LIFE OF A SCHOFIELD WATCH STARTS WITH THE MANUFACTURE

OF THE WATCH CASE.

THE WATCH CASE IS COMPRISED OF TWO PARTS,

THE FRONT, WHICH THE STRAP WILL BE FITTED TO,

AND THE REAR, WHICH IS A GLASS WINDOW

TO DISPLAY THE WATCH MECHANISM.

IT TAKES MANY MAN HOURS TO MAKE A MECHANICAL WRISTWATCH,

AND A MECHANICAL WRISTWATCH ESPECIALLY,

BECAUSE THERE ARE SO MANY MOVING PARTS.

THERE'S SO MUCH ENGINEERING INVOLVED.

A CASE ALONE TAKES

ABOUT 14 HOURS TO MACHINE FROM BILLET

TO THE FINISHED PIECE READY FOR ASSEMBLY.

Narrator: THE FRONT PART OF THE WATCH CASE STARTS OFF

AS A LARGE PIECE OF TITANIUM CALLED A BILLET.

THE BILLET UNDERGOES A LONG

AND RIGOROUS PROCESS CALLED MACHINING

WHERE ITS SHAPE IS SCULPTED

USING THE LATEST COMPUTER NUMERIC CONTROL MACHINERY.

ALSO KNOWN AS CNC MACHINES,

THESE MILLS AND BLADES CAN CUT WITH ABSOLUTE PRECISION

TO ACHIEVE A PERFECT FINISH.

EVEN USING STATE-OF-THE-ART MACHINERY,

THE SHAPING PROCESS STILL TAKES EIGHT HOURS.

TO BEGIN, THE BILLET IS FIXED TO A LATHE

WHERE THE FIRST CUTS AND INITIAL HOLES ARE MADE.

ONCE COMPLETED, THE BILLET IS THEN TAKEN

THROUGH THE FIRST OF MANY MILLED PROCESSES.

HERE, THE INNER THREADS ARE BORED OUT,

CLEANED, AND EXAMINED BY HAND.

THEN IT IS BACK TO THE MILL WHERE THE FRONT,

TOP, AND BACK OF THE NEWLY FORMED CASE IS CARVED OUT.

IT'S HERE THAT WE CAN START TO SEE THE WATCH CASE TAKING SHAPE.

A STAINLESS-STEEL BACK IS FITTED,

THEN IT'S BACK TO THE MILL ONCE AGAIN FOR FINE-TUNING.

THE CASING IS PUT THROUGH ITS FINAL MACHINE PROCESS

BEFORE IT IS SENT TO BE INSPECTED BY HAND.

EACH CASE MUST PASS THROUGH INSPECTION

BEFORE IT IS RELEASED TO THE ASSEMBLY LABS.

ONCE THE CASE PASSES INSPECTION,

IT IS SENT TO THE ASSEMBLY LAB

WHERE SKILLED WATCHMAKERS BEGIN A DETAILED

AND METICULOUS ROUTINE TO HAND BUILD THE WATCHES.

THE FIRST STAGE IS TO USE A MACHINE

CALLED A CRYSTAL PRESS.

IT IS USED TO PRESS THE GLASS INTO THE CASE

TO CREATE A TIGHT FRICTION FIT

AND TO HELP KEEP THE WATCH WATERPROOF.

THE MAKER THEN CAREFULLY SELECTS THE MOVEMENT PARTS BY HAND

FROM A RANGE OF NEW AND OLD STOCK

THAT HAS BEEN FULLY REFURBISHED.

THE WATCH IS COMPRISED

OF AN EXTREMELY COMPLICATED SET OF PARTS,

AND IT CAN TAKE UP TO THREE HOURS

FOR A SKILLED WATCH MAKER TO CAREFULLY

AND PRECISELY PLACE ALL THE MOVEMENTS,

AUTO WORKS, AND ROTORS TOGETHER.

THEN IT COMES TO ACTUAL WATCH ASSEMBLY

AND THE BUILDING OF THE MOVEMENTS.

AND, AGAIN, LOOKING AT THE BETA,

WE USE NEW OLD-STOCK SWISS MOVEMENTS,

AND THESE HAVE TO BE SERVICED.

SO, EFFECTIVELY, THEY'RE STRIPPED DOWN

TO THEIR COMPONENT PARTS, THEN THEY'RE REBUILT.

SO WE'RE LOOKING AT A FURTHER THREE HOURS

TO PUT THAT TOGETHER BY A WATCHMAKER.

SO, WE REALLY ARE ACCUMULATING A LOT OF MAN HOURS

TO BE ABLE TO PUT A WRISTWATCH TOGETHER.

Narrator: THE DIAL IS THEN ADDED ALONG WITH THE HANDS

BEFORE TESTING AT KEY POINTS ENSURES

ALL THE MECHANISMS ARE ALIGNED CORRECTLY.

THE MOVEMENT IS THEN PLACED INSIDE THE CASING

AND FASTENED INTO PLACE

TO MAKE SURE THE FIT IS TIGHT AND WATERPROOF.

THE COMPLETED WATCH IS THEN PUT THROUGH A PRESSURE

AND VACUUM MACHINE

TO TEST THE TOLERANCE LEVELS OF THE WATCH.

AND TO MAKE SURE IT MEETS SCHOFIELD'S HIGHEST STANDARDS,

EVERY WATCH THAT LEAVES THE FACTORY

IS METICULOUSLY INSPECTED,

WITH FINAL INSPECTIONS CARRIED OUT BY HAND

BEFORE BEING PACKAGED INTO

A HAND-CRAFTED BOX READY FOR DELIVERY.

SO, THE NEXT TIME YOU GLANCE

AT THAT ENGINEERING MASTERPIECE

SITTING ON YOUR WRIST,

REMEMBER IT OWES ITS POPULARITY

TO THE HELL ON THE WESTERN FRONT.

WHEN "INCREDIBLE INVENTIONS" RETURNS,

WE FIND OUT WHAT THE EVERYDAY SELFIE

HAS IN COMMON WITH SPY SATELLITES.

Narrator: WHO DOESN'T LOVE TAKING A QUICK FAMILY SNAPSHOT,

A PHOTO OF AN AMAZING EXPERIENCE,

AND EVEN THE MUNDANE SHOT OF WHAT YOU ATE LAST NIGHT?

BUT HAVE YOU EVER CONSIDERED THE TECHNOLOGY

THAT HAS MADE PHOTOGRAPHY SO EASY AND INSTANT?

AND WHAT HAS A SELFIE

GOT IN COMMON WITH SPY SATELLITES?

THE ANSWER IS THE DIGITAL CAMERA.

IF YOU ARE UNDER THE AGE OF 20,

YOU CANNOT POSSIBLY IMAGINE

HOW THIS TECHNOLOGY HAS CHANGED

THE WAY WE TAKE AND SHARE A PICTURE.

IN THE YEARS B.C. -- THAT'S BEFORE CAMERAS --

THE ONLY WAY TO CREATE AN IMAGE WAS TO TAKE OUT AN EASEL

AND START PAINTING AWAY.

THE INVENTION OF THE FILM CAMERA AND ITS INTRODUCTION

TO THE MASS MARKET IN THE 1900s CHANGED ALL THAT.

NOW SCIENCE HAS GIVEN EVERYONE THE ABILITY

TO CAPTURE THAT SPECIAL MOMENT IN TIME.

Gybels: IN A TRADITIONAL FILM CAMERA, THE LIGHT COMES IN,

IS CAPTURED THROUGH A SMALL OPENING,

THEN PROJECTED THROUGH MIRRORS AND LENSES ONTO A FILM SURFACE,

WHICH IS COATED WITH A SUBSTANCE

THAT HAS LIGHT-SENSITIVE MATERIAL IN IT.

SO, IT HAD TO BE DEVELOPED BEFORE YOU COULD SHARE.

THERE WAS NO EASY WAY OF THEN TRANSMITTING IT

IN ALMOST REAL TIME TO SOMEBODY ELSE.

Narrator: WITH THE POPULARITY OF FILM CAMERAS FIRMLY ESTABLISHED,

WHAT WAS THE NEED FOR DIGITAL PHOTOGRAPHY?

THE ANSWER IS IN THE STARS.

THE SUCCESSFUL LAUNCH OF THE SPUTNIK SATELLITE

BY THE RUSSIANS IN OCTOBER 1957,

OPENS UP A NEW FRONTIER IN INTELLIGENCE GATHERING.

SOON, U.S. AND RUSSIAN SPY SATELLITES

EQUIPPED WITH FILM CAMERAS ARE BEING LAUNCHED

TO KEEP AN EYE ON EACH OTHER FROM A LOFTY PERCH OF SPACE.

IN THE EARLY DAYS OF SPY SATELLITES,

THEY USED ACTUAL CAMERAS

WITH FILM ON BOARD THE SATELLITE.

SO, NOW YOU HAVE THIS PROBLEM OF THE SATELLITE THAT SITS IN ORBIT

AROUND THE EARTH CAN'T EASILY BE BROUGHT BACK DOWN TO EARTH,

SO YOU NEED TO GET THE FILM DOWN.

AND THEREFORE, ALL KIND OF ELABORATE SCHEMES

WHEREBY THE FILM WENT INTO A RE-ENTRY CAPSULE

THAT WAS THEN SHOT BACK DOWN,

IT CAME DOWN IN A PARACHUTE,

A PLANE CAME BY AND PICKED IT UP WITH A GRAPPLER HOOK.

THIS CREATES ALL KINDS OF PRACTICAL

AND OTHER DIFFICULTIES.

Narrator: THIS COMPLICATED SYSTEM NEEDED TO BE IMPROVED.

AND THE LAUNCH OF THE $1 BILLION,

15-TON KH-11, OR KEYHOLE CLASS SATELLITE,

IN 1976 SOLVES THIS ISSUE

WITH ITS AMAZING DIGITAL CAMERA POWERED

BY A REVOLUTIONARY CCD,

A CHARGED-COUPLED DEVICE.

Gybels: A CHARGE-COUPLED DEVICE,

IT'S A SURFACE THAT HAS A PROPERTY

THAT WHEN LIGHT FALLS ONTO IT,

IT GENERATES AN ELECTRICAL CHARGE

THAT IS PROPORTIONAL TO THE LIGHT

THAT FALLS ONTO THE SURFACE.

SO, BASICALLY, AN IMAGE, A VISUAL IMAGE,

IS TRANSLATED INTO A SERIES OF ELECTRICAL CHARGES.

THOSE ELECTRICAL CHARGES CAN THEN BE TAKEN

INTO AN ELECTRICAL SIGNAL

THAT CAN BE TRANSMITTED TO A RECEIVER,

AND THEN THAT SIGNAL CAN BE RE-TRANSLATED

INTO VISUAL POINTS OF LIGHT ON A SCREEN

OR ANY OTHER FORM OF IMAGING.

Narrator: THE 800x800 PIXEL CCD

ON BOARD THE KH-11 PROVIDES

A RESOLUTION OF 640,000 PIXELS.

THAT MEANS THE U.S. GOVERNMENT CAN FOCUS ON AN OBJECT

AS SMALL AS 5 INCHES FROM 200 MILES AWAY IN SPACE

AND BEAM ELECTRONIC VERSION OF THE IMAGE

BACK TO EARTH INSTANTLY.

SO, THE MILITARY PROVES THE CCD's WORTH,

BUT WHEN CCD-EQUIPPED DIGITAL CAMERAS

HIT THE SHELVES IN THE 1990s,

THEIR HIGH COST LEADS TO SLOW SALES.

ENTER THE COMPLEMENTARY METAL OXIDE SEMICONDUCTOR,

OR CMOS SENSOR.

DEVELOPED AND REFINED DURING THE LATE 1990s,

THE CMOS SENSOR CAPTURES AN IMAGE

IN A SIMILAR WAY TO THE CCD, BUT IS MADE USING

TRADITIONAL MICROCHIP- MANUFACTURING TECHNIQUES,

UNLIKE THE SPECIALIZED AND EXPENSIVE CCD.

Gybels: CMOS REQUIRES LESS POWER THAN TRADITIONAL CCDs,

SO IT IS QUITE SUITABLE FOR DEVICES LIKE MOBILE PHONES,

WHERE BATTERY POWER COMES AT A PREMIUM.

AND FURTHERMORE, THIS TECHNOLOGY'S VERY SIMILAR

TO OTHER COMPONENTS ALREADY USED IN CAMERAS,

AND THEREFORE IT MAKES FOR A CONVENIENT

AND ECONOMICALLY FEASIBLE WAY OF PRODUCING CAMERAS

FOR THINGS LIKE MOBILE PHONES THAT ARE COMPACT,

DON'T REQUIRE A LOT OF POWER,

YET STILL HAVE GOOD-QUALITY IMAGING PROPERTIES.

Narrator: WITHIN THESE CLEVER SENSORS

POWERING THE CAMERAS INSIDE OUR PHONES,

THE DIGITAL CAMERA IS NOW PART OF OUR EVERYDAY LIVES,

AND IT'S GIVEN US THE ABILITY TO CAPTURE

AND SHARE OUR EXPERIENCES AS NEVER BEFORE.

A DEVICE INVENTED FOR SPYING,

BUT NOW USED FOR THE OBLIGATORY SELFIE --

THE DIGITAL CAMERA -- TRULY AN INCREDIBLE INVENTION.

HOW DO YOU TURN YOUR SMARTPHONE INTO A POWERFUL MICROSCOPE?

FIND OUT WHEN WE RETURN.

Narrator: WE ARE FAMILIAR WITH THE DIGITAL CAMERA

IN OUR MOBILE PHONES CAPTURING EVERY DETAIL OF OUR LIVES.

BUT WHAT ABOUT FOCUSING EVEN CLOSER ON OUR WORLD?

LET'S MAKE OUR MOBILE PHONE INTO A MOBILE MICROSCOPE.

ALL WE NEED IS PLEXIGLASS, WOOD, BOLTS, WASHERS,

A SMALL L.E.D. FLASHLIGHT, AND A LASER POINTER.

NOTICE THE TINY LENS AT THE FRONT OF YOUR PHONE.

WELL, THE SECRET IS TO CHANGE ITS FOCAL PLANE,

THAT'S THE DISTANCE FROM THE CAMERA

TO THE OBJECTS IT'S FOCUSING ON,

BY PUTTING ANOTHER LENS IN FRONT OF IT.

ENTER THE LASER POINTER.

WITH A LASER POINTER, YOU NEED TO CONCENTRATE THE LASER LIGHTS

TO, WELL, A POINT,

AND THE FRONT OF THE POINTER IS A TINY LENS

WHICH CONCENTRATES LIGHT FAR GREATER

THAN OUR PHONE'S CAMERA.

CAREFULLY POP THE LENS OUT OF THE POINTER,

AND BY FIXING IT IN FRONT OF OUR PHONE'S LENS,

WE HAVE CREATED A POWERFUL MICROSCOPE.

WELL, NOT QUITE. THIS SETUP ALLOWS US

TO ZOOM INTO AN OBJECT OVER 100 TIMES.

BUT AT THIS MAGNIFICATION,

HOLDING THE CAMERA BY HAND

IS GOING TO BE A LITTLE TOO SHAKY.

THIS IS WHERE THE WOOD AND BOLTS COME IN.

OUR TESTER CREATES A STAND

BY DRILLING THREE HOLES IN A SQUARE PIECE OF WOOD.

THREE BOLTS ARE ADDED WITH NUTS AND WASHERS SCREWED ON

TO KEEP THEM IN PLACE.

A SMALL SHEET OF PLEXIGLASS HAS TWO HOLES MADE TO ALLOW IT

TO SIT ON THE FRONT TWO BOLTS

AND ACT AS A SHELF.

THREE HOLES ARE DRILLED IN THE LARGER PLEXI SHEET.

AND IT IS THEN FIXED ONTO THE TOP OF THE BOLTS

WITH SCREWS AND WASHERS.

A SMALL HOLE IS THEN DRILLED

INTO WHICH THE LASER LENS IS CAREFULLY PLACED.

FINALLY, THE PHONE IS CAREFULLY POSITIONED

ON TOP OF THE LASER LENS.

BUT WE NEED A SPECIMEN. SO WHAT'S ON HAND?

AH, A HUMAN HAIR.

THIS IS PUT ON THE SPECIMEN TRAY.

AND THE TRAY IS PLACED BETWEEN THE TWO LAYERS OF PLEXIGLASS,

THEN CAREFULLY ADJUSTED FOR FOCUS.

AND PRESTO -- WITH THE LED LIGHT ILLUMINATING THE SUBJECT,

THE BEAUTY OF THE HUMAN HAIR CAN BE SEEN

IN ALL ITS CELLULAR GLORY ON YOUR CELL PHONE.

SO POINT PROVED.

THE CMOS SENSOR INSIDE YOUR PHONE

CAN EASILY BE UNLEASHED

AS AN AMAZING MICROSCOPE.

THE DIGITAL CAMERA -- TRULY AN INCREDIBLE INVENTION.

COMING UP, HOW DOES AMAZING MODERN TECHNOLOGY

HELP OUR WOUNDED WARRIORS?

Narrator: FOR CENTURIES, BATTLES HAVE PRODUCED

SOME PRETTY GRISLY INJURIES.

JUST A GLANCE AT ANY RECORD OF CONFLICT

FROM THE ANCIENT GREEKS TO THE BAYEUX TAPESTRY

TO THE MODERN CONFLICTS IN THE MIDDLE EAST

SHOWS THAT THE LOSS OF LIMBS

BY AX OR ARTILLERY IS A REALITY.

MODERN COMPOSITE MATERIALS MEAN A WOUNDED VETERAN

ISN'T CONDEMNED TO A LIFE OF IMMOBILITY,

UNLIKE THEIR UNFORTUNATE MEDIEVAL FOREBEARS.

HOWEVER, REPLACING A LOST LIMB WITH A METAL OR WOOD ATTACHMENT

ISN'T AS NEW AS YOU MIGHT THINK.

DATING BACK TO ANCIENT EGYPT,

A BODY HAS BEEN FOUND FITTED WITH A WOODEN TOE.

Ghouze: IT WAS FOUND THAT IT BELONGED TO A NOBLE WOMAN.

WITH IT BEING THE GREAT TOE,

I SUPPOSE IT WOULD HAVE GIVEN HER SOME STABILITY TO WALK,

BUT PERHAPS, ALSO, IT WOULD HAVE BEEN SOMETHING

THAT WOULD BE OF COSMETIC USE TO HER.

Narrator: THE BIGGEST ADVANCEMENTS IN PROSTHESIS,

HOWEVER, WOULD COME AS A RESULT OF WORLD WAR II,

AND BY THE VIETNAM ERA, THOUSANDS OF INJURED MEN

WERE GETTING A CHANCE FOR A BETTER LIFE

VIA FITTED ALUMINUM LEGS.

AND THE VETERANS FROM MORE RECENT CONFLICTS,

LIKE IRAQ AND AFGHANISTAN

ARE WEARING THE NEXT GENERATION STILL.

THE AMAZING TECHNOLOGICAL ADVANCES IN PROSTHETICS

ARE ENCAPSULATED IN THIS C-LEG.

THE C-LEG IS THE MOST RESEARCHED

MICROPROCESSOR-CONTROLLED KNEE JOINT IN THE WORLD

AND HAS BEEN ON THE MARKET FOR ALMOST 20 YEARS

AND HAS BECOME THE BEST-SELLING MECHATRONIC KNEE JOINT

IN EVERY COUNTRY IT'S SOLD.

NOW MANUFACTURING UP TO 5,000 C-LEGS A YEAR,

OTTOBOCK HEALTHCARE PRODUCTS CONTINUE TO PRODUCE

THESE LIFE-ALTERING PROSTHETICS

AND SUPPLY THEM TO THOSE IN NEED.

WALKING IS AND SHOULD BE AN AUTOMATIC FUNCTION.

IN A BIOLOGICAL LEG, NERVES ACTING AS SENSORS

SEND SIGNALS TO THE LEG MUSCLES THAT THEN MOVE ACCORDINGLY.

THIS HAPPENS UP TO 20 TIMES EVERY SECOND

IN WHAT IS KNOWN AS A REFLEX LEAP.

IN THE C-LEG, THE MICROPROCESSORS

REPLACE THE BODY SENSORS

WHILE THE HYDRAULICS REPLACE THE MUSCLE FUNCTION.

HOWEVER, WHAT MAKES THE C-LEG SO INTUITIVE

IS THE ALL-IMPORTANT MICROPROCESSOR

THAT ACTS AS THE BRAINS OF THE LEG,

CONTROLLING THE HYDRAULICS BY THE SENORS

THAT ARE VITAL TO GAIT CONTROL.

THE MICROPROCESSOR SITS AT THE TOP OF THE C-LEG,

JUST BELOW THE KNEE JOINT INSIDE THIS ELECTRONIC COVER.

IT IS NOW TIME TO ASSEMBLE THE HYDRAULIC UNIT.

THIS UNIT CONTROL'S THE C-LEG'S VALVE POSITION

AND THE DAMPENING FOR THE EXTENSION

AND FLEXION OF THE KNEE JOINT

BY REGULATING VALVES FOR OIL FLOW.

MAGNETIC SENSORS ARE INSERTED INTO THE HOLDER AND SOLDERED.

THE SERVER ELECTRONICS ARE THEN INSERTED INTO THE CASE.

AND THE PLUGS ARE SOLDERED AND SECURED.

THE ENGINE OF THE C-LEG IS THEN POSITIONED,

TESTED, AND ADJUSTED ACCORDINGLY

BEFORE BEING GLUED INTO THE CASE.

THE ASSEMBLY PROCESS OF THE C-LEG CONTINUES

WITH AN INSPECTION OF THE LEG'S COATED FRAMES

FOR ANY MARKS OR DAMAGE.

DAMPER IS GLUED INTO THE FRAME OF THE LEG

IN ORDER TO PREVENT THE VARIOUS COMPONENTS WITHIN

FROM MOVING AND CLASHING AGAINST THE FRAME

WHILE THE LEG IS USED.

THE SERIAL NUMBERS OF EVERY COMPONENT

THAT MAKES UP THE C-LEG ARE THEN RECORDED

TO ENSURE ACCURACY BEFORE TESTING.

THE BATTERY OF THE C-LEG IS ADDED

AS WELL AS A SLIDING COMPONENT

THAT IS USED TO MEASURE THE KNEE ANGLE.

THE BEEPER THAT WILL SERVE TO ALERT PATIENTS,

ALONG WITH A VIBRATION UNIT,

IS THEN INSERTED AND CONNECTED TO THE MAIN ELECTRONICS.

ONCE THIS IS DONE, THE MEASURING FUNCTION OF THE ANGLE SENSOR

FOR THE C-LEG IS VERIFIED.

THE KNEE-ANGLE SENSOR IS USED AS A WAY

OF MEASURING THE KNEE POSITION

AND OF CONTROLLING THE PROSTHESIS.

THE JOINT IS TURNED ON AND CONNECTED TO P.C. SOFTWARE

AND THEN BENT AND STRETCHED

FROM 1 TO 7 DEGREES AND THEN TESTED.

THE RESULTS ARE RECORDED, AND IF ALL TESTS ARE PASSED,

THE HYDRAULICS CAN THEN BE BUILT INTO THE C-LEG.

EACH C-LEG HAS ITS OWN TESTING PROTOCOL

ACCORDING TO EACH PATIENT'S SPECIFIC NEEDS.

THE FINAL TESTING PROCESS BEGINS WITH CONNECTING

THE JOINT TO A COMPUTER

AND THEN MANUALLY BENDING AND STRETCHING THE JOINT.

THE C-LEG IS THEN MOUNTED ONTO A WALKING SIMULATOR.

HERE, 1,000 STEPS ARE SIMULATED FOR A PERIOD OF 20 MINUTES.

ONCE THE C-LEG HAS UNDERGONE THE RIGOROUS

AND THOROUGH TESTING PROCESS AND PASSED,

IT IS THEN PACKAGED ALONG WITH THE INSTRUCTION MANUAL

FOR THE PATIENTS, AND SHIPPED READY FOR USE.

IN MY OPINION, THE C-LEG HASN'T CHANGED MY LIFE

BECAUSE I CAN DO WITH THE C-LEG EVERYTHING I DID BEFORE.

I CAN GO MOTORCYCLE RIDING.

I CAN GO BICYCLING. I CAN GO SKIING.

I CAN DO EVERYTHING I WANT.

Narrator: USING STATE-OF-THE-ART MATERIALS

AND RESEARCH THAT CAN IMPROVE THE LIVES

OF THOSE THAT NEED THEM,

IT'S SAFE TO SAY THAT THIS C-LEG

IS THE EPITOME OF AN INCREDIBLE INVENTION.

SO, THERE YOU HAVE IT -- A GLANCE TO A HIDDEN HISTORY

AND SUPER SCIENCE OF SOME AMAZING PRODUCTS

WE USE EVERY DAY

BUT HAVE NEVER REALIZED THEIR FASCINATING BACKGROUNDS.

THE WRISTWATCH, THE DIGITAL CAMERA,

AND THE PROSTHETIC LEG --

THEY MAY SEEM COMMON AND ORDINARY.

HOWEVER, THESE PRODUCTS HELPED CHANGE THE WORLD

ONE INCREDIBLE INVENTION AT A TIME.