This mechanical artificial hand, with fingers that could be moved individually by means of tiny internal cogs and levers, was designed and made almost 500 years ago by Ambroise Pare.
Pare (1517-1590) began working as a battefield surgeon in 1536. When treating gunshot wounds on the battlefield, he often amputated limbs.
Pare treated many amputees during his career. He developed safe and effective methods for amputation, and closely followed the progress of all his patients. He therefore recorded many first-hand accounts of phantom limb syndrome, and, in 1551, provided the first medical description of the condition:
For the patients, long after the amputation is made, say they still feel pain in the amputated part. Of this they complain strongly, a thing worthy of wonder and almost incredible to people who have not experienced this.
Eventually, Pare began to focus on designing and making artificial limbs. He tried to replicate natural movement in his devices, and the prostheses he developed heralded the modern era of artificial limbs.
The illustration above comes from Pare's Oeuvres (Collected Works), which was published in 1575. The book also contains illustrations of the artificial arm and leg made by Pare. The latter had a movable knee joint that was controlled by a piece of string, and a flexible spring-operated foot.
Update: A translation of Pare's description of his mechanical hand:
Description of the iron hand.
1. Sprockets attached to each finger, part of the fingers themselves, added and assembled from the back of the hand.
2. Metal shaft going through the center of the sprockets, upon which they turn.
3. Trigger to hold each finger.
4. Stoppers for the triggers, with a pin in the center, to receive the triggers.
5. Main trigger to open the 4 smaller triggers, which hold the fingers.
6. Button at the end of the main trigger; push to open the hand.
7. Spring under the main trigger, which makes it go back, and keeps the hand closed.
8. Springs for each finger, which make the fingers go back and open when closed.
9. Blades of the fingers.
Many thanks to Arthur for the translation.