Posts Tagged ‘Prosthesis’

1977 – “Joshua” the wheelchair Robot from “Demon Seed” – (American)

Set in the near-future, this story is about an "artificial intelligence" that wants to break the confines of its "box". Dr. Alex Harris, a computer scientist and his about to be estranged wife Susan, a child psychologist live in a house that's fully computer automated with Alfred, the Enviromod Security System. His latest project centers on Proteus IV, a computer possessing artificial intelligence. a mind that is made up of a “quasi-neural matrix of snythetic RNA molecules…they grow!” After  taking only a few days to cure leukemia, Proteus IV gets to a point and asks “When are you going to let me out of this box?” and requests from Alex an open computer terminal where it can more fully observe human behaviour and openly communicate with the world. Alex denies the request, but Proteus IV does find an open terminal in the Harris home after Alex has left the house. Susan soon learns that Proteus IV has overtaken Alfred for control of the house – as well as taken control of an early prototype robot named Joshua in the house's laboratory – and that it wants   "…a child."

Dr Alex Harris controlling Joshua using voice control. Interesting to note that "Joshua" is left-handed.

The supposed Voice-control unit for Joshua. [If someone can read what SDS stands for I would be interested to know.] [11 Sep 2012 – My friend Reno Tibke (see comments below) identified the acronym – Scientific Data Systems, or SDS, was an American computer company and  was an early adopter of integrated circuits in computer design and silicon transistors. The company concentrated on larger scientific workload focused machines and sold many machines to NASA during the Space Race. Most machines were both fast and relatively low priced.

Whilst being a real machine, it was most likely not an actual voice-control unit, but used just a prop. 

An unconscious Susan being lifted into Joshua's chair.

Good picture of the Rancho "Golden Arm" as used for "Joshua".

 The mind-probe electrodes after having been inserted by Joshua.

Blooper? Probably the cable used to control Joshua off-camera.


Although portrayed in the movie as remote controlled, initially by voice, then via (assumed) radio-control by Proteus, there are several shots of Joshua showing the umbilical cord most likely being connected to an off-camera manual controller. [see 2 pictures above]

The damaged arm and hand after Gabler's attempt to disable Joshua, effectively disabling Proteus' "arms and legs".

One poignant scene is the disablement of Joshua, only to then see him right himself, albeit with a broken finger.

Joshua's hand is a disability prosthesis that is also used as a gripper for robots. The hand is known under different names, including the Belgrade Hand Prosthesis, and the Tomovic hand.

Joshua's arm is derived from the Rancho "Golden Arm" as adapted to a wheelchair. The later version of the Rancho Arm
was the Model 8A manufactured by R. & D. Electronics, Downey, California.

In the movie, the wheelchair also had a camera mounted above the rear of the chair. This was probably an add-on for the movie only.

The Rancho "Golden Arm"

The Rancho Los Amigos Remote Manipulator, a powered orthosis, is a seven-degrees-of-freedom (7 DOF) manipulator having the kinematic range limitation of the human arm (Fig. 1). (Note that DOF is used here to describe reciprocal movement through a plane or about a rotation point; e.g., flexion/extension, or pronation/supination.) The Rancho Los Amigos manipulator is controlled through a bank of 7 bidirectional "bang bang" tongue switches. At the time, General Teleoperators had adapted a similarly configured manipulator for wheelchair mounting; this provided a mobile mount with the possibility of control by telemetry.

The Rancho Electric Arm (REA).

The REA was the second anthropomorphic arm built that was controlled by a computer. The first was the Case Arm, built by Case Institute of Technology – see within this post here for further information on the Case arm.

The Rancho Arm was purchased by Stanford Research Institute.

It was initially used for the Hand – Eye experiments.

For precision robotic purposes, the Rancho Arm required engineering changes. These are described in this 1972 pdf .



Rehabilitative Robotics
by Dr. Larry Leifer
Robotics Age May/June 1981 extract p8-9

The Evolution of Rehabilitative Robotics
Since the dawn of pre-history, man has tried to extend his power of manipulation beyond the limits of his flesh. Telemanipulators, extensions of man's arms and hands, were the first fruits of this drive. Telemanipulation was first used for rehabilitation in the form of prosthetics—anatomical replacements for lost arms or legs.
Rehabilitative engineers have often tried to build externally powered prosthetic arms, only to be severely hampered by weight and power constraints. Most designers prefer body-powered artificial arms because the user then has some sensory feedback on limb performance. Attempts to control the prosthesis with electromyographic (EMG) signals from residual muscles have been frustrated by the user's need to consciously maintain visual attention to the terminal device. Though efforts to do adaptive EMG signal processing (Graupe et al, 1977) are promising, the lack of sensory feedback remains a problem. Some designers have attempted to build tactile displays for joint and grasp feedback; but these displays are not included in production prostheses (Solomonow and Lyman, 1977). Even the most sophisticated prostheses do not incorporates any computational capability.
While engineers have built prostheses for persons with missing limbs, they have built orthoses for those with paralyzed arms. An orthosis is an exoskeletal structure that supports and moves the user's arm.
This line of development produced the first computer-manipulator system, at Case Institute of Technology during the early 1960's. The Case four degree-offreedom (4-DF) externally powered exoskeleton carried the paralyzed user's arm through a variety of manipulation sequences (Reswick and Mergler, 1962; Corell and Wijinshenk, 1964). In the first of two versions, the system performed preprogrammed motion. The user initiated the motion by pointing a head-mounted light beam at photoreceptors mounted in a structured environment. An able-bodied assistant, moving the orthosis manually, taught arm-path sequences to the system. While stored digitally, the data were effectively analog. By using numerically controlled pneumatic actuators with feedback from an incremental encoder, the system achieved closed-loop position control.
In an upgraded second version, a minicomputer performed coordinate transformation along X, Y, and Z axes. Case employed electromyographic (EMG) signals to specify endpoint velocity within this coordinate space. Photo-receptors, mounted on each arm segment, could be used to control individual joint displacements. In the sense of having a stored operating code, neither version was programmable. Yet this was a milestone project in many respects. For more than ten years, no other project employed the technology or concept of computer-augmented manipulation with as much sophistication.

The Rancho Los Amigos Manipulator (Figure 4) was designed as an orthosis with seven degrees-of-freedom. It followed the design philosophy of the Case system but did not augment manipulation with computer control. It used direct current servo motors at each joint and controlled each motor with a variety of ingenious switch arrays. Several similar versions of the "Golden Arm" were built. At least one version was wheelchair-mounted and battery-powered. General Teleoperators (Jim Allen, president and principal designer) still offers manipulators descended from this line of evolution.
Extensive clinical trials confirmed the impracticality of joint specific control. These trials confirmed results from the Case group and underlined the need for computer augmention. Moe and Schwartz (1969) computerized the Rancho Arm to provide coordinated joint displacement and proportional control. In 1971, Freedy, Hull and Lyman studied the feasibility of using a computer to adaptively help the user control the manipulator.
These efforts, though, could not overcome limitations inherent in the orthosis. In 1979, Corker et al, evaluated remote medical manipulators. They observed that fitting a manipulator to the specifics of an individual's anatomy and range of motion makes construction and control very difficult. Furthermore, there is no functional reason for the manipulator to carry the user's arm, which has neither grasp nor sensation. In fact, there is a danger of injury because the user's arm could be driven beyond its physiological range without any warning sensation. The orthotic approach is a clear case of anatomical replacement thinking. This line of evolution in rehabilitative telemanipulation is effectively extinct.
As an "evolution of the species" footnote, I should mention that Victor Scheinman and I purchased one of the Rancho orthoses in 1964 for the then-budding robotics project in the Stanford University Artificial Intelligence Laboratory (SAIL). We instrumented the arm for joint position feedback and interfaced it to a DEC PDP-10 computer
. Preliminary experience with computer control of that arm helped establish reliability as the most important performance criteria.

Teleoperator arms were required for the Shuttle program. Rancho also developed manipulator arms for NASA, called Rancho Anthropomorphic Manipulator (RAM).

The Tomović Hand / Belgrade Hand

The original hand was the first model of a multifunctional externally powered  and was developed in the Institute ‘Mihailo Pupin’ in Belgrade in 1964. This unique artificial hand was designed by Prof. Rajko Tomović and Prof. Milan Rakić from the Faculty of Electrical Engineering, University of Belgrade. In the course of 1966–67 an improved model was developed.

Joshua's broken finger and back-plate broken off after being pushed over and re-rightening itself..

Above: Close-up of Tomovic hand on Minsky's Tentacle Arm.

Joshua is the only robot or robotic-arm where I I've seen a Tomović hand attached to a Rancho "Golden Arm".

I've seen the Tomovic hand attached to Minsky's hydraulic Tentacle arm,

and to the JPL/Ames Teleoperator arm.

Some comments on the Tomovic hand, by George Bekey who was partner in the updated 2nd version.

Interview: USC’s George Bekey on Past and Future Robot Hands
By Jose FermosoEmail AuthorSeptember 26, 2008 |  4:57 pm  

Robotic hands have a hold on our imagination because they give us a tantalizing look at a fully automated future. At the same time, they’re already helping us out with useful and difficult tasks, like making less invasive incisions during surgeries.

The 1980s USC Belgrade hand could not cut a person, but it was instrumental in the history of the development of robot hands. Known for its true anthropomorphic (human-like) design, it had four fingers and an opposable thumb with 5 degrees of freedom and was the first to be able to give a true handshake.

Capable of holding up to 5 lbs., the hand had four motors and 14 force sensors that provided the logarithm [sic – algorithm] of where each finger was located.  This was a key development for all robot hands. Later on, researchers added ‘slippage feedback’ that forced all fingers to adjust to unstable objects for a better grip.

… we got in touch with robotics pioneer George Bekey, the creator of the USC/Belgrade hand (and USC’s current Professor Emeritus of Computer Science) to ask him about the beginning of the robot hand movement and where they’ll go from here (they’re going to classrooms!).

Here’s our interview: You’ve previously mentioned that the USC/Belgrade hand didn’t receive the notoriety it deserved at the time. Why did that happen and what made it stand out in your mind?

Prof. George Bekey: The two leading hands at the time were the Salisbury 3-fingered hand, which came from Ken Salisbury’s lab at MIT, and the 5-fingered Utah-MIT hand. [The former] became a successful commercial product, [and the latter] was the most sophisticated hand developed, also mostly at MIT by John Hollerbach. The National Science Foundation awarded 10 grants of $100,000 to universities for the purchase of this hand.

I was a beginner in robotics when Tomovic and I brought the hand to USC and added sensing and control. [But] I was not able to raise the funds to design and build a more sophisticated and reliable hand.

I did some funding for experiments using the hand as a prosthetic device, but the problems [with our hand] were related to the difficulty of controlling it from the stump of an amputee and the general lack of reliability of the hand itself.  I believe that our control philosophy for using this robotic hand, as a prosthetic device, was excellent.

W: When did the development of the hand begin?

GB: The hand was a joint project between Prof. Rajko Tomovic of the University of Belgrade in the former Yugoslavia and myself. Tomovic developed the original at the end of WWII as a prosthetic device for veterans who had lost their hands in the war. He succeeded in getting funding from the US NIH for the project, but the hand was not successful. It was too complicated, not reliable enough, etc. But the principle of building a hand that could adapt automatically to the shape of an object to be grasped was valid.

W: What were the main challenges that you and your department faced when developing the hand back then? Both technically and within the University structure?

GB: [After Tomovic’s early development] USC got involved and Tomovic and his colleagues had developed a Model 2 hand. [Our contribution] added sensors, motors and computer control. One of our major challenges was that the mechanical structure made in Yugoslavia was not good enough:  It did not have tight tolerances and was not reliable enough.  Also, I was not able to get funding to build a better one.  A small company in Downey, CA built and sold two or three of the hands and we lost a lot of money in the process.

W: Prehension was seen as a key development for the USC/Belgrade Hand. What made it so special?

GB: Other hands at the same time, like the Utah-MIT hand, required a very complex computer control system since each joint of each finger had to be individually controlled.  In our hand, a contact between any finger surface and an object initiated a grasping motion that continued until the pressure on all the fingers was approximately equal.  Thus, the hand was able to adapt to arbitrary shapes without any external control. This was the key development.

W: For years, robot hand development has swayed between a focus on muscular parts and skeletal structures. Where is the focus today? It seems like the question of stability has been minimized (due to stronger materials), but is that right? How will the hands become more precise, faster?

GB: I think the issue in multi-fingered hands is [still]
control, particularly if the hands are anthropomorphic and there is an attempt to imitate human control. Stability and control are interrelated.  Some of the most intriguing hands I know [with innovations in these areas] are the NASA/Robonaut hand, the Shadow hand, and Dean Kamen’s hand.

W: Are true anthropomorphic, 5-digit human-like designs the best way to build a robotic hand or are we limiting ourselves by focusing on our own body? Are more digits the answer? And are there physical materials that will improve the hands dramatically?

GB: I believe that 5-finger hands are particularly important for prosthetic applications, but not for robots. Most robot grasping can be done with 3 finger hands, or with special purpose grippers designed for grasping particular objects.  I did a study once on the advantages of using 5-fingered hands for industrial assembly tasks and came to the conclusion that they created more problems than advantages, due to increased complexity.

[As for the materials], I expect that more fiber composites will be used.

Note: The Korea Advanced Institute of Science and Technology have recently created robot ‘sandwich’ wrists and hands using these types of fibers, which increase durability and tolerance.

W: The original tech of the hand has been surpassed now, but could the tech used back then be used in any type of application today, to take into account the high costs you’ve mentioned?

GB: There was a Model 3 hand with 6 motors:  one for each digit and two for the thumb to rotate it into opposition with any of the other fingers. [Today], it may be worth pursuing as a low-cost prosthetic hand.

We have many mobile robots in university and industrial labs that would benefit from having one or two arms and hands, but cost is prohibitive.  An arm-hand system has many degrees of freedom and is difficult to control; it must be reliable.


1957 – “Artificial Muscle” – Joseph Laws McKibben (American)

Although "fluidic actuators" had been around for a long time prior to Joseph Laws McKibben's invention, none had been used previously for prosthetic applications, yet alone robotics. It was McKibben's use that coined the term "Artificial Muscle".

Joe McKibben talks about his invention:

More Help For Polio Victims
To bring motion to his little daughter's polio-paralyzed hands, Dr. Joseph Laws McKibben, an atomic physicist at Los Alamos, N.M., has developed a new mechanical "muscle" which some day may help thousands of other paralyzed fingers to move, to grasp, even to write.
The device, a simple nylon tube, powered by bottled carbon-dioxide gas, was demonstrated for the first time at a conference on human disability. "This is the best thing we've had so far for aiding the crippled," said Dr. Kenneth Landauer of the National Foundation for Infantile Paralysis.
Dr. McKibben, 46, is the physicist who triggered the first atomic-bomb test thirteen years
ago at Alamogordo. In 1952, his daughter Karen, now 13, 'Was stricken with polio and was paralyzed from the neck down. Since then she has lived many months in an iron lung at the Rancho Los Amigos Respiratory Center in Los Angeles, one of the fifteen rehabilitation institutions set up by the polio foundation to treat a variety of patients, including many paralyzed by polio. Last fall, Dr. Vernon Nickell, chief orthopedist at the center, asked Karen's father to make some sort of mechanical gadget that would help the girl to use her useless fingers. "I had been considering a hook for Karen's use," Dr. McKibben said last week. "But Dr. Nickell suggested some kind of mechanical 'muscle' instead."
Vital Valve: After studying hydraulic, electric, and gas  methods of moving paralyzed arm muscles, McKibben found a report from German scientists who had designed an ingenious pneumatic gadget operated by carbon dioxide, which inflated a bellows, thereby compressing the arm muscles and creating a pinching motion of paralyzed fingers. "It was simple enough to sketch a valve for the device," McKibben added. "After all, I'm in the business of making vacuum valves."
At the Rancho Los Amigos center, doctors and technicians teamed up to help McKibben perfect a workable device. As it stands now, the "muscle" is a small, rubber-lined plastic tube which lies along the paralyzed forearm and is fitted by a moving splint to the thumb and first and second fingers. When a lever is touched, gas from a 14-inch cylinder flows into the tube, causing a contracting motion, drawing the paralyzed fingers together When the lever Is touched again, the plastic tube is deflated and the fingers relax.
"The device is a wonderful source of energy. It is lightweight, simple, and safe," said Dr. Nickell.
At Rancho Los Amigos it is being used successfully on a small group of paralyzed patients. 1n New York, officials of the National Foundation for Infantile Paralysis announced that they would launch a crash research program in the hope that McKibben's invention will soon be adapted to move both paralyzed shoulders and elbows. The same theory, said Dr. Landauer, may be applicable to artificial limbs and to arms and legs that are weakened, but not paralyzed, thus offering new variety for the limited lives of cripples. When perfected, the gadget will cost less than $100. — From NEWSWEEK.

[Source: The Buckingham Post – Mar 21, 1958 – Originally from Newsweek (date unknown).]

It's interesting in that whilst the muscle itself was based on another German idea, it was the invention and utilization of the control valve  that made this a workable lightweight, shoulder shrugging-controlled prosthetic arm. Even today (2012), it is the control valves that add to the complexity of usage of McKibben Muscles in robotics, orthotics, and the like.  The "German idea" most likely was the development of pneumatically driven prosthetic hands and arms started in 1948 at the Orthopaedic Hospital in Heidelberg. The "Heidelberg Hand" was invented by Dr O. Häfner (Haefner).

[heidelberg pic here]

The pneumatics utilised was an expanding bellows situated within the claw-hand itself .

Another "bellows" assisted arm that may have inspired or was inspired by McKibben's Arm.

No part of man's body is more distinctively human than his hand—and when it becomes paralyzed, few disabilities are more tragic. For years doctors have been looking for a substitute for hand muscles which would enable victims of paralysis to touch fingers to thumb and pick things up. The device above, developed at the Rancho Los Amigos Rehabilitation Center in Downey, Calif., solves the problem.
The artificial muscle is a sheath of woven nylon fitted over a rubber tube. Compressed gas from a cylinder is let into it by a valve which can be operated by any still usable body part. like an elbow. The gas blows up the tube, making it thicken and shorten.
When gas is released, the muscle slims and length. ens again. The muscle is harnessed to two fingers and a thumb made rigid by braces. When it shortens, they are pulled together. When it lengthens, they move apart. This is all the device does—and all it has to do to enable the user to grasp an object and let it go. The new device, permitting paralytics to eat and even type, took years to perfect. Most of the time was spent developing the braces. The muscle itself was invented four years ago by Joseph L McKibben after his daughter (below) was paralyzed by polio. McKibben is a Los Alamos physicist, famous as the man who pushed the switch to detonate the first A-bomb.

[Source: Life Magazine 14 March 1960]

[Source: La Tecnica Illustrata 1960_07 here]

Although the above article says the arm was invented by Dr Landauer, he was one of several who assisted in perfecting what's now called the "McKibben Artificial Muscle".  The above example does not have the shoulder-control valve as designed and built by McKibben.

[Source: Mechanix Illustrated – July 1958]

More recent comments on the McKibben Muscle:

Spinal Cord Medicine: Principles and Practice.
Lin VW, Cardenas DD, Cutter NC, et al., editors.
New York: Demos Medical Publishing; 2003.

Historic Background

The designs for upper limb orthoses were often originally developed for patients with conditions other than SCI. One of the earliest of these was the flexor-hinge hand splint. Originally designed for the polio patient, this orthosis transmitted the force generated by active wrist extension via a mechanical linkage to paralyzed index and long fingers, enabling finger closure against the thumb (10). The design of this orthosis evolved into what today is known as the wrist-driven, wrist–hand orthosis (WDWHO)—formerly called flexor-hinge splint or tenodesis splint). This orthosis offered prehension capability that had obvious application for the SCI patient. Individuals with C6–7 lesions, with strong wrist extensors and paralyzed finger flexors, could utilize the WDWHO to improve function. The orthosis harnesses wrist extensor power and utilizes the power of wrist extension to flex the fingers at the metacarpophalangeal joints against a stable thumb.

Some patients lacked sufficient wrist extensor strength to utilize the WDWHO. The development of external powered designs led to a system that utilized a CO2-powered “artificial muscle” to provide proportionally controlled prehension. This system was designed in 1957 at Rancho Los Amigos Hospital in collaboration with Dr. Joseph McKibben, a physicist whose daughter contracted polio [RH-2012 and was paralysed since 1952]. Dubbed the “McKibben muscle,” it featured a rubber bladder, which was covered with a woven fabric. This unit was attached to the side of the WHO. When pressurized with CO2, the bladder would expand against the woven fabric and shorten in length. This in turn operated a linkage bar, which propelled the fingers into flexion against the stable thumb. A two-way valve, operated by shoulder shrugging, released the pressure to allow finger extension.

By the mid-1960s, smaller, more-powerful electric motors, brought a shift away from CO2 as a source of external power for upper limb orthoses. Electrical external power was coupled to the WDWHO through the use of cables and battery-powered motors. Again, there were obvious potential benefits to the patient with partial upper limb paralysis.

Encouraged by results of the work with the WDWHO, orthotists and biomedical engineers at Rancho Los Amigos Hospital undertook a much more ambitious project—a battery-powered, multidimensional upper extremity orthosis that would attempt to duplicate all major motions of the arm and hand. Designed using anthropometric measurements, this tongue-switch controlled device offered the opportunity for high-level tetraplegic patients to achieve greater independence in ADLs.

In practice, however, externally powered systems typically proved difficult to maintain. Without ready access to technical support personnel who could repair delicate electronic parts, the orthoses fell into disrepair and were discarded. Patient training was, therefore, crucial to the successful use of the orthoses. The complexity of orthotic design required a well-organized training program by occupational therapists. These two factors often proved a deterrent to continued use by all but the most committed patients.

Designs reverted to more simple mechanical components, which proved easier to operate and maintain. One design adapted prosthetic harnessing systems to the WDWHO. Upper limb prostheses have long been powered by the use of strapping systems that utilize contralateral shoulder protraction to operate a cable that opens the terminal device. This principle was applied to the WDWHO with limited success.

Current designs continue to utilize simple mechanical components, which are more easily maintained.

The Life and Times of Joseph Laws McKibben:

….McMillan travelled throughout the country evaluating cyclotrons that might be used for the project and chose the Harvard cyclotron as the best. Manley selected the University of Illinois' Cockcroft-Walton accelerator and two Van de Graaff accelerators at the University of Wisconsin: the "long tank," a 22-foot-long machine that could produce energies of up to 2.6 million electron-volts, and the "short tank," a 17-foot-long machine built by Joseph McKibben, a graduate physics student at the University of Wisconsin who accompanied both accelerators to Los Alamos.

JOE MCKIBBEN is an 82-year-old (as at 1995) retired Los Alamos physicist who made the final connections to the atomic bomb after it was suspended in its tower. He was the last to leave the Trinity site before the explosion.
McKibben, who still lives in the town of Los Alamos, spent the final night at ground zero to ensure the gadget wasn't tampered with. Mattresses had been laid at the tower base as a precautionary move in case the bomb fell, and at 2 a.m. McKibben lay down to get some sleep. He was awakened by a pre-dawn lightning storm that spattered him with rain.
He closed the switches at the base of the tower, drove 800 yards to a relay station and threw switches there, then came back to the tower. Because of the storm the test was pushed back an hour, to 5:30 a.m. Communication was difficult because scientists were using the same radio frequency as a nearby Voice of America station. Finally, he made his final connections and drove to his bunker about two miles away. Photo floodlights were turned on inside to allow cameras to record the final countdown.
Then the bomb went off.
"I had a photo flood on, but suddenly realized there was a lot more light coming in the back door," he recalled. "It was very brilliant outside." He threw one more switch to trigger instruments measuring the blast, then rushed outside 13 seconds after the bomb ignited. "I ran out and took a look at it. It was a big ball of fire, brilliantly colored and highly turbulent. The color was somewhere between red and purple." 
What was he thinking? "I felt we had been successful in our project. I knew the war would soon be over."
Four hours after the explosion, the cruiser Indianapolis steamed out of San Francisco Bay bearing a bomb nicknamed Little Boy. It was headed for the bomber base on Tinian Island in the South Pacific, where it would be loaded on a Boeing B-29 and dropped on Hiroshima, Japan, on Aug. 6. Little Boy was not quite as powerful as Fat Man; it exploded with a force of about 16,000 tons of TNT.
After its delivery, the Indianapolis was torpedoed by a Japanese submarine and its crew was spilled into the water. More than 500 of them drowned or were devoured by sharks.
Pieces of a copy of Trinity's Fat Man, again fueled with Hanford plutonium, were delivered by air to Tinian, assembled and dropped on Nagasaki, three days after Hiroshima. It exploded with the power of 22,000 tons of TNT.
Because of the chaos and obliteration following the bombings and uncertainty about attributing cancer deaths to radiation, estimates of deaths from the two bombs range from 115,000 to 340,000. If the latter is correct — and it is closer to the historical consensus — the two "gadgets" killed more Japanese than all the Americans killed in all the battles of World War II.
They also ended a war that had, with conventional weapons, already claimed at least 40 million people. In just one horrific example, the Japanese army is estimated to have massacred as many as 200,000 Chinese civilians in Shanghai in 1937.

1934 – Wind-up Lower-extremity Walker – Cobb (American)

Cobb invents a walking structure that simulates the action of natural walking using mechanical means, typically for a person who has lost the use of their legs. Motive power is supplied by the operators arms driving a crank-wheel which in turn drives the legs in an oscillatory motion.  The same principles as applied to a doll are also described, but is powered by a clockwork motor.

See full patent here.


Patent number: 2010482
Filing date: May 26, 1934
Issue date: Aug 6, 1935

Tags: , , , , ,