Adding Brakes To Actuated Fingers

November 8, 2021 by Bryan Cockfield 10 Comments

Building exoskeletons for people is a rapidly growing branch of robotics. Whether it’s improving the natural abilities of humans with added strength or helping those with disabilities, the field has plenty of room for new inventions for the augmentation of humans. One of the latest comes to us from a team out of the University of Chicago who recently demonstrated a method of adding brakes to a robotic glove which gives impressive digital control (PDF warning).

The robotic glove is known as DextrEMS but doesn’t actually move the fingers itself. That is handled by a series of electrodes on the forearm which stimulate the finger muscles using Electrical Muscle Stimulation (EMS), hence the name. The problem with EMS for manipulating fingers is that the precision isn’t that great and it tends to cause oscillations. That’s where the glove comes in: each finger includes a series of ratcheting mechanisms that act as brakes which can position the fingers precisely enough to make intelligible signs in sign language or even play a guitar or piano.

For anyone interested in robotics or exoskeletons, the white paper is worth a read. Adding this level of precision to an exoskeleton that manipulates something as small as the fingers opens up a brave new world of robotics, but if you’re looking for something that operates on the scale of an entire human body, take a look at this full-size strength-multiplying exoskeleton that can help you lift superhuman amounts of weight.

Continue reading “Adding Brakes To Actuated Fingers” →

OpenEMS Makes Electromagnetic Field Solving… Merely Difficult

July 28, 2017 by Al Williams 21 Comments

To ordinary people electronics is electronics. However, we know that the guy you want wiring your industrial furnace isn’t the guy you want designing a CPU. Neither of those guys are likely to be the ones you want building an instrumentation amplifier. However, one of the darkest arts of the electronic sects is dealing with electromagnetic fields. Not only is it a rare specialty, but it requires a lot of high-powered math. Enter OpenEMS, a free and open electromagnetic field solver.

We would like to tell you that OpenEMS makes doing things like antenna analysis easy. But that’s like saying Microsoft Word makes it easy to write a novel. In one sense, yes, but you still need to know what you are doing. In fairness, though, the project does provide a good set of tutorials, ranging from a simple wave guide to a sophisticated phased array of patch antennas. Our advice? Start with the waveguide and work your way up from there.

The software uses Octave or MATLAB for scripting, plotting, and support. You can download it for Windows or Linux.

If you want to start with something more intuitive for electromagnetic field visualization, this might help. If you prefer your models more concrete and less abstract, perhaps you should work at Lincoln Lab.

Flying Defibrillators

July 11, 2017 by Dan Maloney 57 Comments

It’s a sad reality that, by and large, cardiopulmonary resuscitation (CPR) doesn’t save lives. Despite all the “you could save a life” marketing aimed at getting people certified in CPR, the instances where even the prompt application of the correct technique results in a save are vanishingly rare, and limited mostly to witnessed arrests in a hospital. Speaking from personal experience, few things are sadder than arriving on-scene as a first responder to see CPR being performed by a husband on his wife and knowing that no matter what we do, it’s not going to end well.

The problem is one of time. Hearts only rarely just stop beating outright; usually some kind of arrhythmia first causes the heart to beat ineffectively, leading to hypoxia and loss of consciousness. From there it’s about a four-minute trip to brain death, but in that brief window chances are pretty good that the heart can be restarted. That’s why witnessed cardiac arrests in a hospital have better survival rates — the needed electric reboot of the heart with a defibrillator is only as far away as the nearest crash cart.

The advent of the automatic external defibrillator (AED) has increased the odds for survival of out-of-hospital cardiac arrest (OHCA), but the penetration of AEDs into public settings is far from complete enough to put one within a few minutes reach of everyone who might need one. So it’s only natural that thoughts would turn to delivering AEDs to cardiac incidents by drones. It seems like a great idea, but will it work? Continue reading “Flying Defibrillators” →

Bristle Bot Controversy

February 19, 2009 by Caleb Kraft 66 Comments

bristle

When the Bristlebots were released back in 2007 by Evil Mad Scientist Laboratories, we all thought they were pretty cool. Apparently someone at Klutz did too. They have released a book, with the title “Invasion of the BristleBots”. The bots seem to be identical and the name is identical. There is no mention of Evil Mad Scientist Laboratories anywhere in it. [Phillip Torrone] has attempted to contact Klutz and the book publisher Scholastic directly to find out more information.

[Windell] and [Lenore] from EMSL had this to say:

“This is the first that I’ve heard of it. Frankly, I am a bit offended. Klutz makes some nice things, and I’m surprised that they wouldn’t have contacted us, asked permission, or at least given us credit. (Locomotion by ratcheting bristles isn’t remotely new — it occurs in nature — but the name ‘Bristlebot’ is surely ours, and I don’t know of any prior implementation with a toothbrush.)”

You probably know EMSL from their other projects such as the Peggy and Meggy jr. How would you feel if a project you did was published without credit? Would you care or not?

EMS Synthi AKS Teardown

June 25, 2008 by Eliot 1 Comment

Here’s another bit of analog synth pr0n for you: Initially sold in 1972, the EMS Synthi AKS was a portable modular analog synthesizer with a built in keyboard and sequencer. The VCS 3 portion of the device had a unique routing matrix pegboard used to connect components together. [firegroove] has opened up his precious machine so that you can see all of the fine little bits that make it tick… and chirp.