hi my name is akifumi takahashi and i'm presenting a work i did together with my colleague jas brooks
my phd advisor hiroyuki kajimoto from university of electro-communications, tokyo
and my internship advisor pedro lopez from the university of chicago
the field of haptics has come a long way in the last decade. we explore haptics for touching
objects in virtual reality learning new physical tasks and much more. here we see an exoskeleton
glove that can move the user's finger involuntarily. unfortunately it uses large motors that are not
trivial to miniaturize. so these devices are very limited in their applications to wearable or
everyday situations. so in order to build more mobile applications researchers in HCI in the
past decade have been exploring another technique called as electrical muscle stimulations or EMS for short .
and you can see here it's very small because it just applies electrodes to the body
now using EMS people have been building all sorts of interactive systems
for instance this system the "possessed hand" simulate fingers to play some simple note combination with
this instrument. this system "affordance++" can make you shake a spray can so you learn how to
manipulate an object that you've never seen before this one, called "muscle plotter," controls your wrist
and plots for you. and this one can move your wrist to tap to a beat so you learn some beat patterns.
but when you zoom out, you see what exactly is the quality of the actuation provided
by these systems. you see all these systems or many others found in the HCI community actuate
only large muscles, like legs, arms, or the wrists, with very coarse movements like wrist up and down
and in fact possessed hand which is proposed about 10 years ago is still the most precise system we got.
so WHAT is preventing ems from getting better. so here i'm gonna move the index finger using EMS
so the first joint which is called MCP is the joint I was targeting but the finger also
moved around the other joint of the same finger. and the pinky also started to move. so actuating
by placing electrodes on the forearm to control finger muscles suffer from the lack of dexterity.
all right so why does this happen? as you can see all the finger muscles anchor at this bone
and so they are very densely packed when you apply the electrodes on the forearm
it's natural that the current goes through adjacent muscles or ones at other different depths
so our approach is to move the electrodes on the back of the hand
so we can precisely target the first joint of the finger without moving the others
now to validate this we ran a study comparing it to the standard approach
of just putting the electrodes on the forearm. we found that the finger moves more independently;
there's less unwanted movement;
our approach is more rotation invariant so you can see that if i turn my wrist it still works well
and turns out it takes less time to calibrate. so using our back of the hand actuation you can build
new applications at a new level of dexterity let me show you a few applications we made
here you see a user doing a simple chord that presses all strings with one finger
and you see a user doing a special drum stroke that requires a very
fine movement with one single finger. you see an user learning how to play a simple melody
now back of the hand is NOT without limitations as i mentioned you can only move that first joint
so there's still a lot of way to do for us to unleash full dexterity of EMS. we need to move
two more joints of the finger and we need to work also in other direction because so far we only bone
flex that finger down but we also need to unleash dexterity of the extending direction. ... so i'm really
excited to see what you all will build with the back of the hand stimulation. thanks for listening