In 2011, TAMAKI Emi (left) developed
PossessedHand (below), a device thattransmits proprioceptive sensations to thebody. The following year, she co-founded
the startup H2L and embarked on
developing the business. The company
launched “UnlimitedHand,” a moreversatile version of PossessedHand forresearchers, and “FirstVR” (left photocenter) for general consumers. Tamaki
said, “I’m glad we started the company
because while gaining feedback from ourusers and thinking about our businesspriorities, we get closer to providing
specific services.” H2L

as the world’s first device thatallows people to experience thesensations of others not just intheory but in actual practice.
PossessedHand is one fruit ofBodySharing—Tamaki’s proposed
concept—which refers to thetechnology and interfaces involvedin the mutual sharing ofexperiences among people, avatars,
and robots through the reciprocaltransmission of proprioceptive
sensations. It makes the sharingof experiences virtually or froma remote location richer andmore real, and can be realized inmany ways. Not only is it possible:
BODYSHARING
TRANSMITTING THE EXPERIENCE OF
PROPRIOCEPTION

Sharing experiences virtually or from a remote location that seem so real, almost as if you have taken over the body ofanother person—this is a technology and concept known as “BodySharing.” Put forward by a Japanese researcher
and entrepreneur, BodySharing aims to make such experiences a reality in the not-so-distant future. Whatpossibilities and new lifestyles can it bring about?
Sharing an enjoyable experience
with someone in another placeby syncing up with their bodily
sensations, and doing so fromyour home—an innovation thathelps make such a sci-fi dreama reality is “PossessedHand,”a device released in 2011 by
TAMAKI Emi, who at the time
was a student at the Universityof Tokyo Graduate School. By
wrapping a belt with electrodes
and cords around your arm, you

can send electrical stimuli similar
to the commands issued by thebrain to the muscles in your handand fingers, conveying what is
known as proprioception—thedeep sensations that allow us
to perceive self-movements, theweight of objects, forces appliedon the body, and other sensory
information. Conveying thosesensations to the body, it ispossible to reproduce the same
movements, positions, and eventhe degree of force applied as felt
by someone else.
“The transmission of notjust sight and sound but also
proprioception creates sharedexperiences that feel more activeand realistic,” said Tamaki, who iscurrently the CEO of H2L Inc.,a startup she co-founded, andalso a professor at the Faculty ofEngineering, University of theRyukyus. PossessedHand has
attracted much global attention

Tamaki giving a presentation on her researchwhen receiving the University of Tokyo
President’s Award for the development ofPossessedHand. She said that it was very helpful
during the development process to have studied
a broad range of fields, including basic
engineering, AI, and physiology. H2L

In addition to business and research, she also
focuses on fostering science-related humanresources in her work as an engineering
professor at the University of the Ryukyus,
where she has taught since 2021 (photo:Tamaki interacting with students during aguest lecture at Waseda University). “With AI
about to surpass human capabilities, thosepeople who will be in demand in the future willbe the generalists who can create something
new through interdisciplinary knowledge.”to relive what someone else isgoing through, but you can let
someone far away experience thesame sensations as you, and theexperiences of a remote robot canalso be shared while manipulating
its movements in real time.
The technology has, moreover,the potential for application
in a broad range of fields. For
example, by reproducing theoptimal movements and degreeof force applied as demonstrated
by a model, the technology could
be utilized in developing skills inmusic or sports, or for physicalrehabilitation.
Tamaki’s pursuit of BodySharing
was triggered when she was inhigh school. Having missed along-awaited family trip due tobeing hospitalized, she was shown
photos and videos of the trip, but
it was far from the sensation of ashared experience that she hadwanted. “I started searching fora way that would make me feellike I had traveled together withmy family, but when I couldn’t
find one, I decided to develop one
myself,” recalled Tamaki. After
graduating from the University of
the Ryukyus, Tamaki immersed
herself in research on robots andinterfaces between humans andcomputers. She then created theprototype for PossessedHand
as an experimental tool at theUniversity of Tokyo Graduate
School.
After she obtained her Ph.D.,
Tamaki co-founded H2L in 2012,and launched “UnlimitedHand,”a more versatile version ofPossessedHand for researchersand developers, in 2015. While

Conveying proprioceptive sensations to the bodyby sending electrical stimuli through a whiteband worn on the arm, UnlimitedHand canrealistically reproduce the weight and presence ofa small bird (bottom left) held in the hand. H2L

PossessedHand only transmits
electrical stimuli from the computer
to the arm, UnlimitedHand canalso measure sensory informationfrom the arm itself and send it tothe computer. “We wanted to spur
on applied research by making thetechnology easier for researchers
to access,” Tamaki said. And
just as she had hoped, morethan 100 research projects using
UnlimitedHand are currently
underway around the world.
Tamaki’s ultimate goal in thedevelopment of BodySharing is
to realize what she calls a “multithread lifestyle.” Tamaki believes
that if physical constraints, such as
time and space, are removed whenpeople experience something,
they will be able to extract justthe parts they want and enjoy
several experiences in parallel. “By2029, I aim to make it possible foreveryone to choose a multi-thread
lifestyle. I want to enrich people’s
lives by allowing them to enjoy
double or triple the number ofexperiences in the same amountof time.”