I know that I will be dating myself here, but, I remember the first artificial heart recipient, Barney Clark. 31 years ago, Dr Jarvik implanted his device (the Jarvik7) into Dr. Barney Clark’s (he was a dentist) chest. Clark survived for 12 days.
One of the issues that needed to be investigated was the power supply. The Jarvik 7, while implanted, had electrical connections that protruded through Clark’s chest, so that the device would keep working.
But, things have changed. My old Palm phone was not required to be plugged into the wall to be charged- instead, I just put the phone down on the speaker attachment (conference device) and the phone charged in 2 hours. Not bad for a device invented in 2008.
Wireless electricity is no longer a science fiction item- but a reality. OK, maybe not totally, but we can transfer power over some 50 cm pretty efficiently (and, of course, safely). This was first conceived about 200 years ago by Michael Faraday, who worked extensively with magnetic induction (ca. 1830s). The principle has been in use for decades- even if not wirelessly. My Lionel train set used transformers; magnetic induction transferred electricity from the primary coil to the second one- without a direct electrical conduit. Inductive chargers are the way our electric toothbrushes get their “juice”.
The difference is that the primary coil (the source) and the secondary coil (the device) in these applications have mated sizes and shapes (one to the other) and a magnetic coupling factor to insure the connection from device to source. (This also minimizes heat buildup in the coils and precludes decreased energy transfer.).
The “science” progressed dramatically with the development of resonant wireless power transfer. In 2007, Drs. Kurs, Karalis, Moffatt, Joannopoulos, Fisher, and Sojacic of MIT published their findings in Science. They were able to transfer 60 W at high efficiency for a distance of 2 m or so.
The ‘resonant frequency’ is considered to be the natural frequency of an oscillating system at which energy can be efficiently transferred. (Consider the backyard swing, where we pump our legs and arms back and forth at the right position – and timing- to obtain the best action, as an example.) Now, consider two resonators (at the same frequency) near one another, so they can connect via magnetic resonance and transfer energy between them.
These folks founded a company (WiTricity, Watertown, MA) to capitalize on their findings. (This is very typical at MIT. Dr. Bob Langer, a fellow Chem E, has done this– often. Among the successful spin-offs from MIT include Digital Equipment (now part of HP), Centocoor, Tyco, MITRE, among many others.)
WiTricity is now working with Thoratec (Pleasanton, CA) to develop a LVAD (left ventricular assist device) to treat cardiac patients. Now that a power cord is not needed, the battery can be within the body and then recharged wirelessly. (The distance between source and device is anticipated to be 25 cm or so.)
The beauty of these wirelessly-charged devices is that there is no need for power cord connections or to effect battery replacement. That makes them perfect for in vivo (implanted) use, and these are the two most failure prone components in devices.
Moreover, the devices can be watertight and sterilizable. That’s why there are various implants, assistive hearing devices (cochlear implants), defibrillators, pacemakers, drug-delivery devices, among others in the works.
…physics at its coolest….
Thank you so much, Caro!
I wish I could charge my phone that way. It also sounds like great strides are being made for heart patients. And I remember Barney Clark.
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Yes, Ann, my new phone (Samsung S3) does not afford me that opportunity, so I have to carry miniUSB cords with me…
But, it’s more important for implantable medical devices than for my phone!
What great advancements. Makes one wonder what else the future holds?
I always wonder, Alessa, so I can think of new things to offer. But, seriously, these will make it easier to offer medical advances to patients. (Now, let’s work on the pricing…)
Roy, that’s just amazing. The people who invent these devices have my greatest respect and a suitable amount of awe, as well.
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Yes, Amy, this technology could mean many fewer operations – no need to cut open the patient to change the battery…
Thanks for the visit! And, the comment.
I love these kind of developments! Right back to the industrial revolution, through to the advances being made today – superb!
Cheers, Gordon
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Thanks, Gordon, for your comment and visit. And, yes, this is pretty neat technology. But, then, again, I AM a geek.
Barney Clark was a very brave man – that device must have been the inspiration behind the Iron Man “heart” in the movies. I was going to ask about pacemakers, but you answered my question at the end of the post. My mother has one and the first one she had ran out of battery life before seven years, which is unusual. Interesting info!
Yes, Suerae, this technology will make it possible to charge the pacemaker battery without an operation- through the skin. Pretty impressive!
Well, it looks like my grandmother was right: the best is yet to come. I wished she had had a proper assistive hearing device too. Hers was a nightmare and we kept having to change the batteries.
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I am not sure they plan to use this for assisted hearing devices- for a while. A cochlear implant would be something they would work on sooner, Muriel.
But, this technology will be widely adapted.
Faraday was one of my father’s favourites. Great post. Tweeted will share more, when google lets me.
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Thanks, Carol! So glad you liked the piece…
I know it’s not the same thing but it is close, in the kitchens we now have saute pans with a special bottom and a portable flat “Hot Plate” where we can cook during a presentation and the food can be red hot but move the pan and place your hand on the Hot plate and it will be cold to your hand. that is neat. i believe it’s called induction cooking.
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You got it, Chef William- induction cooking. Only steel (or clad) pans/pots work. Makes for great cooking!
Look Ma- no wires! http://t.co/Lr0JKY61O1 via @Adjuvancy