There are two options for controlling a robot inside of the human body: Either you try and build some sort of intricate and tiny robot submarine with self contained propulsion and navigation, which would be really really hard to do, or you just make the robot with a tiny bit of something that responds to magnetic fields, and control it externally with some big magnets. The latter approach is vastly less complicated, but it has one major drawback, which is that its very hard to manage multiple robots. <\/p>\n
Heres the problem: Magnetic fields, being fields, arent easily constrained to specific areas. Realistically, if youre using something like a clinical MRI scanner to create a magnetic field, whatever gradient you give the field will affect everything inside of the MRI, whether youve got one single microbot or a vast swarm of them. If you want two different robots to do two different things, youre out of luck. <\/p>\n
One potential way of getting around this is by making each of your robots slightly different, such that consistent control inputs have inconsistent effects on each robot. But for homogenous robots, its much more difficult. In a paper published today in Science Robotics, researchers from Philips, in Hamburg, Germany,describe a technique that can use magnetic fields to selectively actuate individual microbots, or individual components of a robot, even if theyre all made of the same stuff and located within the same field. <\/p>\n
Please enjoy this utterly charming explanatory video from the researchers: <\/p>\n
Coooool. <\/p>\n
Heres how it works: The global magnetic field inside of the device has a hole in it, called a free field point (FFP), where multiple magnetic fields (each generated by a separate coil) meet up. Inside of the FFP, the magnetic field gradient is low. This doesnt help you move things, but it does help you not move things, because you can lock everything that isnt in the FFP in place by cranking up the field gradient. Then, you apply a gentle rotating magnetic field, which spins anything inside of the FFP and not locked down. By moving the FFP around, you can select which things are lockedand which things are free to rotate. <\/p>\n
In this case, the lock is the screws being tilted sideways by the field such that they cant rotate, while the FFP is a region of zero tilt, meaning that the screws can rotate freely. The hardware used in this study was able to individually actuate screws as close together as 3 millimeters. <\/p>\n
The researchers suggest a whole bunch of different ways in which this technique could be of practical, immediate use: <\/p>\n
One class of applications is based on mechanisms driven by several screws that are controlled individually. In orthopedics, this could be implants, whose shape can be adapted to the healing process. In applications such as limb lengthening or early-onset scoliosis, a mechanism based on several controllable screws may offer higher flexibility in extendible prostheses or growth rods. In addition, the approach can be useful in microfluidics, where simple and tiny magnetic pumps and valves may be envisioned that can be individually actuated without an electrical or mechanical link. <\/p>\n
Another class of applications is related to simple micromachines for local therapy delivery, such as remote-controlled drug release from a distribution of injectable magnetic micropills. Remotely switchable radioactive seeds are a special case of this class. Switchable seeds would enable the use of sources with longer half-life or higher dose rates because the radiation can be switched off after the desired dose has been applied. Besides, migrating seeds ending up too close to healthy tissue or sensitive organs could be switched off. <\/p>\n
Using a helically slotted shield, directional seeds with remotely adjustable radiation direction could be built. These would allow further improvements in dose painting and sparing of healthy tissue. In addition, magnetic manipulation has been shown to be scalable to the micrometer regime. Using a catheter, seeds of this size could be discharged into the bloodstream of a tumor-feeding artery so that they are carried into the tumor and embolize small vessels. After localization via imaging, only seeds that ended up in the tumor would be activated remotely. <\/p>\n
[ Paper ] <\/p>\n
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Magnets steer medical microbots through blood vessels 25Sep2012 <\/p>\n<\/p>\n
If the robot masters prostate procedures, brain surgery may be next 8Jul2015 <\/p>\n
Researchers are putting swarms of bacteria to work, using them to perform micro-manipulations, propel microrobots, and act as biosensors25Mar2010 <\/p>\n<\/p>\n
An implantable sleeve mimics the motion of the heart and reverses heart failure in pigs 18Jan <\/p>\n<\/p>\n
Implanted in the body, a tiny micromachine dispenses a dose of medication with each tick 4Jan <\/p>\n<\/p>\n
Team Cleveland took home the gold medal at the world's first Cybathlon 14Oct2016 <\/p>\n<\/p>\n
The cyborg Olympics showcased robotic exoskeletons, brain-computer interfaces, and more 12Oct2016 <\/p>\n<\/p>\n
A 16-year-old from Saudi Arabia develops an exoskeleton and control glove to revolutionize physical therapy for stroke patients 30Sep2016 <\/p>\n<\/p>\n
The exoskeleton built for spinal cord injury patients is now cleared for stroke patients as well 30Sep2016 <\/p>\n<\/p>\n
A hybrid delta biplane design results in efficiency, range, and pinpoint landings 20Sep2016 <\/p>\n<\/p>\n
Patients regained some voluntary movements. Difficult to say which technology was the key factor 11Aug2016 <\/p>\n<\/p>\n
This autonomous mobile robot helps to check in on patients more regularly 2Aug2016 <\/p>\n<\/p>\n
But don't expect these robots to steer themselves through the body any time soon 26Jul2016 <\/p>\n<\/p>\n
This could be the first robot ever to do the worm 25Jul2016 <\/p>\n<\/p>\n
Teleoperated endolumenal bot can navigate inside the body, image and treat conditions without making incisions 7Jun2016 <\/p>\n<\/p>\n
Watch six of the coolest surgical robots in action 31May2016 <\/p>\n<\/p>\n
Precise and dexterous surgical robots may take over the operating room 31May2016 <\/p>\n<\/p>\n
Implanted electrodes make this haptic hand feel like the real deal 17May2016 <\/p>\n<\/p>\n
In a tricky surgical procedure on pigs, independent robotic surgery produced better outcomes 4May2016 <\/p>\n<\/p>\n
So says exoskeleton pioneer Homayoon Kazerooni as he brings Phoenix, his latest invention, to market 25Apr2016 <\/p>\n
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Read more here: <\/p>\n
Magnetic Control Could Help Robots Navigate Inside Your Body - IEEE Spectrum<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" There are two options for controlling a robot inside of the human body: Either you try and build some sort of intricate and tiny robot submarine with self contained propulsion and navigation, which would be really really hard to do, or you just make the robot with a tiny bit of something that responds to magnetic fields, and control it externally with some big magnets. Continue reading