A Stanford University engineering group has come up with a way to manipulate deep body implants – such as pacemakers, nerve stimulators and brain stem devices – wirelessly. 

The discovery highlights years of efforts by Ada Poon, assistant professor of electrical engineering, to eliminate the bulky batteries and clumsy recharging systems that prevent medical devices from being more widely used, Stanford officials noted in the May 19 announcement. Poon led the engineering group that worked on the project.

Poon's team built an electronic device smaller than a grain of rice that acts as a pacemaker. It can be powered or recharged wirelessly by holding a power source about the size of a credit card above the device, outside the body.

"We need to make these devices as small as possible to more easily implant them deep in the body and create new ways to treat illness and alleviate pain," said Poon, in a press statement.

If this approach, which relies on extreme miniaturization, coupled with non-traditional power transfers, works, it could mean a sharp reduction in highly invasive surgeries to repair or make tweaks to such implants.

But there's another implication of its success. It will force the industry to adopt a more effective authentication system and database access network. Consider a Boston-based woman with a brain implant, who is traveling to Hong Kong when the device malfunctions. After the unconscious woman is rushed to a local emergency room, ER staff needs to not only know of the existence of such equipment, but also needs to have an immediate means of access. Complicating matters is that the security of such access must be top-notch, or the nightmare scenario of a murderer wirelessly accessing someone's pacemaker becomes a reality.

The initial purpose of the technique is simply a power transfer, which serves the critical purpose of allowing for a much smaller battery inside the body. On the plus side, this could mean that a patient or medical staff could, in theory, keep such devices functioning infinitely. The down side, though, is that the devices would have much less internal power, meaning that they would fail more quickly should this wireless transfer either not happen or somehow glitch.

But the next envisioned phase goes far beyond merely offering a power supply and into a wireless ability to do just anything that could previously have been done during surgery. 

William Newsome, director of the Stanford Neurosciences Institute, who is not involved in this trial but is quite familiar with it, said such treatments "could be more effective than drugs for some disorders because electroceutical approaches would use implantable devices to directly modulate activity in specific brain circuits. Drugs, by comparison, act globally throughout the brain."

The essence of the discovery is something the university has dubbed mid-field wireless transfer. The idea is to hold about 10 centimeters from the in-body-device, which typically means the transfer device doesn't even need to touch the patient's skin, although it does have to be very near. 

As the paper published in the Proceedings of the National Academy of Sciences detailed: "We use this method to power a microimplant (2 mm, 70 mg) capable of closed-chest wireless control of the heart that is orders of magnitude smaller than conventional pacemakers. With exposure levels below human safety thresholds, milliwatt levels of power can be transferred to a deep-tissue microimplant for both complex electronic function and physiological stimulation. The device consists of a multiturn coil structure, rectifying circuits for AC-DC power conversion, a silicon on-insulator integrated circuit for pulse control, and electrodes, entirely assembled within a 2-mm diameter, 3.5-mm height device small enough to fit inside a catheter. We demonstrate wireless function by operating it in human-scale heart and brain environments, and by wirelessly regulating cardiac rhythm through a chest wall."

Even more intriguing is something envisioned by John Ho, one of the project's researchers. With additional miniaturization, he envisions implants small enough to be delivered into the body via a hypodermic needle. Once in the bloodstream, physicians would navigate the device to the intended area of the body (using external scanners), where it would implant itself.

The radiation emitted is similar to what is broadcast from a smartphone. Although there are studies that question whether mobile signals are dangerous to the brain, Ho argues that given the medical issues involved in heart, brain or nervous system implants, it's not much of a debate.

"For people who need these devices, cellphone levels of radiation is the least of their concerns," Ho said, "given the choice instead of doing incredibly invasive surgery."

The security and access issues are an important consideration. "You have to decide whether or not you want to add encryption," Ho said. "It's more of a protocol problem." 

Like any other electronic device, error is always possible. But far from increasing the probability of error, this system has the potential to allow for a much faster, cheaper and easier method to fix errors and repair the device. This assumes, though, that the medical facility has a means to access and control these devices, along with the associated training.

The IT issue is straightforward: If such devices become commonplace, hospitals might have to support systems to allow for their use. Welcome to the next-generation of micro-medicine, where a wireless system interacts with the ultimate biological Ethernet: the human body's wired network of neurons. Sort of gives being a hospital network engineer an entirely new meaning.