While implantable electronic devices such as pacemakers and drug delivery systems have come on in leaps and bounds in the past 50 years, there is still considerable room for improvement.
Implanted into the chest area, the pacemaker is a small metal box weighing between 20 and 50g which sends electrical pulses to the heart to keep it beating regularly. The device usually lasts about eight years depending on how advanced it is and has been deployed in millions of patients worldwide.
While effective, the technology is reliant on battery power alone, which means invasive surgery is required when the battery runs out. Other potential sources of power including inductive systems, but even these have their downsides. As well as exhibiting differences in efficiency based on location, position and movement, they are often limited in how long each charge lasts.
In the future, it is envisaged that miniaturised, intelligent systems will take over therapeutic and diagnostic functions, while future implantable sensors are expected to be able to measure things like glucose levels, blood pressure and even the oxygen saturation of tumour tissue.
Devices that can effectively administer drugs and even counteract side effects in the process could also be on the cards, but only if a long term, reliable power source can be found.
The Challenge
The challenge this month, then, is to come up with an improved power transfer system for medical devices inside the human body that is small, cost effective and has no harmful side effects.
The technology should be able to remotely supply power to implants, medication dosing systems and other medical applications without touching them. Ideally the device should have a large range and be traceable at any time with respect to its position and location.
The system should also be unobtrusive, able to transmit power through an array of different materials and not require any special gels or adhesives.
The patented solution takes advantage of recent breakthroughs in wireless technology and even has applications outside of the medical field. It is currently being used to stimulate the growth of cartilage and bone cells in a hip implant.
We will publish the solution in the next issue of Eureka. In the mean time, see if you can come up with something better.
-Solution-
Solution to May 2012 Coffee Time Challenge
The solution to this coffee time challenge about how to supply power remotely to medical implants comes from researchers at the Fraunhofer Institute for Ceramic Technologies and Systems in Germany.
The transmitter created by the team consists of an external transmitter module and a mobile generator. The device has a range of about 50cm, can be worn anywhere on the user's body and is capable of transmitting power through an array of materials.
According to researcher Dr Holger Lausch, an electric motor in the transmitter causes a magnet to rotate inside the device, generating a magnetic rotary field. This can harmlessly travel through human tissue, along with virtually any other non-magnetic material. The generator contains a magnetic pellet, which is set in rotation in response to the transmitter's magnetic field. Its spinning movements generate electricity from within the module itself, which in turn powers the implant.
Along with providing power to medical implants and medication dosing systems, the researchers believe scaled-up versions of the system could be used to power hermetically-sealed sensors inside walls or bridges, or wirelessly deliver power to unreachable electronic devices.
