Chitosan bioelectrode sustains metabolic power to medical implants .


Researchers in France have used compounds extracted from shrimp shells and gardenia fruits toextend the lifetime of medical implants attempting to run on bodily fluids.

Lithium ion batteries, which currently power medical devices such as pacemakers, have a finite life expectancy of up to 5 years. Glucose Biofuel Fuel Cells (GBFC), however, have been proposed as battery-free alternatives that enzymatically catalyse glucose oxidation and oxygen reduction from extracellular fluid, including blood and interstitial fluid, to generate electrical power.

Traditional biocathodes use laccase as the oxidising enzyme but high concentrations of chloride ions within extracellular fluid can impair enzyme activity and shorten the lifetime of GBFC’s. To address these issues, a composite material made from chitosan, a naturally abundant biopolymer found in crustacean shells and mushrooms, genipin, a chemical extracted from gardenia fruit, and carbon nanotubes was developed by Donald Martin, and his team at the University of Grenoble, to encapsulate laccase.

The properties genipin has as a natural cross linker provides additional strength to the chitosan polymer. Coupled with the direct electron transfer from capturing laccase within the matrix, the team have increased the stability of the biocathode.

As an anti-inflammatory, genipin also boosts the biocathode’s biocompatibility. ‘We’ve managed to implant an energy harvesting electrochemical device that can last for up to 6 months in the body of a rat without an immune reaction,’ explains Martin. Compared with previous experiments on laccase biocathodes, which achieved a lifespan of 2 weeks in a snail, the chitosan and genipin polymer is a promising improvement.

Frédéric Barrière, an expert in electroactive systems at the University of Rennes 1 in France, recognises the research as a significant advance. ‘Now the challenge is to demonstrate long term, in vivo implantation of a biofuel cell that is capable of constantly powering an implanted low power microelectronic device.’

Yes, You Can Hack a Pacemaker (and Other Medical Devices Too).


On Sunday’s episode of the Emmy award-winning show Homeland, the Vice President of the United States is assassinated by a group of terrorists that have hacked into the pacemaker controlling his heart. In an elaborate plot, they obtain the device’s unique identification number. They then are able to remotely take control and administer large electrical shocks, bringing on a fatal heart attack.

Viewers were shocked — many questioned if something like this was possible in real life. In short: Yes (except, the part about the attacker being halfway across the world is questionable). For years, researchers have been exposing enormous vulnerabilities in Internet-connected implanted medical devices.

There are millions of people who rely on these brilliant technologies to stay alive. But as we put more electronic devices into our bodies, there are serious security challenges that must be addressed. We are familiar with the threat that cyber-crime poses to the computers around us — however, we have not yet prepared for the threat it may pose to the computers inside of us.

Implanted devices have been around for decades, but only in the last decade have these devices become virtually accessible. While they allow for doctors to collect valuable data, many of these devices were distributed without any type of encryption or defensive mechanisms in place. Unlike a regular electronic device that can be loaded with new firmware, medical devices are embedded inside the body and require surgery for “full” updates. One of the greatest constraints to adding additional security features is the very limited amount of battery power available.

Thankfully, there have been no recorded cases of a death or injury resulting from a cyber attack on the body. All demonstrations so far have been conducted for research purposes only. But if somebody decides to use these methods for nefarious purposes, it may go undetected.

Marc Goodman, a global security expert and the track chair for Policy, Law and Ethics at Singularity University, explains just how difficult it is to detect these types of attacks. “Even if a case were to go to the coroner’s office for review,” he asks, “how many public medical examiners would be capable of conducting a complex computer forensics investigation?” Even more troubling was, “The evidence of medical device tampering might not even be located on the body, where the coroner is accustomed to finding it, but rather might be thousands of kilometers away, across an ocean on a foreign computer server.”

Since knowledge of these vulnerabilities became public in 2008, there have been rapid advancements in the types of hacking successfully attempted.

The equipment needed to hack a transmitter used to cost tens of thousands of dollars; last year a researcher hacked his insulin pump using an Arduino module that cost less than $20. Barnaby Jack, a security researcher at McAfee, in April demonstrated a system that could scan for and compromise insulin pumps that communicate wirelessly. With a push of a button on his laptop, he could have any pump within 300 feet dump its entire contents, without even needing to know the devices’ identification numbers. At a different conference, Jack showed how he reverse engineered a pacemaker and could deliver an 830-volt shock to a person’s device from 50 feet away — which he likened to an “anonymous assassination.”

There have also been some fascinating advancements in the emerging field of security for medical devices. Researchers have created a “noise” shield that can block out certain attacks — but have strangely run into problems with telecommunication companies looking to protect their frequencies. There have been the discussions of using ultrasound waves to determine the distance between a transmitted and medical device to prevent far-away attacks. Another team has developed biometric heartbeat sensors to allow devices within a body to communicate with each other, keeping out intruding devices and signals.

But these developments pale in comparison to the enormous difficulty of protecting against “medical cybercrime,” and the rest of the industry is falling badly behind.

In hospitals around the country there has been a dangerous rise of malware infections in computerized equipment. Many of these systems are running very old versions of Windows that are susceptible to viruses from years ago, and some manufacturers will not allow their equipment to be modified, even with security updates, partially due to regulatory restrictions. A solution to this problem requires a rethinking of the legal protections, the loosening of equipment guidelines, as well as increased disclosure to patients.

Government regulators have studied this issue and recommended that the FDA take these concerns into account when approving devices. This may be a helpful first step, but the government will not be able to keep up with the fast developments of cyber-crime. As the digital and physical world continue to come together, we are going to need an aggressive system of testing and updating these systems. The devices of yesterday were not created to protect against the threats of tomorrow.

Source:Forbes