medical devices
Patients Test an Advanced Prosthetic Arm
by andreas on Feb.25, 2009, under medical devices
By surgically rearranging the nerves that normally connect to the lost limb, physicians have developed an intuitive way for amputee patients to control a robotic arm.
Todd Kuiken and colleagues at the Rehabilitation Institute of Chicago first reported the technique in a single patient in 2007, and now they have tested it in several other patients. The patients could all successfully control the advanced prosthetic, which features motorized shoulders, elbows, wrists and hands. They could move the arm in space, mimic hand motions, and pick up a varietyt of objects, including a water glass, a delicate cracker, and a checker rolling across a table.
The motorized arm prostheses most commonly used today co-opt existing shoulder movements to control the hand, elbow or wrist on the limb. These devices can be frustrating and slow: the user must consciously contract those muscles to trigger a movement, and only one movement can be performed at a time.
Kuiken has developed an entirely new kind of interface. Using a surgical procedure called targeted muscle reinnervation, surgeons transfer nerves that previously carried signals to the amputated limb to muscles in the chest and upper arm. The rerouted nerves then grow into the muscles, which contract when the patient thinks about moving the lost limb. Those signals are read by sensors on the prosthetic limb and translated into movement.
More information is available from Technology Review.
Engineers Make Progress In Developing Bionic Eye
by andreas on Nov.11, 2008, under medical devices
Scientist have developed a contact lens with integrated circuitry.
Scientists at the University of Washington have developed contact lenses with integrated circuitry. The engineers tested the lenses on lab rabbits, which wore the contacts for 20-minute intervals without any perceived ill effects. The lenses could be used as integrated personal monitors that might enable wearers to watch movies or surf the web. The engineers are working on integrating LEDs in the lenses to improve their display capabilities.
Study Finds That Headphones Can Interfere With Pacemakers
by andreas on Nov.10, 2008, under medical devices
Earphones that are used for portable music players can interfere with pacemakers when they are held close to the device, according to a recent study that suggests performed at the Medical Device Safety Institute at Beth Israel Medical Center in Boston.
Neodymium, a magnetic substance that is present in most earphones, can prevent defibrillators from detecting abnormal heart rhythms.
The researchers tested eight models of headphones connected to iPods on 60 patients who had a pacemaker or implanted defibrillator.
The research team determined that the earphones caused interference in 15% of the patients who had pacemakers and 30% of the patients with defibrillators. The effect was present whether or not the earphones were plugged in.
The results of the study conflict with the FDA’s conclusion that iPods and other MP3 players are unlikely to interfere with defibrillators and pacemakers.
Using Ultrasound To Treat Pain
by andreas on Oct.29, 2008, under medical devices
The PainShield MD from NanoVibronix
NanoVibronix has introduced a patch-based therapeutic ultrasound system to treat pain. Known as the PainShield MD, the device is a portable, battery-powered electronic unit connected to a disposable patch, which is used to deliver ultrasonic waves to treat localized pain and induce soft tissue healing. Recently cleared by the FDA, the pocket-sized device is designed to be easy to operate. In tests, it has shown to be suited for a range of applications such as reducing acute and chronic pain and for reducing inflammation.
Researchers Rediscover Promising Closed-Circuit Breathing Device
by andreas on Oct.26, 2008, under medical devices
North face of Mount Everest
Scientists have resurrected forgotten research to develop a closed-circuit breathing device that could transform the lives of patients with chronic obstructive pulmonary disease, which will be the third leading cause of death worldwide by 2030, according to the World Health Organisation. The new technology is based on a closed circuit oxygen device invented over 50 years ago by the British rocket scientist Tom Bourdillon, who hoped that it would help take him to the top of the world.
The project is a result of a partnership between Smiths Medical and the University College London
Three days before Edmund Hillary and Tenzing Norgay made the first ascent of Mount Everest in 1953, Bourdillon nearly got there first with the help of his ground-breaking invention. When he and his climbing partner Charles Evans, a British brain surgeon, set out on the first ever summit attempt they were breathing pure oxygen from the device. It helped them climb higher than any man had ever been before and at speeds that have rarely been matched since.
The two men were just 90 metres from the summit when Evans’ device malfunctioned dashing their hopes of becoming the most celebrated mountaineers in the world. Three days later Hillary and Norgay claimed that honour using open circuit oxygen devices. Bourdillon believed that closed circuit oxygen was more efficient and effective than open circuit because a closed circuit efficiently recycles exhaled oxygen, which would be lost to the atmosphere in an open circuit.
His research was forgotten for 50 years but now Smiths Medical and UCL have developed Bourdillon’s idea into a breakthrough medical device that could help patients with COPD, which is a disease of the lungs in which the airways become narrowed leading to a limitation of the flow of air to and from the lungs, causing shortness of breath.
“We are hoping that this new technology will transform the lives of people living with COPD by allowing them to breathe more easily, exercise and ultimately reduce their dependence on oxygen. It is incredible to think that this breakthrough device is based on a British invention designed to help the first mountaineers reach the top of the world,” said Dr Jeremy Russell, head of research and development at Smiths Medical International.
“Bourdillon recognized that the problem on Everest was low levels of oxygen and if you solved the problem of delivering oxygen you would effectively reduce the height of the mountain to sea level,” said Dr McMorrow. “No-one knows exactly why his device failed but when I tested my prototype on Cho Oyu in the Himalayas 2005 it also failed. In my case the soda lime CO2 absorber malfunctioned and it is possible Bourdillon had the same problem although another theory is that it was a frozen valve. A recently invented CO2 absorber called ExtendAir solved the problem on my circuit.”
Last year the device was successfully tested on Mount Everest at the Smiths Medical High Altitude Laboratory at Namche Bazaar, Nepal at 3,400m, (11,154 ft) as part of the Caudwell Xtreme Everest Study (CXE), a medical research project conducted by CASE. Smiths Medical is now optimizing and miniaturizing the prototype for patients.
Exercise is important for COPD patients but existing oxygen systems mean it is often not possible. The size of current open circuit systems mean that patients are often confined to their hospital beds or treated at home with large cylinders that severely restrict their mobility. Portable open circuit systems are not able to deliver high enough volumes of oxygen for long enough to permit exercise. In an open circuit system the faster a person breathes the more they dilute the oxygen with ordinary air. This means that if a patient dependent on oxygen starts to exercise their oxygen levels actually drop as their breathing grows faster.
Dr Russell added: “The new system is portable and should deliver a very high concentration of oxygen for a sustained period of time. It should help keep oxygen levels constant no matter how fast or slowly a patient is breathing.”
More information is available at www.caudwell-xtreme-everest.co.uk.
