In future, you may be able to pace a heart by switching on the light!!! Read on….
In future, you may be able to pace a heart by switching on the light!!! Read on….
Fancy a tattoo? In hospital, it could be your next type of monitor of your vital signs… Read on…
11 August 2011
By James Gallagher, BBC News Health
An "electronic tattoo" could herald a revolution in the way patients are monitored and provide a breakthrough in computer gaming, say US scientists.
They used the device, which is thinner than a human hair, to monitor the heart and brain,according to a study in the journal Science.
The sensor attaches to human skin just like a temporary tattoo and can move, wrinkle and stretch without breaking.
Researchers hope it could replace bulky equipment currently used in hospitals.
A mass of cables, wires, gel-coated sticky pads and monitors are currently needed to keep track of a patient's vital signs.
Scientists say this can be "distressing", such as when a patient with heart problems has to wear a bulky monitor for a month "in order to capture abnormal but rare cardiac events".
With the tattoo, all the electronic parts are built out of wavy, snake-like components, which mean they can cope with being stretched and squeezed.
There are also tiny solar cells which can generate power or get energy from electromagnetic radiation.
The device is small, less than 50 micrometres thick – less than the diameter of a human hair.
The sensor is mounted on to a water-soluble sheet of plastic, so is attached to the body by brushing with water, just like a temporary tattoo.
It sticks on due to weak forces of attraction between the skin and a polyester layer at the base of the sensor, which is the same force which sticks geckos to walls.
In the study, the tattoo was used to measure electrical activity in the leg, heart and brain. It found that the "measurements agree remarkably well" with those taken by traditional methods.
Researchers believe the technology could be used to replace traditional wires and cables.
Smaller, less invasive, sensors could be especially useful for monitoring premature babies or for studying patients with sleep apnoea without them wearing wires through the night, researchers say.
Prof Todd Coleman, from the University of Illinois, said: "If we want to understand brain function in a natural environment, that's completely incompatible with studies in a laboratory.
"The best way to do this is to record neural signals in natural settings, with devices that are invisible to the user."
The device was worn for up to 24 hours without loss of function or skin irritation.
However, there are problems with longer-term use, as the skin constantly produces new cells, while those at the surface die and are brushed off, meaning a new sensor would need to be attached at least every fortnight.
When the tattoo was attached to the throat, it was able to detect differences in words such as up, down, left, right, go and stop.
The researchers managed to use this to control a simple computer game.
John Rogers, professor in material science and engineering at the University of Illinois, said: "Our goal was to develop an electronic technology that could integrate with the skin in a way that is invisible to the user.
"It's a technology that blurs the distinction between electronics and biology."
Prof Zhenqiang Ma, an electrical and computer engineer at the University of Wisconsin, argued that the technology could overcome issues with bulky sensors.
"An electronic skin will help solve these problems and allow monitoring to be simpler, more reliable and uninterrupted.
"It has proved to be viable and low-cost in this demonstration which will greatly facilitate the practical clinical use of the electronic skin."
This is referenced from: Drug Discovery and Development, 19 August, 2011
A novel drug that activates a protein that increases the contraction of heart muscle could lead to a new approach to treating systolic heart failure (SHF), a condition characterised by the inability of the heart to contract strongly enough. The results of the first two clinical studies involving the drug omecamtiv mecarbil, published in a special European Society of Cardiology issue of The Lancet, suggest that it could be a promising treatment for SHF, which currently affects about 20 million people in the USA and Europe and leads to at least 4 million admissions to hospital each year.
Omecamtiv mecarbil was designed by a team lead by Fady Malik from Cytokinetics Inc, South San Francisco, USA, to activate cardiac myosin, a motor protein in heart muscle cells that generates the force required for heart muscle to contract. In preclinical studies, omecamtiv mecarbil improved the strength of each heart muscle contraction, increasing the duration of the contraction and the volume of blood moved, without increasing oxygen consumption. But until now, whether this unique mechanism could be translated into humans was not known.
Currently used inotropic drugs (that alter the force of muscular contractions) improve contractility by increasing the concentration of calcium inside cells, which accelerates the speed of contraction but shortens systolic ejection time and can cause potentially life-threatening side effects such as abnormal heart rhythms and myocardial ischemia (restricted oxygen-rich blood flow to the heart muscle).
John Teerlink from San Francisco Veterans Affairs Medical Center, San Francisco, USA and colleagues report the first trial of omecamtiv mecarbil in humans which was designed to establish the maximum tolerated dose and demonstrate an effect in people. Omecamtiv mecarbil or placebo was given once a week as a 6-hour intravenous infusion to 34 healthy men for 4 weeks. Each sequence consisted of three ascending omecamtiv mecarbil doses (ranging from 0.005 to 1.0 mg/kg per hour) and a placebo infusion.
The maximum tolerated dose was 0.5 mg/kg per hour. Omecamtiv mecarbil increased stroke volume (the volume of blood pumped by the heart with each beat), ejection fraction (measurement of the strength the heart has on contraction) and fractional shortening (measurement of the left ventricle's overall effectiveness during contractions) compared with placebo. Increases in systolic ejection time and systolic function were directly proportional to escalating doses in omecamtiv mecarbil, with no significant adverse effects reported in doses up to 0.625 mg/kg per hour.
The authors say: "This study provides the first clinical evidence for the translation into human beings of a novel mechanism to directly improve cardiac function, namely cardiac myosin activation…and supports potential clinical use of the drug in patients with heart failure."
In the first study of omecamtiv mecarbil in heart failure patients, a team led by John Cleland from University of Hull, East Yorkshire, UK conducted a phase 2 trial to investigate the effects of omecamtiv mecarbil given intravenously over 2, 24, or 72 hours to 45 patients with stable heart failure who were already receiving standard treatment.
Omecamtiv mecarbil gave a significant dose-dependent increase in several measures of the heart's pumping function including increasing the duration of systole, stroke volume, and ejection fraction. A significant association between improving systolic function and increasing plasma concentration was also noted.
The authors say: "Omecamtiv mecarbil has dose-dependent and concentration-dependent effects on cardiac function that appear in plasma concentrations that are well tolerated by patients with stable chronic heart failure."
They conclude: "Further studies are needed to establish whether the observed effects on cardiac function translate into benefits on symptoms, quality of life, exercise capacity, morbidity, or mortality."
In a Comment, Kenneth Dickstein from the University of Bergen, Stavanger University Hospital, Stavanger, Norway says: "The data presented in these two papers supports further investigation of omecamtiv mecarbil's therapeutic role in appropriate patients." But, he adds: "Very few new agents have survived the most rigorous test, the randomised clinical trial assessing clinical outcomes…Let's find out how this theory performs in practice."