hi, Nice reading.Death will not come when one wants it and it will not leave anyone when it comes. SUNDAY PIONEER TRACKING DEATH Sunday, 10 November 2013 | Shalini Saksena | in Sunday Pioneer Two Lancaster University professors rocked the world recently by developing a laser device that can measure through reactivity of blood vessels how far or near death is. SHALINI SAKSENA spoke to one of them to bring you a report on this mammoth jump by mankind, which the inventors insist will revolutionise tracking of diseases Humanity’s fear of death has been eternal. Through ages, people have obsessed about death and when their time will come. Astrologers, palmists, tarot card readers and clairvoyants — all claim they can predict everything man wants to know but have failed to reveal the exact time of death. “Predicting a person’s death is wrong. We fear death. People want to know when they will have a baby, when their child will get married, about their health, job, happiness etc. Death, nobody wants to know. Also, astrologers can only surmise when a person will die, none can claim with surety. Life and death are the only two mysteries in this universe. Even though death is the only truth, its time will always remain a mystery,” says Pandit Ajai Bhambi who has been practising astrology for 35 years in the Capital. Another astrologer tells you why soothsayers don’t predict the time of death. “A palmist once told a client that he will die on June 12, 1987. On that day, the man got up, had a cup of tea, went for a walk and picked up a newspaper and sat down on his recliner. He read the paper and was discussing an article with his wife when he happened to look at the date. He looked at his wife and wondered aloud how he was still alive when the pandit had predicted his death that day. The next instance, he had a massive heart attack and died. Till today, the family believes he would have been alive had he not noticed the date and remembered the prediction,” Pandit Esh Narayan says. But what if there is a more scientific way to find out the exactness of death? Recently, physics professors Aneta Stefanovska and Peter McClintock from UK’s Lancaster University devised a laser test which can tell people how long a person can live. The non-surgical procedure involves applying a laser pulse to the skin through a device which resembles a wristwatch. This assesses how a person’s body will decline by what age by analysing endothelial cells. These cells line the blood capillaries and respond to complex activity in the body. By measuring the oscillations within the cells the time before death can be assessed. The test can also tell you about diseases including cancer and dementia. Stefanovska has been mainly credited with inventing this method of analysing endothelial reactivity. Though media reports the world over said that the test can predict death Stefanovska insists it’s not merely a death test. “This is a device that measures endothelial reactivity. Endothelium is the inner lining of our blood vessels. Each one of us has endothelial cells that, if spread out, are equivalent in area to a football field. Endothelium is a single organ that is all over the body. It is crucial for body functions as it is responsible for the way the blood circulates and, more importantly, how substances transported by the blood (oxygen and ions) are delivered to every cell. The optimal function of the endothelium is crucial for health. Cardiovascular diseases like hypertension, heart failure, diabetes or neurovascular diseases like stroke and dementia are all related to impairment of the endothelial function. The device measures the endothelial function non-invasively, in the capillary bed which is made of endothelium.” There is an interesting story behind why the test is labeled ‘death test’. A journalist from The Sunday Times, who first wrote about it, contacted Stefanovska and asked if the device could be used to estimate the time of death. The answer was, if there is sufficient data for healthy subjects of all ages and estimate the slope of the curve of endothelial reactivity versus age, one can infer that if a person’s age curve is at or below the minimal value, the person concerned can expect serious health complications that may lead to death. So, the way the blood circulates in our body and the ability of the inner lining of the blood vessel to remodel itself with the change in flow due to alteration in blood vessels can define how long a person will live. Though there have been several advances in predicting age in recent years (a blood test can determine how quickly one will age), the connection between age and death had not been made. Researches knew that a person’s weight at the time of birth was an important determinant of health in middle and old age and that people with low birth weight are more susceptible to age-related diseases. But till now, the mechanisms that linked low birth weight to disease in old age had remained a mystery. With the discovery of the laser test, science has been able to find a path to determine this crucial connection. The device, meanwhile, combines a laser light and heating element called a Peltier probe. A non-contact electrodes to measure the electrical activity of the heart, known as ECG. “In the ECG, we detect the R-peak that can be taken as an indicator of the time at which the heart contracted to expel the blood in an actual cycle. It takes some time for the blood to travel from the heart to the smaller capillaries, an interval that gets prolonged if the local area (in the skin) is heated. With the laser light and based on Doppler frequency shift, we can detect this time needed for the pulse to travel to the region of our interest. If the endothelium does not react properly then this time is changed. Also, poor adaptation to temperature changes is indicative of impaired endothelial reactivity. So the device picks up these values and estimates the reactivity. We plan to measure a sufficient number of subjects to be able to tune the reactivity between 0 and 100, with 0 meaning a non-reactive endothelium, and 100 fully reactive endothelium (probably of a healthy youngster),” Stefanovska explains. She also tells you that the development of the device is not yet complete as there are plans to miniaturise it and make it easy to use. The knowledge needed to come to this approach took 20 years. “It included many experimental studies which were published in scientific journals. The signal of the pulse in the capillary bed is quite noisy, so we were working on the methods to best extract information from recorded data. This is the area of non-linear time series analysis where we contributed many original solutions. The last ingredient is the theory of non-autonomous dynamical systems that we worked on over the past decades and recently formulated a new class of systems that we named chronotaxic.” These are systems are capable of working in full strength and stabilising the frequency of oscillation even though they have been disturbed. That is how the heart works. It adapts its beats to the body’s needs and mostly does not lose pace. So, when all ingredients are put together, a picture emerged and the proposal of the endotheliometer was a natural step in this development, Stefanovska says, adding that the potential uses of the test are many and varied. Doctors can use it to check our endothelial health, as they used to test our general health by measuring our body temperature. It can also be used to evaluate the effects of medications; or by an individual to follow his health by observing the effect of diet or lifestyle changes. So, it can be for home use and for use in hospitals. How do two physics professors come up with an invention that is more in tune with biologists? “Such an invention can come from many disciplines. But the complex, dynamical approach we took needs the physics of complex systems and a diversity of expertise in nonlinear dynamics plus some knowledge of physiology. Both Peter and I were lucky to have a chance to collaborate with many cardiovascular and vascular physiologists, cardiologists, anaesthetists, diabetologists, and other clinicians and thereby gained very substantial insight into the function of the cardiovascular system. As physicists, we were not restricted to any one aspect of it, as is the case for most of biological and medical scientists today because they have become so specialised,” Prof Stefanovska states. And it was not just Stefanovska and McClintock who worked on this device. There were many collaborators who contributed. Alan Bernjak did his PhD with Stefanovska and then spent two years as a research fellow at Lancaster. He is the co-applicant on the patent application for the endotheliometer. The idea for a laser test took root after Stefanovska completed her Ph D in 1992 and presented an analysis showing that the blood flow in the capillary bed has many oscillatory components. “To come up with a proposal of a single number for the sound that the blood cells make, we needed to understand the physiological origin of each sound that each cell made and how they interacted with each other in health and disease. After a thorough investigation, we were able to propose the reduction of this complex sound into a single number. In this the role of heating is very important. Last year, we published a paper on what heating does to the capillary bed and this in a way completed all the background knowledge that was needed for this device. Our study of aging, in which we included more than 200 healthy subjects of all ages, was crucial to this test,” Stefanovska says. With the test came several controversies. One was the view that people will undergo the test to know their time of death and then may give up on living. Two, life insurance companies would insist on the death test to determine how much they will have to shell out and how soon. But Stefanovska has a positive view to this. She says the test may alter people’s lifestyles and make them more health conscious. “There is a long way to go still. To miniaturise the device, to test it on a larger number of subjects both healthy and ailing, and to evaluate it against the existing devices of a similar kind is one thing. At present, there are two devices in the market and both are evaluating endothelial reactivity as a response to occlusion (a method by which blood circulation is stopped for several minutes). When it returns, the way in which it does depends strongly on the vascular reactivity. However, these tests can only be done in larger vessels, where there are other structures in addition to the endothelium, like smooth muscle cells that can be impaired. So, a direct comparison is not possible, but we are planning some approaches to compare our method with existing ones,” she states. It will take another five years before the device is finally ready and introduced in the market. However, it’s important, especially to estimate the risk of developing cardiovascular diseases. This is because the endothelium is the largest organ and important for the function of the cardiovascular system and general health. Its role is still under-appreciated, although a Nobel prize was given in 1998 for the discovery of its function. Until 30 years ago, it was believed that it is a passive barrier that prevents blood from leaking out of the vessels. But, it is also involved in a variety of biochemical processes crucial for the functioning of each of the 100 quadrillion or so cells in our body. The laser device offers an elegant, quantitative and non-invasive way of evaluating its function uniquely. Its enormous usefulness for individuals, general practitioners and consultants will largely depend on how handy the device is going to be once it is out. For now, the physicist says that the device will be as precise as our knowledge about all existing states. The bigger the number of cases from which we learn, the more precise the classification of each measurement will be. And even though there is plenty of scepticism at present around the test — people are afraid that the insurance companies may misuse it to adjust premiums — Stefanovska is positive that for all those who want to control our health for well-being and to avoid serious complications, it will be a very useful method. “It will replace many complicated investigations and it can be the most elegant way to see how a treatment (either a drug treatment or lifestyle change) is successful. It can save time for general practitioners, as a test lasting up to five minutes can give quite a good evaluation of a patient’s health and the basis for further examination. The values can easily be stored so that each one of us can be in control of our own destiny and compare the data over days, months and years,” Stefanovska states. ______________________________
Posted on: Thu, 14 Nov 2013 19:25:29 +0000
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