The tragic events around of the disappearance of Malaysia Airlines Flight MH370 have highlighted the fact that the aero engines of large airliners are continually monitored as they fly around the world. The reason why these engines are continually monitored is that engineers on the ground are able to track deterioration and the development of problems long before they become critical and catastrophic; something to be avoided when you are flying in a 500 ton metal tube at 500 miles an hour, 35,000 feet above the ground. The reality of the situation is even more amazing when you consider the fact that beneath the casing are metal blades at over 1000 degrees centigrade spinning around at 10,000 rpm with 0.2 millimetres clearance between the engine casing.
At any one time, there can be up to 150,000 people in aircraft flying around the world and they have all put their absolute trust in the engineers who designed, built and maintained them; they have trust in these engineers that everything will function normally and they will arrive at their destination safely to meet their loved ones or continue with the business that took them on the journey in the first place.
Even with the everyday things we do, without realising it, we trust our lives to engineers. We trust that there will be electricity when we switch the power on at home to give warmth and light; we trust that the water we drink will be fit for drinking when we turn on the tap; we trust that the car we drive at 30, 50 or 70 mph will get us to our destination safely. There is not one thing in our lives that isn’t touched by or dependent upon engineers.
As a result, society, perhaps without realising it, places tremendous trust in engineers. This implicit trust in engineers and engineering is imbedded in our modern society.
The other professionals, in whom we place our absolute trust, are doctors. When our bodies go wrong, we trust that doctors will understand what is going on and that they will have the skills necessary to diagnose the correct drug, repair the broken part through surgery or tell us to change our life style. We then continue on our way, until the next time, with increasing frequency as we get older, and this continues until our human ‘engine’ finally gives up and stops functioning all together.
The analogies are obvious, but have engineers done a better job than doctors in understanding and managing the process of deterioration and failure? Should the medical profession look to engineers, and the techniques they use, to achieve such impressive levels of reliability and extended life on the things that they design and maintain?
One thing we should appreciate is that engineers have far more control over the basic design of the things they maintain; in fact they have absolute control. Engineers have to design the things in the first place; whereas doctors have absolutely no control. They have to take what they have been given as a basic design by an almighty creator, evolution or whatever you may believe has created what we are today. So engineers have the advantage over doctors in that they can learn from the experience of past failures and can change the design the next time round; the engineering equivalent of evolution. In all fairness, this has a major impact on the increasing reliability of the things that engineers design and build.
However, once the design is complete and the product built, there is perhaps a common starting point for both the engineer and the doctor; they both have to keep their ‘patient’ functioning as reliably as possible for as long as possible. Doctors have to cope with a whole variety of different lifestyles that human beings may choose to live under; engineers have to contend with the different operation conditions under which their design has to work.
It could be argued that engineers have adopted a far more structured and analytical approach than doctors to maintaining things and keeping things going for longer and more reliably. So, could doctors and the medical profession look to engineers to help us live longer and have a better quality of life?
It is a fundamental law of nature, the second law of thermodynamics that all things deteriorate and ultimately fail; jet engines, cars and of course human bodies. As yet, we haven’t yet found a way to counteract that law, nor have we found the secret of everlasting life, at least in the physical sense; but let’s not venture into that discussion.
In the past, when things broke down or failed, engineers repaired or replaced them. We still do this now on certain things, if a light bulb goes in our home, we replace it; we don’t go around our house replacing the light bulbs in case they fail, at least most of us don’t. We adopt a ‘breakdown’ approach to maintenance; that is we wait until it’s broken before we fix it. This situation is fine for light bulbs, at least in a domestic environment, because having a light bulb go out is not critical. There are many instances where a breakdown approach to maintenance is perfectly acceptable; situations where it doesn’t matter if something fails; we can repair or replace it when it does fail.
This breakdown approach is, to a greater extent, the approach adopted by the medical profession when it comes to the maintenance of our bodies. We go to a doctor or get referred to hospital when something associated with our bodies has failed, or, when we are experiencing a symptom that could indicate that there could be something the matter with us. In the main, we go to a doctor when we are ill. To a large extent we accept this breakdown approach when it comes to our bodies, however, we would find it totally unacceptable if we waited for an aircraft to drop out the sky to tell us there was something wrong with the engine.
However, could the techniques and processes now used by engineers routinely to achieve tremendous reliability and extended life on complex plant and equipment, be applied by doctors and the medical profession on our bodies to help us live longer and healthier lives?
Engineers now have a much better understanding as to why things fail through techniques such as Failure Mode and Effect Analysis (FMEA) and Reliability Centred Maintenance (RCM), Root Cause Analysis (RCA) and Condition Based Maintenance (CBM). Basically, all fancy acronyms for a very simple logical process involving a series of questions that an engineer asks about the design or piece of equipment, questions such as:
- How can this fail?
- What happens if it does fail?
- Does it matter if it fails, i.e. how critical are the consequences if it does fail?
Then the critical questions are investigated:
- What are the indications that we might get before it fails?
- Can we measure these indications?
- How long will we get these indications before it fails?
But finally and most importantly:
What can we do to prevent the failure before it happens?
Engineers are able to track deterioration and the development of problems long before they become critical and catastrophic failure results. The techniques of Condition Monitoring and Condition Based Maintenance are being applied to a whole variety of different areas where safety and reliability is critical to the operation of equipment.
The application this technology and the intervention of corrective actions long before catastrophic failure occurs is helping engineers to achieve greater reliability and extend the life of plant and machinery far beyond the original design life.
The intriguing question is; could the same approach be applied by the medical profession to help us live longer healthier lives? It would require doctors to adopt a totally different approach to health care; from treating, with drugs or surgery, when something goes wrong with your body, to actually monitoring parameters in your body which indicate the condition of your critical organs and functions. However, more importantly, this process would need to start when you were perfectly healthy to understand how and at what rate you were deteriorating from the healthy norms of your body. Failure in plant and machinery does not generally occur instantaneously, it deteriorates over a period of time, until the condition gets so bad that failure occurs. Our critical organs and functions behave in the same way; an indication of deterioration usually begins to manifest itself long before the situation becomes critical or catastrophic, and the only way to treat the situation is with drugs or surgery.
Such a ‘Condition Based’ approach health care assumes that there are things we can do to keep ourselves healthy and in optimum working order. The obvious one is lifestyle, but this can only be one aspect, people who lead good lifestyles can still experience catastrophic failure of parts of their bodies and its functions. With a condition based approach to healthcare, a doctor needs to know the condition of our critical organs and functions continually, or at least regularly, over the whole of our lives, so that small changes in deterioration can be detected and corrected long before catastrophic failure occurs.
The mainstream medical profession is yet to take up this challenge, maybe because of cost, but it could be the case that it is cheaper in the long run to keep people healthy rather than to treat them when they are sick. Holistic medical practitioners are beginning to adopt this approach to health, because in the early stages of deterioration it is often the case that the function in question is not the problem; the root cause can often be associated with a problem in totally different area of the body. Considering our engineering analogy, there is no point in repairing a pump that is showing signs of failure, if the root cause of that failure is contamination of lubrication in another part of the circuit; you have to address the root cause of the problem that is causing the failure.
Processes such as Failure Mode and Effect Analysis (FMEA) and Reliability Centred Maintenance (RCM), Condition Based Maintenance (CBM) and Root Cause Analysis (RCA) are being used by engineers to achieve tremendous levels of reliability and safety, not just on critical things like aero engines, but also with things connected with all aspects of our lives. Society places tremendous trust in engineers.
It could be argued that engineers have adopted a far more structured and analytical approach than doctors to understanding deterioration and preventing failure. So, could doctors and the medical profession look to engineers and the techniques and processes that we use, to help us live longer and have a better quality of life?
Please Comment, and pass to your medical colleagues.
Additional comment from the author:
Thanks to all those who are commenting on this post, it has raised a lot of interest and debate in the various places the article has been posted. Some of you raised the question around the relevance to the disappearance of flight MH 370. My only point there was that the event prompted quite a bit of public awareness in the media about the fact that condition monitoring was undertaken on aero engines during the flights and fed back to the teams who were maintaining the engines. This, along with all the other techniques used by engineers, have had a major impact on the safety and reliability of aero engines, which could account for the inherent trust that people put in engineers each time they fly in an aircraft. Apologies if the link was a bit tenuous, but I expand on the theme a bit more above.
It is also appreciated that there has been great progress in medical engineering and medical equipment and the medical profession clearly use technology in the diagnosis of illnesses in many areas of medicine. However, the question I was asking in the article was slightly different: can a healthy body be defined through the measurement of a multitude of physiological parameters in the body?
If the answer is yes, even to a certain extent, then if these parameters are measured throughout our life, can small changes from the normal be used to indicate very early onset of deterioration and potential failure of an organ or system in the body that could be corrected long before it became critical and the intervention of drugs and surgery was the only option? If the answer again from medical profession was a qualified, yes, then doctors could, in theory, adopt the same approach to help us maintain a healthy body as we do as engineers, in maintaining plant and equipment in a safe, reliable state for periods of time unheard of a generation ago. If such an approach was possible, and it’s down to the medical profession itself to argue this point, it would require society to adopt a totally different approach to health care, i.e. measuring these physiological parameters throughout your life, when you are healthy, in order to detect small changes, as we do in engineering.
Such an approach to health care would require a total shift in expenditure, which would be front end loaded, rather than back end loaded; but again the use of technology used now by engineers in the monitoring process could significantly reduce the cost of this. One could imagine eventual regular self-monitoring at home of these physiological parameters and uploading onto servers for intelligent tracking of your on-line health, and when a parameter deviated from a norm, your doctor would automatically be alerted and would then intervene. In order to understand if such an approach was feasible, the medical profession would have to look, again as engineers do for their designs, at the total lifetime cost of providing healthcare for an individual. However, engineers can show that by adopting this approach not only can we provide safer, more reliable, longer lasting designs, but we can achieve this at a lower cost than repairing things when they are broken, notwithstanding the financial, environmental and human cost if things we design do fail. How feasible all this from a medical standpoint, I don’t know, I am an engineer not a medical doctor, but it has been incredibly interesting to see the responses from you all, and read your views.