“I’ve been a consultant anaesthetist for the last seven years, but recently I’ve been made a Senior Lecturer in the department. For three years before that, I had an NISCHR grant and have been spending half my time out to do research,” he says. “So I’ve been doing academic stuff for Cardiff University – fairly intensely, for the last three years, but I’ve got a long history of research before that.”
Originally from Singapore, Lim wanted to study medical engineering because he felt that he could do a lot if he looked at creating artificial organs for, say, kidney or liver failure. However, it was not possible for him to stay in Singapore to do this research and so he applied overseas.
“The only place to accept me without an engineering degree was Oxford,” he says. “So I went to Oxford to do a research Masters. My research was on an artificial lung, which was kind of in the field where I want to go, but not quite. I did it because I wanted the experience. Along the way I did Anaesthetics as a sort of filling in the blanks kind of job – I found I liked it and stayed on.”
Michael says that much of the field of anaesthesia seems logical to him because of his background in physiology and physics. Since 1997, he has been working on research projects in the field.
“As a trainee at Oxford I got a BJA/RCoA – that’s the British Journal of Anaesthesia and the Royal College of Anaesthesia – co-funded research fellowship. So I took two years out to develop a simulator,” Lim explains. “It’s an endoscope simulator: you put an endoscope in and you attach it to the device. As you move the endoscope as normal, it behaves like a 3D joystick for your computer, so you can simulate various scenarios, such as how to intubate patients or even how to do colonoscopy. Devices like this are already on the market, but they are quite expensive and proprietary so I wanted to make one that was
During the time that he spent developing this simulator, he became quite heavily interested in computer programming, realising he was able to accomplish more with computing than he could with engineering.
“In engineering you’ve got to build the device, test that it works and if the device doesn’t work go back to the drawing board. With the computer it’s a lot easier – it’s all virtual so it’s easier to change things around,” he explains. “What I’ve been doing for the last three years is building software that helps people model physiological systems. Traditional engineering and mathematics are quite good at what you call linear systems but when things are non-linear, it makes life quite difficult and you’ve got to find all kinds of techniques to accommodate this non-linearity.”
Lim explains that the traditional way to cope with non-linearity is to break down a system into very small linear components and then integrate the bits back into something that approximates the original. However, for Lim, this is not sufficiently accurate.
“In medicine, we are used to simplifying biological systems into linear models. And that’s not always accurate. Take, for example, the heart. When it pumps it squeezes a volume of blood out. If the same volume of blood goes out, as the heart pumps faster, more blood goes through,” Lim says. “But what they found was when the heart squeezes hard, it pushes the blood up into the aorta, which distends and creates a pressure reflection wave back down the heart. The harder you squeeze, the less blood comes out – it’s just counter-intuitive. In a linear system, the harder you push, the more blood comes through. In this case, because of the elasticity of the aorta involved, the harder you squeeze, the less blood comes through.”
Indeed, Lim says that “most of our physiological functions are non-linear – the heart is non-linear, the lungs, there’s non-linearity involved, blood flow is non-linear. Almost everything we have is non-linear.” This non-linearity creates chaotic systems – systems that are notoriously difficult to predict. Therefore, he wants to design a program that is built from the ground up to model non-linearity. “It’s based on computer graphics, a graphical approach rather a mathematical equation approach,” Lim says.
Michael Lim’s research has been funded by NISCHR and the Welsh Government, and although it would have a massive benefit on the training of new doctors, that is not the only application of the software which he is developing.
“Using the software, we can compare the different models. The importance is that if you have a mechanism, you can say, ‘If I change this, how does it affect the system? How do I target my drug or technique better so I get the same effects with less of a drug?’ It’s about improving things and understanding how bodies work. It has a lot more benefits beyond just simulation or teaching.”
But realistically, what impact would Lim’s vision have?
Lim says. “In the long term, I hope to have electronic records of patients, which holds information about what we do to patients – the drugs we gave or the surgery we perform. If we are also able to capture their routinely-monitored waveforms, which hold information about how patients react to what we do, we can combine the two types of data to create a dataset for that patient.”
“I can then feed this information into the software I am developing, causing the template models of how the body works to adapt and create an individualised model for that patient. So the data from you and from me will create two individual models of you and me. It could in theory – and this is a long way off – tell me how I would react to an anaesthetic drug compared to you. So potentially, I can improve things by figuring out which drugs would work for you and which would work for me.”
“When you have a million sets of data, you don’t just have a model of the human body, you have a lot of models of the human body that quantitatively tells us the diversity of the human race.”
In closing, Michael Lim has words which will stand him in good stead as he aims to make the vision for a model of the human race a reality:
“I think what drives me is the feeling that you can do a lot better what we are doing. Sometimes it’s difficult but a lot of the time the solution is to work out an alternative approach to doing things,” he says. “Using the old way we run into difficulties, so let’s try and find a new way. Basically my drive is to try and improve things and I believe we can do that. I believe we should be trying to do that.”
Article by Marc Thomas: