By: Thomas Rouse
Senior Consultant, Medical & Healthcare

12th April 2017

Many moons ago, while writing up my thesis, I had been burning the candle at both ends. Unsurprisingly, I was starting to feel tired and run down. A wise friend encouraged me to heed some sage advice; “When your body speaks, listen!”.

Somehow, that little mantra lodged in my mind, and I could no longer disregard all the hints and messages I was receiving from myself but had previously managed to ignore.

The image of organs communicating their status to our conscious mind, like a conversation or shouted warning has stuck with me. Anthropomorphizing my own subsystems helped me to see them in a different way. It made the internal advice friendly, convincing me to work with my body not against it. As time has passed, that image has developed into a full blown intrigue.

There are many methods of expression within us, with seemingly no end to the fascinating tales biologist friends have provided of the incredible processes that take place. These interactions make us who we are, and reveal how we function. In just the area I specialise in, electrical signals, there is a vast amount of information passing around. It is tempting to say mind-boggling, but that would be incorrect, as we (hopefully) cope without being in a permanently boggled state! Our brain is a very effective filter, alerting us only when there is something of interest.

This is because it’s not just at the limits of our endurance that information appears. It would be nice if there was a simple alarm which only triggered when we have exceeded our specifications, are outside normal parameters, or have a failure. The signals need interpretation, and this is not a trivial matter.

Take for example the electrocardiogram (ECG), we can examine it on a number of levels. Our heart rate can be extracted by looking at the time between the largest spikes in the signal. This can be evaluated as an absolute value, checking it is inside acceptable limits. The safe range can vary depending on factors such as age, or what we are doing at the time. From this, we can then study how the heart rate changes with time. Is the spacing even, and how quickly does it recover after exercise? This is useful information on its own, but is just the tip of the iceberg. The ECG is composed of several features which correspond to different processes in the cardiac cycle. The height and spacing of the different bumps and troughs can provide a vital insight into how the heart is functioning. A skilled interpreter can analyse them to help diagnose a range of conditions. There are enough differences between us, however, that even with a healthy heart, this signal can be used as a biometric identifier.

We already have wearable devices which can show signals such as the ECG outside a hospital environment. The ECG is relatively loud, yet is easily masked by noises generated when moving, or electrical interference such as our 50/60Hz mains supply. Other signals of interest can be a million times quieter, making their reliable extraction something of a black art. Even with a perfect waveform, in most circumstances, diagnosis or monitoring of a condition is difficult or impossible to automate without some expert human intervention. If a specialist is involved, our brain has probably already determined that something is wrong.

The ability to listen and understand the subtle inflections in our internal communications, by benevolently eavesdropping at the point of care or in our daily lives could provide huge benefits from early detection of conditions, or allowing people to leave hospital sooner.

At each stage in a physiological process a signal may be generated. For example, after the initial stimulation, impulses could be detected travelling though the nervous system, when they reach the brainstem, or as they pass towards the higher levels of brain function. Like a game of Chinese whispers, each new wave may be an altered interpretation of the original. We can use this to create more data, by understanding and giving meaning to the interaction between the points in the chain, or simplify it by spying on the neural pathway which extracts what we want.

All these challenges; determining what is being said, getting the raw data, and working out what it means are at a fascinating stage where they are beginning to become possible outside specialist clinical environments. Our body has started the conversation, how are we going to respond?

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