Transcript for unique heart beat signature device could revolutionise healthcare (podcast)

[Beeping sound]

[Narrator]

According to the British Heart Foundation cardio vascular disease kills around two hundred thousand people each year. Earlier diagnosis and a faster and more convenient way of carrying out that diagnosis could obviously save many lives. A research team at the University of Leeds, with funding from EPSRC , are developing a device that could do just that. The team is led by Professor Ben Varcoe.

Professor Ben Varcoe [BV]

What we’ve developed is a device that can detect very, very tiny magnetic fields. The magnetic fields that we can detect are smaller than the magnetic fields that are produced by the heart. The truly novel aspect is the interdisciplinary nature of what we are doing. We’re taking atomic physics and medical physics and putting them together to create a novel device. Our aim was to develop a device where we could take the magnetometer to a patient in a hospital bed. Where the patient is comfortable they can have an image taken, the image is recorded in a way that all of the noise is eliminated by the careful design of the apparatus rather than by the environment that the apparatus was placed in. If you could picture a camera that’s going to take a snapshot of a patients heart, the camera would take an exposure that would last for about a minute and over the minute it would capture several heartbeats. The idea is that the camera doesn’t need to be in contact with the patient, it could be several millimetres away outside a layer of clothing and the image is captured using a coil structure that eliminates the noise of the environment and captures only the image from the patient. By careful design of the cabling we can then send that signal through to a sensor that lives in a sheltered environment which records the actual magnetic image. So what we have been developing is the technology and the techniques to bring the signal from the heart to a sensor and the sensor that we are using is an atomic physics sensor that’s been around for some time, so we know how it works very well. The difficultly was in mating atomic and laser physics to a device that could be in place, in a hospital, being used by non-specialists in laser physics so one that would be robust and would be capable of being used in a relatively electrically noisy environment.

[Narrator]

So how has Ben overcome the difficulties that other researchers in the past have unsuccessfully tried to tackle?

[BV]

The biggest way that we have overcome it is simply with persistence. We’ve been stalking around the problem for some time. This is an off shoot of two areas of research that we are doing; one is in precision in fundamental quantum mechanics and the other area of research is in fundamental measurements of relativity and so as we’ve continued to refine our techniques and understand the system more, we’ve been able to develop an understanding of how the things go together. The real breakthrough was bringing in a student, Melody Blackman, who came in with a medical physics background and so was able to take what we were doing as an atomic physics experiment and make it a real medical device.

[Narrator]

Ben goes on to describe in more detail how the device works and what it looks like.

[BV]

Physically it’s relatively small. It’s about a metre square, it is the main work horse and contained within that is a gas cell and the gas cell is where all of the work is done. This is where we sense the magnetic fields so what we are looking for is a change in the gas introduced by a magnetic field that we apply and gases, especially rubidium in this case, is particularly sensitive to magnetic fields. This sensor is contained; it is housed in several layers of magnetic shielding which enable us to reduce the earths field by about a billion fold. We then have to pipe the signal that we want into this device and we do that using a technique that has already been widely used in medical physics. It’s a series of coils that cancels background noise and keeps only the signal that you are interested in. And by putting those two together we’ve developed a relatively small essentially hand held probe that could be used to detect field and what’s interesting about this is that we can detect the magnetic field with no harmful emissions of any kind in a non contact way where the patient could even keep their clothes on, so we are really looking at the most convenient kind of imaging.

[Narrator]

Due to its unprecedented sensitively to magnetic fluctuations the device could be used to detect a number of medical conditions.

[BV]

It’s particularly good for foetal heart measurements when protecting the actual beat of a foetal heart, so the normal technique is to use a dopil measurement from the surface of the heart. In this case you could actually measure the heart function directly it’s particularly important in foetal diagnosis that you are non contact and emission free. In this case you would have a very comfortable mother and you could do a complete diagnosis of any potentially fatal condition. The other thing that you can use it for is looking at brain function and there are people around that are looking at magnetic fields originating from epilepsy, for example, and the way that the brain responds to various stimuli.

[Narrator]

That was Professor Ben Varcoe from the University of Leeds and following clinical trials it’s hoped that the device could be ready to use for routine diagnosis in around three years.