Nexxus Scotland

Watson, Malcolm and the Split Array Transducer

Dr Malcolm Watson is a first-class example of the old adage that necessity is the mother of invention. Now a clinical lecturer in anaesthesia, he has more than a decade of experience in a range of medical specialities including A&E, general medicine and anaesthesiology.

 A graduate of the University of Glasgow, and the winner of the Glasgow and West of Scotland Society of Anaesthetists research registrar prize and the Scottish Health Innovation Ltd (SHIL) Best NHS Innovation of the Year Award 2006, Dr Watson splits his working time between lecturing and clinical duties providing anaesthesia for elective and emergency surgical and obstetric patients.

The inspiration for the split array transducer was as a direct result of the clinical problems encountered during his clinical work. Much of his work involves the provision of epidural or spinal analgesia and anaesthesia during childbirth. Traditional techniques rely on the ability of the anaesthetists to feel the bones of the back to guide the insertion of the needle. This works well in the majority of patients but is made difficult in the morbidly obese by excess fat overlying the spine.

In recognition of the limitations of existing ultrasound technology Dr Watson therefore developed an innovative new device called the split-array transducer which is an evolution of existing ultrasound technology.

The split-array transducer does two things which were difficult with traditional scanners: firstly, it is designed like a computer mouse which allows the clinician to obtain a scan at an angle of 90° to the patient with the device stabilized on the patient's back. Secondly, it has a guidance aperture in the middle of the transducer for the needle which effectively acts like a sight on a rifle, allowing much more accurate insertion of the epidural needle.

Unfortunately, says Dr Watson, the West of Scotland's health record makes his innovation necessary, not simply desirable. "Obstetric anaesthetists are increasingly commonly confronted with women weighing 160kg or more and the provision of epidural or spinal anaesthesia in these patients is difficult and frequently impossible," he says. "In such massively overweight patients, the risks to them and to their baby's health are also hugely increased".

"Ordinarily we would have to use general anaesthesia if we failed to provide spinal anaesthesia, but that in itself is extremely problematic as it's often difficult to insert a ventilation tube, and you have a significant risk of stomach acid entering the lungs. "

Dr Watson's innovation, then, removes the requirement for obese women to be given general anaesthetic to allow rapid delivery of the infant. Clinical trials in overweight mothers who have elective epidurals are ongoing, but because ultrasound technology itself is well-established, what is being tested is the ability of the new device to speed up the provision of spinal and epidural anaesthesia.

Ease of use is another advantage of this technology. Due to the simplicity of the design, there is no necessity for clinicians to conduct hundreds of ultrasound scans and attend prolonged training courses before they can accurately use the split-array transducer. In fact, Dr Watson says the device can be used by someone with the appropriate training after just 10 ‘practice' scans.

Dr Watson says: "In excess of 20 per cent of the population of the West of Scotland are morbidly obese - that means their weight is a serious and immediate risk to their health and the associated risk of adverse events during almost any medical intervention are significantly increased.

"This device is aimed at removing some of that risk when it comes to childbirth, by enabling clinicians to insert an epidural needle more quickly and accurately than using conventional ultrasound scanners."

The research and development department at Glasgow Royal Infirmary initially identified the intellectual property and funded the first patent and helped form the project team which developed the split array transducer. The project attracted funding from the Chief Scientist's Office, Scottish Enterprise and Scottish Health Innovation Ltd (SHIL), who have also managed the project throughout the development phase.  

The Medical Physics Department in North Glasgow University NHS trust provided redundant scanners which were adapted to act as crude prototypes in the early development stages of the project. In addition, the University of Paisley, advised on the capabilities of ultrasound technology within the limitations of the available funding. Dr Watson's work as a lecturer at the University of Glasgow has also allowed him to work closely with his obstetric anaesthetic colleagues to ensure the utility of the final product.

Dr Watson's innovation has attracted interest from ultrasound manufacturing companies who are considering commercialising the device. A positive outcome from the ongoing clinical trial would enhance the commercial viability of the project.

He says: "When I started this project I received a lot of support from the different public sector organisations and latterly the private sector. The West of Scotland has a great tradition of research and innovation and I found it easy to tap into the levels of support and expertise that are available here. There's a great wealth of talent across the whole life science spectrum which is there to be utilised, and it has really helped to get this product off the ground."

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