The device to measure and apply pressures accurately is being developed in South Australia.
The intelligent intermittent pneumatic compression device’s defining feature is a small tape sensor that is placed between the patient’s skin and the pneumatic compression device to monitor the pressure placed on the leg during lower limb surgery.
Intermittent pneumatic compression is an established method of DVT prevention during and after surgery. The fluctuating pressures the devices apply help to promote circulation and lymphatic drainage and protect against deep vein thrombosis.
Flinders University’s Professor John Arkwright said the problem with existing intermittent pneumatic compression devices was that there was no way of easily measuring the exact amount of pressure on the limb to maximise effectiveness.
Prof Arkwright last year started Arkwright Technologies – a company spun out of Flinders University – to commercialise a fibre-optic, pressure-sensing catheter he developed to record and characterise muscular activity inside the body to a level of detail previously not thought possible.
The same technology, which has also been used to make submarines quieter, was used by Prof Arkwright to develop the tape sensor for the compression device.
“Someone mentioned to me that it was very difficult to measure the compression applied to a leg either with a bandage, a sock or a compression device,” Prof Arkwright said.
“So we tried one of our catheters in a slightly different format and found that it was actually very good at monitoring the pressure that was applied to the leg – it was a bit of a serendipitous discovery but it actually worked extremely well.”
For patients undergoing general surgery without prophylaxis, such as pneumatic compression, the rates of DVT range from 15 per cent to 30 per cent, and fatalities occur in up to 0.9 per cent of patients.
Prophylaxis reduces this risk of DVT ten fold to about 3 per cent.
The new device aims to save people from a condition known as pulmonary embolism – the fifth leading cause of death in Australia ahead of breast cancer and prostate cancer – which is caused by blood clots that travel to the lungs from legs, or deep vein thrombosis.
“What we now have is a way of measuring whether the pressures are correct. Then, in the fullness of time – it’s very early stages yet – we will be able to control the pressure applied to the leg so it is much more accurate,” the Flinders University School of Computer Science, Engineering and Mathematics Professor said.
“The next stage is to undergo a series of clinical studies at Flinders Medical Centre to see what pressures these cuffs are applying and then to see whether applying the correct pressure will affect the incidence of DVTs down the track.
“Tape sensor is getting very close to being ready for commercialisation. The long drawn out part is the longitudinal studies – surgically induced deep vein thrombosis often doesn’t appear for some months after surgery.”
Prof Arkwright said the training of carers and nursing staff on how to bandage and get the correct pressure profile was also a very strong application for the sensor.
“We’re using the same tape sensor to monitor the pressure during bandaging or with the application of compression socks. Because we are the first sensor that enables that measurement to be made, it’s got a lot of potential for teaching people how to bandage correctly and also for trying to discover how compression socks actually work on different shaped legs,” he said.
“A lot of compression socks come in small, medium or large – and people don’t – they come in all shapes and sizes. So to try to find out the best shape of sock or stocking to go on a particular person would be a significant step forward.”
“It’s unlikely that the device would be ever used during a flight but the background study to look at the efficacy of compression either with bandages or compression socks, it’s got a tremendous amount of potential for that and we’re already getting a lot of interest from user communities in that area.”
The technology will be demonstrated this week at the Asia Pacific Lymphology Conference Association in Darwin, in the Northern Territory of Australia.
“We are going to challenge people at the conference to actually apply a bandage to an artificial leg to see how close they can get to a target pressure profile,” Arkwright said.
“What we’re trying to do is to get first to market in the training domain and then we will seek regulatory approval for the device.
“We are continuing to find applications for this fibre-optic technology. We’ve got a project in obstructive sleep apnoea and another one in obstetrics and the odd submarine thrown in as well.”
South Australia’s capital Adelaide has three long-standing public universities, Flinders University, University of South Australia, and the University of Adelaide, each of which are consistently rated highly in the international higher education rankings.Jump to next article