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Laparoscopic surgery, in which the patient’s abdomen is inflated with carbon dioxide and the surgeon uses long instruments through small incisions, is relatively simple to perform but often impossible in practice. Used for procedures including the removal of the appendix or gall bladder, it depends on a reliable supply of gas, an anaesthesia team, and trained personnel. The ability to keep equipment sterile is also very important.
Doing the same procedures without gas removes many of the challenges – spinal anaesthesia can be done by the surgeon, and a mechanical lift device can create the space in the abdomen. A team from the University of Leeds developed such a device, aiming to enable surgery for those who would otherwise not have access.
The design of the Retractor for Abdominal Insufflation-less Surgery (RAIS) was based on the principle of ‘frugal innovation’, the “essence of just keeping things simple,” says Dr Pete Culmer, leader of the healthcare mechatronics research group at Leeds.
“Part of it that's really important is identifying exactly what your clinical need is, or your surgical need in this case, and only when you've got that clear understanding can you get to the core of ‘What does your engineering system have to do?’ The idea of stripping away all that extraneous functionality, which might make it more expensive or less reliable.”
Modern standards
The Leeds team worked closely with a clinical team in rural India during development of the RAIS, taking “three or four” iterations to find an acceptable compromise between complexity and effectiveness according to Culmer, who is also a board member of the IMechE biomedical division.
“There have been some pieces of equipment designed to do this before. The trouble was that they were kind of bulky,” he says. “The pieces of kit weren't really up to modern standards – hard to maintain, quite expensive, really heavy and bulky.”
The new device, which weighs about 3kg instead of 5-10kg, can be clamped on to a table. A framework is positioned over the patient, positioning a ‘lift’ that docks with a ring inserted into the abdominal wall. The surgeon can then wind the lift up, raising the abdominal wall. The independent control means an assistant is not needed to hold parts in place, helping maintain sterility for longer.
Win-win situation
Commercial partner Ortho Life Systems in India has produced 10 of the devices, which cost about £800 – one-third of the price of older retractors. They have been used successfully in clinical centres in rural India and also trialled in Kenya and Uganda, with Sub-Saharan Africa identified as an area of high demand.
Developers of surgical tools often focus on expensive items for wealthy countries, but simple, low-cost innovation such as the RAIS could have a far wider impact.
Culmer says: “There's some fascinating work going on, in terms of things like robotic surgery. I don't want to diminish that, but I think we almost need to contrast it and go: ‘There's a huge proportion of the world who have no access to good healthcare at all.’ So I think there's a lot of scope to address that community, that population.”
Frugal innovation could even provide savings for healthcare systems in richer nations, such as the UK’s NHS.
“It's win-win,” says Culmer. “If you start to identify techniques or equipment or approaches that are lower resource, they equally have an impact back in higher-resource settings.”
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.