Project staff and support

Jean-Pierre O'Brien (Intern, University College London)
Nick Bushell (Company Supervisor, Barnett Waddingham)
Nick Ovenden (Academic Mentor, University College London)
David Leppinen (Academic Mentor, University of Birmingham)
Vera Hazelwood (Technology Translator, Industrial Mathematics KTN)

This Internship project was hosted by VR Technology in conjunction with the University College London and University of Birmingham and. It is part of the KTN's Industrial Mathematics Internships Programme, co-funded by EPSRC. Start date: October 2009; duration: 6 months.

The problem

Breathing compressed air at depth causes an increasing amount of gas to dissolve into tissue. Upon resurfacing this gas comes out of solution and can cause problems leading to Decompression Sickness (DCS). The trick is thus to manage the escape of gas from the body in such a way that the diver can exit the water safely.

Despite compressed air diving having been carried out for over a hundred years, decompression theory has advanced little in that time. For simplicity, the body is said to be divided into 16 compartments each with its own gas dissolution half-time and a decompression profile is calculated to maintain the partial pressure of gas within each compartment below a threshold that has been derived empirically. The coefficients used for decompression tables vary between different organisations for different depths.

VR Technology has identified the need for an improved decompression algorithm for recreational and commercial divers that can be used across a whole range of depths, particularly in the range 0-150m. Their Variable Gradient Model (VGM®) is a first attempt at bridging this divide that also incorporates user customisability to allow for different risk tolerances.

“This project has been an extremely useful and valuable exercise for Jean-Pierre. He has learnt a number of skills in applying novel mathematics to an industrially relevant problem and the project has provided some additional insight into his own PhD research on microbubble contrast agents.” said academic mentor Nick Ovenden, University College London.

“This internship has advanced our understanding of decompression sickness and has identified areas for future work and collaboration. It is a prime example of how mathematical modelling can be used to solve industrial problems.”” said academic mentor David Leppinen, University of Birmingham.