Acoustic shock waves are high amplitude acoustic pulses that contain near-instantaneous jumps in pressure (shocks) due to nonlinear process in the medium.   In medical acoustics shock waves can be used to fragment kidney stones and other calcifications in the body, rupture soft-tissue, stimulate cell and neural responses; promote repair or growth of bone and soft tissue, and interact with exogenous agents for drug delivery.   The pressure amplitudes are typically on the order of 10-100 MPa and the shocks occurring over time scales of 10 ns or less.

Our research investigates the fundamental mechanisms of action by which shock waves interact with biological systems, and in particular the role of the higher temporal and spatial gradients associated with the shocks.   Examples include: the coupling of shock waves into stress waves inside kidney stones to result in fragmentation; how shock waves can alter the phase-state of lipid membranes to enhance fusion between lipid drug-delivery vehicles and cell membranes; the ability of shock waves to disrupt the biofilms that can harbour bacteria; and how shock-wave induced cavitation results in tissue damage.

The main use of shock waves in medicine to date has been lithotripsy, in which shock waves are used to fragment kidney stones so that they can be passed naturally. However, shock waves are increasingly being considered for other applications such as treatment of soft-tissue pain (e.g. tendonitis and heel spurs), promoting repair or growth of bone, neo-vascularisation, disruption of biofilms to fight infection and wound healing. Through a combination of experimental and modelling approaches, we are keen to further understand,  explore and optimize the key shock-wave mechanisms underpinning these emerging applications to enable their clinical translation.