 2. 45 minutes while the gekoTM device is active ELISA analysis will be carried out on samples see appendix. Vascular Endothelial Growth Factor - Therapies which can lead to the development of new, collateral blood vessels, are of particular interest in the field of peripheral arterial disease where narrowing or blockages in existing blood vessels result in tissue ischaemia. Vascular endothelial growth factor VEGF is a signal protein produced by cells that stimulates the growth of new blood vessels from pre-existing vessels. Several previous studies have shown that electrical stimulation increases VEGF levels and in turn increases vessel density in muscles. 