For Medical Professionals

The VEWS® test automates and quantifies two clinically established tests currently performed by highly skilled clinicians:

  • Buerger's leg raise test [1], where a vascular expert inspects skin colour after raising the leg and,
  • Leg raising Pole Test [2,3], where a vascular expert assesses pulse strength when the foot is raised
Figure 1

Optical Sensor Applied to Foot and Toe combined with postural test

VEWS® uses low power near infrared light to assess blood volume changes in the foot, before and after raising the leg. Multiple light wavelengths are used to monitor two sites simultaneously to perform blood volume and skin pallor assessment, without using pressure cuffs. The infrared light works equally well on dark or light coloured skin. The postural test compensates for irrelevant factors (such as skin thickness or pigmentation) by analyzing CHANGES in blood volume and skin pallor between positions.

The VEWS® methodology is based on detecting the impairment of the auto-regulation of leg blood flow that may accompany either a reduction in arterial compliance or an inability to compensate for orthostatic pressure changes.

  1. Insall RL, Davies RJ, Prout WG., Significance of Buerger's test in the assessment of lower limb ischaemia, J R Soc Med. 1989 Dec;82(12):729-31 PUBMED
    http://www.ncbi.nlm.nih.gov/pubmed/2693712
  2. Paraskevas N, Ayari R, Malikov S, Mollo M, Branchereau P, Hut F, Branchereau A, "'Pole test' measurements in critical leg ischaemia", Eur J Vasc Endovasc Surg. 2006 Mar;31(3):253-7 PUBMED
    http://www.ncbi.nlm.nih.gov/pubmed/16297645
  3. Jachertz G, Stappler T, Do DD, Mahler F., The pole-pressure test: an easy alternative in patients with ischemic legs and incompressible arteries, Vasa. 2000 Feb;29(1):59-61 PUBMED
    http://www.ncbi.nlm.nih.gov/pubmed/10731890

Resources

Padd

For rapid, non-invasive assessment of Peripheral Arterial Disease, to prevent heart disease and stroke