1. Cerebral haemodynamics in pregnancy and pre-eclampsia as assessed by transcranial Doppler ultrasonography 
R.W. Sherman, R.A. Bowie, M.M.E. Henfrey, R.P. Mahajan, D. Bogod 
British Journal of Anaesthesia 
Volume 89, Issue 5, Pages (November 2002)
DOI: /bja/aef247
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Example of the THR test. Baseline flow velocity (FV), F1, reduces to F2 at the onset of compression. If autoregulation is effective, FV after the release of compression (F3) shows a hyperaemic response (i.e. F3>F1). The line below the MCAFV trace shows the reflected power of the Doppler signal; unchanged power during the test suggests stable conditions. For the measurement of FV, the time-averaged mean of the outer envelope is taken. The outer envelope defines the upper limit of the frequency waveform for every pulse. It can be generated by computer (software by SciMed UK), and is shown as the continuous black line that joins the peaks of Doppler frequency spectrum during each cardiac cycle.
British Journal of Anaesthesia  , DOI: ( /bja/aef247)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions