Recordings of arterial blood pressure from conscious, freely-moving animals can be made via telemetry devices and are used routinely during the drug discovery and development process to assess the cardiovascular safety of new drug molecules before they are tested in human trials. Fully implantable telemetry devices sample the blood pressure waveform 500 to 1000 times every second (500-1000Hz) to produce high-fidelity recordings of the physiological signal. Despite the many data points that are contained within the blood pressure signal, conventional analysis tends to be quite simplistic involving the measurement of the maximum and minimum points on the pressure wave, equating to the systolic and diastolic arterial blood pressure. These measures are useful and indicate if a drug is causing hyper- or hypotension. But, in only focusing on the maximum and minimum values, a lot of potentially useful data contained in the wave may be discarded. Changes in the shape of the blood pressure waveform are thought to occur because of changes in the state of the underlying network of blood vessels and/or changes in the contraction of the heart. Quantifying these morphological changes is, however, challenging. Vivonics is pleased to be a partner organization in the INSPIRE European Training Network in Safety Pharmacology. We are hosting the secondment of an early-stage researcher (ESR) who is investigating whether a more in-depth characterisation of blood pressure waveform data could enhance cardiovascular safety screening and give more mechanistic insight into the underlying physiological effects of test drugs. A mathematical method known as Symmetric Projection Attractor Reconstruction (SPAR), developed by Nandi and Aston (2020), will be used to make a detailed analysis of arterial blood pressure waveforms. This method utilises all the numerical data available, replotting and revisualizing them in a manner that allows unique quantification of changes in waveform morphology and variability. It is hoped that this additional analysis, from blood pressure data that is already available, will give a more detailed picture of the effects of new drug molecules on the state of the heart and peripheral vasculature. We wish our researcher all the very best in their investigations!
Waveform analysis of blood pressure telemetry data
Nandi, M. & Aston, P. J. Extracting new information from old waveforms: Symmetric projection attractor reconstruction: Where maths meets medicine. Exp. Physiol. 105, 1444–1451 (2020).