title: Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method.
abstract: OBJECTIVE
  The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery.
  
  
  METHODS
  Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery.
  
  
  RESULTS
  A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg.
  
  
  CONCLUSIONS
  The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.
authors: Department of Medical Physics, Tarbiat Modares University, Tehran, Iran.
authors: Effat
authors: 0000-0003-3376-7323
authors: E
authors: Soleimani
authors: Department of Medical Physics, Tarbiat Modares University, Tehran, Iran.
authors: Manijhe
authors: 0000-0003-1598-2038
authors: M
authors: Mokhtari-Dizaji
authors: Department of Medical Engineering, Amirkabir University of Technology, Tehran, Iran.
authors: Nasser
authors: N
authors: Fatouraee
authors: Department of Radiology, Imaging Center of Imam Khomaini Hospital, Tehran Medical Sciences University, Tehran, Iran.
authors: Hazhir
authors: H
authors: Saberi
keywords: Arterial pressure; Calibration; Carotid arteries; Computer assisted image processing; Ultrasonography