Staff profile

Ashraf W Khir has carried out his PhD work (1996-2000) with Prof Kim H Parker in the Deartment of Bioengineering at Imperial College London and his Thesis dealt with the effect of aortic occlusion on the hemodynamics in the ascending aorta and left ventricular performance. The In Vivo experiments were carried out in the late Prof John V Tyberg's laboratory at Calgary Medical Centre and the human data were collected at the Derek Gibson Echocardiography Department at the Royal Brompton Hospital.

Ashraf then spent 3 years (2000-2003) as a postdoctoral fellow at the National Heart and Lung Institute (NHLI), with Prof John R Pepper, studying the mechanics of the Intra Aortic Balloon Pump (IABP).

Ashraf obtained his first tenure post as a lecturer at Brunel University London in 2003, and remained there for 18 years, during which he was promoted to Chair in Cardiovascular Mechanics in 2016 and was the Biomedical Engineering Theme Leader. In January 2022, Ashraf moved to Durham University as the Bioengineering Node Leader and his research is generally in the area of arterial and cardiac (cardiovascular) mechanics.

• I work broadly in the fields of cardiovascular mechanics, with particular interest in the physiological fluid mechanics and ventricular assist devices (VADs). My academic research is linked to two clinical pathologies: hypertension and heart failure and have special interest in the following topics:
• Arterial wall mechanics
• Wave intensity analysis
• Air flow in lungs
• Noninvasive determination of hemodynamic parameters
• In vitro testing and mock circulatory loops
• Characterisation of wave reflections
• Estimation of arterial wave speed
• Rotary and pulsatile blood pumps
• Intra Aortic balloon pump (IABP)
• Arterial wave propagation

• 2020: Board Membership: Council Member of the Biomedical Engineering Association
• 2019: Associate Editor, Journal of Engineering in Medicine (2019 - to date): Associate Editor, Journal of Engineering in Medicine (2019 - to date)
• 2018: Fellow IMechE: Fellow - The Institution of Mechanical Engineers ( IMechE) 2018 - to date)
• 2016: Fellow IPEM: Fellow - The Institute of Physics and Engineering in Medicine (FIPEM)
• 2015: External Examiner: External Examiner MSc Biomedical Engineering, City University (2015 – 2019)
• 2013: Co-Editor ‘Artificial Organs’ Journal (2013 – to date).: Co-Editor ‘Artificial Organs’ Journal (2013 – to date).
• 2010: Board membership: Governing board member of the European Society for Artificial Organs (ESAO, 2010 – 2016)

Conference Paper

• Loza, M., Khir, A. W., & Sanchez, A. (2019). Measuring Regional Wave Speed using a Low Cost Portable Device.
• Negoita, M., Abdullateef, S., Hughes, A. D., Parker, K. H., & Khir, A. W. (2018). Semi-automatic Vendor-Independent Software for Assessment of Local Arterial Stiffness. . https://doi.org/10.22489/cinc.2018.218
• Giudici, A., Hacham, W., & Khir, A. W. (2018). Theoretical and Experimental Reflection Coefficients in Flexible Tubes as a Function of the Mach Number. . https://doi.org/10.22489/cinc.2018.142
• Abdullateef, S., Mariscal-Harana, J., Alastruey, J., & Khir, A. W. (2018). A Study on the Characteristics Influencing the Pressure at the Root of a Distributed One-Dimensional Model of Arterial Blood Flow. . https://doi.org/10.22489/cinc.2018.223
• Negoita, M., Hughes, A. D., Parker, K. H., & Khir, A. W. (2017). Non-invasive Technique for Determining Local Pulse Wave Velocity in Humans Ascending Aorta. . https://doi.org/10.22489/cinc.2017.218-036
• Pomella, N., Rakobowchuk, M., Kolyva, C., & Khir, A. W. (2016). Changes in Non-Invasive Wave Intensity Parameters with Variations of Savitzky-Golay Filter Settings. In A. Murray (Ed.),

Journal Article

• Koch Esteves, N., Khir, A. W., & González‐Alonso, J. (2023). Lower limb hyperthermia augments functional hyperaemia during small muscle mass exercise similarly in trained elderly and young humans. Experimental Physiology, 108(9), 1154-1171. https://doi.org/10.1113/ep091275
• Alastruey, J., Charlton, P. H., Bikia, V., Paliakaite, B., Hametner, B., Bruno, R. M., …Westerhof, B. E. (2023). Arterial pulse wave modeling and analysis for vascular-age studies: a review from VascAgeNet. American Journal of Physiology - Heart and Circulatory Physiology, 325(1), H1-H29. https://doi.org/10.1152/ajpheart.00705.2022
• Giudici, A., Spronck, B., Wilkinson, I., & Khir, A. (2023). Tri-layered constitutive modelling unveils functional differences between the pig ascending and lower thoracic aorta. Journal of the Mechanical Behavior of Biomedical Materials, 141, https://doi.org/10.1016/j.jmbbm.2023.105752
• Abdullateef, S., & Khir, A. W. (2023). The contribution of upper and lower body arterial vessels to the aortic root reflections: A one-dimensional computational study. Computer Methods and Programs in Biomedicine, 238, https://doi.org/10.1016/j.cmpb.2023.107598
• Giudici, A., Li, Y., Yasmin, Cleary, S., Connolly, K., McEniery, C., …Khir, A. W. (2022). Time-course of the human thoracic aorta ageing process assessed using uniaxial mechanical testing and constitutive modelling. Journal of the Mechanical Behavior of Biomedical Materials, 134, Article 105339. https://doi.org/10.1016/j.jmbbm.2022.105339
• Giudici, A., Palombo, C., Kozakova, M., Morizzo, C., Cruickshank, J. K., & Khir, A. W. (2022). Subject-Specific Pressure Normalization of Local Pulse Wave Velocity: Separating Intrinsic From Acute Load-Dependent Stiffening in Hypertensive Patients. Frontiers in Physiology, 12, Article 783457. https://doi.org/10.3389/fphys.2021.783457
• Abdullateef, S., Mariscal-Harana, J., & Khir, A. W. (2021). Impact of tapering of arterial vessels on blood pressure, pulse wave velocity, and wave intensity analysis using one-dimensional computational model. International Journal for Numerical Methods in Biomedical Engineering, 37(11), Article e3312. https://doi.org/10.1002/cnm.3312
• Giudici, A., Palombo, C., Kozakova, M., Morizzo, C., Penno, G., Jamagidze, G., …Khir, A. W. (2021). Noninvasive carotid pressure-diameter loops to identify viscoelastic properties in ageing, hypertension and type 2 diabetes. https://doi.org/10.1097/hjh.0000000000002918
• Giudici, A., Khir, A. W., Reesink, K. D., Delhaas, T., & Spronck, B. (2021). Five years of cardio-ankle vascular index (CAVI) and CAVI(0): how close are we to a pressure-independent index of arterial stiffness?. https://doi.org/10.1097/hjh.0000000000002928
• Cappon, F., Wu, T., Papaioannou, T., Du, X., Hsu, P., & Khir, A. W. (2021). Mock circulatory loops used for testing cardiac assist devices: A review of computational and experimental models. https://doi.org/10.1177/03913988211045405
• Giudici, A., Palombo, C., Morizzo, C., Kozakova, M., Cruickshank, J. K., Wilkinson, I. B., & Khir, A. W. (2021). Transfer-function-free technique for the noninvasive determination of the human arterial pressure waveform. Physiological Reports, 9(18), Article e15040. https://doi.org/10.14814/phy2.15040
• Khir, A. W., Ladyzynski, P., & Executive Comm, E. (2021). Against all odds. https://doi.org/10.1177/03913988211038229
• Giudici, A., Khir, A. W., Szafron, J. M., & Spronck, B. (2021). From Uniaxial Testing of Isolated Layers to a Tri-Layered Arterial Wall: A Novel Constitutive Modelling Framework. Annals of Biomedical Engineering, 49(9), 2454-2467. https://doi.org/10.1007/s10439-021-02775-2
• Khir, A. W., & Pepper, J. R. (2021). Mechanical support of the heart: Where are we heading?. https://doi.org/10.1177/03913988211038216
• Esteves, N. K., Gibson, O. R., Khir, A. W., & Gonzalez-Alonso, J. (2021). Regional thermal hyperemia in the human leg: Evidence of the importance of thermosensitive mechanisms in the control of the peripheral circulation. Physiological Reports, 9(15), Article e14953. https://doi.org/10.14814/phy2.14953
• Manolesou, D. G., Georgiopoulos, G., Lazaris, A. M., Schizas, D., Stamatelopoulos, K. S., Khir, A. W., …Papaioannou, T. G. (2021). Experimental Devices Versus Hand-Sewn Anastomosis of the Aorta: A Systematic Review and Meta-Analysis. Journal of Surgical Research, 258, 200-212. https://doi.org/10.1016/j.jss.2020.08.060
• Li, Y., Giudici, A., Wilkinson, I. B., & Khir, A. W. (2021). Towards the non-invasive determination of arterial wall distensible properties: New approach using old formulae. Journal of Biomechanics, 115, Article 110102. https://doi.org/10.1016/j.jbiomech.2020.110102
• Giudici, A., Wilkinson, I. B., & Khir, A. W. (2021). Review of the Techniques Used for Investigating the Role Elastin and Collagen Play in Arterial Wall Mechanics. IEEE Reviews in Biomedical Engineering, 14, 256-269. https://doi.org/10.1109/rbme.2020.3005448
• Suri, S., Bulte, D., Chiesa, S. T., Ebmeier, K. P., Jezzard, P., Rieger, S. W., …Mackay, C. E. (2021). Study Protocol: The Heart and Brain Study. Frontiers in Physiology, 12, Article 643725. https://doi.org/10.3389/fphys.2021.643725
• Pomella, N., Rietzschel, E., Segers, P., & Khir, A. W. (2020). Implications of Changing the Asymptotic Diastolic Pressure in the Reservoir-wave Model on Wave Intensity Parameters: A Parametric Study. Artery Research, 26(4), 228-235. https://doi.org/10.2991/artres.k.200603.003
• Khir, A. W., & Segers, P. (2020). Physiological fluid mechanics: A special Issue with a taster of forefront research. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 234(11, SI), 1183-1186. https://doi.org/10.1177/0954411920959955
• Davis, J., Khir, A., Barber, L., Reeves, N., Khan, T., DeLuca, M., & Mohagheghi, A. A. (2020). The mechanisms of adaptation for muscle fascicle length changes with exercise: Implications for spastic muscle. Medical Hypotheses, 144, Article 110199. https://doi.org/10.1016/j.mehy.2020.110199
• Pomella, N., Rietzschel, E. R., Segers, P., & Khir, A. W. (2020). Impact of varying diastolic pressure fitting technique for the reservoir-wave model on wave intensity analysis. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 234(11, SI), 1300-1311. https://doi.org/10.1177/0954411920959957
• Giudici, A., Palombo, C., Kozakova, M., Morizzo, C., Losso, L., Nannipieri, M., …Khir, A. W. (2020). Weight Loss After Bariatric Surgery Significantly Improves Carotid and Cardiac Function in Apparently Healthy People with Morbid Obesity. Obesity Surgery, 30(10), 3776-3783. https://doi.org/10.1007/s11695-020-04686-y
• Wu, T., Khir, A. W., Kuetting, M., Du, X., Lin, H., Zhu, Y., & Hsu, P. (2020). A review of implantable pulsatile blood pumps: Engineering perspectives. https://doi.org/10.1177/0391398820902470
• Khir, A. W., & Ladyzynski, P. (2020). Strange times - difficult decisions - hopeful future. https://doi.org/10.1177/0391398820947660
• Park, C. M., Hughes, A. D., Henein, M. Y., & Khir, A. W. (2020). Mechanisms of Aortic Flow Deceleration and the Effect of Wave Reflection on Left Ventricular Function. Frontiers in Physiology, 11, Article 578701. https://doi.org/10.3389/fphys.2020.578701
• Hacham, W. S., & Khir, A. W. (2019). The speed, reflection and intensity of waves propagating in flexible tubes with aneurysm and stenosis: Experimental investigation. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 233(10), 979-988. https://doi.org/10.1177/0954411919859994
• Giudici, A., Palombo, C., Morizzo, C., Danieli, N., Losso, L., Della Latta, D., …Khir, A. (2019). EVALUATING CAROTID ARTERY DYNAMICS USING PRESSURE/DIAMETER WAVEFORMS TO DETERMINE STIFFNESS AND VISCOELASTIC PROPERTIES. https://doi.org/10.1097/01.hjh.0000570968.76870.f2
• Li, Y., Hickson, S. S., McEniery, C. M., Wilkinson, I. B., & Khir, A. W. (2019). Stiffening and ventricular-arterial interaction in the ascending aorta using MRI: ageing effects in healthy humans. https://doi.org/10.1097/hjh.0000000000001886
• Chiesa, S. T., Masi, S., Shipley, M. J., Ellins, E. A., Fraser, A. G., Hughes, A. D., …Deanfield, J. E. (2019). Carotid artery wave intensity in mid- to late-life predicts cognitive decline: the Whitehall II study. European Heart Journal, 40(28), 2300-2309. https://doi.org/10.1093/eurheartj/ehz189
• Chiesa, S. T., Masi, S., Shipley, M. J., Ellins, E., Halcox, J. P., Fraser, A., …Deanfield, J. E. (2019). Accelerated Aortic Stiffening Relative to Carotid Stiffness is Associated With Cognitive Decline: The Whitehall II Study. Circulation, 140(1),
• Pomella, N., Wilhelm, E., Kolyva, C., Gonzalez-Alonso, J., Rakobowchuk, M., & Khir, A. (2018). Noninvasive assessment of carotid arterial wave speed and distensibility Reply. American Journal of Physiology - Heart and Circulatory Physiology, 315(5), H1496-H1498. https://doi.org/10.1152/ajpheart.00656.2018
• Negoita, M., Hughes, A. D., Parker, K. H., & Khir, A. W. (2018). A method for determining local pulse wave velocity in human ascending aorta from sequential ultrasound measurements of diameter and velocity. Physiological Measurement, 39(11), Article 114009. https://doi.org/10.1088/1361-6579/aae8a0
• Pomella, N., Wilhelm, E., Kolyva, C., Gonzalez-Alonso, J., Rakobowchuk, M., & Khir, A. (2018). Noninvasive assessment of the common carotid artery hemodynamics with increasing exercise work rate using wave intensity analysis. American Journal of Physiology - Heart and Circulatory Physiology, 315(2), H233-H241. https://doi.org/10.1152/ajpheart.00667.2017
• Chiesa, S. T., Masi, S., Shipley, M., Ellins, E. A., Fraser, A. G., Hughes, A. D., …Deanfield, J. E. (2018). Carotid Artery Wave Intensity Measured in Mid- to Late-Life Predicts Future Cognitive Decline: The Whitehall II Study. Circulation, 138(1),
• Yasmin, Al Maskari, R., McEniery, C. M., Cleary, S. E., Li, Y., Siew, K., …O'Shaughnessy, K. M. (2018). The matrix proteins aggrecan and fibulin-1 play a key role in determining aortic stiffness. Scientific Reports, 8, Article 8550. https://doi.org/10.1038/s41598-018-25851-5
• Sazonov, I., Khir, A. W., Hacham, W. S., Boileau, E., Carson, J. M., van Loon, R., …Nithiarasu, P. (2017). A novel method for non-invasively detecting the severity and location of aortic aneurysms. Biomechanics and Modeling in Mechanobiology, 16(4), 1225-1242. https://doi.org/10.1007/s10237-017-0884-8
• Pomella, N., Nestorwilhelm, E., Kolyva, C., Gonzalez-Alonso, J., Rakobowchuk, M., & Khir, A. W. (2017). COMMON CAROTID ARTERY DIAMETER, BLOOD FLOW VELOCITY AND WAVE INTENSITY RESPONSES AT REST AND DURING EXERCISE IN YOUNG HEALTHY HUMANS: A REPRODUCIBILITY STUDY. Ultrasound in Medicine and Biology, 43(5), 943-957. https://doi.org/10.1016/j.ultrasmedbio.2016.12.018
• Papaioannou, T. G., Karageorgopoulou, T. D., Sergentanis, T. N., Protogerou, A. D., Psaltopoulou, T., Sharman, J. E., …Tousoulis, D. (2017). Central aortic pressure calibration: ``a bridge too far''? Reply. https://doi.org/10.1097/hjh.0000000000001247
• Kolyva, C., Pepper, J. R., & Khir, A. W. (2016). Newly Shaped Intra-Aortic Balloons Improve the Performance of Counterpulsation at the Semirecumbent Position: An In Vitro Study. Artificial Organs, 40(8), E146-E157. https://doi.org/10.1111/aor.12791
• Papaioannou, T. G., Karageorgopoulou, T. D., Sergentanis, T. N., Protogerou, A. D., Psaltopoulou, T., Sharman, J. E., …Tousoulis, D. (2016). Accuracy of commercial devices and methods for noninvasive estimation of aortic systolic blood pressure a systematic review and meta-analysis of invasive validation studies. https://doi.org/10.1097/hjh.0000000000000921
• Li, Y., Parker, K. H., & Khir, A. W. (2016). Using wave intensity analysis to determine local reflection coefficient in flexible tubes. Journal of Biomechanics, 49(13), 2709-2717. https://doi.org/10.1016/j.jbiomech.2016.06.004
• Bruti, G., Kolyva, C., Pepper, J. R., & Khir, A. W. (2015). Measurements of Intra-Aortic Balloon Wall Movement During Inflation and Deflation: Effects of Angulation. Artificial Organs, 39(8), E154-E163. https://doi.org/10.1111/aor.12509
• Borlotti, A., Park, C., Parker, K. H., & Khir, A. W. (2015). Reservoir and reservoir-less pressure effects on arterial waves in the canine aorta. https://doi.org/10.1097/hjh.0000000000000425
• Kolyva, C., Pantalos, G. M., Pepper, J. R., & Khir, A. W. (2015). Does conventional intra-aortic balloon pump trigger timing produce optimal hemodynamic effects in vivo?. https://doi.org/10.5301/ijao.5000385
• Clavica, F., Parker, K. H., & Khir, A. W. (2015). Wave intensity analysis in air-filled flexible vessels. Journal of Biomechanics, 48(4), 687-694. https://doi.org/10.1016/j.jbiomech.2014.12.037