Publications for Per Ask
Co-author map based on ISI articles 2007-

Keywords

± velocity valve transit system sounds sound signal pulse patients murmurs model heart health flow electrodes electrode doppler blood aortic

Journal Articles

Arash Gharehbaghi, Thierry Dutoit, Per Ask and Leif Sornmo
  Detection of systolic ejection click using time growing neural network
  Medical Engineering and Physics, 2014, 36(4), 477-483.

Linda Rattfält, Fredrik Bjorefors, David Nilsson, Xin Wang, Petronella Norberg and Per Ask
  Properties of screen printed electrocardiography smartware electrodes investigated in an electro-chemical cell
  Biomedical engineering online, 2013, 12, .
   Fulltext  PDF  

Linda Rattfält, Maria Lindén, Peter Hult, Per Ask and Magnus Borga
  Robust Heart Beat Detector Based on Weighted Correlation and Multichannel Input: Implementation on the ECG recorded with textile electrodes
  International Journal of E-Health and Medical Communications, 2013, 4(1), 61-71.

Per Ask, Kristina Ekstrand, Peter Hult, Maria Lindén and Nils-Erik Pettersson
  NovaMedTech - a regional program for supporting new medical technologies in personalized health care
  Studies in Health Technology and Informatics, 2012, 177, 71-5.

Per Ask, N-E Pettersson and K Andersson
  Certification of Clinical Engineers in Sweden
  WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING, VOL 25, PT 12, 2009, 25(12), 430-431.

Peter Hult, Marcus Oscarsson, Linda Rattfält and Per Ask
  A platform for patient monitoring in home health care including an interpretation tool for heart failure patients
  WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING, VOL 25, PT 5, 2009, 25(5), 157-160.

A. Hurtig-Wennlof, Christer Ahlström, R. Egerlid, M. Resare, Per Ask and P. Rask
  Heart sounds are altered by open cardiac surgery
  Experimental and Clinical Cardiology, 2009, 14(2), 18-20.
 Web of Science® Times Cited: 1

Andrew Walker, Egil Henriksen, Ivar Ringqvist and Per Ask
  A Rotating Cylinder Phantom for Flow and Tissue Color Doppler Testing
  Ultrasound in Medicine and Biology, 2009, 35(11), 1892-1898.

Ingrid Ljungvall, Christer Ahlström, Katja Hoglund, Peter Hult, Clarence Kvart, Michele Borgarelli, Per Ask and Jens Haggstrom
  Use of signal analysis of heart sounds and murmurs to assess severity of mitral valve regurgitation attributable to myxomatous mitral valve disease in dogs
  AMERICAN JOURNAL OF VETERINARY RESEARCH, 2009, 70(5), 604-613.
 Web of Science® Times Cited: 9

Marcus Ressner, Tomas Jansson, Jonny Cedefamn, Per Ask and Birgitta Janerot Sjöberg
  Contrast Biases the Autocorrelation Phase Shift Estimation in Doppler Tissue Imaging
  Ultrasound in Medicine and Biology, 2009, 35(3), 447-457.
 Web of Science® Times Cited: 5

Michelle Chew, Joakim Brandberg, Birgitta Janerot Sjöberg, Erik Sloth, J. Michael Hasenkam and Per Ask
  Colour Doppler flow measurements using surface integration of velocity vectors (SIVV): Effect of colour flow gain, pulse repetition frequency and number of imaging planes
  Open medical imaging journal, 2008, 2, 56-61.

Christer Ahlström, Toste Länne, Per Ask and Anders Johansson
  A method for accurate localization of the first heart sound and possible applications
  Physiological Measurement, 2008, 29(3), 417-428.
   Fulltext  PDF  
 Web of Science® Times Cited: 12

Ingrid Ljungvall, Christer Ahlström, Katja Höglund, Peter Hult, Clarence Kvart, Michele Borgarelli, Per Ask and Jens Häggström
  Assessing mitral regurgitation attributable to myxomatous mitral valve disease in dogs using signal analysis of heart sounds and murmurs
  , 2008, , .

Christer Ahlström, Katja Höglund, Peter Hult, Jens Häggström, Clarence Kvart and Per Ask
  Assessing Aortic Stenosis using Sample Entropy of the Phonocardiographic Signal in Dogs
  IEEE Transactions on Biomedical Engineering, 2008, 55(8), 2107-2109.
 Web of Science® Times Cited: 5

K. Hoglund, Christer Ahlström, J. Haggstrom, Per Ask, Peter Hult and C. Kvart
  Time-frequency and complexity analyses for differentiation of physiologic murmurs from heart murmurs caused by aortic stenosis in boxers
  American Journal of Veterinary Research, 2007, 68(9), 962-969.
 Web of Science® Times Cited: 11

Linda Rattfält, Maria Lindén, Peter Hult, Lena Berglin and Per Ask
  Electrical characteristics of conductive yarns and textile electrodes for medical applications
  Medical and Biological Engineering and Computing, 2007, 45(12), 1251-1257.
 Web of Science® Times Cited: 21

Christer Ahlström, Anders Johansson, Peter Hult and Per Ask
  Chaotic dynamics of respiratory sounds
  Chaos, Solitons & Fractals, 2006, 29(5), 1054-1062.
 Web of Science® Times Cited: 9

Anders Johansson, Christer Ahlström, Toste Länne and Per Ask
  Pulse wave transit time for monitoring respiration rate
  Medical and Biological Engineering and Computing, 2006, 44(6), 471-478.
 Web of Science® Times Cited: 14

Marcus Ressner, Lars-Åke Brodin, Tomas Jansson, Lars Hoff, Per Ask and Birgitta Janerot-Sjöberg
  Effects of ultrasound contrast agents on doppler tissue velocity estimation
  Journal of the American Society of Echocardiography, 2006, 19(2), 154-164.
 Web of Science® Times Cited: 8

Christer Ahlström, Peter Hult, Peter Rask, Jan-Erik Karlsson, Eva Nylander, Ulf Dahlström and Per Ask
  Feature Extraction for Systolic Heart Murmur Classification
  Annals of Biomedical Engineering, 2006, 34(11), 1666-1677.
 Web of Science® Times Cited: 35

Christer Ahlström, Anders Johansson, Fredrik Uhlin, Toste Länne and Per Ask
  Noninvasive investigation of blood pressure changes using the pulse wave transit time: A novel approach in the monitoring of hemodialysis patients
  Journal of Artificial Organs, 2005, 8(3), 192-197.

Peter Hult, Tore Fjällbrant, Karin Hildén, Ulf Dahlström, Bengt Wranne and Per Ask
  Detection of the third heart sound using a tailored wavelet approach: Method verification
  Medical and Biological Engineering and Computing, 2005, 43(2), 212-217.
 Web of Science® Times Cited: 8

Christer Ahlström, Olle Liljefeldt, Peter Hult and Per Ask
  Heart sound cancellation from lung sound recordings using recurrence time statistics and nonlinear prediction
  IEEE Signal Processing Letters, 2005, 12(12), 812-815.
   Fulltext  PDF  
 Web of Science® Times Cited: 12

Adriana Kvikliene, Rytis Jurkonis, Marcus Ressner, Lars Hoff, Tomas Jansson, Birgitta Janerot Sjöberg, Arunas Lukosevicius and Per Ask
  Modelling of nonlinear effects and the response of ultrasound contrast micro bubbles: simulation and experiment
  Ultrasonics, 2004, 42(01-Sep), 301-307.
 Web of Science® Times Cited: 14

Peter Hult, Tore Fjällbrant, Bengt Wranne, O. Engdahl and Per Ask
  An improved bioacoustic method for monitoring of respiration
  Technology and Health Care, 2004, 12(4), 323-332.

Peter Hult, Per Ask, Tore Fjällbrant and Bengt Wranne
  Detection of the third heart sound using a tailored wavelet approach
  Medical and Biological Engineering and Computing, 2004, 42(2), 253-258.
 Web of Science® Times Cited: 10

Andrew Walker, Eva Olsson, Bengt Wranne, Ivar Ringqvist and Per Ask
  Accuracy of spectral Doppler flow and tissue velocity measurements in ultrasound systems
  Ultrasound in Medicine and Biology, 2004, 30(1), 127-132.
 Web of Science® Times Cited: 22

O. Bech-Hanssen, P. Gjertsson, E. Houltz, Bengt Wranne, Per Ask, Dan Loyd and K. Caidahl
  Net Pressure Gradients in Aortic Prosthetic Valves can be Estimated by Doppler
  Journal of the American Society of Echocardiography, 2003, 16(8), 858-866.
 Web of Science® Times Cited: 6

Per Ask, Sture Hägglund, J. Olsson, N-E Pettersson, Bengt Arne Sjöqvist and Hans Åhlfeldt
  3G-satsning och 'pensionärsdatorer' kan lösa hälso- och sjukvårdens problem
  Läkartidningen, 2003, 100, 1257-1258.

Roger Andersson, Dan Loyd and Per Ask
  Cross-sectional changes in an asymmetric tube with bearing on non-invasive pressure measurements
  Technology and Health Care, 2003, 11(1), 11-20.

Andrew Walker, Eva Olsson, Bengt Wranne, Ivar Ringqvist and Per Ask
  Time delays in ultrasound systems can result in fallacious measurements.
  Ultrasound in Medicine and Biology, 2002, 28, 259-263.
 Web of Science® Times Cited: 14

Roger Andersson and Per Ask
  Force to restore the shape of an asymmetric extracorporeal tube as the basis for non-invasive pressure measurements
  International Journal of Artificial Organs, 2002, 25(4), 281-289.

Roger Andersson and Per Ask
  An asymmetric dialysis tube as an integrated part of a pressure-monitoring sensor
  Technology and Health Care, 2001, 9(5), 417-425.

Odd Bech-Hansen, Kenneth Caidahl, Ingemar Wallentin, Per Ask and Bengt Wranne
  Assessment of effective orifice area of prosthetic aortic valves with Doppler echocardiography: An in vivo and in vitro study
  Journal of Thoracic and Cardiovascular Surgery, 2001, 122(2), 287-295.
 Web of Science® Times Cited: 17

Michelle Chew, Joakim Brandberg, Steinar Bjarum, Katrine Baek-Jensen, Erik Sloth, Per Ask, J. Michael Hasenkam and Birgitta Janerot Sjöberg
  Pediatric cardiac output measurement using surface integration of velocity vectors: an in vivo validation study
  Critical Care Medicine, 2000, 28(11), 3664-3671.

O Bech-Hanssen, K Caidahl, I Wallentin, J Brandberg, Bengt Wranne and Per Ask
  Aortic prosthetic valve design and size: Relation to Doppler echocardiographic findings and pressure recovery - An in vitro study
  Journal of the American Society of Echocardiography, 2000, 13(1), 39-50.
 Web of Science® Times Cited: 16

Michelle Chew, Joakim Brandberg, Peter Canard, Erik Sloth, Per Ask and Michael Hasenkam
  Doppler flow measurement using surface integration of velocity vectors (Sivv): in vitro validation
  Ultrasound in Medicine and Biology, 2000, 26(2), 255-262.

M Imura, T Kuroda, O Oshiro, K Chihara, Joakim Brandberg and Per Ask
  3-D flow visualization for construction of the model of the blood flow in the heart
  Japanese Journal of Applied Physics, 2000, 39(5 B), 3246-3251.

Peter Hult, Per Ask and Bengt Wranne
  A bioacoustic method for timing of the different phases of the breathing cycle and monitoring of breathing frequency
  Medical Engineering and Physics, 2000, 22(6), 425-433.
 Web of Science® Times Cited: 22

Joakim Brandberg, Birgitta Janerot Sjöberg and Per Ask
  Increased accuracy of echocardiographic measurement of flow using automated spherical integration of multiple plane velocity vectors
  Ultrasound in Medicine and Biology, 1999, 25(2), 249-257.

Christina Danbolt, Peter Hult, Lita Tibbling Grahn and Per Ask
  Validation and characterization of the computerized laryngeal analyzer (CLA) technique
  Dysphagia (New York. Print), 1999, 14(4), 191-195.

Joakim Brandberg, Michelle Chew, Michael Hasenkam, Per Ask and Birgitta Janerot-Sjöberg
  Cardiac output measurement using ultrasound in a paediatric model: In-vivo validation of the surface integration of velocity vectros (SIVV) technique
  Clinical Physiology, 1999, 19(3), 198-198.

Michelle Chew, Joakim Brandberg, Erik Sloth, Per Ask and Birgitta Janerot-Sjöberg
  Non-invasive cardiac output measurement using colour Doppler ultrasound - the SIVV approach
  Acta Anaesthesiologica Scandinavica, 1999, 114, 91-92.

Bengt Wranne, Per Ask and Bertil Hök
  Inte så lätt att använda stetoskopet på rätt sätt: Askulationens svåra konst bör ha stort utrymme i läkarutbildningen.
  Läkartidningen, 1999, 96, 2981-2984.

Ann Bolger, Lars Eidenvall, Per Ask, Dan Loyd and Bengt Wranne
  Understanding continuous wave Doppler signal intensity as a measure of regurgitant severity
  Journal of the American Society of Echocardiography, 1997, 10, 613-622.

FA Flachskampf, J Köhler, Per Ask, W Lepper, G Haltern and P Hanrath
  Overestimation of flow velocity through leaks in mechanical prosthese and other small orifices
  Echocardiography, 1997, 10, 904-914.

Urban Lönn, J Wulff, K-Y Keck, Bengt Wranne, Per Ask, Bengt Peterzén and Henrik Casimir Ahn
  Flow characteristics of the hemopump: An experimental in Vitro study
  Annals of Thoracic Surgery, 1997, 63(1), 162-166.

Dan Loyd, Matts Karlsson, B-E Erlandsson and Per Ask
  Computer analysis of hyperthermia treatment of the prostate
  Advances in Engineering Software, 1997, 28, 347-351.

Anders Thurin, G Goushegir, Per Ask and O Thulesius
  Venous flow in an in vitro model: effect of extravascular pressure
  Journal of Vascular Investigation, 1997, 3, 130-136.

K Storck, Matts Karlsson, Per Ask and Dan Loyd
  Heat transfer simulation in the evaluation of the nasal thermistor technique
  IEEE Transactions on Biomedical Engineering, 1996, 43, 1187-1191.

Lars Eidenvall, Per Ask, Dan Loyd and Bengt Wranne
  Determination of regurgitant flow and volume by integrating actual proximal velocities over hemispheres (IPROV) in two orthogonal planes
  Journal of the American Society of Echocardiography, 1996, 9(4), 527-538.

Y Sun, Birgitta Janerot-Sjöberg, Per Ask, Dan Loyd and Bengt Wranne
  Mathematical model that characterizes transmitral and pulmonary venous flow velocity patterns
  American journal of physiology, 1995, 268, 476-489.

Y Sun, Per Ask, Birgitta Janerot-Sjöberg, Lars Eidenvall, Dan Loyd and Bengt Wranne
  Estimation of pulsatile flow by surface integration of velocity vectors in Doppler ultrasound images from two arthogonal planes
  Journal of the American Society of Echocardiography, 1995, 8, 904-914.

Lars Eidenvall, S A Barclay, Dan Loyd, Bengt Wranne and Per Ask
  Regurgitant heart valve flow from 3D proximal velocity field - continued search for the ideal method
  Medical & Biological Engineering & Computing, 1995, 33, 131-139.

C Xiong, Bertil Hök, Tomas Strömberg, Dan Loyd, Bengt Wranne and Per Ask
  A bioacoustic method for timing of respiration at cardiac investigations
  Clinical Physiology, 1995, 15, 151-157.

Per Ask, Bertil Hök, Dan Loyd and Heikki Teriö
  Bioacoustic signals from stenotic tube flow
  Medical & Biological Engineering & Computing, 1995, 33, 669-675.

Anders Spångberg, Bengt Folkestad, B Kristjansson and Per Ask
  New method to quantify the urodynamic improvement when treating bladder utlet obstruction - The efficacy of transurethral resectionin benign prostatic hypertrophy
  Neurology, 1995, 14(4), 325-335.

Birgitta Janerot-Sjöberg, Per Ask, Dan Loyd and Bengt Wranne
  Subaortic flow profile in aortic valve disease - a two dimensional color Doppler study
  Journal of the American Society of Echocardiography, 1994, 7, 276-284.

Jan Engvall, Matts Karlsson, Per Ask, Dan Loyd, Eva Nylander and Bengt Wranne
  Importance of collateral vessels in aortic coarctation: Computer simulation at rest and exercise using transmission line elements
  Medical & Biological Engineering & Computing, 1994, 32, 115-122.

Lars Eidenvall, Birgitta Janerot-Sjöberg, Per Ask, Dan Loyd and Bengt Wranne
  2D Doppler Flowvelocity profiles can be time corrected with an external ECG delay device
  Journal of the American Society of Echocardiography, 1992, 5, 405-413.

Per Ask, P.Å. Öberg, S. Ödman, T. Tenland and M. Skogh
  ECG Electrodes: A Study of Electrical and Mechanical Long-term Properties
  Acta Anaesthesiologica Scandinavica, 1979, 23(2), 189-206.

Per Ask and Lita Tibbling
  Clinical evaluation of different fluid-filled systems for oesophageal manometry
  Scandinavian Journal of Gastroenterology, 1979, 14(1), 1-5.

Per Ask, H. Sökjer and Lita Tibbling
  Mechanisms affecting lower oesophageal sphincter opening and oesophageal retention: A combined X-ray and manometry study
  Scandinavian Journal of Gastroenterology, 1978, 13(7), 857-861.

Per Ask and Lita Tibbling
  A simple device measuring differences in level in the oesophagus
  Acta Oto-Laryngologica, 1978, 85(3-4), 296-297.

Per Ask, P. Åke Öberg and Lita Tibbling
  Static and dynamic characteristics of fluid-filled esophageal manometry systems
  American Journal of Physiology, 1977, 233(5), E389-E396.

Lita Tibbling, Per Ask and H. Sökjer
  Oesophagus fysiology mot bakgrund av nya medicintekniska landvinningar
  Svensk Oe NH Tidskrift, 1977, 1(2), 1-1.

Per Ask, Lita Tibbling and Åke Öberg
  Metodutveckling för oesophagus-diagnostik
  Svensk ÖNH-Tidskrift, 1977, 1(1), 1-1.

Per Ask
  EKG-elektroder: en svag länk vid övervakning
  Medicinsk Teknik, 1974, (4), 12-15.

Chapters in Books

Per Ask and Åke Öberg
  Blood flow measurements
  The measurement instrumentation sensors handbook, CRC Press, 1999, .


Matts Karlsson, Jan Engvall, Per Ask, Bengt Wranne and Dan Loyd
  Orifice flow in stenotic and regurgitant valve lesions - Modelling and computer simulations
  Biofluid mechanics, Computational Mechanics Publications, 1994, .


Conference Articles

Linda Rattfält, Michel Chedid and Per Ask
  Tillverkningsmetodens inverkan på elektriska egenskaper hos textila elektroder.
  Posterpresentation på Medecinteknikdagarna, Conventum,2007, 2007.


Christer Ahlström, Anders Johansson, Toste Länne and Per Ask
  Monitorering av andning and blodtrycksförändringar baserat på EKG och hjärtljud
  Medicinteknik dagarna,2007, 2007.


Linda Rattfält, Michel Chedid, Peter Hult, Maria Lindén and Per Ask
  Electrical Properties of Textile Electrodes
  Engineering in Medicine and Biology Society, 2007. EMBS 2007, 2007.


Christer Ahlström, Per Ask, Peter Rask, Jan-Erik Karlsson, Eva Nylander, Ulf Dahlström and Peter Hult
  Assessment of Suspected Aortic Stenosis by Auto Mutual Information Analysis of Murmurs
  Engineering in Medicine and Biology Society, 2007. EMBS 2007, 2007.


 Web of Science® Times Cited: 2

Marcus Ressner, L-Å. Brodin, Tomas Jansson, Per Ask and Birgitta Janerot-Sjöberg
  How Ultrasound Contrast Agents effects Doppler Tissue Velocity Estimation
  World Conference on Medical Physics and Biological Engineering, Seoul, 2006.


Christer Ahlström, Peter Hult, P Rask, J-E Karlsson, Eva Nylander, Ulf Dahlström and Per Ask
  Using the intelligent stethoscope for extraction of features for systolic heart murmur classification
  World Congress on Medical Physics and Biomedical Engineering WC2006,2006, 2006.


Christer Ahlström, Katja Höglund, Peter Hult, Jens Häggström, Clarence Kvart and Per Ask
  Distinguishing Innocent Murmurs from Murmurs caused by Aortic Stenosis by Recurrence Quantification Analysis
  ROCEEDINGS OF WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY, VOL 18, 2006.


 Web of Science® Times Cited: 1

Linda Rattfält, Christer Ahlström, Lena Berglin, Maria Lindén, Peter Hult, Per Ask and Urban Wiklund
  A Canonical correlation approach to heart beat detection in textile ECG measurements
  IET 3rd International Conference On Advances in Medical, Signal and Information Processing, 2006. MEDSIP 2006, 2006.


Christer Ahlström, Peter Hult and Per Ask
  Thresholding distance plots using true recurrence points
  Acoustics, Speech and Signal Processing, 2006. ICASSP 2006, 2006.


Christer Ahlström, Peter Hult and Per Ask
  Detection of the 3rd Heart Sound using Recurrence Time Statistics
  Proc. 31st IEEE Int. Conf. on Acoustics, Speech and Signal Processing, Toulouse, France, 2006, 2006.


Marcus Ressner, Lars-Åke Brodin, Tomas Jansson, Lars Hoff, Per Ask and Birgitta Janerot-Sjöberg
  Effekter av ultraljudskontrast vid hastighetsestimering med vävnadsdoppler
  Svenska Läkaresällskapets Riksstämma 2005,2005, 2005.


Linda Rattfält, Peter Hult, Maria Lindén, Caroline Hagström, Lena Berglin and Per Ask
  Kroppsnära multisensorer och smarta textiplagg för vård och övervakning i hemmet.
  Läkarsällskapets Riksstämma 2005,2005, 2005.


Peter Hult, Christer Ahlström, Linda Rattfält, Cecilia Hagström, Nils-Erik Pettersson and Per Ask
  The intelligent stethoscope
  EMBEC05,2005, 2005.


Marcus Ressner, Adriana Kvikliene, Lars Hoff, Rytis Jurkonis, Tomas Jansson, Birgitta Janerot-Sjöberg, Arunas Lukosevicius and Per Ask
  Ultrasound contrast microbubbles: simulations and in vitro experiments
  EMBEC05,2005, 2005.


Christer Ahlström, Peter Hult and Per Ask
  Wheeze analysis and detection with non-linear phase-space embedding
  Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005, 2005.


Marcus Ressner, Adriana Kvikliene, Lars Hoff, Rytis Jurkonis, Tomas Jansson, Birgitta Janerot-Sjöberg, Arunas Lukosevicius and Per Ask
  Ultrasound contrast for perfusion studies
  Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005, 2005.


Peter Hult, Christer Ahlström, Linda Rattfält, Caroline Hagström, Nils-Erik Pettersson and Per Ask
  The intelligent stethoscope as a tool in modern health care
  Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005, 2005.


Marcus Ressner, Adriana Kvikliene, Lars Hoff, Rytis Jurkonis, Tomas Jansson, Birgitta Janerot-Sjöberg, Arunas Lukosevicius and Per Ask
  Backscattered ultrasound from contrast microbubbles: effects of tissue and bubble interaction
  EMBS,2004, 2004.


Christer Ahlström, Anders Johansson, Toste Länne and Per Ask
  A respiration monitor based on electrocardiographic and photoplethysmographic sensor fusion
  IEEE Engineering in Medical and Biological Society,2004, 2004.


Christer Ahlström, Peter Hult, Birgitta Schmekel and Per Ask
  Automatisk detektering av ronki med icke-linjära metoder
  Svenska Läkaresällskapets riksstämma,2004, 2004.


Christer Ahlström, Peter Hult, Birgitta Schmekel and Per Ask
  Wheeze detection with nonlinear statespace embedding
  International Lung Sound Association,2004, 2004.


Per Ask, Marcus Ressner, Birgitta Janerot-Sjöberg, Tomas Jansson, Rytis Jurkonis, Adriana Kvikliene and Lars Hoff
  Simulation of ultrasound contrast bubble response and the non-linear ultrasound field - combining with in vitro experiments
  New England Doppler Conference,2003, 2003.


Odd Bech Hanssen, Bengt Wranne, Per Ask, Dan Loyd and Kenneth Caidahl
  The net pressure gradients after pressure recovery can be predicted by Doppler in aortic bileaflet prostheses.
  American Society of Echocardiography,2001, 2001.


Roger Andersson, Dan Loyd and Per Ask
  Pressure sensed non-invasively directly on the extra corporeal blood line tubes
  Int Conference of the IEEE Engineering in Medicine and Biology Society,2001, 2001.


Roger Andersson and Per Ask
  Pressure sensed non-invasively directly on the extracorporeal dialysis tube
  ESAO Congress,2001, 2001.


M Imura, T Kuroda, O Oshiro, K Chihara, Joakim Brandberg and Per Ask
  In-vitro blood flow visualization using 3-D reconstructionn of color doppler images
  Image and Graphic Technology toward 21 Century and Beyound,2000, 2000.


Odd Bech Hanssen, Bengt Wranne, Per Ask and Kenneth Caidahl
  Doppler echocardiography ubderestimates prosthetic effective orifice area (EOA)
  Am Society of Echocardiography,2000, 2000.


Peter Hult, Tore Fjällbrant, S Dahle, P Danielsson and Per Ask
  A method for respiration in monitoring by use of a bioacoustic signal
  Medical signal and information processing MEDSIP,2000, 2000.


Ursula Hass, Per Ask and Karin Wårdell
  Competence Centre NIMED and it's graduate education - collaboration between university and industry.
  Ann Int Conf of the IEEE Engineering in Medicine and Biology Society,1999, 1999.


Matts Karlsson, Dan Loyd, Per Ask, K Lindström and Håkan Elmqvist
  CORTECH tutor - a distributed biomedical engineering graduate training initiative
  The 1st Joint Meeting of BMES and EMBS,1999, 1999.


Michelle Chew, Joakim Brandberg, Birgitta Janerot-Sjöberg, Erik Sloth, Per Ask and Michael Hasenkam
  Noninvasive cardiac output measurement using Doppler echocardiography; current status and future perspective using Surface Integration of Velocity Vectors (SIVV)
  Danish Society of Anesthesiologists,1999, 1999.


Joakim Brandberg, Matts Karlsson, Dan Loyd, Bengt Wranne and Per Ask
  Integration of proximal velocities (IPROV) - An improvment of the pisa method for estimation of regurgitant flow.
  European Soc for Noninvasive Cardiovascular Dynamics,1998, 1998.


MS Chew, Joakim Brandberg, p Cannard, E Sloth, JM Hasenkam and Per Ask
  Evaluation of the surface integration of velocity vectors (SIVV) method in tubular flow model
  European Soc for Noninvasive cardiovascular dynamics,1998, 1998.


Per Ask, Joakim Brandberg, Birgitta Janerot-Sjöberg, Matts Karlsson, Dan Loyd and Bengt Wranne
  Assessment of heart valve function with echocardiography
  World Congress on Medical Physics and Biomedical Engineering,1997, 1997.


Per Ask, F Flaschemkampf and M Hasenkam
  Non-invasive approach to hemodynamic assessment of heart valves (INVADYNE)
  World congress on Medical Physics and Biomedical Engineering,1997, 1997.


Per Ask
  How to assess heart valve function with echocardiography
  European Conference on Engineering and Medicine,1997, 1997.


Joakim Brandberg, Birgitta Janerot-Sjöberg, Peter Wodlin, Dan Loyd, Per Ask and Y Sun
  In vivo estimation of cardiovascular flows with surface integration of velocity vectors from color Doppler imaging
  Annual International Conference of the IEEE Engineering in Medicine and Biology Society,1996, 1996.


Joakim Brandberg, Birgitta Janerot-Sjöberg, Peter Wodlin, Per Ask and Y Sun
  The SIVV technique for quantifying cardiovascular flows in vivo
  Congress of the European Society of Cardiology,1996, 1996.


Joakim Brandberg, Matts Karlsson, Lars Eidenvall, Birgitta Janerot-Sjöberg, Dan Loyd, Bengt Wranne and Per Ask
  Automated calculation of regrgitation from proximal 2D Doppler data
  Congress of the European Society of Cardiology,1996, 1996.


Lars Eidenvall, Per Ask, Dan Loyd and Bengt Wranne
  Determination of regurgitant flow in a pulsatile model by integrating velocities from the entire 3D proximal velocity field
  American Heart Association,1993, 1992.


Per Ask, Lita Tibbling and P.Å. Öberg
  Bandbreddskrav hos oesophagusmanometriska system.
  Läkarsällskapets Riksstämma, 1978.


Per Ask, Lita Tibbling and Åke Öberg
  Metodutveckling för oesophagus-diagnostik
  Läkarsällskapets Riksstämma, 1976.


Per Ask, Lita Tibbling and Åke Öberg
  Compliance and bandwidth of oesophagus manometry systems
  11th International Conference on Medical and Biological Engineering, Ottawa, Canada, 1976.


Per Ask, Marcus Skogh and Åke Öberg
  Elektriska och mekaniska egenskaper hos EKG-elektroder
  Läkarsällskapets Riksstämma, 1974.


Ph.D. Theses

Linda Rattfält
  Smartware electrodes for ECG measurements: Design, evaluation and signal processing
  2013.


  Fulltext PDF

Marcus Ressner
  On Nonlinear Acoustics in Contrast Echocardiography
  2010.


Andrew Walker
  Testing of Doppler Ultrasound Systems
  2009.


  Fulltext PDF

Christer Ahlström
  Nonlinear phonocardiographic Signal Processing
  2008.


  Fulltext PDF

Per Ask  Oesophageal manometry: design and evaluation of measurement systems
  1978.


Licentiate Theses

Christer Ahlström
  Processing of the Phonocardiographic Signal: methods for the intelligent stethoscope
  2006.


  Fulltext PDF

Andrew Walker
  Performance testing of ultrasound Doppler equipment
  2003.


  Fulltext PDF

Reports

Per Ask, Marcus Skogh, Åke Öberg and Torsten Tenland
  Undersökning av EKG-elektroders elektriska och mekaniska långtidsegenskaper. Kompletterande studie 1
  Institutionen för medicinsk teknik, Universitetet i Linköping, 0009, 1975.


Per Ask, Marcus Skogh and Åke Öberg
  Undersökning av EKG-elektroners elektriska och mekaniska långtidsegenskaper
  1974.


Per Ask, Marcus Skogh and Åke Öberg
  Undersökning av EKG-elektroders elektriska och mekaniska långtidsegenskaper
  Linköpings högskola, Institutionen för medicinsk teknik, 0005, 1974.