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  • 101.
    Lindahl, Olof
    et al.
    Umeå universitet.
    Forchheimer, Robert
    Linköping University, Image Coding Group.
    Li, Haibo
    Umeå University, Digital Media Lab.
    System och förfarande för tolkning av visuell information överför till en person genom taktil inverkan på känselorgan på personens kroppPatent (Other (popular science, discussion, etc.))
  • 102.
    Lindahl, Olof
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Department of Radiation Sciences, Umeå University, Centrum för medicinsk teknik och fysik (CMTF).
    Nyberg, Morgan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå University. Department of Applied Physics and Electronics, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Centrum för medicinsk teknik och fysik (CMTF).
    Erratum: Prostate cancer detection using a combination of Raman spectroscopy and stiffness sensing2014In: 1st Global Conference on Biomedical Engineering & 9th Asian-Pacific Conference on Medical and Biological Engineering: October 9-12, 2014, Tainan, Taiwan / [ed] Fong-Chin Su; Shyh-Hau Wang; Ming-Long Yeh, New York: Encyclopedia of Global Archaeology/Springer Verlag, 2014, p. e1-Conference paper (Refereed)
    Abstract [en]

    IFMBE Proceedings Vol. 47: ”1st Global Conference on Biomedical Engineering & 9th Asian-Pacific Conference on Medical and Biological Engineering” missed the contribution ”Prostate cancer detection using a combination of Raman spectroscopy and stiffness sensing” written by Olof Lindahl for technical reasons. The editors apologize for the mistake.

  • 103.
    Lindahl, Olof
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Department of Radiation Sciences, Umeå University, Centrum för medicinsk teknik och fysik (CMTF).
    Nyberg, Morgan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå University. Department of Applied Physics and Electronics, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Centrum för medicinsk teknik och fysik (CMTF).
    Prostate cancer detection using a combination of Raman spectroscopy and stiffness sensing2014In: 1st Global Conference on Biomedical Engineering & 9th Asian-Pacific Conference on Medical and Biological Engineering: October 9-12, 2014, Tainan, Taiwan / [ed] Fong-Chin Su; Shyh-Hau Wang; Ming-Long Yeh, New York: Encyclopedia of Global Archaeology/Springer Verlag, 2014, p. 267-270Conference paper (Refereed)
    Abstract [en]

    Prostate cancer (PCa) is the most common cancer form for men in Europe. A sensor system combining Raman spectroscopy and stiffness sensing with a resonance sensor has recently been developed by us for prostate cancer detection. In this study the sensor system has been used for measurements on two slices of fresh human prostate tissue. The stiffness sensor could detect locations slices with significantly different stiffness contrasts (p < 0.05). Raman spectroscopic measurements could be performed with the dual-modality probe for tissue classification. The findings are important for the continued development of a combination probe for prostate cancer detection

  • 104. Lindahl, Olof
    et al.
    Nyström, Åke
    Umeå University Hospital, Department of Hand Surgery.
    Bjerle, Per
    Umeå University, Department of Clinical Physiology.
    Boström, A.
    Grip strength of the human hand: measurements on normal subjects with a new hand strength analysis system (Hastras)1994In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 18, no 3, p. 101-103Article in journal (Refereed)
    Abstract [en]

    This study describes a method of acquiring data from healthy and non-injured men that can be used as reference data when measuring the grip strength of the human hand using newly developed, PC-based hand strength analysis equipment--'Hastras'. Hastras can be used for continuous measurement and recording of force when the subject grips a sensor with maximum power. Computerized analysis of the force signal gives information about maximum force, fatigue, area and rise (force/s). The statistical analysis of the measurements on 81 subjects are consistent with earlier published data from other hand strength equipment. It is concluded that Hastras gives easy processing and storage of data, and also a detailed analysis of grip function.

  • 105. Lindahl, Olof
    et al.
    Omata, Sadao
    Nihon University.
    Combination of the impression technique and a tactile sensor helps the classification of oedema1994In: Special issue on bioengineering in Latin America: published on the occasion of the World Congress on Medical Physics and Biomedical Engineering, Rio de Janeiro, Brazil, 21-26 August 1994 / [ed] M.E. Valentinuzzi, 1994Conference paper (Other academic)
  • 106. Lindahl, Olof
    et al.
    Omata, Sadao
    Nihon University.
    Impression technique for the assessment of oedema: comparison with a new tactile sensor that measures physical properties of tissue1995In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 33, no 1, p. 27-32Article in journal (Refereed)
    Abstract [en]

    To measure tissue oedema, the impression technique and a new tactile sensor technique are compared and evaluated in a silicone rubber model and in an in vivo rat testis model. The principles of the two techniques differ in that the impression technique evaluates interstitial fluid flow FT and peak force F(O) when tissue is compressed, whereas the tactile sensor evaluates the hardness/softness or change in resonance frequency delta f when a vibrating rod is attached to tissue. Both techniques can detect changes in silicone hardness/softness or in hormone-induced changes of testis interstitial fluid. Although both F(O) and FT are significantly correlated to delta f in the experiments, it is concluded that F(O) is the most promising impression parameter to give valuable information about the hardness of living tissue as compared with delta f. The comparison indicates that the impression technique is the most easy to interpret, non-invasive tool to assess tissue oedema so far developed.

  • 107. Lindahl, Olof
    et al.
    Omata, Sadao
    Nihon University.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    A tactile sensor for detection of physical properties of human skin in vivo1998In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 22, no 4, p. 147-53Article in journal (Refereed)
    Abstract [en]

    A spring loaded tactile sensor with displacement sensing has been evaluated for non-invasive assessment of physical properties, stiffness and elasticity, of human skin in vivo. The tactile sensor consists of a peizoelectric vibrator (61 kHz) with a vibration pickup, electronics and PC with software for measurement of the change in frequency when the sensor is attached to an object. Integrated with the tactile sensor is a displacement sensor that shows the compression of the spring that loads the sensor element against the object during measurement. Under certain conditions (e.g. fixed contact pressure) this change in frequency monitors the acoustic impedance of the object and is related to the stiffness of soft tissue. The experimental results on silicone gum and on healthy Japanese and Swedish women indicated that the instrument was able to detect changes in stiffness and elastic related properties of human skin, related to age, day-to-day variations and application of cosmetics. The instrument was concluded to be easy to handle and suitable for field work

  • 108. Lindahl, Olof
    et al.
    Rudell, Bertil
    Linköping University, Department of Occupational and Environmental Medicine, Centre for Public Health Sciences.
    Bäcklund, Tomas
    Umeå University Hospital, Department of Biomedical Engineering.
    An electromechanical breathing device for minimal particle loss while inhaling aerosols1993In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 17, no 4, p. 138-40Article in journal (Refereed)
    Abstract [en]

    The design of an electromechanical breathing mask that minimizes particle loss during inhalation of aerosols from a provocation box is described. The device measures air flow by means of an anemometer. A provocation example is depicted and the possibility of measuring the provocation dose is discussed. The breathing device here described has been shown to be easy to use and to give reliable results

  • 109. Lindahl, Olof
    et al.
    Tesar, George
    Umeå School of Business and Economics, Umeå University.
    Commercialitation and survival of innovation2003In: Strategic technology management: building bridges between sciences, engineering and business management, London: Imperial College Press, 2003, p. 81-95Chapter in book (Other academic)
  • 110. Lindahl, Olof
    et al.
    Zdolsek, Hans-Joachim
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Sjöberg, Folke
    Linköping University Hospital, Department of Hand and Plastic Surgery.
    Measurement of interstitial fluid changes in dialysis patiens1997In: World Congress on Medical Physics and Biomedical Engineering: Nice, France, 14.-19.09.1997, 1997, p. 634-Conference paper (Other academic)
  • 111. Lindahl, Olof
    et al.
    Zdolsek, Hans-Joachim
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Sjöberg, Folke
    Linköping University Hospital, Department of Hand and Plastic Surgery.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Impression measurement on and analysis of human postburn oedema1993In: Proceedings of the IXth Nordic meeting on medical and biological engineering, International federation for medical and biological engineering , 1993, p. 44-Conference paper (Other academic)
  • 112. Lindahl, Olof
    et al.
    Zdolsek, Joachim
    University Hospital, Linkoping, Department of Plastic Surgery, Hand Surgery, and Burns.
    Sjöberg, Folke
    University Hospital, Linkoping, Department of Plastic Surgery, Hand Surgery, and Burns.
    Ängquist, Karl-Axel
    Umeå University, Department of Physiology.
    Human postburn oedema measured with the impression method1993In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 19, no 6, p. 479-84Article in journal (Refereed)
    Abstract [en]

    The course of tissue swelling in human non-injured skin after burn injury was investigated with a non-invasive impression method that measures force and tissue fluid translocation during mechanical compression of the skin. Time-dependent changes in the fluid translocation and the interstitial-pressure related to impression force were measured on 11 occasions, during 3 weeks, in seven patients postburn. A mathematical model was fitted to the impression force curves and the parameters of the model depicted the time-dependent compartmental fluid shift in the postburn generalized oedema. Tissue fluid translocation increased significantly (P < 0.05) up to a maximum value after 6 days postburn and declined thereafter. This indicated a continuous increase in the generalized postburn oedema for the first 6 days postburn. Impression force at 3 weeks postburn was significantly lower (P < 0.001) as compared with the half-day postburn value, indicating an increased tissue pressure during the first days postburn. Parameter analysis indicated a flux of water-like fluid from the vasculature to the interstitial space during the first 6 days postburn. The spread of the values registered between different measurement sites was, however, large.

  • 113. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Impressionsmedtoden för bedömning av ödem1990In: STU-seminarium i biomedicinsk mätteknik, Uppsala 1990, Styrelsen för teknisk utveckling , 1990Conference paper (Other academic)
  • 114. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Impressionsmetoden för bedömning av ödem1993In: NUTEK-seminarium i biomedicinsk mätteknik, Stockholm 1993, NUTEK , 1993Conference paper (Other academic)
  • 115. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Impressionsmetoden för bedömning av ödem1991In: STU-seminarium i biomedicinsk mätteknik, Huddinge 1991, Styrelsen för teknisk utveckling , 1991Conference paper (Other academic)
  • 116. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University, Department of Physiology.
    The impression technique for assessment of tissue oedema1993In: Biomedical measurements, Stockholm: NUTEK , 1993, p. 113-119Chapter in book (Other academic)
  • 117. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Utvärdering av impressionsmetoden1992In: Program & sammanfattningar. 49: Älvsjö, Stockholm 25-27 november 1992, Stockholm: Svenska läkaresällskapet , 1992, p. 265-Conference paper (Other academic)
  • 118. Lindahl, Olof
    et al.
    Ängquist, Karl-Axel
    Umeå University, Department of Physiology.
    Ödman, Svante
    Linköping University, Department of Biomedical Engineering.
    Impression technique for the assessment of oedema: technical improvement and methodological evaluation of a new technique1991In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 29, no 6, p. 591-7Article in journal (Refereed)
    Abstract [en]

    A new instrument for the assessment of oedema based on the impression method is described. The measurement parameters are defined and the errors corresponding to the electrical and mechanical stability of the instrument are measured. The overall accuracy is calculated theoretically for the translocated volume. The accuracy and reproducibility are evaluated on plastic foam. The clinical procedure to measure oedema with this instrument is described. We show that the accuracy of the translocated volume parameter is very dependent on the overall stability of the instrument and that this instrument has an overall relative error of less than 7.3 per cent for a representative measurement. Experimental measurements on plastic foam show that the measurement parameters could be reproduced with standard deviations of less than 6 per cent and that the standard deviations for translocated volume are within the calculated overall relative error. Measurements on four patients with chronic oedema in an extremity show significantly different results on locations where pitting could be recognised compared to the contralateral nonoedematous extremity.

  • 119.
    Lindberg, Peter
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt
    Umeå University. Department of Applied Physics and Electronics.
    Bergh, Anders
    Department of Medical Biosciences Pathology, Umeå University.
    Ljungberg, Börje
    Department of Surgical and Preoperative Science, Urology and Andrology, Umeå University.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    An image analysis method for prostate tissue classification preliminary validation with resonance sensor data2009In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 33, no 1, p. 18-24Article in journal (Refereed)
    Abstract [en]

    Resonance sensor systems have been shown to be able to distinguish between cancerous and normal prostate tissue, in vitro. The aim of this study was to improve the accuracy of the tissue determination, to simplify the tissue classification process with computerized morphometrical analysis, to decrease the risk of human errors, and to reduce the processing time. In this article we present our newly developed computerized classification method based on image analysis. In relation to earlier resonance sensor studies we increased the number of normal prostate tissue classes into stroma, epithelial tissue, lumen and stones. The linearity between the impression depth and tissue classes was calculated using multiple linear regression (R2 = 0.68, n = 109, p < 0.001) and partial least squares (R2 = 0.55, n = 109, p < 0.001). Thus it can be concluded that there existed a linear relationship between the impression depth and the tissue classes. The new image analysis method was easy to handle and decreased the classification time by 80%.

  • 120.
    Lindberg, Peter
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Bergh, Anders
    Umeå University, Department of Medical Biosciences, Pathology.
    Ljungberg, Börje
    Umeå University, Department of Surgical and Perioperative Science, Urology and Andrology.
    Lindahl, Olof
    Stiffness measurements on prostate with an improved resonance sensor system2006In: World Congress on Medical Physics and Biomedical Engineering: August 2 - September 1, 2006. Seoul, IFMBE , 2006Conference paper (Other academic)
  • 121.
    Lindberg, Peter
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Bergh, Anders
    Umeå University, Department of Medical Biosciences, Pathology.
    Lundberg, Börje
    Umeå University, Department of Surgical and Perioperative Science, Urology and Andrology.
    Lindahl, Olof
    An improved resonance sensor system for detecting cancerous tissue in prostate2005In: Proceedings of the XIIIth Nordic Baltic Conference on Biomedical Engineering and Medical Physics: NBC'05, IFMBE , 2005, p. 132-133Conference paper (Other academic)
  • 122.
    Lindberg, Peter
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Lindahl, Olof
    Utveckling av ny apparatur med taktil sensor för dektering av prostatacancer2004In: Svenska läkaresällskapets riksstämma 24-26 november 2004, Stockholm: Svenska läkaresällskapet , 2004, p. F13-Conference paper (Other academic)
  • 123.
    Liu, LI
    et al.
    Umeå University, Digital Media Lab.
    Lindahl, Olof
    Li, Haibo
    Umeå University, Digital Media Lab.
    Tactile video2002In: Vinnova och SSFs medicintekniska konferens 2002, Vinnova , 2002Conference paper (Other academic)
  • 124.
    Murayama, Yoshinobu
    et al.
    Department of Electrical and Electronics Engineering, College of Engineering , Nihon University .
    Lindahl, Olof
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Sensitivity improvements of a resonance-based tactile sensor2017In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 41, no 2, p. 131-140Article in journal (Refereed)
    Abstract [en]

    Resonance-based contact-impedance measurement refers to the application of resonance sensors based on the measurement of the changes in the resonance curve of an ultrasonic resonator in contact with a surface. The advantage of the resonance sensor is that it is very sensitive to small changes in the contact impedance. A sensitive micro tactile sensor (MTS) was developed, which measured the elasticity of soft living tissues at the single-cell level. In the present paper, we studied the method of improving the touch and stiffness sensitivity of the MTS. First, the dependence of touch sensitivity in relation to the resonator length was studied by calculating the sensitivity coefficient at each length ranging from 9 to 40 mm. The highest touch sensitivity was obtained with a 30-mm-long glass needle driven at a resonance frequency of 100 kHz. Next, the numerical calculation of contact impedance showed that the highest stiffness sensitivity was achieved when the driving frequency was 100 kHz and the contact-tip diameter of the MTS was 10 μm. The theoretical model was then confirmed experimentally using a phase-locked-loop-based digital feedback oscillation circuit. It was found that the developed MTS, whose resonant frequency was 97.030 kHz, performed with the highest sensitivity of 53.2 × 106 Hz/N at the driving frequency of 97.986 kHz, i.e. the highest sensitivity was achieved at 956 Hz above the resonant frequency.

  • 125.
    Norén, Niklas
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Bergh, Anders
    Umeå University Hospital, Department of Biomedical Engineering.
    Ljungberg, Börje
    Umeå University, Department of Surgical and Perioperative Science, Urology and Andrology.
    Lindahl, Olof
    Vidareutvecklad fjäder-dämpar modell för prostatavävnad2004In: Svenska läkaresällskapets riksstämma 24-26 november 2004, Stockholm: Svenska läkaresällskapet , 2004, p. F14-Conference paper (Other academic)
  • 126.
    Norén, Niklas
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Lindahl, Olof
    Fjäder-dämpar modell för prostaavävnad utvärderad på silikon2003In: Program & sammanfattningar: Svenska Läkaresällskapets riksstämma, [60], Stockholmsmässan, Älvsjö, 26-28 november 2003, Stockholm: Svenska läkaresällskapet , 2003, p. 242-Conference paper (Other academic)
  • 127.
    Norén, Niklas
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Lindahl, Olof
    Spring-damper model for prostate tissue evaluated on sillicone2004In: World Congress on Medical Physics and Biomedical Engineering: Sydney24--29 August 2003, 2004Conference paper (Other academic)
  • 128.
    Nyberg, Morgan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Candefjord, Stefan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Jalkanen, Ville
    Umeå University. Department of Applied Physics and Electronics.
    Ramser, Kerstin
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A combined tactile and Raman probe for tissue characterization: design considerations2012In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 23, no 6Article in journal (Refereed)
    Abstract [en]

    Histopathology is the golden standard for cancer diagnosis and involves the characterization of tissue components. It is labour intensive and time consuming. We have earlier proposed a combined fibre-optic near-infrared Raman spectroscopy (NIR-RS) and tactile resonance method (TRM) probe for detecting positive surgical margins as a complement to interoperative histopathology. The aims of this study were to investigate the effects of attaching an RS probe inside a cylindrical TRM sensor and to investigate how laser-induced heating of the fibre-optic NIR-RS affected the temperature of the RS probe tip and an encasing TRM sensor. In addition, the possibility to perform fibre-optic NIR-RS in a well-lit environment was investigated. A small amount of rubber latex was preferable for attaching the thin RS probe inside the TRM sensor. The temperature rise of the TRM sensor due to a fibre-optic NIR-RS at 270 mW during 20 s was less than 2 °C. Fibre-optic NIR-RS was feasible in a dimmed bright environment using a small light shield and automatic subtraction of a pre-recorded contaminant spectrum. The results are promising for a combined probe for tissue characterization.

  • 129. Nyberg, Morgan
    et al.
    Jalkanen, Ville
    Umeå University. Department of Applied Physics and Electronics, Umeå universitet.
    Ramser, Kerstin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Ljungberg, Börje
    Umeå University, Department of Surgical and Perioperative Science, Urology and Andrology.
    Bergh, Anders
    Umeå University, Department of Physiology, Umeå University, Department of Medical Biosciences, Pathology, Umeå University Hospital, Department of Biomedical Engineering.
    Lindahl, Olof
    Dual-modality probe intended for prostate cancer detection combining Raman spectroscopy and tactile resonance technology—discrimination of normal human prostate tissues ex vivo2015In: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 39, no 3, p. 198-207Article in journal (Refereed)
    Abstract [en]

    Prostate cancer is the most common cancer for men in the western world. For the first time, a dual-modality probe, combining Raman spectroscopy and tactile resonance technology, has been used for assessment of fresh human prostate tissue. The study investigates the potential of the dual-modality probe by testing its ability to differentiate prostate tissue types ex vivo. Measurements on four prostates show that the tactile resonance modality was able to discriminate soft epithelial tissue and stiff stroma (p < 0.05). The Raman spectra exhibited a strong fluorescent background at the current experimental settings. However, stroma could be discerned from epithelia by integrating the value of the spectral background. Combining both parameters by a stepwise analysis resulted in 100% sensitivity and 91% specificity. Although no cancer tissue was analysed, the results are promising for further development of the instrument and method for discriminating prostate tissues and cancer

  • 130. Nyberg, Morgan
    et al.
    Ramser, Kerstin
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Cancer detection probe combining Raman and resonance sensor technology: experimental study on temperature dependence and effects of molding2009In: World Congress on Medical Physics and Biomedical Engineering: September 7 - 12, 2009, Munich, Germany / [ed] Olaf Dössel; Wolfgang C. Schlegel, Berlin: Springer Science+Business Media B.V., 2009, Vol. 7, p. 331-334Conference paper (Refereed)
    Abstract [en]

    Prostate cancer is a major health problem among men in Europe and the USA. Tactile resonance technology and Raman spectroscopy have both shown promising results in vitro, detecting and diagnosing cancer tumors respectively. A new approach, combining the strength of resonance technology and Raman spectroscopy is investigated. This study deals with the effects of molding a Raman fiber optic probe into a cylindrical resonance sensor element (RSE) to achieve a combined probe. Heat induced by the Raman spectroscopy laser might affect temperature dependent properties of the RSE. Also, molding a Raman probe into a RSE will affect its properties. The RSE temperature dependency was investigated using the resonance sensor system Venustron®. The Raman fiber optic probe was simulated by a thin steel pipe which was molded into a single cylindrical RSE. The effects on the frequency characteristics when modifying the RSE were investigated with a network analyzer. Although the resonance frequency of a RSE is temperature dependent, the frequency shift, as used for calculating stiffness, is not noticeably affected by moderate temperature variations. The RSE properties change less by using a small amount of filler material and a small diameter of the Raman probe.

  • 131. Nyberg, Morgan
    et al.
    Ramser, Kerstin
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Lindahl, Olof
    Kombinationsinstrument för detektering av prostatacancer: effekter vid ingjutning av Ramanprobe i resonanssensor och temperaturberoende2009Conference paper (Other academic)
    Abstract [sv]

    Kombinationsinstrument för detektering av prostatacancer – effekter vid ingjutning av Ramanprobe i resonanssensor och temperaturberoendeMorgan Nyberg Doktorand Institutionen för systemteknik, Luleå tekniska universitetKerstin Ramser Universitetslektor Institutionen för systemteknik, Luleå tekniska universitetOlof A. Lindahl Professor Institutionen för systemteknik, Luleå tekniska universitetBakgrundProstatacancer är den cancer som orsakar flest dödsfall bland svenska män. Nya metoder för att detektera och lokalisera prostatatumörer behövs eftersom inga pålitliga metoder finns. Vår avsikt var att utveckla ett nytt instrument som kombinerar resonanssensorteknik och Ramanspektroskopi. Det skulle möjliggöra att detektera och diagnostisera tumörer direkt vid patientundersökningar, vilket minskar risken för komplikationer. Båda teknikerna har visat lovande resultat in vitro. Resonanssensorelement (RSE) består av piezoelektriska kristaller. Förändringen i resonansfrekvens (Δf) för RSE när det kommer i kontakt med ett objekt visar objektets styvhet. Avvikande styvhet kan bero på en tumör. Ramanspektroskopi är en optisk metod som ger information om molekylärt innehåll och förändringar, som kan identifiera cancer. Idén är att integrera en endoskopiskt utformad Ramanprobe som innehåller optiska fibrer i ett cylindriskt ihåligt RSE. I denna studie undersöktes hur kombinationsinstrumentet bäst skall utformas för att undvika förlust i känslighet av RSE:t. Resonansfrekvensen för piezoelektriska material är temperaturberoende. Ett kliniskt instrument används i miljöer med varierande temperatur. Här undersöktes hur detta påverkar förmågan att avgöra styvhet.MetodEffekterna på Δf undersöktes då tunna stålrör (Ø 0,8 mm och Ø 1,2 mm) gjöts in i ett rörformat RSE (l = 15 mm, Øy = 5 mm Øi = 2,8 mm) med kautchuk (Wacker Elastosil RT622, Wacker Chemie GmbH, München, Tyskland). Effekten av mängden gjutmassa uppmättes genom att jämföra hel och halv fyllnad. Effekter av temperaturvariation på Δf undersöktes med ett resonanssystem Venustron® (Axiom Co. Ltd., Koriyama Fukushima, Japan). Mätningarna genomfördes på silikonplatta. I ena fallet varierades hela uppställningens temperatur, i det andra varierades silikonplattans temperatur så övrig utrustning hölls rumstempererad.ResultatResonansfrekvensen och signalkvaliteten förändrades minst med tunnaste stålröret samt med minsta mängden gjutmassa. Största skillnaden i Δf uppmättes till 20,7 Hz vid 1,00 mm djup då hela uppställningens temperatur varierades (22,7°C – 28,4°C). Det är i linje med storleken på feluppskattningarna i tidigare undersökningar gjorda med resonanssensorteknik i rumstemperatur.SammanfattningDenna studie visar på att integration av Raman probe i RSE med bibehållen förmåga att avläsa styvhet är möjlig om man väljer en god metod samt att RSE har försumbar temperaturdrift vid måttliga temperaturvariationer.

  • 132.
    Nyberg, Morgan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Ramser, Kerstin
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Optical fibre probe NIR Raman measurements in ambient light and in combination with a tactile resonance sensor for possible cancer detection2013In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, no 14, p. 4029-4034Article in journal (Refereed)
  • 133.
    Ramser, Kerstin
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Alrifaiy, Ahmed
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Ett multifunktionelt mätsystem som kan efterlikna förhållanden under en stroke: hur försvarar sig neuroner mot akut syrebrist?2013Conference paper (Other academic)
    Abstract [sv]

    På senare tid har aktuell forskning gett inblick i hur vår kropp fungerar på den biokemiska nivån. Det har lett till nya terapeutiska strategier för att förhindra eller bota neurologiska sjukdomar såsom hjärncancer, stroke, Alzheimers och Parkinsons. Framstegen beror till stor grad på utvecklandet av mätmetoder som ger kunskap om hur små organismer beter sig på den biomolekylära nivån. Vår tvärvetenskapliga forskning är inriktad på att utveckla metoder för att undersöka hur levande biologiska neuroner eller hjärnvävnad försvarar sig mot syrebrist eller andra stressituationer. Vi har inriktat oss på hemoproteiner då det nyligen har visat sig att de kan förhindra skador som uppstår vid syrebrist. Vi sammankopplar ett flertal mätmetoder och ett mikroflödessystem under ett mikroskop för att undersöka hemoproteiners verkan på enstaka neuroner i nära fysiologiska miljöer, det vill säga så likt det levande som möjligt. Det har visat sig vara viktigt att kunna studera nervcellernas elektriska signaler som är ett mått på stressnivån samtidigt som man mäter hur hemoproteiner samverkar med olika molekyler och proteiner. De elektriska signaleringsegenskaperna hos nervceller eller tunna hjärnsnitt mäts lämpligen genom patch-clamp teknik. Optisk Raman spektroskopi och UV-Vis spektroskopi fungerar väl för att studera haemoproteiner och de första Ramanmätningarna på tunna hjärnskivor visade att det går att skilja åt olika hemoproteiner. För att kunna kontrollera syrehalten krävs det en sluten gastät flödeskammare med möjlighet till patch-clamp där man snabbt kan flöda olika lösningar av varierande syre-, och salthalt. I detta system är patch-clamp pipetten fixerad till en position och cellerna förs till pipetten med hjälp av en optisk pincett som är en beröringsfri optisk manipuleringsmetod där biologiska celler fångas i ett starkt fokuserat laserljus som här förflyttas med hjälp av ett xyz-bord. Vi kommer att presentera de senaste framstegen i utvecklandet av mätsystemet där röda blodceller användes som modell.

  • 134.
    Sjöberg, Folke
    et al.
    Linköping University Hospital, Department of Hand and Plastic Surgery.
    Lindahl, Olof
    Nettelblad, Hans
    Linköping University Hospital, Department of Plastic Surgery, Hand Surgery and Burns.
    Zdolsek, Hans-Joachim
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Is it possible to noninvasievly quantify the generalized burn oedema?1994In: 9th Congress : Abstracts and programme: International Society for Burn Injuries, International Society for Burn Injuries , 1994, p. 256-Conference paper (Other academic)
  • 135. Wiklund, U.
    et al.
    Karlsson, S.
    Lindahl, Olof
    Datorbaserad utrustning för mätning och dokumentation av tryckgivarsystems dynamiska egenskaper1984In: Program & sammanfattningar. 41: Älvsjö Stockholm 28-30 nov 1984, Stockholm: Svenska läkaresällskapet , 1984, p. 207-Conference paper (Other academic)
  • 136.
    Zdolsek, Hans-Joachim
    et al.
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Lindahl, Olof
    Sjöberg, Folke
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Non-invasive assessment of fluid volume status in the interstitium after haemodialysis2000In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 21, no 2, p. 211-20Article in journal (Refereed)
    Abstract [en]

    During dialysis excess fluid is removed from uraemic patients. The excess fluid is mainly located in the skin and subcutaneous tissues. In this study we wished, with two noninvasive techniques, the IM (impression method) and BIA (bioimpedance analysis), to study what mechanical (IM) and electrical cellular membrane (BIA) effects the fluid withdrawal has on these tissues. The IM measures the resistive force of the tissues when mechanically compressed. From the force curve two parameters are calculated, the F(0), indicative of interstitial tissue pressure and the FT corresponding to the translocation of tissue fluid (interstitial movable water). The BIA phase angle shift (phi), i.e. geometrical angular transformation of the ratio between reactance and resistance, which has been associated with cellular membrane function, was used as a measurement of electrical cellular membrane effects. Twenty patients were studied before and after haemodialysis measuring the F(0), FT and phi. Theresults showed that the patients lost a median of 3.7 kg during the haemodialysis. F(0) increased until after dialysis, but did not reach significant values, whereas FT increased significantly after dialysis, p < 0.001, as compared with before. After a peak at one hour postdialysis the FT value returned to predialysis values at four hours after termination of dialysis. Also phi increased from before to after dialysis, p < 0.001, but already after one hour it returned to predialysis values. It is common knowledge that dialysis alters the dynamics of fluid in the interstitium of the skin and subcutis. We conclude that the impression method is sensitive enough to detect and chronicle these changes. Furthermore, with the BIA, (phase angle) signs of changes in the electrical properties of the tissues, possibly reflecting cellular membrane function, could be detected

  • 137.
    Zdolsek, Hans-Joachim
    et al.
    Linköping University Hospital, Department of Anaesthesiology and Intensive Care.
    Lindahl, Olof
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Lennmarken, Claes
    Linköping University Hospital.
    Sjöberg, Folke
    Linköping University Hospital, Department of Hand and Plastic Surgery.
    Non-invasive assessment of compartmental fluid shifts: is it possible1992In: Svensk förening för anestesi och intensivvård: årsmöte Lund 1992, SFAI , 1992Conference paper (Other academic)
  • 138.
    Zdolsek, Hans-Joachim
    et al.
    University Hospital, Linköping, Department of Anaesthesiology and Intensive Care.
    Lindahl, Olof
    Ängquist, Karl-Axel
    Umeå University Hospital, Department of Surgery.
    Sjöberg, Folke
    University Hospital, Linköping, Department of Hand and Plastic Surgery.
    Non-invasive assessment of intercompartmental fluid shifts in burn victims1998In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 24, no 3, p. 233-40Article in journal (Refereed)
    Abstract [en]

    Two non-invasive methods (the bioimpedance technique, BIA, and the impression method, IM) were studied, to find out whether they are sensitive enough to detect and chronicle the development of the oedema and fluid resuscitation effects (Parkland formula) that occur secondary to a major burn. Ten patients with a total burned body surface area (TBSA) of more than 10% were included in this prospective study. Total body water (TBW), as measured by the resistance (BIA) or F(0) variable (IM), reached a maximum on day 2. The tissue fluid translocation (INT) variable (IM) followed a different course, increasing slowly to reach a maximum on day 6, when it was 40% higher than the 12 h value. TBW and the interstitial translocatable fluid were still increased 1 week post-burn. The non-invasive measurements of TBW (resistance by BIA and F(0) by IM) reflected the anticipated changes in TBW. The phase angle (BIA) indicative of cellular membrane effects of burn and sepsis had its lowest values at day 1.5, and stayed significantly low until day 4. Interestingly, the phase angle was lowest in the two cases that died subsequently. The different time course of the INT value (IM), which reflected the translocatable interstitial fluid volume in skin, may be the result of resuscitation fluid remaining in this compartment, due to the excess sodium content together with a possible change in tissue compliance secondary to the early total water peak on day 2

  • 139.
    Åstrand, Anders P.
    et al.
    Umeå university.
    Jalkanen, Ville
    Umeå university.
    Andersson, Britt M.
    Umeå university.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A flexible sensor system using resonance technology for soft tissue stiffness measurements: evaluation on silicone2011In: 15th Nordic Baltic Conference on Biomedical Engineering and Medical Physics: 14 - 17 June 2011, Aalborg, Denmark / NBC 2011 / [ed] Kim Dremstrup, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2011, p. 21-24Conference paper (Refereed)
    Abstract [en]

    One of the most common forms of cancer among men in Europe and the United States is prostate cancer. The cancerous tissue is less soft, and has different biomechanical properties compared to healthy tissue. It has been shown that tactile sensors can be used to distinguish this difference. If a piezoelectric sensor is set to oscillate at its resonance frequency through a feed back circuit, a frequency shift is observed when the sensor comes in contact with a surface. This shift can be correlated to the stiffness of the tissue. A flexible instrument has been developed, with which it is possible to scan both flat and spherical bodies and where the sensor can be tilted to have different contact angles. Measurements performed in this study on flat silicone discs of different stiffness showed a relationship between both the frequency shift and the impression depth for the different silicone discs, when a constant force was applied. The results are promising for future studies on silicone with different geometries and finally on prostate tissue to complete the evaluation.

  • 140.
    Åstrand, Anders P.
    et al.
    Umeå University. Department of Applied Physics and Electronics.
    Jalkanen, Ville
    Umeå University. Department of Applied Physics and Electronics.
    Andersson, Britt M.
    Umeå University. Department of Applied Physics and Electronics.
    Lindahl, Olof
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Detection of stiff nodules embedded in soft tissue phantoms, mimicking cancer tumours, using a tactile resonance sensor2014In: Journal of Biomedical Science and Engineering, ISSN 1937-6871, E-ISSN 1937-688X, Vol. 7, no 4, p. 181-193Article in journal (Refereed)
    Abstract [en]

    Background: Prostate cancer (PCa) is the most common form of cancer among males in Europe and in the USA and the most common curative treatment is removal of the prostate, i.e. prostatectomy. After the removal, the prostate is histopathologically analysed. One area of interest is to examine the perifery of the prostate, as tumours on and near the surface can indicate that the PCa has spread to other parts of the body. There are no current methods to examine the surface of the prostate at the time of surgery. Tactile resonance sensors can be used for detecting areas of different stiffness in soft tissue. Human prostate tissue affected by cancer is usually stiffer than healthy tissue, and for this purpose, a tactile resonance sensor was developed. The aim of this study was to investigate the depth at which embedded stiffer volumes could be detected, using soft tissue phantoms. Methods: With the tactile resonance sensor used in this study, the shift of the resonance frequency and the force at contact with tissue can be measured, and combined into a tissue stiffness parameter. The detection sensitivity of the sensor at impression depths, 0.4 and 0.8 mm, was measured for detection of inserted nodules of stiff silicone in softer silicone and in chicken muscle tissue, mimicking prostate tissue with cancer tumours. Results: Measurements on the silicone samples detected the hidden stiffer object at a depth of 1 - 4 mm with a difference in the stiffness parameter of 80 - 900 mN/kHz (p < 0.028, n = 48). At the depth 5 - 6 mm the difference was smaller but still significant < 30 mN/kHz (p < 0.05, n = 24). For the measurements on chicken muscle, the detectable depth was 4 mm (p < 0.05, n = 24). Conclusion: This model study suggests that, with only a small impression depth of ≤1 mm, the resonance sensor system described here can detect stiffness variations located at least 4 mm in silicone and chicken muscle, mimicking tumours in prostate tissue.

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