Endre søk
Begrens søket
12 1 - 50 of 52
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Alrifaiy, Ahmed
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå University of Technology.
    Bitaraf, Nazanin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå University of Technology.
    Druzin, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Luleå University of Technology.
    Ramser, K
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå University of Technology.
    Hypoxia on a chip: a novel approach for patch-clamp studies in a microfluidic system with full oxygen control2013Inngår i: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2013, s. 313-316Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A new approach to perform patch-clamp experiments on living cells under controlled anoxic and normoxic conditions was developed and tested. To provide an optimal control over the oxygen content and the biochemical environment a patch-clamp recording micropipette was integrated within an oxygen tight poly-methyl methacrylate (PMMA) based microchip. The oxygen content within the microfluidic chamber surrounding patch-clamp micropipette was maintained at 0.5-1.5 % by a continuous flow of artificial extracellular solution purged with nitrogen. The nerve and glial cells acutely obtained from the male rat brain were trapped by the optical tweezers and steered towards the patch-clamp micropipette through the channels of the microchip in order to achieve a close contact between the pipette and the cellular membrane. The patch-clamp recordings revealed that optical tweezers did not affect the electrophysiological properties of the tested cells suggesting that optical trapping is a safe and non-traumatizing method to manipulate living cells in the microfluidic system. Thus, our approach of combining optical tweezers and a gas-tight microfluidic chamber may be applied in various electrophysiological investigations of single cells were optimal control of the experimental conditions and the sample in a closed environment are necessary.

  • 2. Alrifaiy, Ahmed
    et al.
    Borg, Johan
    Lindahl, Olof A.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology; CMTF, Centre for Biomedical Engineering and Physics, Luleå and Umeå, Sweden; Department of Engineering Sciences and Mathematics, Luleå University of Technology.
    Ramser, Kerstin
    A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy-first investigations of single biological cells2015Inngår i: Biomedical engineering online, ISSN 1475-925X, E-ISSN 1475-925X, Vol. 14, artikkel-id 36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O-2 to an anoxic value of 0.0-0.5% O-2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 +/- 1 s and a fully developed deoxygenated spectrum was observed after 298 +/- 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 +/- 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 +/- 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 +/- 0.412 M Omega and 889.7 +/- 1.74 M Omega respectively.

  • 3. Alrifaiy, Ahmed
    et al.
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Ramser, Kerstin
    Polymer-based microfluidic devices for pharmacy, biology and tissue engineering2012Inngår i: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 4, nr 3, s. 1349-1398Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    This paper reviews microfluidic technologies with emphasis on applications in the fields of pharmacy, biology, and tissue engineering. Design and fabrication of microfluidic systems are discussed with respect to specific biological concerns, such as biocompatibility and cell viability. Recent applications and developments on genetic analysis, cell culture, cell manipulation, biosensors, pathogen detection systems, diagnostic devices, high-throughput screening and biomaterial synthesis for tissue engineering are presented. The pros and cons of materials like polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), polycarbonate (PC), cyclic olefin copolymer (COC), glass, and silicon are discussed in terms of biocompatibility and fabrication aspects. Microfluidic devices are widely used in life sciences. Here, commercialization and research trends of microfluidics as new, easy to use, and cost-effective measurement tools at the cell/tissue level are critically reviewed.

  • 4.
    Eklund, Anders
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    An applanation resonator sensor for measuring intraocular pressure using combined continuous force and area measurement2003Inngår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 44, nr 7, s. 3017-3024Artikkel i tidsskrift (Fagfellevurdert)
  • 5.
    Eklund, Anders
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap.
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Andersson, Britt M
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Evaluation of applanation resonator sensors for intra-ocular pressure measurement: results from clinical and in vitro studies.2003Inngår i: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 41, nr 2, s. 190-197Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Glaucoma is an eye disease that, in its most common form, is characterised by high intra-ocular pressure (IOP), reduced visual field and optic nerve damage. For diagnostic purposes and for follow-up after treatment, it is important to have simple and reliable methods for measuring IOP. Recently, an applanation resonator sensor (ARS) for measuring IOP was introduced and evaluated using an in vitro pig-eye model. In the present study, the first clinical evaluation of the same probe has been carried out, with experiments in vivo on human eyes. There was a low but significant correlation between IOP(ARS) and the IOP measured with a Goldmann applanation tonometer (r = 0.40, p = 0.001, n = 72). However, off-centre positioning of the sensor against the cornea caused a non-negligible source of error. The sensor probe was redesigned to have a spherical, instead of flat, contact surface against the eye and was evaluated in the in vitro model. The new probe showed reduced sensitivity to off-centre positioning, with a decrease in relative deviation from 89% to 11% (1 mm radius). For normalised data, linear regression between IOP(ARS) and direct IOP measurement in the vitreous chamber showed a correlation of r = 0.97 (p < 0.001, n = 108) and a standard deviation for the residuals of SD < or = 2.18 mm Hg (n = 108). It was concluded that a spherical contact surface should be preferred and that further development towards a clinical instrument should focus on probe design and signal analysis.

  • 6.
    Fröjse, Rolf
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Arnerlöv, Conny
    Hedberg, Bengt
    Häggström, Mats
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ängquist, Karl-Axel
    A new method for continuous tonometric pCO2 measurement - in vitro studies.1999Inngår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 20, nr 2, s. 129-136Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The available methods for tonometric pCO2 measurement only provide the possibility of performing intermittent registrations. A new method allowing continuous tonometric pCO2 measurement has been developed and tested in an in vitro model. A standard tonometer for intestinal pCO2 measurement was modified to allow continuous perfusion of the balloon with physiological saline solution in a closed system. The pCO2 in the system was determined in a specially constructed measurement chamber with a TCM20 percutaneous pCO2 monitor. In this in vitro model the tonometer balloon was placed in a saline bath with a constant pCO2 concentration and the measurements from the closed circulating system were compared with those obtained from a standard tonometer placed in the same bath. In 8 and 24 h experiments the circulating system measured the pCO2 value as accurately and reliably as traditional tonometry. This study indicates that the new method makes continuous monitoring of pCO2 possible.

  • 7.
    Fröjse, Rolf
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Hedberg, Bengt
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Häggström, Mats
    Ängquist, Karl-Axel
    Arnerlöv, Conny
    Intestinal pHi studied with continuous saline tonometry during ischaemia and reperfusion in the pig.2002Inngår i: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 24, nr 2, s. 150-155Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE: To evaluate continuous saline tonometry for detection of progressive intestinal ischaemia and reperfusion in a porcine model. DESIGN: In eight anaesthetised pigs, small bowel mucosal pCO2 was recorded by means of two identical equipments for continuous saline tonometry and a standard tonometry balloon during ischaemia and reperfusion. RESULTS: Both systems of saline tonometry functioned stably during the four hour protocol ischaemia, although not significant until after 45 min for one of the tonometers. CONCLUSION: The equipment for continuous saline tonometry has a good reactivity, an accuracy comparable with standard tonometry.

  • 8.
    Fröjse, Rolf
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Hedberg, Bengt
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Häggström, Mats
    Ängquist, Karl-Axel
    Arnerlöv, Conny
    Validation of a novel method for continuous saline tonometry in a procine model.2001Inngår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 22, nr 3, s. 453-460Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Only intermittent and semi-continuous tonometric measurement of gastric and intestinal pHi is possible with the equipment available today. Earlier we developed a system for continuous saline tonometry and tested it in vitro. To assess the in vivo reliability of this method for continuous gastrointestinal saline tonometry, a standard tonometer for measurement of intestinal pCO2 and corresponding pHi was modified to allow continuous perfusion of physiological saline in a closed system and tested in a porcine model. In 11 anaesthetized and haemodynamically stable pigs, two continuous tonometry balloons were inserted into the distal small bowel, and a standard tonometry balloon was used as reference. To test long-term function of the continuous tonometers the research protocol lasted for eight hours. The two continuous saline tonometers performed well, and after an equilibration time of three hours the mean pHi values were stable between 7.35 and 7.43 and between 7.32 and 7.39 respectively. The standard tonometer measured stable pHi values. These preliminary studies indicate that continuous saline tonometry performs well over eight hours with a small bias and a good precision.

  • 9.
    Hallberg, Per
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Santala, Kenneth
    Koskela, Timo
    Lindahl, Olof A.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Underestimation of intraocular pressure after photorefractive keratectomy - a biomechanical analysisArtikkel i tidsskrift (Fagfellevurdert)
  • 10.
    Hallberg, Per
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bäcklund, Tomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Eklund, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Applanation resonance tonometry for intraocular pressure in humans2004Inngår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 25, nr 4, s. 1053-1065Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Glaucoma is a group of diseases associated with optic nerve damage and loss of visual field. The aetiology is not completely understood, but one of the major risk factors is elevated intraocular pressure (IOP). Reliable methods for measuring the IOP are therefore important. The aim of the study was to investigate the ability of the applanation resonance tonometry (ART) system, based on continuous force and area recording, to measure IOP in humans. Both the phase of initial indentation (IOPIndentation) and the phase when the sensor was removed (IOPRemoval) from the cornea were analysed. The Goldmann applanation tonometry (GAT) was used as reference method. The study included 24 healthy volunteers with normal IOP and 24 patients with elevated IOP. The correlation and standard deviation (SD) between IOPIndentation and IOPGAT was R = 0.92 (p < 0.001), SD = 3.6 mmHg, n = 104, and between IOPRemoval and IOPGAT R = 0.94 (p < 0.001), SD = 3.1 mmHg, n = 104. In conclusion, resonance sensor technology has made it possible to introduce a new multi-point method for measuring IOP, and the method is relevant for measuring IOP in humans. The study indicates that with further development towards elimination of position dependence, the ART has the potential to become a useful clinical instrument for IOP measurement.

  • 11.
    Hallberg, Per
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Santala, Kenneth
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindahl, Olof A
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Comparison of Goldmann applanation and applanation resonance tonometry in a biomicroscope-based in vitro porcine eye model2006Inngår i: J Med Eng Technol, ISSN 0309-1902, Vol. 30, nr 6, s. 345-352Artikkel i tidsskrift (Fagfellevurdert)
  • 12.
    Hellström, Thomas
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden.
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden.
    Karlsson, Marcus
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden.
    Hohnloser, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden.
    Bråndal, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin. University Hospital of Northern Sweden, Umeå, Sweden.
    Hu, Xiaolei
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. University Hospital of Northern Sweden, Umeå, Sweden; Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Sweden.
    Wester, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin. University Hospital of Northern Sweden, Umeå, Sweden.
    An intelligent rollator for mobility impaired persons, especially stroke patients2016Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 40, nr 5, s. 270-279Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An intelligent rollator (IRO) was developed that aims at obstacle detection and guidance to avoid collisions and accidental falls. The IRO is a retrofit four-wheeled rollator with an embedded computer, two solenoid brakes, rotation sensors on the wheels and IR-distance sensors. The value reported by each distance sensor was compared in the computer to a nominal distance. Deviations indicated a present obstacle and caused activation of one of the brakes in order to influence the direction of motion to avoid the obstacle. The IRO was tested by seven healthy subjects with simulated restricted and blurred sight and five stroke subjects on a standardised indoor track with obstacles. All tested subjects walked faster with intelligence deactivated. Three out of five stroke patients experienced more detected obstacles with intelligence activated. This suggests enhanced safety during walking with IRO. Further studies are required to explore the full value of the IRO.

  • 13.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Bergh, Anders
    Umeå universitet, Medicinsk fakultet, Medicinsk biovetenskap. Umeå universitet, Medicinsk fakultet, Medicinsk biovetenskap, Patologi.
    Ljungberg, Börje
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap. Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Detection of prostate cancer with a resonance sensor2005Inngår i: IFMBE Proccedings: NBC'05 Umeå 13th Nordic Baltic Conferenceon Biomedical Engineering and Medical Physics, Umeå, 2005, s. 130-131Konferansepaper (Fagfellevurdert)
  • 14.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Indentation loading response of a resonance sensor: discriminating prostate cancer and normal tissue2013Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 37, nr 7, s. 416-423Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Prostate cancer is the most common type of cancer among men worldwide. Mechanical properties of prostate tissue are promising for distinguishing prostate cancer from healthy prostate tissue. The aim was to investigate the indentation loading response of a resonance sensor for discriminating prostate cancer tissue from normal tissue. Indentation measurements were done on prostate tissue specimens ex vivo from 10 patients from radical prostatectomy. The measurement areas were analysed using standard histological methods. The stiffness parameter was linearly dependent on the loading force (average R2 = 0.90) and an increased loading force caused a greater stiffness contrast of prostate cancer vs normal tissue. The accuracy of the stiffness contrast was assessed by the ROC curve with the area under the curve being 0.941 for a loading force of 12.8 mN. The results are promising for the development of a resonance sensor instrument for detecting prostate cancer.

  • 15.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Eklund, Anders
    Medicinsk teknik och informatik, Biomedical Engineering and Informatics, Umeå University Hospital.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    A resonance sensor technique to detect cancer in prostate - Model experiments in silicone2002Inngår i: IFMBE Proceedings: The 12th Nordic Baltic Conference on Biomedical Engineering and Medical Physics, Reykjavik, 2002, s. 33-34Konferansepaper (Fagfellevurdert)
  • 16.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Andersson, Britt M
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Bergh, Anders
    Umeå universitet, Medicinsk fakultet, Medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Resonance sensor for prostate tissue stiffness measurements – detecting prostate cancer2006Inngår i: World Congress on Biomedical Engineering and Medical Physics, August 27 - September 1, 2006, Seoul, Korea, IFMBE , 2006Konferansepaper (Fagfellevurdert)
  • 17.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Andersson, Britt M
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Bergh, Anders
    Umeå universitet, Medicinsk fakultet, Medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap.
    Lindahl, Olof A
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Prostate tissue stiffness as measured with a resonance sensor system: a study on silicone and human prostate tissue in vitro.2006Inngår i: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 44, nr 7, s. 593-603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Prostate cancer is the most common form of cancer in men in Europe and in the USA. Some prostate tumours are stiffer than the surrounding normal tissue, and it could therefore be of interest to measure prostate tissue stiffness. Resonance sensor technology based on piezoelectric resonance detects variations in tissue stiffness due to a change in the resonance frequency. An impression-controlled resonance sensor system was used to detect stiffness in silicone rubber and in human prostate tissue in vitro using two parameters, both combinations of frequency change and force. Variations in silicone rubber stiffness due to the mixing ratio of the two components could be detected (p<0.05) using both parameters. Measurements on prostate tissue showed that there existed a statistically significant (MANOVA test, p<0.001) reproducible difference between tumour tissue (n=13) and normal healthy tissue (n=98) when studying a multivariate parameter set. Both the tumour tissue and normal tissue groups had variations within them, which were assumed to be related to differences in tissue composition. Other sources of error could be uneven surfaces and different levels of dehydration for the prostates. Our results indicated that the resonance sensor could be used to detect stiffness variations in silicone and in human prostate tissue in vitro. This is promising for the development of a future diagnostic tool for prostate cancer.

  • 18.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Andersson, Britt M
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Bergh, Anders
    Umeå universitet, Medicinsk fakultet, Medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap.
    Lindahl, Olof A
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Resonance sensor measurements of stiffness variations in prostate tissue in vitro: a weighted tissue proportion model2006Inngår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 27, nr 12, s. 1373-86Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Prostate cancer is the most common type of cancer in men in Europe and the US. The methods to detect prostate cancer are still precarious and new techniques are needed. A piezoelectric transducer element in a feedback system is set to vibrate with its resonance frequency. When the sensor element contacts an object a change in the resonance frequency is observed, and this feature has been utilized in sensor systems to describe physical properties of different objects. For medical applications it has been used to measure stiffness variations due to various patho-physiological conditions. In this study the sensor's ability to measure the stiffness of prostate tissue, from two excised prostatectomy specimens in vitro, was analysed. The specimens were also subjected to morphometric measurements, and the sensor parameter was compared with the morphology of the tissue with linear regression. In the probe impression interval 0.5-1.7 mm, the maximum R(2) > or = 0.60 (p < 0.05, n = 75). An increase in the proportion of prostate stones (corpora amylacea), stroma, or cancer in relation to healthy glandular tissue increased the measured stiffness. Cancer and stroma had the greatest effect on the measured stiffness. The deeper the sensor was pressed, the greater, i.e., deeper, volume it sensed. Tissue sections deeper in the tissue were assigned a lower mathematical weighting than sections closer to the sensor probe. It is concluded that cancer increases the measured stiffness as compared with healthy glandular tissue, but areas with predominantly stroma or many stones could be more difficult to differ from cancer.

  • 19.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Resonanssensorteknik för detektering av prostatacancer2010Inngår i: Medicinteknikdagarna 2010 / [ed] Ronnie Lundström, Umeå: Svensk förening för medicinsk teknik och fysik , 2010, s. 193-193Konferansepaper (Fagfellevurdert)
  • 20.
    Jalkanen, Ville
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Eklund, Anders
    Medicinsk teknik och informatik, Biomedical Engineering and Informatics, Umeå University Hospital.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskaplig fakultet, Centrum för medicinsk teknik och fysik.
    Force and frequency shift from a resonance sensor for detection of prostate cancer2003Inngår i: IFMBE Proceedings: World Congress on Medical Physics and Biomedical Engineering, Sydney, 2003Konferansepaper (Fagfellevurdert)
  • 21.
    Jonsson, Ulf G.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    A FEM-Based Method Using Harmonic Overtones to Determine the Effective Elastic, Dielectric, and Piezoelectric Parameters of Freely Vibrating Thick Piezoelectric Disks2013Inngår i: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, Vol. 60, nr 1, s. 243-255Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To gain an understanding of the electroelasticproperties of tactile piezoelectric sensors used in the characterizationof soft tissue, the frequency-dependent electric impedanceresponse of thick piezoelectric disks has been calculatedusing finite element modeling. To fit the calculated to the measuredresponse, a new method was developed using harmonicovertones for tuning of the calculated effective elastic, piezoelectric,and dielectric parameters. To validate the results, theimpedance responses of 10 piezoelectric disks with diameterto-thickness ratios of 20, 6, and 2 have been measured from10 kHz to 5 MHz. A two-dimensional, general purpose finiteelement partial differential equation solver with adaptive meshingcapability run in the frequency-stepped mode, was used.The equations and boundary conditions used by the solver arepresented. Calculated and measured impedance responses arepresented, and resonance frequencies have been compared indetail. The comparison shows excellent agreement, with averagerelative differences in frequency of 0.27%, 0.19%, and0.54% for the samples with diameter-to-thickness ratios of 20,6, and 2, respectively. The method of tuning the effective elastic,piezoelectric, and dielectric parameters is an importantstep toward a finite element model that describes the propertiesof tactile sensors in detail.

  • 22.
    Jonsson, Ulf
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Resonanssensorer för biologiska mätningar: Simulering av resonansspektra från en ansatt FEM-modell och motsvarande mätning av spektra hos piezoelektriska diskar - en jämförelse2010Konferansepaper (Fagfellevurdert)
  • 23.
    Jonsson, Ulf G
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    A finite element model of soft tissue used in the investigation of the properties of piezoelectric tactile sensors2012Inngår i: Medicinteknikdagarna 2012, 2012Konferansepaper (Fagfellevurdert)
  • 24.
    Jonsson, Ulf G
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Dept. of Engineering Sciences and Mathematics, Luleå University of Technology, Sweden.
    Andersson, Britt M
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Modeling the high-frequency complex modulus of a silicone rubber using standing lamb waves and an inverse finite element method2014Inngår i: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, Vol. 61, nr 12, s. 2106-2120Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To gain an understanding of the high-frequency elastic properties of silicone rubber, a finite element model of a cylindrical piezoelectric element, in contact with a silicone rubber disk, was constructed. The frequency dependent elastic modulus of the silicone rubber was modeled by a four parameter fractional derivative viscoelastic model in the 100 kHz to 250 kHz frequency range. The calculations were carried out in the range of the first radial resonance frequency of the sensor. At the resonance, the hyperelastic effect of the silicone rubber was modeled by a hyperelastic compensating function. The calculated response was matched to the measured response by using the transitional peaks in the impedance spectrum that originates from the switching of standing Lamb wave modes in the silicone rubber. To validate the results, the impedance responses of three 5 mm thick silicone rubber disks, with different radial lengths, were measured. The calculated and measured transitional frequencies have been compared in detail. The comparison showed very good agreement, with average relative differences of 0.7 %, 0.6 %, and 0.7 % for the silicone rubber samples with radial lengths of 38.0 mm, 21.4 mm, and 11.0 mm, respectively. The average, complex, elastic modulus of the samples were: (0.97 + 0.009i) GPa at 100 kHz and (0.97 + 0.005i) GPa at 250 kHz.

  • 25.
    Li, Liu
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    ur Réhman, Shafiq
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Li, Haibo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Vibrotactile chair: A social interface for blind2006Inngår i: Proceedings SSBA 2006: Symposium on image analysis, Umeå, March 16-17, 2006 / [ed] Fredrik Georgsson, 1971-, Niclas Börlin, 1968-, Umeå: Umeå universitet. Institutionen för datavetenskap , 2006, s. 117-120Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In this paper we present our vibrotactile chair, a social interface for the blind. With this chair the blind can get on-line emotion information from the person he / she is heading to. This greatly enhances communication ability and improve the quality of social life of the blind. In the paper we are discussing technical challenges and design principles behind the chair, and introduce the experimental platform: tactile facial expression appearance recognition system (TEARS)TM".

  • 26.
    Lindahl, O A
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Constantinou, C E
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Murayama, Y
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Omata, S
    Tactile resonance sensors in medicine.2009Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 33, nr 4, s. 263-273Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tactile sensors in general are used for measuring the physical parameters associated with contact between sensor and object. Tactile resonance sensors in particular are based on the principle of measuring the frequency shift, Deltaf, defined as the difference between a freely vibrating sensor resonance frequency and the resonance frequency measured when the sensor makes contact to an object. Deltaf is therefore related to the acoustic impedance of the object and can be used to characterize its material properties. In medicine, tactile resonance sensor systems have been developed for the detection of cancer, human ovum fertility, eye pressure and oedema. In 1992 a Japanese research group published a paper presenting a unique phase shift circuit to facilitate resonance measurements. In this review we summarize the current state-of-the-art of tactile resonance sensors in medicine based on the phase shift circuit and discuss the relevance of the measured parameters for clinical diagnosis. Future trends and applications enabled by this technology are also predicted.

  • 27.
    Lindahl, Olof A
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå University of Technology,.
    From biomedical research to viable products on the health care market: a North Sweden model called CMTF2009Inngår i: IFMBE Proceedings / [ed] Olaf Dössel & Wolfgang C. Schlegel, Springer, 2009, Vol. 25/12, nr 12, s. 127-130Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A centre for research in Biomedical engineering and physics (CMTF) has been built up in Northern Sweden. The CMTF has resulted in increased growth of the biomedical engineering activities both in academia and in the industry in Northern Sweden. Fore example six new companies have resulted from the research. Cooperation was built up between the CMTF and 15 established companies. A research company for business development of the research results from the centre has been established and is owned by the project managers in the centre. The company is called CMTF Business Development Co Ltd and it has also increased the interest for business development questions among the scientists in the centre, i.e. encouraged entrepreneurship.

  • 28.
    Lindahl, Olof A.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet.
    Nyberg, Morgan
    Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet.
    Jalkanen, Ville
    Department of engineering sciences and mathematics, Luleå University of Technology, Luleå, Sweden.
    Ramser, Kerstin
    Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet.
    Prostate cancer detection using a combination of Raman spectroscopy and stiffness sensing2015Inngår i: 1st Global Conference on Biomedical Engineering and 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, Springer International Publishing , 2015, s. 267-270Konferansepaper (Fagfellevurdert)
    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.

  • 29.
    Lindahl, Olof A
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Ramser, K.
    Bäcklund, Tomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Prostate cancer detection ex vivo combining Raman spectroscopy and tactile resonance technology2018Inngår i: EMBEC & NBC 2017 / [ed] Eskola, H Vaisanen, O Viik, J Hyttinen, J, SPRINGER-VERLAG SINGAPORE PTE LTD , 2018, s. 193-196Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Prostate cancer is the most common cancer for men in the western world. The most prevalent curative treatment is radical prostatectomy. However, prostate surgery can give unwanted side effects and there is a need for an instrument that can provide decision support to the surgeon during surgery on the presence of cancer cells in the surgical margin. A dual modality probe, combining Raman spectroscopy and tactile resonance technology, has been used for detecting cancer in fresh human prostate tissue. The tactile resonance modality measures the tissue stiffness and Raman spectroscopy depicts the molecular content in tissue, both related to cancer. After ethical approval, the study investigated the potential of the dual-modality probe by testing its ability to differentiate between normal and cancerous prostate tissue ex vivo. It also investigated the minimal amount of measurement points needed to securely detect cancer on the surface of prostate tissue. Measurements on three prostate tissue slices show that the tactile resonance modality measuring stiffness was able to detect differences between normal and cancerous tissue on a significant level of 90%, but the sample size was too low to draw any firm conclusions. It was also suggested from the study results that the high wavenumber region in the Raman spectrum can give valuable information about cancer in prostate tissue. A number of 24 measurement points were enough for detecting cancer in prostate slices in this study. It can be suggested from this study that combining these two sensor modalities is promising for accurate detection of prostate cancer that is needed during prostate surgery, but more measurements including more prostates must be performed before the full value of the study result can be established.

  • 30.
    Lindahl, Olof
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Luleå tekniska universitet.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Hallberg, Josef
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå tekniska universitet.
    A Triple-Helix model for refining biomedical engineering research into spin-off companies for the health care market2013Inngår i: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer, 2013, s. 2088-2090Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Triple-Helix activities at the centre for biomedical engineering and physics (CMTF) have generated growth both in academia at the universities and in the industry in Northern Sweden. Cooperation was built up between the 26 research projects and about 15 established companies in the field of biomedical engineering. The established researcher - owned company for business development of the research results from the CMTF, CMTF Business Development Co Ltd, has so far launched one spin-off company and has 15 new business leads to business develop. The activities have also increased the interest for commercial and entrepreneurship questions among the scientists in the centre. So far a total of seven spin-off companies have resulted from the CMTF-research since the year 2000.

  • 31.
    Lindahl, Olof
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lundström, Ronnie
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Hallberg, Josef
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    A tripple-helix model for refining biomedical engineering research into innovations and spin-off companies2012Inngår i: Medicinteknikdagarna 2012, 2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Triple-Helix activities within the center for biomedical engineering and physics (CMTF) have generated growth in academic research as well as industry in Northern Sweden in the field of biomedical engineering. Currently CMTF holds 26 ongoing research projects involving more than 150 researchers. So far a total of eight spin-off companies have resulted from research in CMTF since the year 2000. A researcher-owned company, CMTF Business Development Co Ltd, has been established for business development of the research results from the CMTF, which so far have launched two spin-off companies and 15 new business leads for business development. The activities have also increased the interest for innovations and entrepreneurship among the scientists in the center.

  • 32.
    Lindahl, Olof
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin.
    Hallberg, Josef
    Luleå tekniska universitet.
    CMTF en forskningsorganisation med slutmålet att förädla resultaten till produkter på hälso- och sjukvårdsmarknaden2011Konferansepaper (Fagfellevurdert)
  • 33.
    Lindahl, Olof
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin.
    Hallberg, Josef
    Luleå tekniska universitet.
    Development of spin-off companies for health care from biomedical research results2011Inngår i: European Conference of the International Federation for Medical and Biological Engineering, 14-18 sept, 2011: vol. 5, Budapest, Ungern, 2011Konferansepaper (Fagfellevurdert)
  • 34.
    Lindahl, Olof
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lundström, Ronnie
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    From biomedical research to spin-off companies for the health care market2010Inngår i: The XII Mediterranean Conference on Medical and Biological Engineering and Computing: vol. 29, part 4, Springer, 2010, s. 624-626Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Through research at the centre for biomedical engineering and physics (CMTF) seven new companies have been established in Northern Sweden. The activities have generated growth both in academia at the universities and in the industry in Northern Sweden. Cooperation was built up between the 23 research projects and more than 20 established companies in the field of biomedical engineering. A researcher-owned company for business development of the research results from the CMTF has been established, CMTF Business Development Co Ltd, and has launched its first spin-off company in the autumn 2009. It has also increased the interest for commercial and entrepreneurship questions among the scientists in the centre. So far seven spin-off companies have resulted from the CMTF-research.

  • 35.
    Lindahl, Olof
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ramser, Kerstin
    Luleå tekniska universitet.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    CMTF: en 10-årig triple-helix modell för medicinteknisk innovationsutveckling2010Konferansepaper (Annet vitenskapelig)
  • 36.
    Lindberg, Peter
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    An improved resonance sensor system for detecting cancerous tissue in the prostate2005Inngår i: Proceedings of 13th Nordic Baltic Conference on Biomedical Engineering and Medical Physics / [ed] Ronnie Lundström, Britt Andersson, Helena Grip, Swedish Society for Medical Engineering and Medical Physics , 2005, s. 132-133Konferansepaper (Fagfellevurdert)
  • 37. Murayama, Yoshinobu
    et al.
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Sensitivity improvements of a resonance-based tactile sensor.2017Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 41, nr 2, s. 131-140Artikkel i tidsskrift (Fagfellevurdert)
    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 × 10(6) Hz/N at the driving frequency of 97.986 kHz, i.e. the highest sensitivity was achieved at 956 Hz above the resonant frequency.

  • 38.
    Norén, Niklas
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Spring-damper model for prostate tissue2005Inngår i: 13th Nordic-Baltic conference on biomedical engineering and medical physics, IFMBE , 2005, s. 281-282Konferansepaper (Fagfellevurdert)
  • 39.
    Nyberg, Morgan
    et al.
    Luleå University of Technology.
    Candefjord, Stefan
    Luleå University of Technology and Chalmers University of Technology.
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Luleå University of Technology.
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    A combined tactile and Raman probe for tissue characterization - design considerations2012Inngår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 23, nr 6, s. 065901-Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 40.
    Nyberg, Morgan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Dept. of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Dept. of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Lindahl, Olof A.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Dept. of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Dual-modality probe intended for prostate cancer detection combining Raman spectroscopy and tactile resonance technology—discrimination of normal human prostate tissues ex vivo2015Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 39, nr 3, s. 198-207Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 41.
    Nyberg, Morgan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Institutionen för teknikvetenskap och matematik, Luleå tekniksa universitet.
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Ramser, Kerstin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet.
    Ljungberg, Börje
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Institutionen för teknikvetenskap och matematik, Luleå tekniksa universitet.
    First study on freshly operated prostate tissue using a combination of Raman spectroscopy and tactile resonance sensor technology2014Inngår i: Medicinteknikdagarna 2014: Göteborg, 14-16 oktober, 2014, 2014, s. 26-26Konferansepaper (Fagfellevurdert)
  • 42.
    Nyberg, Morgan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ramser, Kerstin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Optical fibre probe NIR Raman measurements in ambient light and in combination with a tactile resonance sensor for possible cancer detection2013Inngår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 14, s. 4029-4034Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    First measurements on a combined instrument with a thin fibre optic Raman probe mounted inside a hollow tactile resonance sensor have been performed in ambient light on porcine tissue. The ambient fluorescent light was removed successfully from the spectra. The stiffness and the biomolecular composition of the tissue were analysed.

  • 43.
    Nyberg, Morgan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Computer Science, Electrical and Space Engineering, Luleå University of Technology.
    Ville, Jalkanen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Ramser, Kerstin
    Computer Science, Electrical and Space Engineering, Luleå University of Technology.
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    First clinical study of prostate cancer detection with a dual sensor combining tactile resonance technique with fiber optical Raman spectroscopy2013Inngår i: 9th Workshop on FT-IR Spectroscopy in Microbiological and Medical Diagnostics, 2013Konferansepaper (Fagfellevurdert)
  • 44.
    Åstrand, Anders
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Börje, Ljungberg
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Anders, Bergh
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Lindahl, Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Prostate cancer detection with a tactile resonance sensor: measurement considerations and clinical setup2017Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, nr 11, artikkel-id 2453Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tumors in the human prostate are usually stiffer compared to surrounding non-malignant glandular tissue, and tactile resonance sensors measuring stiffness can be used to detect prostate cancer. To explore this further, we used a tactile resonance sensor system combined with a rotatable sample holder where whole surgically removed prostates could be attached to detect tumors on, and beneath, the surface ex vivo. Model studies on tissue phantoms made of silicone and porcine tissue were performed. Finally, two resected human prostate glands were studied. Embedded stiff silicone inclusions placed 4 mm under the surface could be detected in both the silicone and biological tissue models, with a sensor indentation of 0.6 mm. Areas with different amounts of prostate cancer (PCa) could be distinguished from normal tissue (p < 0.05), when the tumor was located in the anterior part, whereas small tumors located in the dorsal aspect were undetected. The study indicates that PCa may be detected in a whole resected prostate with an uneven surface and through its capsule. This is promising for the development of a clinically useful instrument to detect prostate cancer during surgery.

  • 45.
    Åstrand, Anders
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Lindahl, Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    A flexible resonance sensor instrument for measurements of soft tissue: evaluation on silicone modelsManuskript (preprint) (Annet vitenskapelig)
  • 46.
    Åstrand, Anders
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ansättningsvinkelns betydelse vid mätning med piezoelektriska resonanssensorer på vävnadsmodeller av silikon2011Inngår i: Medicinteknikdagarna 2011, 2011, s. 110-110Konferansepaper (Annet vitenskapelig)
  • 47.
    Åstrand, Anders
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Stiffness measurements on spherical surfaces of prostate models using a resonance sensor2013Inngår i: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2013, s. 1401-1404Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Prostate cancer is one of the most common formsof cancer among men in Europe and the United States.Piezoelectric resonance sensors can be used in medicalresearch for measurements of stiffness of human tissue.Cancer tissue is usually stiffer and has different biomechanicalproperties compared to healthy tissue. The frequency shiftobserved when a piezoelectric resonance sensor comes intocontact with a tissue surface has been suggested to correlatewith the stiffness variations, e.g. due to cancer. An instrumenthas been developed, with which it is possible to scan flat andspherical objects and where the sensor can be tilted fordifferent contact angles. Measurements performed in thisstudy on spherical tissue models made of silicone, showed theimportance of keeping the contact angle perpendicular to thesurface of the sphere. The results are promising for futurestudies on prostate tissue to complete the evaluation of theinstrument.

  • 48.
    Åstrand, Anders
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Contact angle and indentation velocity dependency for a resonance sensor: Evaluation on soft tissue silicone models2013Inngår i: Journal of Medical Engineering & Technology, ISSN 0309-1902, E-ISSN 1464-522X, Vol. 37, nr 3, s. 185-196Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Human tissue stiffness can vary due to different tissue conditions such as cancer tumours. Earlier studies show that stiffness may be detected with a resonance sensor that measures frequency shift and contact force at application. Through the frequency shift and the contact force, a tissue stiffness parameter can be derived. This study evaluated how the probe application angle and indentation velocity affected the results and determined the maximum parameter errors. The evaluation was made on flat silicone discs with specified hardness. The frequency shift, the force and the stiffness parameter all varied with contact angle and indentation velocity. A contact angle of ≤10° was acceptable for reliable measurements. A low indentation velocity was recommended. The maximum errors for the system were <1.1% of the measured values. It was concluded that contact angle and indentation velocity have to be considered in the clinical setting. The angular dependency is especially important in clinical use for studying stiffness of human soft tissue, e.g. in prostate cancer diagnosis.

  • 49.
    Åstrand, Anders P.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet.
    Initial Measurements on Whole Human Prostate ex vivo with a Tactile Resonance Sensor in Order to Detect Prostate Cancer2015Inngår i: 16th Nordic-Baltic Conference on Biomedical Engineering: 16. NBC & 10. MTD 2014 joint conferences. October 14-16, 2014, Gothenburg, Sweden / [ed] Henrik Mindedal, Mikael Persson, Springer International Publishing , 2015, s. 120-123Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Prostate cancer (PCa) is the most common form of cancer among the male population in Europe and the USA. PCa can be suspected by a blood test for a specific prostate antigen, a PSA-test, followed by a digital rectal examination (DRE). The objective with the DRE is to investigate the presence of stiff nodules on the prostate. Stiff nodules can indicate PCa and biopsies are taken from the suspicious parts of the prostate using guidance of a transrectal ultrasound. Microscopic evaluation of the biopsies is used for final diagnosis. Superficial tumor growth on, and beneath the surface of the gland is of special interest as it suggests that the cancer has spread to other parts of the body.

    Tactile resonance sensors can be used to distinguish between areas of different stiffness in soft tissue. The aim was to detect tumors on, and beneath the surface of a whole human prostate ex vivo.

    A tactile resonance sensor system (TRSS) based on a piezoelectric resonance sensor and a force sensor has been used to detect areas with increased stiffness in soft tissue. The TRSS has a rotatable sample holder for measurements on spherical shaped samples. Stiffness measurements were made on samples of porcine muscle tissue with embedded stiff silicone nodules placed under the surface. Further measurements were made on a resected whole human prostate with PCa.

    The results showed that through the measured stiffness parameter, the stiff silicone nodules placed down to 4 mm under the surface could be detected. The measurements on the prostate showed that elevated values of the stiffness parameter correlated (p < 0.05) with areas in the anterior of the prostate where cancer tumors were detected by histopathological evaluation. The tumors were significantly stiffer than the healthy tissue in the dorsal region.

    The results are promising for further development of a clinically useful instrument to detect superficial PCa.

  • 50.
    Åstrand, Anders P.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jalkanen, Ville
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Andersson, Britt M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindahl, Olof A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Luleå Univ Technol, Dept Comp Sci, Elect & Space Engn, Luleå, Sweden.
    A flexible sensor system using resonance technology for soft tissue stiffness measurements: evaluation on silicone2011Inngår i: 15TH NORDIC-BALTIC CONFERENCE ON BIOMEDICAL ENGINEERING AND MEDICAL PHYSICS (NBC 2011) / [ed] K. Dremstrup, S. Rees, M.Ø. Jensen, Aalborg: Springer , 2011, s. 21-24Konferansepaper (Fagfellevurdert)
    Abstract [en]

    One of the most common forms of cancer amongmen in Europe and the United States is prostate cancer. Thecancerous tissue is less soft, and has different biomechanicalproperties compared to healthy tissue. It has been shown thattactile sensors can be used to distinguish this difference. If apiezoelectric sensor is set to oscillate at its resonance frequencythrough a feed back circuit, a frequency shift is observed whenthe sensor comes in contact with a surface. This shift can becorrelated to the stiffness of the tissue. A flexible instrumenthas been developed, with which it is possible to scan both flatand spherical bodies and where the sensor can be tilted to havedifferent contact angles. Measurements performed in thisstudy on flat silicone discs of different stiffness showed arelationship between both the frequency shift and theimpression depth for the different silicone discs, when aconstant force was applied. The results are promising forfuture studies on silicone with different geometries and finallyon prostate tissue to complete the evaluation.

12 1 - 50 of 52
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf