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Research paper thumbnail of A Triple-Helix model for refining biomedical engineering research into spin-off companies for the health care market

IFMBE Proceedings, 2013

Triple-Helix activities at the centre for biomedical engineering and physics (CMTF) have generate... more 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 wa ...

Research paper thumbnail of Improving the UNC Passive Aerosol Sampler Model Based on Comparison with Commonly Used Aerosol Sampling Methods

Annals of Work Exposures and Health

Objectives: In an occupational environment, passive sampling could be an alternative to active sa... more Objectives: In an occupational environment, passive sampling could be an alternative to active sampling with pumps for sampling of dust. One passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). It is often analysed by microscopic imaging. Promising results have been shown for particles above 2.5 µm, but indicate large underestimations for PM 2.5. The aim of this study was to evaluate, and possibly improve, the UNC sampler for stationary sampling in a working environment. Methods: Sampling was carried out at 8-h intervals during 24 h in four locations in an open pit mine with UNC samplers, respirable cyclones, PM 10 and PM 2.5 impactors, and an aerodynamic particle sizer (APS). The wind was minimal. For quantification, two modifications of the UNC sampler analysis model, UNC sampler with hybrid model and UNC sampler with area factor, were compared with the original one, UNC sampler with mesh factor derived from wind tunnel experiments. The effect of increased resolution for the microscopic imaging was examined. Results: Use of the area factor and a higher resolution eliminated the underestimation for PM 10 and PM 2.5. The model with area factor had the overall lowest deviation versus the impactor and the cyclone. The intraclass correlation (ICC) showed that the UNC sampler had a higher precision and better ability to distinguish between different exposure levels compared to the cyclone (ICC: 0.51 versus 0.24), but lower precision compared to the impactor (PM 10 : 0.79 versus 0.99; PM 2.5 : 0.30 versus 0.45). The particle size distributions as calculated from the different UNC sampler analysis models were visually compared with the distributions determined by APS. The distributions were obviously different when the UNC sampler with mesh factor was used but came to a reasonable agreement when the area factor was used.

Research paper thumbnail of Prostate Cancer Detection with a Tactile Resonance Sensor—Measurement Considerations and Clinical Setup

Sensors

Tumors in the human prostate are usually stiffer compared to surrounding non-malignant glandular ... more 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.

Research paper thumbnail of Resistivity of high-Tc superconductors: Linear in T at constant P, non-linear at constant V

Solid State Communications

Research paper thumbnail of A Pilot Study: The UNC Passive Aerosol Sampler in a Working Environment

Annals of Work Exposures and Health

Objectives Dust is generally sampled on a filter using air pumps, but passive sampling could be a... more Objectives Dust is generally sampled on a filter using air pumps, but passive sampling could be a cost-effective alternative. One promising passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). The aim of this study is to characterize and compare the UNC sampler’s performance with PM10 and PM2.5 impactors in a working environment. Methods Area sampling was carried out at different mining locations using UNC samplers in parallel with PM2.5 and PM10 impactors. Two different collection surfaces, polycarbonate (PC) and carbon tabs (CT), were employed for the UNC sampling. Sampling was carried out for 4–25 hours. Results The UNC samplers underestimated the concentrations compared to PM10 and PM2.5 impactor data. At the location with the highest aerosol concentration, the time-averaged mean of PC showed 24% and CT 35% of the impactor result for PM2.5. For PM10, it was 39% with PC and 58% with CT. Sample blank values differed between PC and CT. For PM2....

Research paper thumbnail of Thermal diffusivity and thermal conductivity of YBa2Cu3O7-d and YBa2Cu4O8 between 20 and 300 K

Research paper thumbnail of The first study on whole human prostate ex vivo using a tactile resonance sensor for cancer detection

Research paper thumbnail of Resonanssensorer för biologiska mätningar : Simulering av resonansspektra från en ansatt FEM-modell och motsvarande mätning av spektra hos piezoelektriska diskar - en jämförelse

Research paper thumbnail of A tripple-helix model for refining biomedical engineering research into innovations and spin-off companies

Research paper thumbnail of Spring-damper model for prostate tissue

Research paper thumbnail of A flexible resonance sensor instrument for measurements of soft tissue : evaluation on silicone models

Research paper thumbnail of CMTF –en 10-årig triple-helix modell för medicinteknisk innovationsutveckling

Research paper thumbnail of Evaluation of applanation resonator sensors for intra-ocular pressure measurement: Results from clinical and in vitro studies

Medical and Biological Engineering and Computing, Mar 1, 2003

Glaucoma is an eye disease that, in its most common form, is characterised by high intra-ocular p... more Glaucoma is an eye disease that, in its most common form, is characterised by high intra-ocular pressure (lOP), 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 lOP. Recently, an applanation resonator sensor (ARS) for measuring lOP 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 IOPARs and the lOP measured with a Goldmann applanation tonometer (r-0.40, p-O.O01, 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% (lmm radius). For normalised data, linear regression between IOPARs and direct lOP measurement in the vitreous chamber showed a correlation of r-0.97 (p< O.O01, n-108) and a standard deviation for the residuals of SD< 2.18mm 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.

Research paper thumbnail of Ansättningsvinkelns betydelse vid mätning med piezoelektriska resonanssensorer på vävnadsmodeller av silikon

Research paper thumbnail of Using Standing Lamb waves and the Finite Element Method to Detect Hard Inclusions in Silicone Rubber Disks

Research paper thumbnail of Thermal conductivity and thermal diffusivity of dense, bulk YBa2Cu4O8

Research paper thumbnail of Svängande sensorer hittar prostatacancer

Research paper thumbnail of A finite element model of soft tissue used in the investigation of the properties of piezoelectric tactile sensors

Research paper thumbnail of Detection of prostate cancer with a resonance sensor

Research paper thumbnail of Resonance sensor for prostate tissue stiffness measurements – detecting prostate cancer

Research paper thumbnail of A Triple-Helix model for refining biomedical engineering research into spin-off companies for the health care market

IFMBE Proceedings, 2013

Triple-Helix activities at the centre for biomedical engineering and physics (CMTF) have generate... more 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 wa ...

Research paper thumbnail of Improving the UNC Passive Aerosol Sampler Model Based on Comparison with Commonly Used Aerosol Sampling Methods

Annals of Work Exposures and Health

Objectives: In an occupational environment, passive sampling could be an alternative to active sa... more Objectives: In an occupational environment, passive sampling could be an alternative to active sampling with pumps for sampling of dust. One passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). It is often analysed by microscopic imaging. Promising results have been shown for particles above 2.5 µm, but indicate large underestimations for PM 2.5. The aim of this study was to evaluate, and possibly improve, the UNC sampler for stationary sampling in a working environment. Methods: Sampling was carried out at 8-h intervals during 24 h in four locations in an open pit mine with UNC samplers, respirable cyclones, PM 10 and PM 2.5 impactors, and an aerodynamic particle sizer (APS). The wind was minimal. For quantification, two modifications of the UNC sampler analysis model, UNC sampler with hybrid model and UNC sampler with area factor, were compared with the original one, UNC sampler with mesh factor derived from wind tunnel experiments. The effect of increased resolution for the microscopic imaging was examined. Results: Use of the area factor and a higher resolution eliminated the underestimation for PM 10 and PM 2.5. The model with area factor had the overall lowest deviation versus the impactor and the cyclone. The intraclass correlation (ICC) showed that the UNC sampler had a higher precision and better ability to distinguish between different exposure levels compared to the cyclone (ICC: 0.51 versus 0.24), but lower precision compared to the impactor (PM 10 : 0.79 versus 0.99; PM 2.5 : 0.30 versus 0.45). The particle size distributions as calculated from the different UNC sampler analysis models were visually compared with the distributions determined by APS. The distributions were obviously different when the UNC sampler with mesh factor was used but came to a reasonable agreement when the area factor was used.

Research paper thumbnail of Prostate Cancer Detection with a Tactile Resonance Sensor—Measurement Considerations and Clinical Setup

Sensors

Tumors in the human prostate are usually stiffer compared to surrounding non-malignant glandular ... more 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.

Research paper thumbnail of Resistivity of high-Tc superconductors: Linear in T at constant P, non-linear at constant V

Solid State Communications

Research paper thumbnail of A Pilot Study: The UNC Passive Aerosol Sampler in a Working Environment

Annals of Work Exposures and Health

Objectives Dust is generally sampled on a filter using air pumps, but passive sampling could be a... more Objectives Dust is generally sampled on a filter using air pumps, but passive sampling could be a cost-effective alternative. One promising passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). The aim of this study is to characterize and compare the UNC sampler’s performance with PM10 and PM2.5 impactors in a working environment. Methods Area sampling was carried out at different mining locations using UNC samplers in parallel with PM2.5 and PM10 impactors. Two different collection surfaces, polycarbonate (PC) and carbon tabs (CT), were employed for the UNC sampling. Sampling was carried out for 4–25 hours. Results The UNC samplers underestimated the concentrations compared to PM10 and PM2.5 impactor data. At the location with the highest aerosol concentration, the time-averaged mean of PC showed 24% and CT 35% of the impactor result for PM2.5. For PM10, it was 39% with PC and 58% with CT. Sample blank values differed between PC and CT. For PM2....

Research paper thumbnail of Thermal diffusivity and thermal conductivity of YBa2Cu3O7-d and YBa2Cu4O8 between 20 and 300 K

Research paper thumbnail of The first study on whole human prostate ex vivo using a tactile resonance sensor for cancer detection

Research paper thumbnail of Resonanssensorer för biologiska mätningar : Simulering av resonansspektra från en ansatt FEM-modell och motsvarande mätning av spektra hos piezoelektriska diskar - en jämförelse

Research paper thumbnail of A tripple-helix model for refining biomedical engineering research into innovations and spin-off companies

Research paper thumbnail of Spring-damper model for prostate tissue

Research paper thumbnail of A flexible resonance sensor instrument for measurements of soft tissue : evaluation on silicone models

Research paper thumbnail of CMTF –en 10-årig triple-helix modell för medicinteknisk innovationsutveckling

Research paper thumbnail of Evaluation of applanation resonator sensors for intra-ocular pressure measurement: Results from clinical and in vitro studies

Medical and Biological Engineering and Computing, Mar 1, 2003

Glaucoma is an eye disease that, in its most common form, is characterised by high intra-ocular p... more Glaucoma is an eye disease that, in its most common form, is characterised by high intra-ocular pressure (lOP), 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 lOP. Recently, an applanation resonator sensor (ARS) for measuring lOP 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 IOPARs and the lOP measured with a Goldmann applanation tonometer (r-0.40, p-O.O01, 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% (lmm radius). For normalised data, linear regression between IOPARs and direct lOP measurement in the vitreous chamber showed a correlation of r-0.97 (p< O.O01, n-108) and a standard deviation for the residuals of SD< 2.18mm 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.

Research paper thumbnail of Ansättningsvinkelns betydelse vid mätning med piezoelektriska resonanssensorer på vävnadsmodeller av silikon

Research paper thumbnail of Using Standing Lamb waves and the Finite Element Method to Detect Hard Inclusions in Silicone Rubber Disks

Research paper thumbnail of Thermal conductivity and thermal diffusivity of dense, bulk YBa2Cu4O8

Research paper thumbnail of Svängande sensorer hittar prostatacancer

Research paper thumbnail of A finite element model of soft tissue used in the investigation of the properties of piezoelectric tactile sensors

Research paper thumbnail of Detection of prostate cancer with a resonance sensor

Research paper thumbnail of Resonance sensor for prostate tissue stiffness measurements – detecting prostate cancer