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  • 1.
    Hagblad, Jimmie
    Mälardalen University, School of Innovation, Design and Engineering.
    Non-invasive techniques for assessment of peripheral blood flow at different vascular depths2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Missing or reduced blood flow can lead to pressure ulcers. Monitoring blood flow in areas prone to pressure ulcer development would be a valuable tool for prevention of pressure ulcers.

    PPG and LDF are both established non invasive optical techniques that can be used to estimate the changes in blood flow in different tissue volumes. The aim of this thesis was to combine the established techniques, LDF and PPG, into one flexible silicon probe intended for evaluation of peripheral blood flow in tissue volumes prone to pressure ulcer development. Further, a temperature sensor was integrated.

    Two probe configurations combining LDF and PPG has been evaluated regarding the ability to separate between shallow, medium and deep blood flow variations, and skin temperature changes. Further, techniques to reduce or totally avoid interference between LDF and PPG have been investigated.

    The probes can be used to discriminate between blood flows at different vascular depths. The vascular depths reached by the different channels correspond to the depths of interest when investigating pressure ulcer aetiology. The probe itself has shown not to affect the skin surface temperature, neither due to the silicon sheet or the light. The skin temperature can be expected to rise and approach the body core temperature by lying in supine position alone, which has to be taken into consideration when designing studies.

    By switching between the different light sources, interference can be totally avoided. When rapid blood flow variations at several vascular depths are of interest to evaluate, a peripheral placement of the LDF-fibre and an increased illumination power of the PPG-LEDs might be used to minimize the interference between LDF and PPG.

    Both probes have shown potential to be used for investigation of the processes in pressure ulcer development.

  • 2.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Goran
    Linkoping Univ.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Technical issues related to the long-term monitoring of blood flow at different depths using LDF and PPG2012In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 33, no 6, p. 985-996Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate an integrated probe using LDF and multiple PPG, for the long-term aspects of skin temperature and blood flow variations at different tissue depths, and especially to investigate whether the presence of the probe affects the temperature. Measurements of temperature and blood flow were performed over 60 min on the lower back of ten subjects, lying on a mattress. The surface temperature of the skin was also measured before and after the 60 min period, and repeated with three probe configurations with the probe switched on, turned off and in the absence of a probe. A general increase in the blood flow was found to occur during the 60 min interval at all depths reached by this probe, but with variations over time. No difference was found in temperatures recorded for the different probe configurations. According to our measurements, the presence of the probe does not affect the skin surface temperature at 60 min. Our investigation shows that skin temperature can be expected to increase and approach the body core temperature by just lying in supine position on the mattress. The increase in temperature and blood flow that is known to occur, possibly attributable to pressure-induced vasodilatation, must be taken into consideration when performing these kinds of measurements.

  • 3.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    A probe combining two optical techniques for monitoring of blood flow in different vascular depths - investigation of interference2010In: pHealth 2010: 7th International Conference on Wearable Micro and Nano Technologies for Personalized Health, Berlin, Germany, 2010Conference paper (Refereed)
  • 4.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Linköpings Universitet, IMT.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Assessment of the optical interference in a PPG-LDF system used for estimation of tissue blood flow2011In: IFMBE PROCEEDINGS: 15th Nordic-Baltic Conference on Biomedical Engineering and Medical Physics, NBC 2011; Aalborg; 14 June 2011 through 17 June 2011 / [ed] Kim Dremstrup, 2011Conference paper (Refereed)
  • 5.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Interference free monitoring of blood flow at multiple depths2010Conference paper (Refereed)
  • 6.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Linköpings Universitet, IMT.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Long-term monitoring of blood flow at different depths using LDF and PPG - issues to considerManuscript (preprint) (Other academic)
  • 7.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Long term monitoring of blood flow at multiple depths – observations of changes2012Conference paper (Refereed)
    Abstract [en]

    Detecting reduced circulation, which is a major factor in the development of pressure ulcers, can be done using optical methods. PPG and LDF can be combined and used to evaluate blood flow at different depths. In this study the use of a probe combining PPG and LDF to monitor multiple tissue depths is evaluated. The effects on blood flow and temperature without additional provocation was examined. Measurements were performed during 60 min and the use of an active probe was compared with the use of a semi-active probe turned off a major part of the time. Changes in temperature and blood flow using these probe configurations (active and semi-active probe) are compared; four different 5 min segments during a 60 min measurement. A general increase in both temperature and blood flow is found but this increase could not be concluded to occur due to the light sources of the probe.

  • 8.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Health, Care and Social Welfare.
    Folke, Mia
    Mälardalen University, School of Health, Care and Social Welfare.
    Lindén, Maria
    Mälardalen University, School of Health, Care and Social Welfare.
    Long term monitoring of blood flow at multiple depths - observations of changes.2012In: Studies in Health Technology and Informatics, ISSN 0926-9630, E-ISSN 1879-8365, Vol. 177, p. 107-112Article in journal (Refereed)
    Abstract [en]

    Detecting reduced circulation, which is a major factor in the development of pressure ulcers, can be done using optical methods. PPG and LDF can be combined and used to evaluate blood flow at different depths. In this study the use of a probe combining PPG and LDF to monitor multiple tissue depths is evaluated. The effects on blood flow and temperature without additional provocation was examined. Measurements were performed during 60 min and the use of an active probe was compared with the use of a semi-active probe turned off a major part of the time. Changes in temperature and blood flow using these probe configurations (active and semi-active probe) are compared; four different 5 min segments during a 60 min measurement. A general increase in both temperature and blood flow is found but this increase could not be concluded to occur due to the light sources of the probe.

  • 9.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Temperatureffekter vid användandet av blodflödesprob med ppg och ldf2012In: Medicinteknikdagarna 2012 Programbok, 2012Conference paper (Refereed)
    Abstract [en]

    För att utvärdera blodflöde kan optiska metoder användas. Denna studie har genomförts för att undersöka eventuella temperatureffekter pga ljuskällorna i en optisk prob som baseras på PPG och LDF. Temperaturförändringar vid två olika mätscenarion jämfördes. Skillnader i temperaturökning kan ses, men resultatet indikerar att påverkan från ljuset endast utgör en liten del av den totala ökningen.

  • 10.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Wireless ECG-monitoring during daily activities2008Conference paper (Refereed)
  • 11.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Mälardalen University, School of Innovation, Design and Engineering.
    Kaisdotter Andersson (Jonsson), Annika
    Mälardalen University, School of Innovation, Design and Engineering.
    Bergstrand, Sara
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindgren, Margareta
    Mälardalen University, School of Innovation, Design and Engineering.
    Ek, Anna-Christina
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    A technique based on laser Doppler flowmetry and photoplethysmography for simultaneously monitoring blood flow at different tissue depths2010In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 48, no 5, p. 415-422Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to validate a non-invasive optical probe for simultaneous blood flow measurement at different vascular depths combining three photoplethysmography (PPG) channels and laser Doppler flowmeter (LDF). Wavelengths of the PPG were near-infrared 810 nm with source-to-detector separation of 10 and 25 mm, and green 560 nm with source-to-detector separation of 4 mm. The probe is intended for clinical studies of pressure ulcer aetiology. The probe was placed over the trapezius muscle, and depths from the skin to the trapezius muscle were measured using ultrasound and varied between 3.8 and 23 mm in the 11 subjects included. A provocation procedure inducing a local enhancement of blood flow in the trapezius muscle was used. Blood flows at rest and post-exercise were compared. It can be concluded that this probe is useful as a tool for discriminating between blood flows at different vascular tissue depths. The vascular depths reached for the different channels in this study were at least 23 mm for the near-infrared PPG channel (source-to-detector separation 25 mm), 10-15 mm for the near-infrared PPG channel (separation 10 mm), and shallower than 4 mm for both the green PPG channel (separation 4 mm) and LDF.

  • 12.
    Hagblad, Jimmie
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindberg, Lars-Göran
    Mälardalen University, School of Innovation, Design and Engineering.
    Kaisdotter Andersson (Jonsson), Annika
    Mälardalen University, School of Innovation, Design and Engineering.
    Bergstrand, Sara
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindgren, Margareta
    Mälardalen University, School of Innovation, Design and Engineering.
    Ek, Anna-Christina
    Mälardalen University, School of Innovation, Design and Engineering.
    Folke, Mia
    Mälardalen University, School of Innovation, Design and Engineering.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Simultan registrering av blodflode pa flera djup2009In: Medicinteknikdagarna, Vasteras, 2009Conference paper (Refereed)
1 - 12 of 12
CiteExportLink to result list
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  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
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  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
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  • Other locale
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Output format
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