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- Jönsson, Björn, 1951-, et al.
(author)
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Automatic ankle pressure measurements using PPG in ankle-brachial pressure index determination
- 2005
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In: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 30:4, s. 395-401
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Journal article (peer-reviewed)abstract
- ObjectiveTo evaluate a new technique using a photoplethysmographic (PPG) probe for automatic ankle pressure measurements.DesignComparative study on two techniques for ankle pressure measurement.SettingUniversity hospital.MaterialThirty-five patients with leg arterial disease and eight healthy volunteers. Ankle-brachial indices (ABPI) were measured using conventional CW Doppler technique and PPG-based prototype equipment for the ankle pressure recordings.Chief outcome measuresABPIs calculated from CW Doppler and PPG ankle pressure measurements. The PPG signals were analysed both by visual judgement and by a software based, automatic algorithm.Main resultsThe mean difference between ABPIs calculated from CW Doppler recordings and PPG (visual analysis) was −0.01 (limits of agreement (±two standard deviations) +0.16 to −0.19). The correlation coefficient was 0.93. When the algorithm was used, the mean difference (CW Doppler−PPG) was 0.05 (limits of agreement 0.28 to −0.18, r=0.89).ConclusionsThe PPG method is a promising technique with an inherent potential for automatisation of the ankle pressure measurements, thereby reducing the observer-dependency in ABPI recordings.
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- Laurent, Claes, 1958-, et al.
(author)
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Noninvasive monitoring of systolic blood pressure on the arm utilizing photoplethysmography (PPG) : clinical report
- 2004
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In: <em>Proc. SPIE</em> 5318, Advanced Biomedical and Clinical Diagnostic Systems II. - Bellingham WA, USA : SPIE. ; , s. 99-
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Conference paper (peer-reviewed)abstract
- A soft (silicone) probe, containing six light emitting diodes (880 nm) and three photo detectors, utilizes photoplethysmography (PPG) to monitor pulsations from the brachialis artery under an occluding cuff during deflation. When the arterial pulse returns, measured by PPG, the corresponding pressure in the cuff is determined. This pressure is assumed to equal the systolic pressure. An assessment trial was performed on 21 patients (9 women and 12 men, aged 27-69) at the Neuro-Intensive care unit. Since the patients were already provided with arterial needles, invasive blood pressure could be used as the reference. By choosing a threshold, for detecting pulses, as a fraction (4%) of the maximum amplitude, the systolic blood pressure was underestimated (-0.57 mmHg, SD 12.1). The range of systolic pressure for the patients was 95.5 - 199.0 mmHg, n=14. The method is promising, but improvements still have to be made in order to improve the technique.
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- Rattfält, Linda, et al.
(author)
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A platform for physiological signals including an intelligent stethoscope
- 2009
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In: IFMBE Proceedings. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783540892076 ; , s. 1038-1041
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Conference paper (peer-reviewed)abstract
- We have developed a physiological signal platform where presently phonocardiographic (PCG) and electrocardiographic (ECG) signals can be acquired and on which our signal analysis techniques can be implemented. The platform can also be used to store patient data, to enable comparison over time and invoke distance consultation if necessary. Our studies so far indicate that with our signal analysis techniques of heart sounds we are able to separate normal subject from those with aortic stenosis and mitral insufficiency. Further we are able to identify the third heart sound. The platform is being tested in a primary health care setting.
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