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Newsletter from JoR Measurement
Data Acquisition for physiology research and education
jor.se/measurement |
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Laser doppler measurements - more than just blood perfusion |
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Laser doppler is most often used to measure variations in local blood perfusion, either invasively via a needle / catheter that can be inserted into tissue / vessels or with surface probes on the skin when measuring in a peripheral vessel a few millimeters under the skin. You then typically filter out noise and variations to get an average relative measure of local blood perfusion.
What does fluctuations in blood perfusion mean?
There is more exciting information to be inferred from a laser doppler measurement if you analyze what is normally filtered out. Blood circulation is modulated by systemic pulsations, as well as respiration. But there may be more information in the slower variations. Studies have looked at the frequency components in the variations of peripheral blood flow, such as fingertips, and there seems to be a connection between metabolic activation, autonomic nervous system and muscle activity that modulates blood flow in different approximate frequency bands with the following approximate center frequencies: |
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0.015 Hz Metabolism
0.045 Hz Sympathetic activation
0.09 Hz Muscle activation
0.3 Hz Respiration
1.3 Hz HR
To calculate the corresponding scores, in addition to the usual handling of average blood flow, AcqKnowledge can perform a spectral analysis, a power density spectrum that is then integrated for the various frequency bands in much the same way for spectral-based HRV. This results in a potential extra index-score for the various regulatory components that affect blood flow. |
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Do not miss this! Use BIOPAC's publication search! - Effect of energy drink on metabolism and nervous system with BIOPAC's laser doppler
If you are looking for published references for various applications where BIOPAC's system has been used, we can recommend this compilation with help links and categories. An example that appears in the publication searchers on laser doppler measurement is an application where one tries to measure the effect of energy drinks via laser doppler on your fingertips. |
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Determination of the Effect of Having Energy Drinks by Analyzing Blood Perfusion Signal
”We observed a significant change in metabolic and sympathetic nerve activity after having energy drinks. The frequency component relating metabolic and sympathetic nerve activity increase around 300% and 140%..."
Read the article here! |
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DEMO offer on laser doppler system!
We currently have several laser doppler systems LDF100C including a set of surface probes TSD140 in stock since a big study where they have been used only for a short time and are in good condition. We are now offering these as "demo systems" at a unique discount. We deliver the system newly calibrated, and with a 3-month warranty. These laser dopplers are designed to be connected to an MP160 or MP150 system. For detailed information please contact Fredrik at fredrik@jor.se who is our responsible contact person for BIOPAC's products.
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Nice restrictions!
We at JoR AB wish everyone a nice summer, and keep our fingers crossed that everything is still going in the right direction this coming fall and to all of you who had your trials postponed due to the pandemic will eventually have a new chance to resume these.
Feel free to contact us if you have any thoughts or questions about laser doppler measurements, or how to analyze the signal to get the various frequency components in AcqKnowledge. |
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Please contact us and tells us more about your projects and needs, and we will give you tailored advice. We have data acquisition system for both research and education.
Do you prefer to get these newsletters in swedish in the future?
Please E-mail biopac@jor.se and let us know. |
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