The authors would like to acknowledge Dr A. Meneses, whose previous work contributed to the refinement of the protocol described herein. Additionally, the authors would like to thank all of the research participants who have donated their time to enable protocols such as this to be developed in order to further clinical and scientific understanding.

All methods described here have been approved by the human research ethics committee of the University of the Sunshine Coast. Furthermore, all participants gave their written informed consent to participate in the measurements outlined in this protocol. Please note, vascular occlusion testing in the lower limb is contra-indicated in individuals who have previously had a revascularization procedure involving a vascular graft or stenting of the femoral or popliteal arteries. After preparing the equipment, the participant i...

Optimizing NIRS for Assessing Lower Limb Vascular Function

<ol>
	<li>Hasani, W. S. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+global+estimate+of+premature+cardiovascular+mortality:+A+systematic+review+and+meta-analysis+of+age-standardized+mortality+rate.">The global estimate of premature cardiovascular mortality: A systematic review and meta-analysis of age-standardized mortality rate.</a> BMC Public Health. 23 (1), 1561 (2023).</li><li>Horvath, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+peripheral+artery+disease:+Narrative+review.">Epidemiology of peripheral artery disease: Narrative review.</a> Life (Basel). 12 (7), 1041 (2022).</li><li>Jodheea-Jutton, A., Hindocha, S., Bhaw-Luximon, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Health+economics+of+diabetic+foot+ulcer+and+recent+trends+to+accelerate+treatment).">Health economics of diabetic foot ulcer and recent trends to accelerate treatment).</a> Foot (Edinb). 52, 101909 (2022).</li><li>Rodrigues, B. T., Vangaveti, V. N., Urkude, R., Biros, E., Malabu, U. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+and+risk+factors+of+lower+limb+amputations+in+patients+with+diabetic+foot+ulcers:+A+systematic+review+and+meta-analysis.">Prevalence and risk factors of lower limb amputations in patients with diabetic foot ulcers: A systematic review and meta-analysis.</a> Diabetes Metab Syndr-Clinin Res Rev. 16 (2), 102397 (2022).</li><li>Jung, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcirculation+in+hypertensive+patients.">Microcirculation in hypertensive patients.</a> Biorheology. 50 (5-6), 241-255 (2013).</li><li>Bethel, M., Annex, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+arterial+disease:+A+small+and+large+vessel+problem.">Peripheral arterial disease: A small and large vessel problem.</a> AmHeart J Plus: Cardio Res Prac. 28, 133291 (2023).</li><li>Thijssen, D. H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expert+consensus+and+evidence-based+recommendations+for+the+assessment+of+flow-mediated+dilation+in+humans.">Expert consensus and evidence-based recommendations for the assessment of flow-mediated dilation in humans.</a> Eur Heart J. 40 (30), 2534-2547 (2019).</li><li>Sanada, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+function+in+patients+with+lower+extremity+peripheral+arterial+disease:+A+comparison+of+functions+in+upper+and+lower+extremities.">Vascular function in patients with lower extremity peripheral arterial disease: A comparison of functions in upper and lower extremities.</a> Atherosclerosis. 178 (1), 179-185 (2005).</li><li>Barstow, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+near-infrared+spectroscopy+and+its+application+to+skeletal+muscle+research.">Understanding near-infrared spectroscopy and its application to skeletal muscle research.</a> J App Phys. 126 (5), 1360-1376 (2019).</li><li>Rogers, E. M., Banks, N. F., Jenkins, N. D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolic+and+microvascular+function+assessed+using+near-infrared+spectroscopy+with+vascular+occlusion+in+women:+Age+differences+and+reliability.">Metabolic and microvascular function assessed using near-infrared spectroscopy with vascular occlusion in women: Age differences and reliability.</a> Exp Physiol. 108 (1), 123-134 (2023).</li><li>Manfredini, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+toe+flexion+nirs+assisted+test+for+rapid+assessment+of+foot+perfusion+in+peripheral+arterial+disease:+Feasibility,+validity,+and+diagnostic+accuracy.">A toe flexion nirs assisted test for rapid assessment of foot perfusion in peripheral arterial disease: Feasibility, validity, and diagnostic accuracy.</a> Eur J Vasc Endovasc Surg. 54 (2), 187-194 (2017).</li><li>Boezeman, R. P., Moll, F. L., Unlu, C., De Vries, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+review+of+clinical+applications+of+monitoring+muscle+tissue+oxygenation+with+near-infrared+spectroscopy+in+vascular+disease.">Systematic review of clinical applications of monitoring muscle tissue oxygenation with near-infrared spectroscopy in vascular disease.</a> Microvasc Res. 104, 11-22 (2016).</li><li>Baltrunas, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+revascularization+effect+using+near-infrared+spectroscopy+in+below+the+knee+arteries.">Measurement of revascularization effect using near-infrared spectroscopy in below the knee arteries.</a> Rev Cardiovasc Med. 23 (9), 299 (2022).</li><li>Tuesta, M., Yanez-Sepulveda, R., Verdugo-Marchese, H., Mateluna, C., Alvear-Ordenes, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Near-infrared+spectroscopy+used+to+assess+physiological+muscle+adaptations+in+exercise+clinical+trials:+A+systematic+review.">Near-infrared spectroscopy used to assess physiological muscle adaptations in exercise clinical trials: A systematic review.</a> Biology (Basel). 11 (7), 1073 (2022).</li><li>Cornelis, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+near-infrared+spectroscopy+to+evaluate+the+effect+of+exercise+on+peripheral+muscle+oxygenation+in+patients+with+lower+extremity+artery+disease:+A+systematic+review.">The use of near-infrared spectroscopy to evaluate the effect of exercise on peripheral muscle oxygenation in patients with lower extremity artery disease: A systematic review.</a> Eur J Vasc Endovasc Surg. 61 (5), 837-847 (2021).</li><li>Whyte, E., Thomas, S., Marzolini, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Muscle+oxygenation+of+the+paretic+and+nonparetic+legs+during+and+after+exercise+in+chronic+stroke:+Implications+for+mobility.">Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility.</a> PM R. 15 (10), 1239-1248 (2023).</li><li>Soares, R. N., George, M. A., Proctor, D. N., Murias, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differences+in+vascular+function+between+trained+and+untrained+limbs+assessed+by+near-infrared+spectroscopy.">Differences in vascular function between trained and untrained limbs assessed by near-infrared spectroscopy.</a> Eur J Appl Physiol. 118 (10), 2241-2248 (2018).</li><li>Joseph, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Near+infrared+spectroscopy+in+peripheral+artery+disease+and+the+diabetic+foot:+A+systematic+review.">Near infrared spectroscopy in peripheral artery disease and the diabetic foot: A systematic review.</a> Diabetes Metab Res Rev. 38 (7), 3571 (2022).</li><li>Willingham, T. B., Southern, W. M., Mccully, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+reactive+hyperemia+in+the+lower+limb+using+near-infrared+spectroscopy.">Measuring reactive hyperemia in the lower limb using near-infrared spectroscopy.</a> J Biomed Opt. 21 (9), 091302 (2016).</li><li>Jones, S., Chiesa, S. T., Chaturvedi, N., Hughes, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+developments+in+near-infrared+spectroscopy+(nirs)+for+the+assessment+of+local+skeletal+muscle+microvascular+function+and+capacity+to+utilise+oxygen.">Recent developments in near-infrared spectroscopy (nirs) for the assessment of local skeletal muscle microvascular function and capacity to utilise oxygen.</a> Artery Res. 16, 25-33 (2016).</li><li>Soares, R. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+a+rehabilitation+program+on+microvascular+function+of+CHD+patients+assessed+by+near-infrared+spectroscopy.">Effects of a rehabilitation program on microvascular function of CHD patients assessed by near-infrared spectroscopy.</a> Physiol Rep. 7 (11), e14145 (2019).</li><li>Baltrunas, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+near-infrared+spectroscopy+in+the+diagnosis+of+peripheral+artery+disease:+A+systematic+review.">The use of near-infrared spectroscopy in the diagnosis of peripheral artery disease: A systematic review.</a> Vascular. 30 (4), 715-727 (2022).</li><li>Young, G. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+cuff-occlusion+duration+on+contrast-enhanced+ultrasound+assessments+of+calf+muscle+microvascular+blood+flow+responsiveness+in+older+adults.">Influence of cuff-occlusion duration on contrast-enhanced ultrasound assessments of calf muscle microvascular blood flow responsiveness in older adults.</a> Exp Physiol. 105 (12), 2238-2245 (2020).</li><li>Young, G. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+association+between+contrast-enhanced+ultrasound+and+near-infrared+spectroscopy-derived+measures+of+calf+muscle+microvascular+responsiveness+in+older+adults.">The association between contrast-enhanced ultrasound and near-infrared spectroscopy-derived measures of calf muscle microvascular responsiveness in older adults.</a> Heart Lung Circ. 30 (11), 1726-1733 (2021).</li><li>Rosenberry, R., Nelson, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactive+hyperemia:+A+review+of+methods,+mechanisms,+and+considerations.">Reactive hyperemia: A review of methods, mechanisms, and considerations.</a> Am J Physiol Regul Integr Comp Physiol. 318 (3), R605-R618 (2020).</li><li>Iannetta, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+of+microvascular+responsiveness+measures+derived+from+near-infrared+spectroscopy+across+a+variety+of+ischemic+periods+in+young+and+older+individuals.">Reliability of microvascular responsiveness measures derived from near-infrared spectroscopy across a variety of ischemic periods in young and older individuals.</a> Microvasc Res. 122, 117-124 (2019).</li><li>Celermajer, D. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+detection+of+endothelial+dysfunction+in+children+and+adults+at+risk+of+atherosclerosis.">Non-invasive detection of endothelial dysfunction in children and adults at risk of atherosclerosis.</a> Lancet. 340 (8828), 1111-1115 (1992).</li><li>Thijssen, D. H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+flow-mediated+dilation+in+humans:+A+methodological+and+physiological+guideline.">Assessment of flow-mediated dilation in humans: A methodological and physiological guideline.</a> Am J Physiol-Heart Circ Physiol. 300 (1), H2-H12 (2011).</li><li>Inaba, Y., Chen, J. A., Bergmann, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+future+cardiovascular+outcomes+by+flow-mediated+vasodilatation+of+brachial+artery:+A+meta-analysis.">Prediction of future cardiovascular outcomes by flow-mediated vasodilatation of brachial artery: A meta-analysis.</a> Int J Cardiovasc Imaging. 26 (6), 631-640 (2010).</li><li>Soares, R. N., De Oliveira, G. V., Alvares, T. S., Murias, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+the+analysis+strategy+on+the+correlation+between+the+NIRS+reperfusion+measures+and+the+FMD+response.">The effects of the analysis strategy on the correlation between the NIRS reperfusion measures and the FMD response.</a> Microvasc Res. 127, 103922 (2020).</li><li>Tucker, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+into+the+determinants+of+skeletal+muscle+oxygen+consumption:+Novel+insight+from+near-infrared+diffuse+correlation+spectroscopy.">Studies into the determinants of skeletal muscle oxygen consumption: Novel insight from near-infrared diffuse correlation spectroscopy.</a> J Physiol-London. 597 (11), 2887-2901 (2019).</li><li>Tucker, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Near-infrared+diffuse+correlation+spectroscopy+tracks+changes+in+oxygen+delivery+and+utilization+during+exercise+with+and+without+isolated+arterial+compression.">Near-infrared diffuse correlation spectroscopy tracks changes in oxygen delivery and utilization during exercise with and without isolated arterial compression.</a> Am J Physiol Regul Integr Comp Physiol. 318 (1), R81-R88 (2020).</li><li>Wassenaar, E. B., Van Den Brand, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+of+near-infrared+spectroscopy+in+people+with+dark+skin+pigmentation.">Reliability of near-infrared spectroscopy in people with dark skin pigmentation.</a> J Clinic Monit Comput. 19 (3), 195-199 (2005).</li><li>Soares, R. N., Murias, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Near-infrared+spectroscopy+assessment+of+microvasculature+detects+difference+in+lower+limb+vascular+responsiveness+in+obese+compared+to+lean+individuals.">Near-infrared spectroscopy assessment of microvasculature detects difference in lower limb vascular responsiveness in obese compared to lean individuals.</a> Microvasc Res. 118, 31-35 (2018).</li><li>Boezeman, R. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+of+foot+oxygenation+with+near-infrared+spectroscopy+in+patients+with+critical+limb+ischemia+undergoing+percutaneous+transluminal+angioplasty:+A+pilot+study.">Monitoring of foot oxygenation with near-infrared spectroscopy in patients with critical limb ischemia undergoing percutaneous transluminal angioplasty: A pilot study.</a> Eur J Vasc Endovasc Surg. 52 (5), 650-656 (2016).</li><li>Lin, B. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+wireless+near-infrared+spectroscopy+to+predict+wound+prognosis+in+diabetic+foot+ulcers.">Using wireless near-infrared spectroscopy to predict wound prognosis in diabetic foot ulcers.</a> Adv Skin Wound Care. 33 (1), 1-12 (2020).</li><li>Weingarten, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffuse+near-infrared+spectroscopy+prediction+of+healing+in+diabetic+foot+ulcers:+A+human+study+and+cost+analysis.">Diffuse near-infrared spectroscopy prediction of healing in diabetic foot ulcers: A human study and cost analysis.</a> Wound Repair. 20 (2), A44-A44 (2012).</li><li>Murrow, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Near-infrared+spectroscopy-guided+exercise+training+for+claudication+in+peripheral+arterial+disease.">Near-infrared spectroscopy-guided exercise training for claudication in peripheral arterial disease.</a> Eur J Prev Cardiol. 26 (5), 471-480 (2018).</li></ol>

This article outlines standardized procedures for the assessment of lower limb reactive hyperemia using CW-NIRS TSI to evaluate microvascular function. This protocol has been refined by examination of cuff occlusion duration on response magnitude, NIRS test-retest reliability during reactive hyperemia, as well as the level of agreement between NIRS and other methods of microvascular evaluation such as contrast-enhanced ultrasound23,24. A longer cuff-occlusion dur...

Cardiovascular disease (CVD) is the leading contributor to global mortality1. While myocardial infarction and stroke are the most common manifestations of CVD, vascular diseases of the lower limbs, such as peripheral arterial disease (PAD) and diabetic foot disease, contribute substantially to the personal, social, and healthcare burden of CVD2,3,4. Importantly, these disease states are characterized by microvascular and macrovascular dysfunction5 that contribute to symptoms (e.g., intermittent claudication), functional impairment, poor mobility as well as social isolation and reduced quality of life6. Historically, upper-limb vascular assessment techniques have been used as a measure of systemic vascular function and associated cardiovascular risk; however, these methods are potentially not sensitive to local impairments in lower limb vascular function7,8. While there is currently a range of techniques used to assess vascular function in the lower limb, such as flow-mediated dilatation (FMD) and contrast-enhanced ultrasound, each method has disadvantages and limitations, such as equipment cost, operator skill, or the need for invasive venous access. For these reasons, there is a need for standardized and effective techniques to evaluate lower limb vascular (dys)function that can be more readily implemented in research and clinical settings.
Continuous wave near-infrared spectroscopy (CW-NIRS) is a non-invasive, low-cost, and portable method that quantifies the relative changes in hemoglobin oxygenation in vivo. As the NIRS oxygenated and deoxygenated hemoglobin signals are derived from the small (&#60;1 mm in diameter) vessels, local skeletal muscle metabolism and microvascular function are able to be evaluated9. Specifically, the tissue saturation index (TSI) [TSI = oxygenated hemoglobin/ (oxygenated hemoglobin + deoxygenated hemoglobin) x 100], provides a quantitative measure of tissue oxygenation9. When measured before, during, and after occlusion and reactive hyperemia, the changes in TSI indicate &#39;end-organ&#39; vascular responsiveness, relative to the pre-occlusion baseline. Importantly, this method is sensitive to alterations in muscle microvascular responsiveness and perfusion associated with ageing10, disease progression11, and clinical interventions (e.g., revascularization surgery12,13 or exercise rehabilitation14,15,16,17) in individuals with, or at risk of microvascular dysfunction.
The availability of NIRS systems has led to a rapid rise in the number of research studies reporting microvascular function18. However, differences in reactive hyperemia&#160;testing protocols, omission of detailed, repeatable NIRS methods, as well as a lack of uniformity in the description, presentation, and analysis of NIRS response parameters make comparisons across individual trials challenging. This limits the collation of data for meta-analysis and the formulation of clinical assessment recommendations9,15.
Therefore, in this article, we describe our laboratory&#39;s standardized NIRS and vascular occlusion testing protocols for the assessment of lower limb reactive hyperemia. By disseminating these methods, we aim to contribute to the improved standardization and repeatability of data collection procedures and harmonized reporting.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Cuff Inflator Air Source</td>
			<td>Hokanson&#160;</td>
			<td>AG101 AIR SOURCE</td>
			<td></td>
		</tr>
		<tr>
			<td>Elastic Cohesive Bandage</td>
			<td>MaxoWrap</td>
			<td>18228-BL</td>
			<td>For blocking out ambient light</td>
		</tr>
		<tr>
			<td>OxySoft</td>
			<td>Artinis</td>
			<td>3.3.341 x64</td>
			<td></td>
		</tr>
		<tr>
			<td>PortaLite (NIRS)</td>
			<td>Artinis</td>
			<td>0302-00019-00</td>
			<td></td>
		</tr>
		<tr>
			<td>PortaSync MKII (Remote)</td>
			<td>Artinis</td>
			<td>0702-00860-00</td>
			<td>For Marking milestones during measurement</td>
		</tr>
		<tr>
			<td>Rapid Cuff Inflator</td>
			<td>Hokanson&#160;</td>
			<td>E20 RAPID CUFF INFLATOR</td>
			<td></td>
		</tr>
		<tr>
			<td>Thigh Cuff</td>
			<td>Hokanson&#160;</td>
			<td>CC17</td>
			<td></td>
		</tr>
		<tr>
			<td>Transpore Surgical Tape</td>
			<td>3M</td>
			<td>1527-1</td>
			<td>For fixing probe to skin</td>
		</tr>
	</tbody>
</table>

near-infrared spectroscopy during reactive hyperemia for the assessment of lower limb vascular function 

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. Importantly, microvascular dysfunction can occur prior to, or alongside, macrovascular pathology, and both potentially contribute to patient symptoms and disease burden. Here, we describe a non-invasive approach using near-infrared spectroscopy (NIRS) during reactive hyperemia, which provides a standardized assessment of lower limb vascular (dys)function and a potential method to evaluate the efficacy of therapeutic interventions. Unlike alternative methods, such as contrast-enhanced ultrasound, this approach does not require venous access or sophisticated image analysis, and it is inexpensive and less operator-dependent. This description of the NIRS method includes representative results and standard terminology alongside the discussion of measurement considerations, limitations, and alternative methods. Future application of this work will improve standardization of vascular research design, data collection procedures, and harmonized reporting, thereby enhancing translational research outcomes in the areas of lower limb vascular (dys)function, disease, and treatment.

Author Spotlight: Enhancing Vascular Function and Physical Capacity in Cardiovascular Disease Through Novel Interventions and NIRS Technology

Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function 

Our research is focused on understanding how impairments in vascular function and blood flow contribute to the decline in physical function with age and age-related cardiovascular conditions. We also aim to develop novel therapies and exercise interventions that target vascular function and enhance physical capacity in quality of life in people living with cardiovascular disease. Differences in testing protocols, omission of detailed, repeatable NIRS methods, and a lack of uniformity in the description, presentation, and analysis of NIRS response parameters makes comparisons across individual trials challenging.This limits the collation of data for meta-analysis and the formulation of clinical assessment recommendations. Compared to plethysmography, NRS has high temporal resolution and directly evaluates changes in microvasculature. Compared to ultrasound, NIRS does not require sophisticated image analysis or intravenous contrast agents.The relative ease and affordability of NIRS means that users can be trained rapidly, enabling multicenter investigations with minimal inter operator variability. We're focused on improving skeletal muscle microvascular function through interventions like ischemic preconditioning and blood flow restriction exercise training. We're currently testing the effect of neuromuscular electrical stimulation as a therapy to promote vascular function and to enhance walking capacity in people with peripheral artery disease.

Near-infrared spectroscopy 
Continuous wave near-infrared spectroscopy devices measure relative changes in oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin, which reflect local O2 delivery and utilization via light-emitting sources and photodetectors, set&#160;specific distances apart. Wavelengths of light between ~700 nm and 850 nm are emitted, corresponding with the peak absorbency of O2Hb and HHb. Once near-infrared light has penetrated skeletal muscle...

Read this Scientific Article Protocol about Author Spotlight: Enhancing Vascular Function and Physical Capacity in Cardiovascular Disease Through Novel Interventions and NIRS Technology at JoVE.com

Here, we describe a non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia in the lower limb. This protocol provides a standardized assessment of vascular and microvascular responsiveness that may be used to determine the presence of vascular dysfunction as well as the efficacy of therapeutic interventions.

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. ...

near-infrared-spectroscopy-during-reactive-hyperemia-for-assessment