Coherent hemodynamics spectroscopy: initial applications in the neurocritical care unit

Kristen T. Tgavalekos; Angelo Sassaroli; Xuemei Cai; Joshua Kornbluth; Sergio Fantini

doi:10.1117/12.2251021

18 February 2017 Coherent hemodynamics spectroscopy: initial applications in the neurocritical care unit

Kristen T. Tgavalekos, Angelo Sassaroli, Xuemei Cai, Joshua Kornbluth, Sergio Fantini

Proceedings Volume 10059, Optical Tomography and Spectroscopy of Tissue XII; 100591F (2017) https://doi.org/10.1117/12.2251021
Event: SPIE BiOS, 2017, San Francisco, California, United States

Abstract

We used coherent hemodynamics spectroscopy (CHS) and near-infrared spectroscopy (NIRS) to measure the absolute cerebral blood flow (CBF) and cerebral autoregulation efficiency of a patient with intraventricular hemorrhage in the neurocritical care unit. Mean arterial pressure oscillations were induced with cyclic thigh cuff inflations at a super-systolic pressure. The oscillations in oxyhemoglobin ([HbO₂]) and deoxyhemoglobin ([Hb]) cerebral concentrations were used to compute CHS amplitude and phase spectra that were fit with the frequency-domain equations of our hemodynamic model. From the fitted parameters, we obtained measures of local autoregulation efficiency (cutoff frequency: 0.07 ± 0.02 Hz) and absolute regional CBF (33 ± 9 ml/100g/min). We introduce a new approach for computing CHS spectra using coherence criteria and time-varying transfer function analysis. We show that with this approach we can maximize the number of frequency points in the CHS spectra for more effective fitting with our hemodynamic model. Finally, we show how absolute measurements of the cerebral concentrations of [HbO₂] and [Hb] at baseline can be used to further enhance the fitting procedure.

Citation Download Citation

Kristen T. Tgavalekos, Angelo Sassaroli, Xuemei Cai, Joshua Kornbluth, and Sergio Fantini "Coherent hemodynamics spectroscopy: initial applications in the neurocritical care unit", Proc. SPIE 10059, Optical Tomography and Spectroscopy of Tissue XII, 100591F (18 February 2017); https://doi.org/10.1117/12.2251021

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