====== Near-Infrared Spectroscopy for Brain death ======

Compared to traditional diagnostic methods of [[brain death]], [[near-infrared spectroscopy]] (NIRS) is a non-invasive, objective, [[cost-effective]], and safe way of assessment of brain death. Eighteen brain dead patients and 20 healthy subjects were studied by [[NIRS]], with a multiple-phase protocol at varied fractions of inspired O2 ([[FIO2]]). They found that the changes in the concentration ratios of [[oxyhemoglobin]] to [[deoxyhemoglobin]] (Δ[HbO2]/Δ[Hb]) in the cerebral [[cortex]] of brain dead patients were significantly higher than those of healthy subjects, and its low-to-high FIO2 phase was most sensitive, with a recommended threshold in the range 1.40-1.50. The study indicated that NIRS is a promising [[technology]] for assessing brain death. The success of this application potentially offers a supplementary technique for the assessment of brain death in real-time in order to be able to promptly offer quality-assured donor organs
((Pan B, Pu J, Li T, Zhao M, Yang X. Online Noninvasive Assessment of Human Brain Death by Near-Infrared Spectroscopy with Protocol of O2 Inspiration. Adv Exp Med Biol. 2021;1269:347-352. doi: 10.1007/978-3-030-48238-1_55. PMID: 33966241.)).
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In 2018 used a portable fNIRS oximeter to measure the physiological data of fifteen brain death patients and twenty-two patients under natural state. The varied fractional concentration of inspired oxygen (FIO2) were provided in different phases. They found that the ratio of the concentration changes in oxy-hemoglobin to deoxy-hemoglobin(Δ[HbO2]/Δ[Hb])in normal patients is significantly lower than in brain death patients, and it restores oxygen change process in the low-high-low paradigm is more remarkable. This resulting promotion indicates the potential of the fNIRS-measured hemodynamic index in diagnosing brain death
((Li T, Pan B. Functional near infrared spectroscopy in the noninvasive assessment of brain death. Annu Int Conf IEEE Eng Med Biol Soc. 2018 Jul;2018:1538-1541. doi: 10.1109/EMBC.2018.8512489. PMID: 30440686.)).