The noninvasive device based on a modified Penaz technique cannot replace arterial blood pressure monitoring or TEE in anesthetized patients undergoing neurosurgery in sitting position 1).

1)
Schramm P, Tzanova I, Gööck T, Hagen F, Schmidtmann I, Engelhard K, Pestel G. Noninvasive Hemodynamic Measurements During Neurosurgical Procedures in Sitting Position. J Neurosurg Anesthesiol. 2016 Mar 18. [Epub ahead of print] PubMed PMID: 26998648.