Avaliação de um modelo de parâmetros distribuídos aplicado à estimação da geometria arterial na hipertensão

Abstract

Arterial hypertension leads to structural adaptation of arteries, mainly hypertrophy or remodeling, which precedes target-organ injuries. Determination of both mechanical and geometrical variables related to arterial system allows physicians to identify early arterial adaptation derived from systemic hypertension and to propose therapeutics. This work presents the evaluation of an electric-hydraulic model, and associated method, for determination of geometrical and mechanical parameters of forearm arteries. The proposed method requires only noninvasive acquisition of two pressure pulses at distinct sites. Series of pressure pulses from radial artery were simulated using acquired brachial artery pulses and a simplified distributed-model of the forearm arteries. The model presents three sections, representing brachial, radial, and hand vasculature. Brachial and radial arteries were represented with resistive (friction), inductive (blood mass), and capacitive (arterial compliance) elements. The hand was modeled with resistive (small vessels and capillaries) and capacitive elements (small vessels compliance). The results show that an average estimation error of 3.7% is small compared to "in vivo" findings (changes up to 15%), indicating that the procedure can be used to assess the remodeling of medium-sized arteries on primary systemic arterial hypertension.