1 A real-time non-invasive system monitoring haemodynamic parameters in critical conditions by peripheral blood pressure wave analysis Pasquale Arpaia 1 , Pasquale Cimmino 1 , Fabrizio Clemente 2 , Antonio Panaggio 2 1. Dip.to di Ingegneria, Università del Sannio, Corso Garibaldi 107, 82100 Benevento, ITALY. Ph : +39 0824 305804-17, Fax: +39 0824 305840, E-mail: arpaia@unisannio.it; pcimmino@email.it 2. Consiglio Nazionale delle Ricerche, Istituto di Ingegneria Biomedica - via Salaria km 29,300 - 00016 Monterotondo S. (RM), Ph: +39 (0)690 67 26 92, Fax: +39 (0) 6 90 67 28 29, E-mail: clemente@isib.cnr.it; antonio.panaggio@isib.cnr.it Abstract - A non-invasive measurement platform for peripheral blood pressure monitoring and integrated diagnosis based on a piezo film pulse sensor and suitable processing algorithms running on a laptop PC has been developed. Different parameters (such as cardiac output and systolic pressure variation) for integrated haemodynamic management in critical conditions are determined by using mathematical and/or physiopatological models. Moreover, once connected to classical patient monitors, the system computes further parameters used for haemodynamic assessment of critical patients. Experimental results of the clinical in-vivo validation in operating theatres and in intensive care units are reported. I. Introduction In the management of critically ill patients, continuous recording and analysis of physiological signals, as well as on-line interactive acquisition and processing, allows information about both patient status and therapy effects can be gathered in real time [1]. In particular, arterial pressure waveform drew considerable attention for assessment of cardiovascular systems for critical patients [2]–[3]. Direct blood pressure monitoring through an arterial catheter is presently considered as the most accurate method using commercially available devices (Picco plus©, LiDCO TM plus, Vigileo TM ). However, being invasive, this methodology can be not applied in ambulatory study and, moreover, it presents various disadvantages, such as patient discomfort, need for skilled professional (for catheter insertion), and possibility of complications. In last years, some non-invasive commercial systems arose, such as Tensys® medical TL-150, Biopac NIBP100A, Medwave Vasotrac® APM205A, and FINAPRES Finometer®. Nonetheless, they are dedicated proprietary systems not useful for experimenting innovative techniques, such as new sensors, as well as new algorithms. As a matter of fact, currently, research is more and more focused on non-invasive pressure monitoring from peripheral artery (radial artery) and on consequent synthesis of systemic circulation characteristics [4]-[5]-[6]. In this paper, a non-invasive measurement platform for peripheral blood pressure monitoring is proposed with the aim of constituting a sound basis for experimenting innovative haemodynamic real- time analysis. After a description of the platform prototype, a suitable clinical measurement layout, for gathering information about haemodynamic condition by Pulse Wave Analysis (PWA), is presented. Finally, in-vivo results of the validation of the proposed prototype on patients during cardiac and vascular surgery are discussed. II. Measurement system prototype A measurement platform for haemodynamic assessment in clinical environment has to be designed by considering the following features [7]: • simultaneous acquisition and visualization up to five waveforms, • computation and visualization in real time of additional derived parameters, • user-friendly interface and display of a graphic trend, • on-demand capability of storing waveforms for further off-line analysis, • set up of all measurements and set values. The system has to be connected to innovative non-invasive sensors [8], as well as to acquire signals from analog output of classical medical devices. Finally, it has to provide a sound basis for developing