NONINVASIVE BIOLOGICAL PARAMETERS MEASUREMENT IN HEART PROSTHESIS

• Published in: International journal of artificial organs Vol. 34; no. 8; p. 612
• Main Authors: Gawlikawski, M, Kustosz, R, Gibinski, P, Nowicki, A, Palko, T, Pustelny, T, Gorka, K, Kapis, A, Mocha, J, Sobotnicki, A, Czerw, M, Opilski, Z, Lewandowski, M, Karlowicz, P
• Format: Journal Article
• Language: English
• Published: 01-08-2011
• ISSN: 0391-3988

Objectives: For optimization, monitoring and partial-automation of mechanical heart support it is necessary to measure appropriate biological signals. The paper presents noninvasive measurement methods of those parameters. Goal of this study was to construct and examine selected biological parameters measurement methods dedicated to pulsatile VAD. This work is a part of the Polish Artificial Heart project. Methods: The following biophysical quantities measurement methods were investigated: blood flow (ultrasound Doppler velocity profile methods), temporary blood volume in the pump (Helmholtz resonance and rheoimpedance methods), blood pressure (piezoresistive sensors separated from blood through the polyurethane membrane) and epicardial ECG. Investigations were performed on in-vitro models, which simulated essential biophysical phenomena. Trial measurements were performed on animals (110kg pig). Results: Accuracy of Doppler volumetric blood flow measurement was 20%. For the rheoimpedance method, the difference between measured and reference volume (calculated by flow integration) was 0.44mL with standard deviation=3.5mL (Bland-Altman plot). Helmholtz resonance method allowed to measure blood chamber volume with unreliability of 5%. Accuracy about 3mmHg and negligible hysteresis were obtained for blood pressure measurement gauge. QRS detector efficiency (estimated according to EN-60601-1-2-47 regulation) was > 99%. Conclusions: The performed investigations allowed to select measurement methods appropriate to utilization in final construction of pulsatile VAD. The following methods were chosen: Doppler blood flow, pressure measurement by piezoresistive sensor and QRS detection from epicardial ECG. While developing VAD manufacturing technology the gauges construction limits should be taken into consideration.