Abstract
Vascular grafts are artificial conduits properly designed to substitute a diseased blood vessel. However prosthetic fail can occur without premonitory symptoms. Continuous monitoring of the system can provide useful information not only to extend the graft’s life but also to optimize the patient’s therapy. In this respect, various techniques have been used, but all of them affect the mechanical properties of the artificial vessel. To overcome these drawbacks, an ultrathin and flexible smart patch based on piezoelectric Aluminum Nitride (AlN) integrated on the extraluminal surface of the prosthesis is presented. The sensor can be conformally wrapped around the external surface of the prosthesis. Its design, mechanical properties and dimensions are properly characterized and optimized in order to maximize performances and to avoid any interference with the graft structure during its activity. The sensorized graft is tested in vitro using a pulsatile recirculating flow system that mimics the physiological and pathological blood flow conditions. In this way, the ability of the device to measure real-time variations of the hemodynamics parameters has been tested. The obtained high sensitivity of 0.012 V Pa−1 m−2, joint to the inherent biocompatibility and non-toxicity of the used materials, demonstrates that the device can successfully monitor the prosthesis functioning under different conditions, opening new perspectives for real-time vascular graft surveillance.
Highlights
A prosthetic vascular graft is an artificial conduit, designed on the patient’s arterial anatomy, to bypass a diseased vessel
The flexible piezoelectric smart patch consists of a sensing element with a rectangular shape whose active area is composed of a multilayered stack consisting of aluminum nitride-interlayer (AlN-IL), molybdenum bottom electrode (Mo), piezoelectric aluminum nitride (AlN) and molybdenum top electrode (Mo)
The quality of the piezoelectric Aluminum Nitride (AlN) deposited on polyimide was verified by means of morphological analysis and piezo force microscopy
Summary
A prosthetic vascular graft is an artificial conduit, designed on the patient’s arterial anatomy, to bypass a diseased vessel. Www.nature.com/scientificreports with the blood-stream, which causes the deformation of a strain gauge[4,9] These pressure sensors can detect the hemodynamic variation with a good sensitivity, they require a voltage supply and traditional electronic components which alters the structure of the graft itself. The reported results show how the piezoelectric transduction is really useful to monitor hemodynamic variations and the presence of small occlusions in the graft, but the sensor dimensions with its high thickness still affects the mechanical behavior of the graft structure. The piezoelectric device, wrapped on the extraluminal surface of the graft, generates an electric response due to the wall deformation, providing important information about the blood flow hemodynamics in the artificial vessel. This work encompasses the fabrication and characterization of the flexible smart patch, the finite element modeling (FEM) and shows the experimental results derived from the study of the graft-sensor system, exploiting an ad-hoc measurement set-up
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
