Abstract: TH-PO767

Feasibility of Laser Doppler Vibrometry to Quantitate Arterio-Venous Fistula Thrill

Session Information

Category: Dialysis

  • 603 Hemodialysis: Vascular Access

Authors

  • Campos, Israel, Renal Research Institute, New York, New York, United States
  • Williams, Schantel, Renal Research Institute, New York, New York, United States
  • Rosales, Laura, Renal Research Institute, New York, New York, United States
  • Zhu, Fansan, Renal Research Institute, New York, New York, United States
  • Kotanko, Peter, Renal Research Institute, New York, New York, United States
Background

Clinical examination is the corner stone of identifying arterio-venous fistula (AVF) pathologies and recognizing changes in AVF thrill carries important information. While currently subjective, quantitating AVF thrill objectively may improve the diagnosis of AVF pathologies. AVF thrill is vibrational in nature and depends on AVF pressure and flow rate. The aims of this study was to evaluate how pressure and flow rate affect the vibrational characteristics.

Methods

In this bench study we used a 3D printed AVF cannulation simulator (Phacon, Germany) with artificial “skin” above the AVF and a pumping system to provide flow. In this study, the pump rate was set to 60 per minute. Two series of experiments were conducted. In one series the pressures varied and the flow was set constant. In a second series of experiments the pressure was set constant and the pumping amplitude varied. The motion characteristics (amplitude, velocity) of the artificial “skin” above the AVF were measured by laser Doppler vibrometry (PDV100, Polytec, Germany). The set-up is shown in Fig. 1.

Results

The laser Doppler vibrometry provided excellent high-resolution measurements of the “skin” movements. The “skin” movements clearly depended on both AVF pressure and stroke volume (Fig.2a, b and Fig.3a-c).

Conclusion

Our in vitro study demonstrates that, first, laser Doppler vibrometry can determine regional “skin” vibrations above AVF with high accuracy and precision. Second, vibration characteristics (“thrill”) of the ”skin” above the AVF depend on both flow and pressure. Clinical studies are required to extend these findings to hemodialysis patients with AVF as vascular access.