Figure 3.

PRISMA flow chart showing the number of articles included and removed at each stage of the search process (US = Ultrasound, MRI = Magnetic Resonance Imaging, and LDV = Laser Doppler Vibrometers). Note that the numbers may differ from the sum from each excitation and measurement category because some papers: 1) used more than one excitation or measurement method, 2) do not state which excitation or measurement method was used, and/or 3) appear in both excitation and measurement categories.