Homemade Ultrasound Stand-Off Gel Pads: A Multi-Parameter Performance Study

Stand-off gel pads made of natural ingredients may provide a low-cost option in clinical ultrasound imaging. This study investigated the performance and safety of homemade pads.

Thirty stand-off gel pads were made of aloe vera, xanthan gum and cucumber. Testing of each was performed to assess mechanical failure, moisture loss, contamination rate and image quality. Mechanical strength was measured using a tensile testing machine; drying rate was calculated using the moisture loss formula; contamination was evaluated through colony counting; and image quality was assessed using a chicken breast phantom.

There was a significant difference in compressive force resistance between the stand-off gel pads (p = 0.044). The force required was higher for those made of xanthan gum compared with cucumber (p = 0.047). There was a significant difference in moisture loss (p < 0.001). Aloe vera gel exhibited a higher moisture loss (9.65% ± 0.15%) compared with xanthan gum (5.94% ± 0.11%) and cucumber (5.81% ± 0.11%) (p < 0.001). There was a significant difference in axial resolution (p = 0.037), lateral resolution (p = 0.029) and striations in the chicken breast parenchyma (p = 0.037). Speckle artefacts are presented in xanthan-gum-based stand-off gel pad. There was a borderline significant difference of artefact presence in images produced using all pads (p = 0.050). Microbial counts were too low to be quantified.

A cucumber stand-off gel pad is a practical alternative for clinical use owing to its structural integrity, retained moisture and low microbial contamination. The image quality produced using the pad was comparable with the conventional glove-filled-with-water stand-off method.