Fig. 1

a Transverse view of the geometry model for the pelvic region. For the sake of clarity only the involved muscles are included in the bottom plot. Note that in the frontal body view the X-axis points to the right, the Y-axis points toward the dorsal region and the Z-axis points upwards (into the cranial region). b Lateral view of the rectum, bladder and prostate organs with a magnification of the interior region of the rectum where the TRUS probe exerts pressure