A 3D-printed circular track positions a standard linear probe at 18 calibrated angles. Segmentation isolates the anatomy; optimization-based registration stitches it into a continuous 360-degree panoramic view.
360°
Panoramic field of view
18
Imaging perspectives
0.9945
Segmentation accuracy
4
In-vivo subjects
Acquisition System
Hardware
A low-cost 3D-printed circular track with a custom probe holder replaces expensive motorized gantries and electromagnetic trackers. The probe slides into precision-milled slots whose positions are known from the CAD model, giving the reconstruction pipeline its initial transformation estimates for free.
Circular track with 18 equidistant slots at 20° intervals. The probe holder ensures repeatable alignment at each position.
3D-Printed Track
Designed in Fusion 360 and printed in PLA (0.4 mm nozzle, 20% infill). The cylindrical housing has an inner diameter of 11 cm, outer diameter of 13 cm, and a height of 16 cm. 18 precision slots spaced at 20-degree intervals position the probe with known transformation parameters.
Probe Holder
A custom mask precisely dimensioned to the L11-5v transducer (arc length 8 cm, height 2 cm, width 5.3 cm, thickness 0.9 cm). The holder locks the probe into each slot, preventing misalignment during acquisition and ensuring that slot-based transformation estimates are accurate.
Acquisition Platform
Verasonics Vantage 128-channel research system with the L11-5v 128-element linear array transducer operating at 7.6 MHz centre frequency. The region of interest is immersed in a water bath inside the cylindrical track for acoustic coupling.
Reconstruction Pipeline
Algorithm
Images acquired at each slot pass through a four-stage pipeline. Deep-learning segmentation isolates the region of interest; optimization-based registration aligns the segmented frames; the fused panoramic image emerges from pixel-wise maximum intensity projection.
01
Acquire
18 images at calibrated slot positions around the track
02
Segment
U-Net isolates the bone region of interest from background
03
Register
SSIM-based optimization aligns each frame sequentially
04
Fuse
Maximum intensity projection produces the 360° panorama
System Specifications
Parameters
Design parameters of the 3D-printed mechanical track, probe holder, and ultrasound acquisition platform as reported in the study.
Inner Diameter
11 cmCylindrical housing bore
Outer Diameter
13 cmTrack outer wall
Track Height
16 cmCylindrical housing
Slot Count
1820° angular spacing
Centre Frequency
7.6 MHzL11-5v linear array
Elements
128Linear array transducer
Frame Size
742 × 542 pxPer-slot acquisition
Print Material
PLA0.4 mm nozzle, 20% infill
Acquisition System
VerasonicsVantage 128-channel
Key Results
Validation
The approach was validated with in-vivo wrist imaging on four healthy subjects. Each reconstruction compounds 18 views into a continuous 360-degree surface map of the wrist bone.
Segmentation
U-Net Bone Segmentation
A five-level U-Net trained on 150 manually segmented wrist images from 3 subjects. The segmentation step isolates the bone region to improve registration by reducing background interference.
99.45%
test accuracy (0.9928 validation)
Registration
SSIM-Based Optimization
Sequential rigid registration using structural similarity (SSIM) as the cost function. Slot positions provide initial transformation estimates; a surrogate optimizer refines them over approximately 30 iterations until SSIM converges.
SSIM
cost function with surrogate optimizer
Reconstruction
360-Degree Panoramic View
The fused panoramic image reveals the full wrist bone surface from all perspectives. Compared to uncorrected slot-based alignment, the optimization step eliminates discontinuities and restores anatomical connectivity.
360°
continuous surface view
Validation
In-Vivo Wrist Imaging
Validated on 4 healthy subjects following the Helsinki Declaration. Each subject’s wrist was imaged at all 18 slot positions, producing a complete panoramic reconstruction of the wrist bone surface.
4
subjects, 18 views each
Publication
Reference
The study behind this page, presented at the IEEE International Symposium on Biomedical Imaging.
IEEE ISBI 2024
Towards Multi-Perspective Panoramic Ultrasound Imaging Using Low-Cost 3D Printed Track and 1D Linear Probe
Joel Joy · A. N. Madhavanunni · Gayathri Malamal · Mahesh Raveendranatha Panicker
2024 IEEE International Symposium on Biomedical Imaging (ISBI), pp. 1–4, May 2024. Athens, Greece.