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Robot-Assisted US-Based Vertebral Segmentation for Pedicle Screw Trajectory Identification

Not Applicable
Completed
Conditions
Healthy
Interventions
Other: Robot-assisted US Scan of the vertebra L1 to S1
Other: Handheld US scan of the vertebra L1 to S1
Radiation: ULD CT scan of the vertebra L1 to S1
Registration Number
NCT05904418
Lead Sponsor
Philipp Fürnstahl
Brief Summary

This other clinical trial compares robot-assisted US scanning with handheld US scanning and ground-truth CT data of the lumbar spine in healthy, young volunteers. The main questions it aims to answer are:

* Is a 3D reconstruction of a lumbar spine from robot-assisted US scanning equivalent to or better quality than a 3D reconstruction from handheld US scanning?

* Can a machine learning algorithm automatically segment the bone anatomy from robot-assisted and handheld US scanning to generate 3D lumbar spine reconstructions?

* Can pedicle screw trajectories be identified based on posterior vertebral landmarks of 3D reconstructions of lumbar spines from both robot-assisted and handheld US scanning?

Participants will:

* fill out a medical history questionnaire

* get clinically examined

* have an ultra-low-dose (ULD) CT Scan of the vertebra L1 to S1

* have a handheld US scan of the vertebra L1 to S1

* have a robot-assisted US Scan of the vertebra L1 to S1

* fill out a post-study questionnaire

Detailed Description

The following hypotheses are tested:

1. A 3D reconstruction of a lumbar spine from robot-assisted US scanning is equivalent to or of better quality than a 3D reconstruction handheld US scanning.

2. A machine learning algorithm can automatically segment the bone anatomy from robot-assisted and handheld US scanning to generate said 3D lumbar spine reconstructions.

3. Pedicle screw trajectories can be identified based on posterior vertebral landmarks of 3D reconstructions of lumbar spines from robot-assisted and handheld US scanning.

The project consists of three pillars as objectives to help solidify the US reconstruction of the lumbar spine as a novel navigational method in interventional spine applications.

* 1st Pillar: A first-of-a-kind in-vivo robot-assisted and handheld US reconstruction dataset of the lumbar spine in healthy subjects is acquired. The collected dataset is compared to ground truth CT data to assess quality.

* 2nd Pillar: A novel machine learning algorithm is trained to segment the US reconstructions of all the collected lumbar spine data into each identified vertebra.

* 3rd Pillar: A novel measurement method to identify pedicle screw trajectories based on posterior vertebral landmarks is applied to the segmented US reconstructions. This research further promotes US for future use in robot-assisted interventions.

This project consists of two phases. First, a preliminary pilot study is planned to assess the project's feasibility and improve the planned workflow and safety measures. For this pilot, the investigators will mouth-to-mouth recruit two volunteers. After completing and thoroughly evaluating the pilot, the investigators will conduct the actual study.

The volunteers for the actual study are selected through public calls for participation. Possible volunteers are young, healthy, and not affected by illness or deformation of the lumbar spine. The selected volunteers are screened by asking about their medical history. If included and willing to participate, the volunteers are invited to the study at Balgrist Campus and will be clinically examined regarding the lumbar spine. Furthermore, a low-dose CT scan, a handheld US scan, and a robot-assisted US scan are held.

The CT scans are manually segmented into 3D surface models to obtain a "segmentation ground truth". A novel machine learning algorithm automatically performs 3D reconstruction and segments the robot-assisted and handheld US scans.

The 3D US reconstructions are then utilized to identify pedicle screw trajectories through a novel method based on the posterior anatomical landmarks of lumbar vertebrae.

This single-center study combines the clinical and computer-science knowledge from the Research in Orthopedic Computer Science (ROCS) team of the University of Zurich, Switzerland, with the robotics and US application knowledge from the Faculty of Engineering of the University of Leuven, Belgium. The data collection is performed at Balgrist Campus.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
63
Inclusion Criteria
  • Oral and written informed consent from the volunteer
  • Volunteers aged ≥18 y/o and ≤35 y/o
  • BMI above or equal to 19 kg/m2 or below or equal to 25 kg/m2
  • Proficient in German or English language
Exclusion Criteria
  • Documented volunteer refusal

  • Volunteers in whom CT cannot be performed

  • Positive pregnancy test prior to radiology (contraindication to CT)

  • Pregnancy

  • Chronic pain in the lumbar spine

  • Moderate or severe deformity of the lumbar spine

  • Any prior intervention to the lumbar spine:

    • Chiropractic adjustment therapy
    • Injections such as local anesthetics and corticosteroids
    • Surgery
  • Fracture of the lumbar spine

  • BMI below 19 kg/m2 or above 25 kg/m2

  • Anatomies, such as subcutaneous fat or tendon, occlude the bony surface or do not allow a clear image in the US scan

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Young, healthy volunteersHandheld US scan of the vertebra L1 to S11. Medical History (20 minutes) 2. Clinical examination (20 minutes) 3. Clothes changing time (15 minutes) 4. ULD CT scan of the vertebra L1 to S1 (30 minutes) 5. Clothes changing time (15 minutes) 6. Handheld US scan of the vertebra L1 to S1 (20 minutes) 7. Platform changing time (15 minutes) 8. Path planning and robot-assisted US Scan of the vertebra L1 to S1 (40 minutes) 9. Clothes changing time (15 minutes) 10. Volunteer Questionnaire (10 minutes) Total study time per volunteer: 3 Hours 20 minutes
Young, healthy volunteersRobot-assisted US Scan of the vertebra L1 to S11. Medical History (20 minutes) 2. Clinical examination (20 minutes) 3. Clothes changing time (15 minutes) 4. ULD CT scan of the vertebra L1 to S1 (30 minutes) 5. Clothes changing time (15 minutes) 6. Handheld US scan of the vertebra L1 to S1 (20 minutes) 7. Platform changing time (15 minutes) 8. Path planning and robot-assisted US Scan of the vertebra L1 to S1 (40 minutes) 9. Clothes changing time (15 minutes) 10. Volunteer Questionnaire (10 minutes) Total study time per volunteer: 3 Hours 20 minutes
Young, healthy volunteersULD CT scan of the vertebra L1 to S11. Medical History (20 minutes) 2. Clinical examination (20 minutes) 3. Clothes changing time (15 minutes) 4. ULD CT scan of the vertebra L1 to S1 (30 minutes) 5. Clothes changing time (15 minutes) 6. Handheld US scan of the vertebra L1 to S1 (20 minutes) 7. Platform changing time (15 minutes) 8. Path planning and robot-assisted US Scan of the vertebra L1 to S1 (40 minutes) 9. Clothes changing time (15 minutes) 10. Volunteer Questionnaire (10 minutes) Total study time per volunteer: 3 Hours 20 minutes
Primary Outcome Measures
NameTimeMethod
Pedicle screw placement - Trajectory errors in terms of directionUp to 1 year

Evaluating the directional accuracy of the Pedicle screw placement

Pedicle screw placement - Trajectory errors in terms of positionUp to 1 year

Evaluating the positional accuracy of the Pedicle screw placement

Target registration errors between US reconstructions and ground truth CT dataUp to 1 year

Evaluating the accuracy of the US reconstructions

Secondary Outcome Measures
NameTimeMethod
BMIUp to 4 weeks

weight and height

GenderUp to 4 weeks

female, male, non-binary, do not know, other

Tegner activity scoreUp to 4 weeks

Subjective activity score of the volunteers

ODI Oswestry Low Back Pain Disability IndexUp to 4 weeks

Standardized Low Back Pain Disability Index

AgeUp to 4 weeks

in years

Smoking statusUp to 4 weeks

yes/no; if yes, pack years

Trial Locations

Locations (1)

University Hospital Balgrist, Balgrist Campus

🇨🇭

Zurich, Switzerland

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