Validation of a Method to Measure Soft Tissue Thickness Using Near Infrared Laser Light

Not Applicable

• Conditions: Cranial Soft Tissue
• Interventions: Device: MRI scan; Device: Laser scan; Procedure: Dental cast creation

• Registration Number: NCT01924338
• Lead Sponsor: Dr. Floris Ernst

Brief Summary

The study is intended to verify a newly developed method to measure the thickness of cranial soft tissue. In the study, a high-resolution MRI scan is used as ground truth for a laser scan of the forehead. The laser scan is acquired point by point with a prototype scanning unit developed at the University of Luebeck's Institute for Robotics.

The measured tissue thickness using the near-infrared scanning approach is validated against the ground truth obtained by the MRI scan. The average accuracy of the reconstruction method is then computed over all subjects from the individual study arms.

The required laser intensity and exposure time as well as the achieved measurement accuracy is evaluated with respect to the different skin types of the test subjects. Correlation between these features and the skin type according to the Fitzpatrick scale will be computed.

For 1/3 of the subjects, the laser and MRI scans are repeated after 2 and 8 weeks. The results of the scans are compared and time dependency is analysed.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2013-08-12
• Study First Submitted QC: 2013-08-15
• Study First Posted: 2013-08-16
• Study Start: 2013-09
• Status Verified: 2014-08
• Last Update Submitted: 2014-08-20
• Last Update Posted: 2014-08-21
• Primary Completion: 2014-12
• Study Completion: 2015-02

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

• male and female adults
• variations in skin type (at least 10 subjects with skin types I & II, at least 2 subjects with skin type III, at least 3 subjects with skin type IV, at least 3 subjects with skin types V & VI)
• optional: availability of high-resolution CT or CBCT (cone-beam CT) scan of the forehead

Exclusion Criteria

• allergies or intolerances against ABS (acrylonitrile butadiene styrene), PMMA (polymethyl methacrylate) or alginate
• elevated light sensitivity of the skin
• exclusion criteria for MRI (claustrophobia, motoric disorders, tattoos, body piercings, metallic implants in the skull, epilepsy, cardiac pacemakers)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Skin type III	Dental cast creation	Volunteers classified as skin type III according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin type III	Laser scan	Volunteers classified as skin type III according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types I and II	Dental cast creation	Volunteers classified as skin types I and II according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin type III	MRI scan	Volunteers classified as skin type III according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types V and VI	MRI scan	Volunteers classified as skin types V and VI according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types V and VI	Dental cast creation	Volunteers classified as skin types V and VI according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types I and II	MRI scan	Volunteers classified as skin types I and II according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types I and II	Laser scan	Volunteers classified as skin types I and II according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin type IV	Dental cast creation	Volunteers classified as skin type IV according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin types V and VI	Laser scan	Volunteers classified as skin types V and VI according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin type IV	MRI scan	Volunteers classified as skin type IV according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan
Skin type IV	Laser scan	Volunteers classified as skin type IV according to the Fitzpatrick Scale Procedures: dental cast creation, MRI scan, laser scan

Primary Outcome Measures

Name	Time	Method
Average accuracy of tissue thickness measurement method [mm]	up to 6 months

Secondary Outcome Measures

Name	Time	Method
Long-term stability of measured features - accuracy	up to 8 months	Change in measurement accuracy \[mm\]
Long-term stability of measured features - required exposure time	up to 8 months	Change in required exposure time \[ms\]
System dependency on skin color - exposure time	up to 6 months	Correlation between skin types (according to the Fitzpatrick scale) and the outcome (required exposure time \[ms\])
Long-term stability of measured features - required intensity	up to 8 months	Change in required laser intensity \[mW\]
System dependency on skin color - accuracy	up to 6 months	Correlation between skin types (according to the Fitzpatrick scale) and the outcome (accuracy of tissue thickness measurement \[mm\])
System dependency on skin color - required intensity	up to 6 months	Correlation between skin types (according to the Fitzpatrick scale) and the outcome (required laser intensity \[mW\])

Trial Locations

Locations (2)

University of Luebeck, Institute for Robotics; 🇩🇪 Lübeck, Schleswig-Holstein, Germany

Clinic for Maxillofacial Surgery of the University Hospital Schleswig-Holstein; 🇩🇪 Lübeck, Schleswig-Holstein, Germany