A Novel Dermoscopic Probe for Determining Elasticity Measurements of the Skin Group 7: Erica Bozeman Markesha Cook Stephanie Cruz January 24, 2007

Design Objective "Structural alterations within cancerous skin-lesions cause unexpected patterns of anatomical deformation in response to mechanical forces." Dr. Michael Miga Hypothesis: If structural alterations in skin cancer lesions differs from that of normal skin when a mechanical force is applied, then a systematic method of measuring the force response of a skin lesion can be compared to that of normal skin to determine the presence of skin cancer. Conduct phantom experiments Design skin-friendly stretching apparatus Develop systematic method of testing skin forces

Skin Cancer Types of skin cancer Basal Cell carcinoma Squamous cell carcinoma Melanoma Facts and Statistics Over 1 million new cases of skin cancer diagnosed in US (2006) 1 American dies of melanoma every 67 minutes Treating melanoma costs about $740 million each year World Health Organization 60,000 deaths worldwide/yr 48,000 melanoma; 12,000 other

Current Methods of Detection Clinical eye Accuracy varies with experience Biopsy Dermoscopy 10X magnification, liquid polarizing lens Only ~75-80% accurate Serial photography Software expensive (~30,000) Slow Specialty clinics In vivo confocal microscopy Experimental

Dermatologist Recommendations Dr. Darrel Ellis Faster More accurate Less expensive Ideal device  Small enough to carry in pocket and use with one hand

Our Proposed Device Safe Easy Non-invasive Quick Effective Cost-efficient

Force Sensor Initial Design: Sony XCD- X710CR camera Mild Skin adhesive

Potential Design

SKIN 25.4 mm Sony XCD- X710CR camera Mild Skin adhesive Force Sensor 130 mm FOV: 32mm

Design Specifications: Ultra-Low Profile Load Cell - S215 Strain Gauge Technology Mechanical motion  electronic signal Measures up to 8 N (2 lb- force) Dimensions: x 5.99 mm (1.1 x.236 in) Rigidly mounted on platform beam Cost:$155

Using the PDE Toolbox: Assessing the Expected Outputs of our Device

Step 1:

Step 2: Melanoma Е ≈ 52 kPa ν ≈ Normal Skin Е ≈ 10 kPa ν ≈ 0.485

Colormap of Stress in the X-direction σ x = Force/ Area σ x ≈ 18 kPa Area=0.01m x.02m Force ≈ 3.6 N

Now Let’s Compare the Geometric Shapes: Rectangular CrescentCube

Budget Force Sensor $ Probe Materials $50 3M Micropore Surgical tape $10.00

Important Design Dates End of January Finalize Device Design Mid February Independent Testing Completed End of February Device Built Mid March Comparative analysis using Dr. Miga’s model April Finalize results; prepare for design presentation

References M. I. Miga, M. P. Rothney, J. J. Ou, "Modality independent elastography (MIE): Potential applications in dermoscopy", Medical Physics, vol. 32, no. 5, pp , Tsap, Leonid V. et al. Efficient Nonlinear Finite Element Modeling of Nonrigid Objects via Optimization of Mesh Models. Computer Vision and Image Understanding. Vol 69, No. 3 March 1998 pp Wan Abas, W.A.B and J.C. Barbenal. Uniaxial Tension Test of Human Skin In Vivo. J. Biomed. Engng. Vol 4 January 1982 pp

Questions