Development of a Smartphone-Based Skin Simulation Model for Medical Education

Abstract

Introduction: Teaching dermatology to medical students entails a series of lectures, pictures, and hands-on skin examinations to convey a sense of skin features and textures, often by use of simulated skin models. However, such methods can often lack accurate visual and tactile texture representation of skin lesions. To facilitate learning, we have developed a smartphone-based skin simulation model, which provides a configurable visual and tactile sense of a lesion by using the ubiquitous availability of smartphone-based mobile platforms.

Methods: A polydimethylsiloxane (PDMS) overlay was used as a configurable translucent elastomer material to model the stiffness and texture of skin. A novel custom smartphone-based app was developed to capture images of various skin lesions, which were subsequently displayed on a tablet or second smartphone, over which the PDMS model skin elastomer was placed. Using the local Bluetooth connection between mobile devices, an iterative feedback algorithm corrected the visual distortion caused by the optical scattering of the translucent elastomer, enabling better virtual visualization of the lesion.

Results: The developed smartphone-based app corrected the distortion of images projected through the simulated skin elastomer. Surface topography of the developed PDMS elastomer provided a more accurate representation of skin texture.

Conclusions: In this investigation, we developed a smartphone-based skin lesion visualization app with a simulated skin elastomer for training/education in not only dermatology but also all general medical specialties that examine the skin. This technique has the potential to advance the educational experience by giving students the ability to see, touch, and feel pragmatic skin textures and lesions.

FIGURE 1.

Development of a PDMS elastomer skin overlay. A, Photograph of a commercially available nontransparent silicone-based elastomer. B, Photograph of the simulated PDMS skin elastomer and paraffin mold. C, Photograph of the thin, translucent, stretchable PDMS skin elastomer showing representation of skin texture and elevated skin features such as moles and skin tags. D, Application of the simulated skin PDMS elastomer placed on a smartphone screen to simulate both the tactile nature and visual appearance of skin lesions.

FIGURE 2.

Illustration of the smartphone-based skin simulation model. An original digital image of a skin lesion visualized through the semitransparent elastomer will be distorted. The distortion is corrected through an iterative feedback algorithm, which simultaneously corrects the color, contrast, and intensity, until the corrected visualized image closely matches the image characteristics of the skin and lesion in the original digital image.

FIGURE 3.

Characterization of a simulated PDMS skin elastomer. The top row shows cross-sectional and surface topography of the silicone elastomer skin model. The bottom row shows cross-sectional and surface topography of the fabricated semitransparent PDMS elastomer. The solid line boxes highlight the raised topography imaged with OCT and shown in the second and fourth columns, from the left. The dotted line boxes indicate the flat regions of the elastomers that were imaged with OCT and shown in the third column from the left. Scale bars represent 500 μm.

FIGURE 4.

Representative images showing displayed, distorted, and corrected images of various skin conditions. A, Superficial basal cell carcinoma. B, Seborrheic keratosis. C, Cutaneous horn with squamous cell carcinoma. D, Pyogenic granuloma. E, Psoriasis. An MSE was calculated for the ROIs shown by the square dotted boxes.

FIGURE 5.

Histogram plots of the displayed, distorted, and corrected images from uniform and nonuniform surfaces. A, Corresponds to Figure 4B. B, Corresponds to Figure 4E. The plots were generated based on the pixel values within the ROI.