Design and benchtop validation of a handheld integrated dynamic breast imaging system for noninvasive characterization of suspicious breast lesions.

We have developed a portable, handheld, integrated, dynamic breast imaging system that integrates a near infrared tissue oximeter, clinical ultrasound, and two pressure sensors for noninvasive detection of pressure-induced structural and functional dynamics of suspicious breast lesions. A series of benchtop tests were conducted to validate multiple performance characteristics of the integrated dynamic near infrared/ultrasound breast imaging system (idNIRUS), including the reconstruction of the absorptive heterogeneities and the generation of the dynamic compression stimuli. In absorptive heterogeneity testing, we reconstructed the absorption coefficients of transparent polypropylene tubing circulated with a skim milk-India ink mixture and embedded in a gel wax tissue simulating phantom. High linear correlations (R(2) greater than 0.989) were observed between the reconstructed and the measured absorption coefficients of the embedded tubing. In dynamic compression testing, five volunteer operators generated ten successive compression sessions by compressing the idNIRUS imager on a breast self examination wearable model following the computer simulated pressure profile. The manually generated pressure profiles demonstrated an accuracy of 95.7% and operator-dependent variation of less than 5%. The results of the current benchtop tests will help to optimize the most appropriate testing conditions for our future planned clinical trial.