Multicontrast Pocket Colposcopy Cervical Cancer Diagnostic Algorithm for Referral Populations.

Objective and Impact Statement. We use deep learning models to classify cervix images-collected with a low-cost, portable Pocket colposcope-with biopsy-confirmed high-grade precancer and cancer. We boost classification performance on a screened-positive population by using a class-balanced loss and incorporating green-light colposcopy image pairs, which come at no additional cost to the provider. Introduction. Because the majority of the 300,000 annual deaths due to cervical cancer occur in countries with low- or middle-Human Development Indices, an automated classification algorithm could overcome limitations caused by the low prevalence of trained professionals and diagnostic variability in provider visual interpretations. Methods. Our dataset consists of cervical images (n=1,760) from 880 patient visits. After optimizing the network architecture and incorporating a weighted loss function, we explore two methods of incorporating green light image pairs into the network to boost the classification performance and sensitivity of our model on a test set. Results. We achieve an area under the receiver-operator characteristic curve, sensitivity, and specificity of 0.87, 75%, and 88%, respectively. The addition of the class-balanced loss and green light cervical contrast to a Resnet-18 backbone results in a 2.5 times improvement in sensitivity. Conclusion. Our methodology, which has already been tested on a prescreened population, can boost classification performance and, in the future, be coupled with Pap smear or HPV triaging, thereby broadening access to early detection of precursor lesions before they advance to cancer.

A verification and parametric analysis of an analytical model of a flexural vibration mode piezoelectric transformer.

In this paper, a circuit model equivalent to that proposed in a previous work was verified through experimental and finite element methods. On the basis of this verified model, the impact of the parameters on the electrical characteristics of a circular flexural vibration mode piezoelectric transformer was systematically investigated through the orthogonal experiment design method. Some interesting and valuable rules were found. Additionally, the research process showed that the orthogonal experimental design method itself can partly act as an optimization design method for the circular flexural vibration mode piezoelectric transformer design.