INTRODUCTION & OBJECTIVES

Treatment of dyspareunia usually consists on stretching the vaginal duct with dilators and is known to be invasive, lengthy and uncomfortable. Designing better treatments can be facilitated by better understanding of the physiological phenomena.

POPULATION SAMPLE

DAMIANO: maybe describe the setup of the VPI experiments? But actually we don't use data...

METHODS

We use engineering-oriented approaches to develop a mathematical model describing how vaginal pressure transforms into pain. For this we combine insights from medical literature with logical relations to form a qualitative model prone to mathematical analyses.

RESULTS

The resulting model exhibits two distinct loops named circle of fear (COF) and circle of pleasure (COP). The COF describes the dynamic relations between perceived fear, pelvic floor tension and pain, and captures the facts that: i) if pelvic muscles are active before or at the beginning of the penetrative act then vaginal stimuli may lead to pain; ii) muscular tension tend to be increased by fear; and iii) inducing opportune positive erotic stimuli may reduce fear. 

The COP instead simplifies the Basson model of the female sexual response, and describes the interplay among subjective arousal, physiological arousal and pleasure by postulating that: i) the physiological arousal increases if the patient is being simultaneously sexually stimulated and subjectively aroused; ii) the subjective arousal increases when the patient is sexually stimulated and when perceiving a pleasurable physical sensation; and iii) physiological arousal affects the subjective arousal not directly but rather through the intermediate state variable of physical pleasure.

CONCLUSION & RECOMMENDATIONS

The model, corresponding to a set of ordinary differential equations, mimics the physiological responses measured in clinical settings and predicts qualitatively how a patient will respond to different erotic stimuli and vaginal pressures. The model is thus a first step towards developing tools for designing better treatments in terms of dilation patterns. Future works will be to tune its parameters starting from collected medical evidence and complete it so to account for more variables.