Clinical applicability of a new tactile sensor for evaluating rigidity of the penis: A comparative study with Rigiscan

Abstract

Background: A new tactile sensor was developed for detecting hardness of living tissue by Omata et al. in 1992. This paper reports applicability of the sensor for evaluation of penile rigidity. Methods: Nine patients from a group of 12 patients with penile erectile dysfunction were selected as subjects of this study. All patients agreed to artificial erection and monitoring of penile rigidity by a new tactile sensor and the Rigiscan system. The 9 patients selected all developed more than 1 cm circumferential expansion of the penis after an injection of smooth muscle relaxant into the corpus cavernosum. The sensor equipment consisted of a piezoelectric element that vibrated, and a pickup that detected vibration frequency. When the end of the sensor was pressed against a surface of the penis, the resonance frequency of the sensor changed and indicated rigidity of the organ. Rigidity of the penile shaft was simultaneously monitored with the sensor and the Rigiscan system before and after an injection of 40 mg papaverine or 20 μg prostaglandin E1. The sensor's measurements of rigidity were compared with those of Rigiscan. Results: Reproducibility of rigidity measured with the tactile sensor was satisfactory. Statistical analysis was made on 85 simultaneous pairs of rigidity values from the tactile sensor and Rigiscan. The analysis indicated significant correlation between the values. Conclusion: The tactile sensor as well as Rigiscan will be of use for evaluating rigidity of the penis.