Authors: Xiangyang Wang, Ruojiang Wang, Yuyang Zhang, You Wu, Xu Wu, Zihao Luo, Yu Chang, Xiansheng Zhang, and Tingrui Pan
Abstract
Erectile dysfunction (ED) is a prevalent type of sexual dysfunction, and continuous monitoring of penile tumescence and rigidity during spontaneous nocturnal erections is crucial for its diagnosis and classification. However, the current clinical standard device, limited by its active mechanical load, is bulky and nonwearable and strongly interferes with erections, which compromises both monitoring reliability and patient compliance. Here, we report a wearable adaptive rigidity monitoring (WARM) system that employs a measurement principle without active loads, allowing for the assessment of penile tumescence and rigidity through a specifically designed elastic dual-ring sensor. The dualring sensor, comprising two strain-sensing rings with distinct elastic moduli, provides high resolution (0.1%), robust mechanical and electrical stability (sustaining over 1000 cycles), and strong interference resistance. An integrated flexible printed circuit (FPC) collects and processes sensing signals, which are then transmitted to the host computer via Bluetooth for ED assessment. Additionally, we validated the WARM system against the clinical standard device using both a penile model and healthy volunteers, achieving high consistency. Furthermore, the system facilitates the continuous evaluation of penile erections during nocturnal tumescence tests with concurrent sleep monitoring, demonstrating its ability to minimize interference with nocturnal erections. In conclusion, the WARM system offers a fully integrated, wearable solution for continuous, precise, and patient-friendly measurement of penile tumescence and rigidity, potentially providing more reliable and accessible outcomes than existing technologies.
Fig. Feasibility testing of the WARM system. (A) Penile tumescence simulator consisting of an expandable penile model, a flow controller for adjusting the model rigidity and circumference, and a computer with the corresponding control software. (B) Comparison of the tumescence measurements of the expandable penile model at varying internal pressures using both the WARM system and the RigiScan (N = 3), benchmarked against standard measurements from a flexible measuring tape. (C) Comparison of the rigidity measurements of the expandable penile model at different internal pressures utilizing both the WARM system and the RigiScan (N = 3). (D) Linear regression analysis of rigidity measurements from both systems. The coefficient of determination R2 for the linear regression is 0.98. (E) Comparison of tumescence and rigidity measurements between the two systems during the simulated penile erection process. The internal pressure of the penile model is designed to increase from 0 to 60 mmHg at a rate of 1 mmHg/s and then remain for 3 min, 1 min, or 0 min before decreasing rapidly to 0 mmHg
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Keywords: erectile dysfunction; rigidity monitoring; iFlow controller
Microsystems & Nanoengineering 2024, 10, 131