本研究旨在開發一套應用於夜間陰莖生理監測之可穿戴式量測系統，以長時間同步記錄陰莖局部光體積變化描記法（Photoplethysmography， PPG）訊號與勃起狀態變化。系統以 STM32U5 系列微控制器作為核心控制單元，整合兩組 AFE4490 類比前端，建立左右側雙通道穿透式 PPG 擷取架構，並加入勃起狀態感測模組，使局部血液容積脈波與勃起狀態資訊可於共同時間基準下進行記錄。系統同時整合藍牙低功耗通訊（Bluetooth Low Energy， BLE）、SD card 本地資料儲存、鋰電池供電與電源管理功能，以支援即時訊號觀察與數小時之長時間量測。 為評估系統於實際穿戴情境下之量測可行性，本研究進行三位受試者之長時間人體測試，各次量測時間皆超過 300 min。受試者 S1 的量測涵蓋清醒視覺刺激誘發勃起與後續睡眠期間，並可於多個時間區段取得可辨識之雙通道 PPG 訊號；S2 於量測前段可取得具有週期性的 PPG 訊號，但後段訊號品質下降，且量測結束後發現感測器已有脫落情形；S3 則於大部分量測期間未能取得穩定且可辨識之 PPG 脈波，顯示長時間量測之資料品質仍受到感測器貼附位置與接觸穩定性的明顯影響。 在可用量測區段中，觀察到陰莖局部 PPG 振幅可能隨勃起狀態變化呈現由大逐漸減小或由小逐漸增大的不同型態，且兩位受試者之資料中皆曾出現 PPG 波形極性反向（polarity inversion）現象。另於 S3 的量測中，利用智慧型手環所提供之睡眠分期資訊進行時間對照，可觀察部分勃起狀態變化區段與快速動眼期（Rapid Eye Movement， REM）時段在時間上接近或部分重疊。惟智慧型手環之睡眠分期並非臨床標準睡眠分期，且本研究亦未同步取得陰莖都卜勒超音波或其他血流動力學參考量測，因此目前僅就實際觀察到之訊號現象進行描述，不進一步推論其所對應之血流動態或生理機制。 綜合而言，本研究完成一套可同步取得雙通道陰莖局部 PPG 與勃起狀態資訊之可穿戴式長時間量測平台，並透過實際人體測試驗證其數小時連續記錄之可行性。量測結果亦顯示，感測器固定與長時間接觸穩定性為目前影響 PPG 資料品質的重要因素。未來若能進一步改善感測器固定方式、增加受試者數量，並加入同步血流或睡眠參考量測，將有助於進一步探討陰莖局部 PPG 在不同勃起與睡眠狀態下之訊號變化特性。 關鍵字： 可穿戴式裝置、光體積變化描記法、陰莖生理監測、勃起狀態感測、長時間生理訊號量測;This study aims to develop a wearable measurement system for nocturnal penile physiological monitoring， enabling long-term and synchronized recording of local penile photoplethysmography (PPG) signals and erection-state changes. The system employs an STM32U5 series microcontroller as the main control unit and integrates two AFE4490 analog front ends to establish a bilateral dual-channel transmission-mode PPG acquisition architecture. An erection-state sensing module is also incorporated so that local blood-volume pulse signals and erection-state information can be recorded on a common time base. In addition， Bluetooth Low Energy (BLE)， local SD card storage， battery-powered operation， and power-management functions are integrated to support real-time signal observation and continuous measurements lasting several hours. To evaluate the feasibility of the system under practical wearable conditions， long-duration measurements were conducted in three participants， with each recording lasting more than 300 min. For participant S1， the measurement covered both visually induced erection while awake and the subsequent sleep period， and identifiable bilateral PPG signals were obtained during multiple recording intervals. For S2， periodic PPG signals were observed during the early part of the measurement， whereas signal quality gradually deteriorated during the later period; sensor detachment was found after the participant awoke. For S3， stable and clearly identifiable PPG pulses could not be obtained during most of the recording. These results indicate that sensor placement and contact stability remain important factors affecting signal quality during long-term measurements. Within usable recording segments， local penile PPG amplitude exhibited different temporal patterns during erection-state changes， including gradual increases and decreases. PPG polarity inversion was also observed in two participants. In addition， sleep-stage information obtained from a consumer smart wearable device was used for temporal comparison in S3， and some erection-state changes occurred close to or partially overlapped with periods labeled as rapid eye movement (REM) sleep. However， the sleep stages provided by the wearable device were not derived from clinical-standard polysomnography， and no simultaneous penile Doppler ultrasound or other hemodynamic reference measurements were available. Therefore， the observed PPG amplitude changes and polarity inversion are described as measurement phenomena rather than being interpreted as specific changes in blood flow or physiological mechanisms. In summary， this study establishes a wearable platform capable of synchronized long-term recording of bilateral penile PPG signals and erection-state information and demonstrates its feasibility through multi-hour human measurements. The results further show that sensor fixation and long-term contact stability are major factors affecting PPG data quality. Future work should focus on improving sensor attachment， increasing the number of participants， and incorporating synchronized hemodynamic or sleep reference measurements to further investigate the characteristics of penile PPG under different erection and sleep states. Keywords: wearable device， photoplethysmography， penile physiological monitoring， erection-state sensing， long-term physiological monitoring
