A wearable monitoring device comprises a storage unit, a photoplethysmograph and a control unit. The photoplethysmograph comprises a light emitting unit and a light detecting unit which generates a photoplethysmogram. When the wearable monitoring device is operated in a wearing detection mode, the control unit is utilized to control the light emitting unit not to emit light and control the storage unit to store the photoplethysmogram as a first detection value, and control the light emitting unit to emit light and control the storage unit to store the photoplethysmogram as a second detection value. Further, according to the first detection value and the second detection value, a third detection value is worked out. When the control unit determines that the consecutive times of the first detection value falling in a first range of values and the third detection value falling in a second range of values amount to a predetermined number of times, the wearable monitoring device is switched from the wearing detection mode to a monitoring mode.一種穿戴式監控裝置,包含一儲存單元、一光體積描述器及一控制單元。光體積描述器包括一發光單元及一產生一光體積描述訊號的光偵測單元。當穿戴式監控裝置執行於一穿戴檢測模式,控制單元控制發光單元不發光並控制儲存單元將光體積描述訊號儲存成一第一檢測值,且控制發光單元發光並控制儲存單元將光體積描述訊號儲存成一第二檢測值,且根據第一檢測值及第二檢測值計算出一第三檢測值。當控制單元判斷第一檢測值在一第一數值範圍內且第三檢測值在一第二數值範圍內的連續次數到達一預定次數,穿戴式監控裝置由穿戴檢測模式進入一監控模式。S01~S13‧‧‧流程步驟
