A photoplethysmographic (PPG) device is disclosed. The PPG device can include one or more light emitters and one or more light sensors to generate the multiple light paths for measuring a PPG signal and perfusion indices of a user. The multiple light paths between each pair of light emitters and light detectors can include different separation distances to generate both an accurate PPG signal and a perfusion index value to accommodate a variety of users and usage conditions. In some examples, the multiple light paths can include the same separation distances for noise cancellation due to artifacts resulting from, for example, tilt and/or pull of the device, a user’s hair, a user’s skin pigmentation, and/or motion. The PPG device can further include one or more lenses and/or reflectors to increase the signal strength and/or and to obscure the optical components and associated wiring from being visible to a user’s eye.揭示一種光體積描記(PPG)裝置。該PPG裝置可包括一或多個光發射器及一或多個光感測器以產生用於量測使用者之PPG訊號及灌注指數的多重光路徑。每一對光發射器與光偵測器之間的該等多重光路徑可包括不同分隔距離以產生準確PPG訊號與灌注指數值兩者，從而適應多種使用者及使用條件。在一些實例中，該等多重光路徑可包括相同分隔距離以實現因由(例如)該裝置之傾斜及/或牽拉、使用者毛髮、使用者皮膚色素沉著及/或運動產生之偽訊所致的雜訊消除。該PPG裝置可進一步包括一或多個透鏡及/或反射器以增加訊號強度及/或遮蔽該等光學組件及關聯佈線以免被使用者眼睛看到。
