Reflective PPG Wearable for Continuous Blood Pressure Monitoring

The BB-613WP is a wrist-worn or skin attached device indicated for use in measuring and displaying functional oxygen saturation of arterial hemoglobin (%SpO2) and pulse rate using photoplethysmography (PPG) technology. Most commercially available devices transmit light in specific red (~ 650 nm) and infrared (~ 880 nm) wavelengths through the tested tissue, and a detector on the other side absorbs the transmitted light. These wavelengths have a unique absorbance pattern upon interaction with oxy- and deoxyhemoglobin. The detector measures the changing absorbance at each of the wavelengths allowing it to determine the absorbance resulting from the pulsating arterial blood alone excluding venous blood, skin, bone, muscle, and fat. The BB-613WP uses a unique reflective PPG technology, where, unlike most devices, the light source (Light Emitting Diodes, LEDs) and sensor array are placed on the same side (backside) of the device. As the LEDs transmit light into the subject’s skin, part of this light is reflected from the tissue and is detected by a photodiode detector. The high temporal and quantitative resolution of the device allows it to capture minute changes in tissue reflectance, calculating numerous vital signs derived from pulse contours, including advanced hemodynamic parameters such as tracking changes in blood pressure. This is based on Pulse Wave Transit Time (PWTT) which is obtained utilizing pulse measurements from the integrated SpO2 sensor, following a calibration process using an oscillometric blood pressure monitor. Once a calibration measurement is taken using the cuff-based BP device, the values are entered into a user’s application. The calibration is valid for three months, after which a new calibration measurement should be taken and introduced into the application using the same method.
The results are displayed on the LCD screen of the wristwatch device as well as on the mobile application installed on the user’s smartphone. From there, the data is transmitted in real-time to a web application used by health care providers.