Development of a Wearable Device for Continuous Tracking of a Patient’s Vital Signs

Wearable devices and technologies are shaping the modern approach to healthcare. The objective of this project was to design and construct a working prototype of an easy to use, cost-conscious, wearable device that allows a patient to continuously and non-invasively monitor several parameters of health outside of a clinical setting. These health parameters include body temperature, heart rate, blood pressure, and blood oxygen levels. 
By design, the device is to be worn continuously on the patient’s upper arm with new measurements, not including blood pressure, taken every five seconds and blood pressure measured every 3.5 minutes for as long as the user wishes measurements to be taken. To achieve this, the device prototype was constructed using a standard at-home blood pressure cuff as a foundation. A majority of the original blood pressure monitor was removed; however, some components, such as the pressure sensor and air pump, were incorporated into the new wearable design. The cuff was further instrumented with non-invasive sensors to achieve easy, comprehensive measurements. To measure the desired parameters, the techniques of oscillometric blood pressure measurement and photoplethysmography were used. 
To record and process the sensor data, a mobile application interface for the device was created. The application receives real-time measurements from the user and displays the measured values on a phone, tablet, or computer. All readings from the sensors are transmitted to the mobile application through a Bluetooth module connected to the microcontroller. Warnings for the user will also be displayed on the screen in the case of unhealthy levels measured or any sudden changes in the present values. For added functionality in an emergency situation, the application is equipped with a CPR metronome, which can be activated when needed to ensure consistency in chest compressions during cardiopulmonary resuscitation. 
The current market of comparable wearables — including arm bands, chest straps, or smartwatches — may be cost-prohibitive and often requires mobile data or a subscription service for use. The design of this device resulted in a significantly lower price while maintaining or exceeding the utility of others currently available to consumers. The target market for this device is primarily patients who are located in economically-distressed, remote regions where traveling to a clinic, especially on a frequent basis, is difficult, if not impossible. This wearable device may be used to combat the travel burden facing remote inhabitants by providing the opportunity to monitor elements of health in one’s own home rather than in a clinical setting.