The Patchkeeper

Fig 1. PatchKeeper device with flexible ECG electrodes

The Patchkeeper is built with BT840E Bluetooth Low Energy (BLE) module from Fanstel. It contains a nRF52840 chip from Nordic Semiconductor, which contains a 64 MHz Cortex-M4 processor with FPU. The BLE can be turned on for real time data steaming during measurement. In the meantime, all the data is saved in micro-SD card inside the device. We also developed an iPhone based mobile APP for real time clock update and real time data monitoring.

The PK also contains a 400mAh Lithium polymer battery which can last about 20 hours under continuous recording of all sensor data. The battery can be charged through USB-C port.

The Patchkeeper device have been used in several projects, including human body abdominal sound for digestive tract monitoring and changes induced via daily stresses (see Ref 1), as shown in Fig 2.

Fig 2. The Patchkeeper as used on human for body abdominal sound monitoring of digestive tract influenced by daily stress.

In other projects we used PK in a different form factor on pet dog where we tracked (24/7) dog’s activity to investigate dog’s personality (see Ref 2), as shown in Fig 2.

Fig 3. The Patchkeeper as used for pet’s 24/7 activity monitoring and dog personality inference.

Since the PK device offers very high sensitivity for tracking internal sounds propagated through solid or liquidous media (like flash or water) we are looking for a new form of PK device which can be easily attached to any external functional device (functional box). With an elegant audio interface enabling Intimate attchement to any functional box the PK may provide internal audio life of the system while operating. As any mechanical and micromechanical system produce characteristic sounds while operating, tracking such sounds open opportunities for larger system optimizations or predictive maintenances.