The Holter Mode is intended as a tool for the medical professional who requires a 24hr ECG recording of their patient. While the tattoo and T1 Monitor replace the traditional bulky Holter devices, the app offers a user-friendly method for the technician to start the monitoring session and retrieve the data. In this mode, the T1 Monitor functions autonomously and stores raw data on the onboard microSD card, offering long-term data storage without the need for charging. The technician can upload this raw data for the medical professional to view in the medical control centre. The data can also be accessed in the Umana T1 Biosignals Studio, for offline processing, further analysis and report generation.