The goal of this clinical trial is to evaluate the feasibility and effectiveness of a ring-type blood pressure measurement device compared to a 24-hour ambulatory blood pressure monitoring device in patients with hypertension or suspected hypertension. The main question it aims to answer is whether the 24-hour blood pressure measurement accuracy of the ring-type blood pressure monitor is similar to that of the 24-hour ambulatory blood pressure monitor. To participate, subjects must wear a ring blood pressure monitor and an ambulatory blood pressure monitor simultaneously for 24 hours.

Inclusion Criteria:

1. Patients scheduled for 24-hour ambulatory blood pressure monitoring for diagnostic purposes among those suspected of having hypertension

2. Confirmed hypertensive patients scheduled for 24-hour ambulatory blood pressure monitoring for treatment purposes

   • Either criterion 1 or 2 are planned to be selected as study participants.

Exclusion Criteria:

• Participants who do not consent to the study
• Individuals with a Body Mass Index of 30 or above (there's a concern of measurement errors as the standard 24-hour ambulatory blood pressure cuffs may not fit well)
• Pregnancy
• Baseline heart disease patients: individuals with a history of hospitalization due to heart failure, valvular disease, or myocardial infarction
• Patients diagnosed with atrial fibrillation on a 12 lead EKG within the past 6 months
• End-stage renal disease (patients undergoing dialysis)
• Users of mobile phones that are not compatible with the test device (CART-I plus) used in the study