Collect raw data from CS BP Pillow System and Arterial line (A-line) in volunteers. The data collected in the study will be used for development of the CS BP algorithm.

This is a prospective data collection single-site study designed to collect blood pressure (BP) waveforms and estimate BP via the CS BP Pillow System, in parallel with arterial line (A-line data). The data collected will be used for algorithm development of the CS BP system.

The study includes a screening phase followed by BP data collection session using the CS Pillow System and an A-line. Participants will be recruited by the Investigator according to the study eligibility criteria.

A total of 40 participants who meet eligibility criteria will be enrolled in the study in 2 cohorts: Cohort I and Cohort II. Each Cohort will include 20 participants. The cohorts will be identical with respect to study procedures and distribution of sex, body mass index (BMI), age, and blood pressure classification groups.

After informed consent is obtained, demographic information, medical history, current medications use and wrist circumference measurement will be recorded. A modified Allen's test, a lateral difference test and additional assessments will be performed to confirm eligibility criteria. In participants who meet the eligibility criteria, the CS BP Pillow will be placed over the radial artery and an A-line will be inserted into the radial artery of the contralateral hand. A dynamic response calculation will be performed to confirm the integrity of the inserted line.

After the participant has rested for at least 5 minutes, simultaneous BP recordings using the CS BP Pillow System and the A-line will begin and continue for about 1 hour.

Upon completion of data collection, all devices will be removed, and adverse events will be assessed and documented.

The end of study for each participant is defined as the completion of device removal and completion of adverse event follow-up. The end of the study is defined as completion of 40 evaluable participant datasets

Inclusion Criteria:

• 40-80 years old.
• Ability and willingness to sign and understand an informed consent form.
• The participant has a palpable radial pulse in both wrists.
• The participant is willing and able to be fitted with the investigational device, A-line, and reference cuff, and is willing and able to undergo all study procedures, including 1 hour of recording with the investigational device and A-line.

Exclusion Criteria:

• Participant who are currently enrolled in another clinical investigation in which the intervention might compromise the safety of the participant or interfere with the data collected.
• Participant whose body habitus precludes them from wearing the investigational device on their wrist.
• Female participants who self-reported as pregnant based on a urine pregnancy test, or who are self-reported as trying to get pregnant or who are breastfeeding.
• Participant whose BMI is greater than 35.
• Participant with a documented medical history of cardiac arrhythmia.
• Participant with diagnosed diabetes mellitus.
• Participant with implanted cardiac defibrillators or pacemakers, Ventricular Assist Device (VAD) or other mechanical circulatory support devices, whether intracorporal or extracorporeal.
• Participant with stage 4 or stage 5 end-stage renal disease, or participants with arteriovenous shunts.
• Participant with pheochromocytoma or primary hyperaldosteronism.
• Participant with diagnosed heart failure with New York Heart Association (NYHA) class III/IV, or participants with a history of stroke.
• Participant with a known clotting disorders or currently taking a prescription anticoagulants (daily aspirin use is permitted).
• Participant with an infection requiring antibiotics.
• Participant with peripheral artery disease
• Participants with compromised circulation, including Raynaud's syndrome.
• Participant has a fracture, severe trauma, or anatomical deformity involving the wrist intended for placement of the investigational product, which could interfere with proper fitting or function of the device.
• Participant with moderate to severe valvulopathies.
• Participant with primary vasculitis.
• Participant with tremors or otherwise unable to remain still for 1 hour.
• The left to right arm lateral difference of the average systolic blood pressure values is more than 15 mmHg or the lateral difference of the average diastolic blood pressure values is more than 10 mmHg.