The purpose of this study is to compare measurements of blood pressure (BP) between the Philips non-invasive blood pressure (NIBP) system (including NIBP cuff and portable patient monitor) and invasive radial for Subject Group 2 and 3, and radial or umbilical arterial line for neonates (A-line) in critical care patients.

A multi-center, multi-phase, prospective, self-controlled, observational study.

• Phase I - A pilot phase designed for feasibility and the potential for algorithm development (enhancement).
• Phase II - Pivotal Phase: At the completion of Phase I -and finalization of the algorithm (if applicable), Phase II is designed for the purpose of establishing equivalence of the Philips NIBP system with the gold standard radial or umbilical (neonates) arterial line.

Inclusion Criteria:

• Patient admitted into the NICU, PICU, ICU, or OR (operating room)
• Adult aged 18 years and older, or parent/legal guardian of minor, willing and able to understand and provide informed consent/assent
• Indication for NIBP cuff
• Indication for radial arterial line for Subject Group 2 and Subject Group 3, and radial or umbilical arterial line for Subject Group 1
• Meet the following stratification criteria across the study:

Stratification (per the ISO 81060-2:2018/Amd-2:2024):

• Subject Group 1:

  • At least 3 patients shall be <1000 g in weight
  • At least 3 patients shall be 1000 to 2000 g in weight
  • At least 3 patients shall be > 2000 g in weight
  • At least 3 patients shall be ≥ 29 days and < 1 year of age
  • At least 3 patients shall be ≥ 1 year and < 3 years of age
  • The remaining patients may be from any of the above age or weight groups in order to complete the sample size
  • A patient can be in more than one category simultaneously

• Subject Group 2:

  • At least 30% male, 30% female
  • Limb circumference distributed as specified in ISO81060-2:2018/Amd2:2024.

• Subject Group 3:

  • At least 30% male, 30% female
  • Limb circumference distributed as specified in ISO81060- 2:2018/Amd-2:2024.
  • At least 10% SBP ≤ 100mmHg
  • At least 10% SBP ≥ 160mmHg
  • At least 10% DBP ≤ 70mmHg
  • At least 10% DBP ≥ 85mmHg

Exclusion Criteria:

• Inability to place the study device appropriately due to patient's anatomy or condition
• Known pregnancy or lactating women (self-report)
• Patients treated with an intra-aortic balloon pump
• Aortic and mitral regurgitation (> 2 nd degree)
• Measurements taken in the lateral position
• Currently participating in another clinical trial with any product, treatment and/or medication that clinically interferes with the study endpoint(s)
• If valid SBP reference measurements for lateral difference is > 15 mmHg (except for neonates with umbilical A-line)
• If valid DBP reference measurements for lateral difference is > 10 mmHg (except for neonates with umbilical A-line)
• At the Principal Investigator's discretion, subject does not qualify to participate in the study for any reasons that are not mentioned above

The clinical study will be conducted in neonate, infant, pediatric, and adult patients admitted into the NICU/PICU/ICU/OR.