In this study we aimed to investigate the performance and effectiveness of NOL and/or NOLedge as a tool for pain assessment in geriatric and critical ill non communicating patients.

Our hypothesis was that NOL and the NOLedge may have good correlation with the health-care professional assessment PAINAD, BPS values, even with the use of the drugs affecting autonomic nervous system.

Inclusion Criteria:

• Male and female, Age > 18 years old.
• Spontaneously breathing or mechanically ventilated
• Any patient who is unable to express his/her own level of personal pain by using visual scales according to the hospital standard
• Written informed consent provided by the participant (if they have capacity) or guardian (if they do not have capacity) or a written proxy informed consent from a legally authorized representative empowered to make health-related decisions for the potential study participant.

Exclusion Criteria:

• A patient whose staff or research team believes that his or her participation in the research will cause suffering to the patient.
• Unstable condition preventing planned routine procedures of care, and conditions precluding the use of PMD-200: absence of sinus cardiac rhythm.

Patients with a clinical syndrome due to disease of a progressive nature, which leads to disturbances in multiple higher cortical functions, including memory, thinking, orientation, comprehension, calculation, learning capacity, language and judgment;

1. Older adults with advanced dementia;
2. Critically ill/unconscious patients;
3. Patients at the end of life stage.
4. Ventilated patients.