Patients with IBD, including both Crohn's disease and ulcerative colitis, require accurate monitoring of intestinal inflammation for optimal follow-up and treatment. Traditional markers like C-reactive protein (CRP) and faecal calprotectin are useful but are either invasive or disliked by patients and a proper continuous monitoring is not feasible with fragmented biomarker information.

The NimBio technology provides support for the clinicians who are managing IBD patients' care based on a wearable technology that allows tracking responsiveness of blood flow properties (also called hemorheology) to inflammatory processes. NimBio's technology analyses blood flow properties using photoplethysmography (PPG), an optical signal, which detects blood flow changes in the microvascular bed of tissues. The PPG signal is obtained from a commercially available wearable (bracelet) which is convenient for the patients. Based on the impact of inflammation on parameters influencing hemorheology (mainly blood vessel stiffness, blood viscosity and red blood cell aggregation) and the fact that the PPG signal mirrors blood flow characteristics, PPG measurements are associated with changes in inflammatory biomarkers and therefore correlate with disease activity.

This offers a possibility for continuous, non-invasive monitoring of inflammation. The study aims to further validate the NimBio Inflammometer and its value for monitoring inflammatory changes and dynamics in patients with IBD at the University Hospitals Leuven.

Patients with IBD, including both Crohn's disease and ulcerative colitis, require accurate monitoring of intestinal inflammation for optimal follow-up and treatment. Traditional markers like C-reactive protein (CRP) and faecal calprotectin are useful but are either invasive or disliked by patients and a proper continuous monitoring is not feasible with fragmented biomarker information.

The NimBio technology provides support for the clinicians who are managing IBD patients' care based on a wearable technology that allows tracking responsiveness of blood flow properties (also called hemorheology) to inflammatory processes. NimBio's technology analyses blood flow properties using photoplethysmography (PPG), an optical signal, which detects blood flow changes in the microvascular bed of tissues. The PPG signal is obtained from a commercially available wearable (bracelet) which is convenient for the patients. Based on the impact of inflammation on parameters influencing hemorheology (mainly blood vessel stiffness, blood viscosity and red blood cell aggregation) and the fact that the PPG signal mirrors blood flow characteristics, PPG measurements are associated with changes in inflammatory biomarkers and therefore correlate with disease activity.

This offers a possibility for continuous, non-invasive monitoring of inflammation. The study aims to further validate the NimBio Inflammometer and its value for monitoring inflammatory changes and dynamics in patients with IBD at the University Hospitals Leuven

Inclusion Criteria:

1. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures

2. At least 18 years of age at the time of signing the Informed Consent Form (ICF)

3. Diagnosis of IBD (Crohn's disease or ulcerative colitis) or IBDU

4. Hospitalized or ambulatory patients with active IBD defined as:

   1. HBI ≥ 5, or PMS score ≥3, and
   2. Faecal Calprotectin ≥200 μg/g or CRP > 10 mg/ml, and
   3. Access to iOS or Android-based smartphone with internet access

5. Ambulatory patients would be recruited to the study with a gender ratio that will not deviate from a 40:60 ratio in favor of either gender

Exclusion Criteria:

1. Pregnancy
2. Allergy to steel or elastomer/rubber
3. Using a pacemaker, implantable cardiac defibrillator, neurostimulator, or other electronic medical equipment