Rheumatoid Arthritis Disease Activity Monitor

Rheumatoid Arthritis (RA) is an autoimmune disease. There are four stages of
the disease:
1. Synovial inflammation
2. Swelling of synovium
3. Pannus formation
4. Advanced bone and cartilage destruction
Currently, there is no cure for RA, making the disease a chronic condition. RA
is more prevalent in elderly and women. With medication it is possible to delay
the onset of complications. Over the last decade, the treatment of RA has
changed. Where treatment was palliative until pain medication was ineffective,
the treatment is now more aggressive with early administration of disease
modifying drugs (DMARDs).
The treatment for RA is staged. First, the patient receives generic, low-cost
drugs. If this treatment becomes ineffective, the treatment is adjusted with
different and usually more advanced drugs. Biologics are a category drugs that
are considered most advanced and most expensive.
For effective treatment, there are two unmet needs.
• A tool to aid early diagnosis, as this allows early treatment and delay of
complications and physical restrictions for patients.
• A safe, simple and cheap tool to monitor disease progress to allow traceable,
operator-independent informed decisions on treatment adjustments.
Non-invasive optical methods offer several advantages over existing modalities.
Optical contrast can be related to physiological parameters in the body, such
as blood concentration and oxygenation. At relevant wavelengths and
intensities, optical radiation is completely harmless. The cost of optical
methods is low compared to other modalities. An important application, where
optical methods can help diagnosis and treatment is detection of inflammation
of joints in patients suffering from rheumatoid arthritis (RA). Due to the
highly scattering nature of tissue, non-invasive optical methods for medical
imaging are limited to the extremities of the human body. For application in
joint diseases, this is acceptable, because imaging of hands can provide
sufficient clinical information.

Primary objectives
This is a retrospective, nonrandomized controlled observational study,
conducted in a single center to evaluate the potential of optical attenuation
measurements to establish disease activity for rheumatoid arthritis patients.
Secondary objectives
Establish parameters from transient optical transmission measurements of the
joint that relate to clinical evaluation results of individual joints
Evaluate relation between disease activity (DAS-28 score) and the optical
attenuation spectra of the fingers of a patient.

This is a cross sectional, nonrandomized controlled observational study,
conducted in a single center to evaluate the potential of optical attenuation
measurements to establish disease activity for rheumatoid arthritis patients.

The subject will sit for 5 minutes with a hand placed on a sphere. One finger
will be placed between two sets of two fibers. During the 5 minutes of the
measurement a pressure cuff will be inflated twice to 50mmHg for the duration
of 1 minute.
Based on the risk management report, the risks are classified as negligible.