Objective Measurement of Pain Using the Algometer

It is generally recognized that pain assessment and management in newborns and children is
an unmet need. According to the American Medical Association, "The pediatric population is
at risk of inadequate pain management, with age-related factors affecting pain management in
children. Children are often given minimal or no analgesia for procedures that would
routinely be treated aggressively in adults. Although much is now known about pain
management in children, it has not been widely or effectively translated into routine
clinical practice."1 Although some clinically validated methods exist (e.g. CRIES, PPIP,
Faces, etc.), no "gold standard" of pain assessment has been adopted in clinical practice.
All are hindered by ambiguous behavioral correlates to the pain stimuli standards as well as
the subjective variability inherent in both clinical and parent evaluators 2.

Other apparatus/methods for pain assessment suffer from similar shortcomings. For example,
pain tolerance threshold (PTT) and current perception threshold (CPT) determinations both
rely on verbal response from a patient. Those determinations are subjective and
semi-quantitative and use electrical stimulation to directly excite both large and small
diameter sensory nerve fibers. The CPT determination represents the minimum amount of a
potentially noxious electrical stimulus that can be perceived, while the PTT determination
represents the maximum amount of noxious electrical stimulation that can be tolerated when
used as a clinical diagnostic tool. Thus, PTT depends on a subject's verbal response and
requires patient exposure to aversive electrical stimulation, which causes both undesirable
discomfort but also elicits the affective component of pain.

Therefore, the development of tools for assessment and management of pain in newborns and
children is a high priority and represents a significant unmet medical need. Both
inadequately treated pain or over administration of analgesics can have deleterious
physiologic consequences for neonates, infants and children. While a number of methods are
in use, no "gold standard" for pain assessment exists. (Anand 2007) To accomplish meaningful
pain management in children one must first be able to objectively assess pain, particularly
in patients who are (1) non-verbal (e.g. neonates, infants), (2) lacking understanding and
adequate verbalization skills (e.g. young children, developmentally disabled individuals)
and (3) patients with compromising neuropathic clinical presentations. To address these
critical issues with pain management, the Human Algometer and method are under development
by Drs. Finkel and Quezado from the Pain Medicine Program at the Sheikh Zayed Institute. In
brief, this device integrates a neurospecific neurostimulation of sensory nerve fibers
involved in pain response and near infra-red spectroscopy (NIRS) signal acquisition derived
from pain related hemodynamic changes in the somatosensory cortex. The device has the
ability to collect data on the NIRS response in the cerebral cortex to noxious stimulation
provided by the neurostimulation component. Signal processing of data from this trial and
subsequent trials will result in (1) the detection and optimization of a NIRS signal
specific to increased neuronal blood flow over the somatosensory cortex (nociceptive
response) and the frontal cortex (affective component). The individual neurostimulatory and
NIRS signal acquisition components integrated into this novel device are based in part or
whole on previously FDA approved devices from Neurotron, Inc. and Covidien plc (former
Somanetics INVOS ™) respectively.

Inclusion Criteria:

- the subject 18-65 years of age.

- the subject is a healthy adult with significant ongoing medical conditions

- the subject is willing to remain at the research site for the duration of the study
session.

- the subject is willing and able to provide written informed consent to study
participation.

Exclusion Criteria:

- the subject has consumed alcohol within the last 12 hours prior to testing

- subject has pain at the time of testing anywhere in the body