Frequently Asked Questions
The body’s response to an invader (a virus) begins prior to the onset of symptoms, such as elevated body temperature or fever. And, the body’s response to a virus can remain in a presymptomatic state for as long as two weeks before symptom expression. Because the virus is present during the presymptomatic phase, infected (but not symptomatic) individuals can fuel the spread of virus via viral shedding. Viral shedding is the process of viral replication in the body that is followed by a release into the environment. Presymptomatic viral shedding presents a significant challenge to public health and to organizations. In organizations, the clinical implications from the spread of virus (i.e. a significant number of individuals infected and ill) can quickly translate to significant operational and economic risk for an organization.
Prior to symptom expression, the presence of a virus is reflected in the vasomotor (vessel constriction, vessel dilation, and blood flow) and inflammatory activity in the face. The patterns exhibited in the vasomotor and inflammatory response indicate a healthy state or high suspicion for the presence of influenza-like illness, including COVID-19. The surface skin in the face provides the roadmap to early detection of virus.
Reference: Center for Disease and Infection Control (CDC), MMWR, “Presymptomatic Transmission of SARS-CoV-2 – Singapore, January 23-March 16, 2020”, April 10, 2020, Wei, et al).
Viral Sign interprets an infrared image from a thermal camera to produce a comprehensive thermal signature of the face. The thermal signature, reflective of vasomotor and inflammatory states in the face, enables the AI in Viral Sign to identify pattern consistent with the presence of flu-like illness, including COVID-19.
Viral Sign is deployed in South America (Brazil), Europe, Middle East, and in the United States. The deployments include a diverse mix of manufacturers, distribution centers, government building, transportation centers, and healthcare organizations. To date, over 800,000+ screens have been conducted by Viral Sign in the manufacturing, food processing, healthcare, and hospitality sectors.
Unlike point thermometers or thermal cameras, Viral Sign does not rely on single point or maximum temperature of the face. Point clinical thermometer temperature assessment evaluates a single point on the forehead, ear, or wrist.
The weaknesses of point thermometer measurement include
• Great variability in readings and lower accuracy,
• Exposes the operator to risk of infection,
• Exposes those being screened to a person who may be infected,
• Variability due to circadian rhythm, activity, humidity, and ambient environment,
• Utilization of NSAIDs can mask the accurate recognition of elevated temperature, and
• Individuals may present symptoms shortly after testing as they move from pre-symptomatic to illness status.
Thermal cameras rely only on a single point of maximum temperature, despite receiving an image formed by several temperature points. This is similar in many respects to the use of point temperature thermometers. In addition, thermal cameras do not limit the analysis of temperature to the maximum temperature point of human skin. The thermal camera can randomly retrieve temperature measurements outside the human body. The eyes are a region that can get moist due to tears. Tearing in the eyes does not correlate with fever. Vascular diseases or lesions in this region of the face can hinder the analysis also based on a single point.
Organizations deploy Viral Sign at locations that serve as points of entry into the client facility. The aim is to screen the individual prior to exposure to other individuals. In this setting, the Viral Sign camera is placed in a stationary location or locations. Larger organizations and/or facilities may require multiple Viral Sign cameras.
Prior to launching Viral Sign at the client location, the Viral Sign team can provide insight to ensure the number of camera locations is optimized to the facility and the screening workflow.
Viral Sign captures the number of screens by period (day, month, year) and the distribution of the results for “Okay” (low risk), “Evaluate” (medium risk), and “Risk” (high risk). The data is presented in a longitudinal manner so that the client can assess trends and patterns in their data set. These reports can be provided directly to the client or the client may source a client-specific dashboard as needed.
The thermal signature for the individual is not associated with the individual’s personal identity, unless the RFID function is deployed. If the client desires use of the RFID interface, the appropriate safeguards are in place consistent with HIPAA to ensure the protection of data. t
The calibration process considers both the ambient environment at the screening location (where the camera is located) and the environment individuals are leaving before entering the screening process. The calibration process is designed to recognize the change in the “From Environment” to the “Screening Environment”. Still, if an individual is entering from an extreme environment, it is appropriate to have the individual acclimate to the indoor climate before screening.
The findings from the Sao Paulo, Brazil research will be presented at the American Association of Thermography annual meeting on September 11th and 12th of 2020. These findings will be very revealing because Sao Paulo was/is a hot spot for COVID. A review of other findings specific to the use of screening intervention to mitigate the transfer of virus can be made available.
Viral Sign is a locked AI platform. The thermal signature of the individual is compared and contrasted against known patterns indicative of the presence of ILI. Viral Sign is not continuous AI as it does not incorporate each screening event to continuously revise the algorithm.
Autoimmune conditions, such as multiple sclerosis and rheumatoid arthritis, may generate a false positive. These conditions are characterized by low or overactive activity of the immune system. With that said, it is unlikely due to the inflammatory response characterized by these conditions is typically isolated to a specific area of the body and not the face.
If an individual is entering from an extreme environment or has been very active immediately prior to screening, it is appropriate to have the individual acclimate to the indoor climate before screening.
The glasses must be removed because the lens (or glass) blocks the receipt of infrared data from the eye region. In effect, the glasses act as a mirror reflecting the transmission of the infrared light back to the individual.