Guest post by C. Webster Marsh, a lighting design controls specialist at HLB Lighting Design in Boston, MA. His views do not necessarily reflect those of HLB.
In my latest education express course, Integration and Building Automation, I discuss basic uses for a Building Automation System (BAS). One use not mentioned is Contact Tracing, which has been brought to the foreground primarily due to the COVID-19 pandemic (also known as Coronavirus). Contact tracing is potentially an essential part of safely re-opening businesses during Coronavirus and since lighting fixtures and lighting controls are necessary wherever people occupy a building, building management can make use of intelligent lighting control systems to improve their contact tracing methods to ensure their occupants are safe.
What is Contact Tracing?
The Centers for Disease Control and Prevention (CDC) defines Contact Tracing as:
“… working with a patient (symptomatic and asymptomatic) who has been diagnosed with an infectious disease to identify and provide support to people (contacts) who may have been infected through exposure to the patient. This process prevents further transmission of disease by separating people who have (or may have) an infectious disease from people who do not.”
As of the date this article was written, Coronavirus is seeing a resurgence in cases due to an increase in indoor activities as schools re-open and outdoor temperatures drop, forcing people to spend more time inside. Because of this, contact tracing is becoming more essential but also more challenging to do. New technology can help with contact tracing by collecting and responding to data. According to the CDC, for effective contact tracing the following criteria must be met:
- Have people regularly screened for signs and symptoms of Coronavirus.
- Regularly test people for Coronavirus.
- Enforce effective social distancing policies to reduce close contact.
- Identify people who test positive and have them self-quarantine.
- Identify any individuals who had close contact with any infected people. Close contact means anyone who has been within 6 feet of the person who tested positive for at least 15 minutes or has occupied the same shared space, such as an office, over the 2 days before illness onset or testing date.
The current method of contact tracing that the CDC employs relies on a network of trained people, known as Contact Tracers, to identify and interview people who test positive and to communicate with everyone surrounding the possible exposure. This process is lengthy, expensive, and relies on the patient’s memory, which can be inaccurate. An intelligent BAS can help improve this process by providing more reliable data that can speed up the time between a positive test and effective quarantine measures.
Contact Tracing with a BAS
There are several ways that a BAS can help improve the contact tracing process, but it should be noted that contact tracing cannot function effectively without regular screening, testing, social distancing, and quarantine protocols. Investments in a BAS that uses contact tracing should be simultaneous with investments in screening, testing, social distancing policies, and strict stay-at-home policies for infected people.
BAS integration is often done with a Networked Lighting Controls (NLC) system, a system in which different spaces may communicate with each other to share information. An NLC provides varying levels of granularity. Depending on the system design and intent, the granularity of the system’s control can be very broad, such as controlling each space type, or it can be very specific, such as controlling each luminaire. Very specific granularity on an NLC is often achieved by embedding sensors into each luminaire so luminaires can respond to their immediate surroundings more effectively.
In a system that implements a very specific level of granularity, one may consider utilizing Internet of Things (or IoT) for contact tracing. IoT enables anything to connect to the Internet and so it can be used as a dynamic system that monitors and tracks traffic or resources throughout the building. This allows the BAS to identify high traffic areas or bottlenecks while also reviewing whether proper social distancing is being followed or not. Building management can make use of this data to improve social distancing policies, reconfigure their workspaces, or to focus cleaning efforts on higher use areas. A common method of IoT contact tracing is done via smartphone apps connected to the lighting control system or BAS. With this option, every occupant would have an app that is wirelessly connected to the lighting control system. The lighting control system would then track people’s locations in the building and their proximity to others (aka space density). The control system also alerts people if they have had close contact with someone that had a positive test result so that they can self-quarantine until they are able to get tested.
An alternative option to using smartphones is to use Bluetooth low energy beacons (or BLE), which is becoming a common device in badges or other IoT devices as they use very little power. Contact tracing can be done using BLE beacons that communicate with nearby lighting controls devices so that location tracking can be accomplished without the need for a smartphone. These devices are still battery powered but can run for months without needing a new battery or a recharge.
Additionally, the BAS can actively work to protect its occupants. Traffic can be re-routed or controlled throughout a building to ensure proper social distancing is maintained. With IoT enabled devices connected to a BAS, shared devices or desks can be identified as “in-use” or special lighting can be activated to route occupants around high traffic areas, reducing close contact events.
Current Challenges with Contact Tracing
The biggest challenges with any contact tracing program are privacy and security. Most systems have redundancies to ensure that anonymity is maintained at all times, and therefore if someone tested positive, others would not know who it was, but rather that they had close contact with someone who had a positive test. Anonymity is a double-edged sword, however. Because of tight restrictions on data, the information one building collects cannot be shared with other buildings and so this elevated form of contact tracing stops once the occupant leaves the building.
Additionally, systems that require the occupants to carry a smartphone with them everywhere means that data could become inaccurate if, for instance, someone left that device on the charger while they went somewhere else in the building or if not everyone has a smartphone. Alternatively, BLE beacons that use little energy often have a limited range and so the BAS may need more devices to ensure constant communication with BLE beacons is achieved.
One other challenge to overcome is reducing shared surfaces that can transmit viruses and bacteria, such as a light switch. While occupancy sensors are a great option to reduce shared surfaces, manual overrides may still be necessary, which can come in the form of a manual switch. In some cases, the manual switch must remain, such as in instances when a switch is required to meet energy code. There are, however, touchless options, including providing lighting controls via smartphone, which allows building occupants to control the lighting from their phones; installing proximity sensors switches at entrances, so that occupants only need to wave their hand in front of the switch; or voice-activated controls like Alexa or Google.
Building management can support contact tracing with modern Building Automation Systems by tracking people’s location and proximity. With this data, proper social distancing can be ensured, and close contact events will be accurately logged so the correct people are contacted in the event of an infection.
It is important to note that contact tracing technology is constantly changing, and the information in this article may be outdated by the time you read it. There are ongoing improvements among manufacturers for contact tracing methods such as communication range, data privacy and security, and location accuracy, so the best option is to stay up to date on the latest information from the CDC and each manufacturer.