Despite the negative connotations of sunburn or premature aging attached to Ultraviolet light (waves having a wavelength of less than 400nm), the market for UV LED is seeing spike like never before. The UV LED technology has become apparent as a viable option for a range of applications including detection, curing, sterilization, and security.
Today, the healthcare workers fighting on the frontlines against the extremely virulent COVID-19 are indeed unequipped. The scarcity of PPE (Personal Protective Equipment) kits have forced the workers to use not so protective gloves and masks. Even though countries are trying their best to manufacture as many PPE kits possible, it’s getting difficult to keep up with the rising number of cases. Thus, the use of devices like UV LEDs in hospitals and other places where contamination is a risk can give rise to a much safer environment, even in the absence of proper PPE kits.
What’s driving this growth?
- Traditional CCFL bulbs are often composed of mercury, which is infamous for its toxic nature. UV LEDs on the other hand are devoid of that.
- UV LEDs are much smaller in size.
- UV LEDs are more durable and have better immunity from vibrations and impact, saving replacement and maintenance costs.
- The UV LED technology consumes less ink and minimizes waste
What is UV LED technology?
UV represents the invisible wavelengths that fall between x-ray and visible light on the electromagnetic spectrum. The UV range can be further divided into UV-A, UV-B, UV-C, and Vacuum-UV.
Figure 1- Electromagnetic Spectrum – PathPartner Radar SDK for UV LEDs
UV-C rays are the ones with the shortest wavelengths, followed by UV-B, and UV-A rays which have the longest wavelengths. UV-A and a small portion of UV-B rays are what we usually come in contact with, as all of UV-C and a portion of UV-B rays are absorbed by the ozone layer, allowing only the leftovers to enter the Earth’s atmosphere. UV-A, being the one with the longest wavelength, can penetrate the skin.
UV radiation has been widely used in industrial processes and medical practices. Certain dental procedures utilizing UV such as destroying bacteria, producing fluorescent effects, curing of inks and resins, and phototherapy. UV lamps have emerged as an efficient tool to treat a condition known as psoriasis (a skin condition causing itchy, scaly, red patches).
UV-C, the portion representing wavelengths between 200 - 280 nanometres (nm), and the highest energy, are used in disinfecting products like UV LEDs. The Light Emitting Diodes (LEDs) generate a good number of UV-C photons which when directed towards bacteria, viruses and other pathogens render them harmless within seconds of exposure. When UV-rays hit the surface of a virus or bacteria molecule, they destroy the molecular bonds that hold the DNA. Thus, UV LEDs can be used to eliminate viruses, bacteria and moulds from water, air, and surfaces.
This is how the deployment of UV LEDs might help in eliminating the COVID-19 virus from various surfaces and further reduce the risks of outbreaks in the future.
Figure 2- UV-C radiation breaking DNA of Virus – PathPartner Radar SDK for UV LEDs
How UV LEDs can be made more efficient and safer?
As iterated earlier, light-emitting at this wavelength can be dangerous to humans and other life forms. Exposure to UV-C can cause life-threatening diseases like skin cancer and when viewed with naked eyes can even cause permanent loss of vision. Thus, one must be very careful while using them. Usually, it’s manually taken care of by the professionals in charge to ensure that humans do not come in contact with the radiation directly.
Figure 3- Automatic UV-C radiation in an empty room – PathPartner Radar SDK for UV LEDs
This is where the role of Radar technology comes into the picture. Radar can keep track of the occupancy level of a room and ensure that the UV-C radiation automatically emanates only when the given room is completely evacuated. A Radar sensor’s ability to accurately detect the position, number, and movement of every individual can further help in directing the UV-C radiation to particular areas rather than unnecessarily direct them everywhere. A Radar sensor’s capability of people-counting can make the process of automatic sanitization more efficient by optimizing its frequency. Thus, with a Radar sensor, UV-C radiation can be automatically on if and when needed and direct itself to where it is exactly needed.
What is mmWave Radar technology?
Millimeter-wave (mmWave) is a special class of radar technology that uses electromagnetic waves of millimeter range (i.e. a short-wavelength) for the detection of objects and providing the range, velocity and angle of these objects. It is a contactless-technology that operates in the spectrum between 30 GHz - 300 GHz. The use of small wavelengths has certain advantages when it comes to accuracy, penetrability through certain materials, imperviousness, and infrastructural requirements.
The above-mentioned characteristics of mmWave Radar sensors help it overcome most of the challenges associated with people detection and counting.
Detection of human beings – Due to its accuracy, it can detect even small bodily (respiratory) movements, thus differentiating living objects from the surrounding inanimate objects like chairs, tables, etc. Due to its penetrability through certain materials like plastic, drywall, and clothing, its readings aren’t impacted due to the presence of any such materials around.
Due to the use of short-wavelength, the size of system components such as the antenna required to process mmWave signals is small. High resolution is another advantage of short wavelengths.
Imperviousness to environmental conditions – mmWave technology isn’t impacted by the presence of rain, fog, dust, or snow and works perfectly fine even in a murky room.
Based on TI’s mmWave Sensor, we have devised a ready-to-integrate SDK that is apt for detecting and counting people, overcoming the remaining challenges. Our solution also supports NXP, Infineon radar sensors.
Figure 4- PathPartner Radar SDK for UV LEDs
The given diagram demonstrates the people-counting demo pipeline running on TI’s mmWave Radar sensor using DSP C74x and ARM - Cortex R4 core.
CFAR (Constant false alarm rate) adaptive algorithm is used to single out the signal returned from the target against the noise and clutter in the background.
The Direction of Arrival (DoA) estimation of the detected object is done by MUSIC algorithm. We can provide a wider FOV, thus enabling the coverage of a large area with fewer sensors. Till +/- 60 degrees, our accuracy remains well within 1 degree. Thus, people of every height will be detected accurately. To date, our best accuracy achieved is 0.1 degrees.
Gtrack is the main algorithm behind object tracking.
Figure 5 – PathPartner Radar SDK for UV LEDs
The given diagram demonstrates the workflow of our people-counting solution.
The Radar SDK will be connected to a PC via USB/UART.
The PC can do the initial configuration of the Radar SDK and trigger the sensor.
Radar SDK will then capture the real-time data and process the data on internal cores.
The output of the processing will be displayed in a Radar Application GUI on the PC.
The number of detected people will be displayed in the GUI accordingly.
Want to know more about our Radar-based people-counting application? Leave us a mail at firstname.lastname@example.org
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