WO2019008227A1

WO2019008227A1 - System and method for controlling growth of microorganisms

Info

Publication number: WO2019008227A1
Application number: PCT/FI2018/050498
Authority: WO
Inventors: Mika Nummenpalo; Petteri JAUHIAINEN; Pekka RÄBINÄ; Maria LEINO; Niko HUHTINEN; Jyrki Jokinen
Original assignee: S1 Sähkö Oy
Priority date: 2017-07-03
Filing date: 2018-06-26
Publication date: 2019-01-10
Also published as: FI128996B; FI20175639A; FI20175639A1

Abstract

Disclosed is a system for controlling growth of microorganisms, comprising a first light source (104, 204) for radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres to control growth of microorganisms; a second light source (106, 206) for radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres to kill microorganisms; a light sensor (110, 212) for detecting an intensity of a light; a motion sensor (112, 214, 306, 406) for detecting a moving object (408); and a microcontroller (108), communicatively connected to the first light source, the second light source, the light sensor and the motion sensor, configured to modify an intensity of the blue light based on the light sensor data; and control an intensity of the ultra-violet light based on detection of a moving object by the motion sensor.

Description

SYSTEM AND METHOD FOR CONTROLLING GROWTH OF MICROORGANISMS

TECHNICAL FIELD

The present disclosure relates generally to a sterilization system, and more specifically, to a system and a method for controlling growth of microorganisms using blue and ultra-violet light.

BACKGROUND

Sterilization refers to any process that eliminates, removes, kills, or deactivates biological agents such as fungi, bacteria, viruses, spore forms, prions, unicellular eukaryotic organisms such as Plasmodium, etc. present in a region, such as a surface, a volume of fluid, medication, or in a compound. Sterilization can be performed through various means including heat, chemicals, irradiation, high pressure and filtration. Typically, the sterilization is performed using an autoclave that supplies high-pressure saturated steam at 121 °C for a particular time period based on a size of a load in the autoclave, which is mainly used in medical applications.

Ethylene oxide (EtO) sterilization is mainly used to sterilize medical and pharmaceutical products. Gamma sterilization process uses Cobalt 60 radiation to kill microorganisms on a variety of different products. But, these above techniques are not suitable for sterilizing a space. Ultra-violet (UV) disinfection methods use appropriate wavelengths of ultra-violet light that can damage the body's microbial DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). Further, emission of ultra-violet light can cause damage to human eyes, and prolonged exposure can cause burns and skin cancer in humans. Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks in existing sterilization methods and systems that use ultra-violet light due to the damage caused to humans when exposed to ultra-violet light over time. SUMMARY

The present disclosure provides a system for controlling growth of microorganisms, comprising :

- a first light source for radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres to control the growth of microorganisms; - a second light source for radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres to kill the microorganisms;

- a light sensor for detecting an intensity of a light;

- a motion sensor for detecting a moving object; and

- a microcontroller, communicatively connected to the first light source, the second light source, the light sensor and the motion sensor, configured to

- modify an intensity of the blue light based on the light sensor data; and

- control an intensity of the ultra-violet light based on detection of a moving object by the motion sensor.

The present disclosure also provides a method for controlling growth of microorganisms, comprising :

- radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres, using a first light source;

- radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres, using a second light source;

- detecting an intensity of a light, using a light sensor; - detecting a moving object, using a motion sensor;

- adjusting an intensity of the blue light based on the light sensor data, using a microcontroller; and

- controlling an intensity of the ultra-violet light using the microcontroller, based on detection of a moving object by the motion sensor.

Embodiments of the present disclosure substantially eliminate or at least partially address the aforementioned problems in the prior art for sterilization using existing sterilization methods and systems that use ultraviolet light due to damage caused to people when exposed to the ultra-violet light over a period of time.

Additional aspects, advantages, features and objects of the present disclosure are made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow. It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers. Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein :

FIG. 1 is a schematic illustration of a system for controlling growth of microorganisms in accordance with an embodiment of the present disclosure;

FIG. 2 is a schematic illustration of a system that comprises a third light source for controlling growth of microorganisms in accordance with an embodiment of the present disclosure;

FIG. 3 illustrates an exemplary view that depicts an operation of a system when no moving object is detected in accordance with an embodiment of the present disclosure;

FIG. 4 illustrates an exemplary view that depicts an operation of a system when a moving object is detected in accordance with an embodiment of the present disclosure; and FIGS. 5A and 5B are flow diagrams illustrating a method of controlling growth of microorganisms in accordance with an embodiment of the present disclosure.

In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing. DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

- a first light source for radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres to control the growth of microorganisms;

- a second light source for radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres to kill the microorganisms;

- a light sensor for detecting an intensity of a light;

- a motion sensor for detecting a moving object; and

- modify an intensity of the blue light based on the light sensor data; and

The present system thus controls the growth of microorganisms and kills the microorganisms without causing damage to mammalian cells. The system further reduces a level of pathogenic microorganisms by effectively killing the pathogenic microorganisms using the blue light and the ultraviolet light. The first light source and the second light source may be light emitting diodes (LEDs). A range of the first wavelength may be optimally selected for controlling the microorganisms. In an embodiment, more than one first light source is used to radiate the blue light for controlling the growth of the microorganisms. In another embodiment, more than one second light source is used to radiate the ultra-violet light for killing the microorganisms. In one embodiment, the ultra-violet light is ultra-violet C light (UVC light).

In an embodiment, more than one light sensor is used to accurately detect the intensity of the light. The light sensor sends the light sensor data comprising information related to the intensity of the light to the microcontroller. The moving object may be a person, an animal etc. In an embodiment, the motion sensor is a passive infrared sensor. The motion sensor may detect proximity of a human or animal by detecting a change in infrared thermal heat patterns in front of the motion sensor. The motion sensor may use a pair of pyroelectric elements that react to changes in temperature. Instantaneous differences in an output of the two pyroelectric elements are detected as movement, especially movement by a heat- bearing object, such as a human or animal.

In an embodiment, the microcontroller increases the intensity of the blue light for controlling the growth of microorganisms based on the light sensor data and also increases the intensity of the ultra-violet light to kill the microorganisms when the motion sensor does not detect any moving object. The first light source may continuously radiate the blue light to limit the growth of microorganisms. When no moving object is is detected by the motion sensor, the second light source may be switched ON to radiate the ultra-violet light to kill the microorganisms. The second light source may be switched OFF completely when a moving object is detected by the motion sensor. Alternatively, the intensity of the ultra-violet light may be decreased when the motion sensor detects the moving object. The continuous emission of the blue light and the periodic emission of ultra-violet light may destroy a genome of the microorganisms, thereby controlling their growth. Light intensity is a measure of the light energy transferred per unit area. For example, the intensity of the blue light may be 10 milliwatts per square centimetre of area.

In an embodiment, using the blue light and the ultra-violet light, the system kills the microorganisms (e.g. pathogens) based on a purpose and a risk level of targeted premises. The risk level of the premises may be classified into a high risk level, a medium risk level and a low risk level. The high risk level premises may be, for example, hospitals, laboratories, food production industries etc. The medium risk level premises may be, for example, toilets, bathrooms, restaurants, schools, homes for the elderly etc. The low risk level premises may be stores, offices etc. According to an embodiment, the system further comprises a third light source communicatively connected to the microcontroller, wherein the third light source is configured to radiate a white light at a third wavelength that ranges between 500 to 700 nanometres.

According to another embodiment, when the motion sensor detects the moving object, the microcontroller is configured to adjust the intensity of the blue light and an intensity of the white light based on the light sensor data for controlling the growth of microorganisms. In an embodiment, the microcontroller increases the intensity of the blue light and decreases the intensity of the white light based on the light sensor data to effectively control the growth of microorganisms. The microcontroller may adjust the intensity of the blue light in such a way that the blue light balance remains constant. In an embodiment, the blue light balance is pre-configured based on a person's requirement or tolerance level to the blue light.

According to yet another embodiment, the microcontroller is configured to determine a colour temperature based on the light sensor data, wherein the microcontroller is configured to adjust the intensity of the blue light and the intensity of the white light to maintain the colour temperature within a desired range. In an embodiment, the microcontroller decreases the intensity of the blue light and increases the intensity of the white light based on the light sensor data to maintain the colour temperature within the desired range when the moving object is detected. The microcontroller may determine the colour temperature based on the intensity of the light.

According to yet another embodiment, the microcontroller is configured to gradually increase the intensity of the blue light and decrease the intensity of the white light to maintain the overall intensity of light constant, based on a tolerance level of a person exposed to the blue light. In one embodiment, the microcontroller may gradually increase the intensity of the blue light by one percent per minute based on the tolerance level of the person and proportionally decrease the intensity of the white light in order to maintain the overall intensity of light constant. In an embodiment, increasing the intensity of the blue light using the microcontroller, without decreasing the intensity of the white light, may increase the overall intensity of the light. The tolerance level of the person may be provided as an input to the microcontroller. The input may be provided to the microcontroller using a remote terminal. In an embodiment, the remote terminal may be communicatively connected to the microcontroller through a network. According to yet another embodiment, a first fluency of the first light source is more than 0.1 milliwatts per square centimetre and a second fluency of the second light source is more than 0.01 milliwatts per square centimetre.

According to yet another embodiment, the first fluency of the first light source ranges between 0.1 to 400 milliwatts per square centimetre and the second fluency of the second light source ranges between 0.01 to 10 milliwatts per square centimetre on a surface that is being disinfected.

In an embodiment, a range of the first fluency is optimally selected to control the growth of microorganisms. In another embodiment, a range of the second fluency is optimally selected to kill the microorganisms. A fluency is a function of a measurement of light energy transmitted per surface unit. The fluency may be calculated by multiplying a power density (in Watt per square centimetre) with an irradiation time (in seconds). In one embodiment, the first fluency is calculated by multiplying the power density of the blue light with the irradiation time of the blue light. In another embodiment, the second fluency is calculated by multiplying the power density of the ultra-violet light with the irradiation time of the ultra-violet light.

According to yet another embodiment, the system further comprises a sever communicatively connected to the microcontroller for providing a first timing plan or schedule for adjusting the intensity of the blue light and for controlling the intensity of the ultra-violet light to kill the microorganisms. According to yet another embodiment, the microcontroller is configured to adjust the intensity of the blue light and to control the intensity of the ultra- violet light based on the first timing plan if no moving object is detected by the motion sensor. The server may be communicatively connected to the microcontroller through a network. The server may comprise a server database that configured to store the first timing plan. The first timing plan may be pre- configured using the server. The first timing plan is a function of the schedule based on which the first light source and the second light source are adjusted to control the growth of microorganisms and to kill the microorganisms. The first timing plan may comprise a time period in a day at which the intensity of the blue light and the intensity of the ultra-violet light is to be adjusted or controlled to kill the microorganisms. According to yet another embodiment, the server is configured to provide a second timing plan to the microcontroller for adjusting the intensity of the blue light and the intensity of the white light to control the growth of microorganisms. According to yet another embodiment, the microcontroller is configured to adjust the intensity of the blue light and the intensity of the white light based on the second timing plan and the light sensor data if the moving object is detected by the motion sensor.

In an embodiment, the server database is configured to store the second timing plan. The second timing plan may be pre-configured in the server. The second timing plan is a function of time at which the first light source and the third light source are to be adjusted to control the growth of microorganisms. The second timing plan may comprise a time period in a day at which the blue light and the white light are to be adjusted to limit or control the growth of microorganisms and to maintain the colour temperature within the desired range. The present disclosure provides also a method for controlling growth of microorganisms, comprising : - radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres, using a first light source;

- detecting an intensity of a light, using a light sensor;

- detecting a moving object, using a motion sensor;

According to an embodiment, the method further comprises the steps of

- radiating a white light at a third wavelength that ranges between 500 to 700 nanometres, using a third light source; and

- adjusting the intensity of the blue light and an intensity of the white light based on the light sensor data using the microcontroller, when the moving object is detected by the motion sensor.

According to another embodiment, the first wavelength is optimally selected for killing A-deoxyribonucleic acid (A-DNA) microorganisms. According to yet another embodiment, a range of the second wavelength is optimally selected for damaging B-deoxyribonucleic acid (B-DNA) microorganisms, wherein the blue light at the first wavelength produces reactive oxygen to destroy a cell wall of the microorganisms.

The advantages of the present method are thus identical to those disclosed above in connection with the present system and the embodiments listed above in connection with the system apply mutatis mutandis to the method.

Embodiments of the present disclosure control the growth of microorganisms and kill the microorganisms without causing damage to the people. Embodiments of the present disclosure further reduce a level of microorganisms by effectively killing the microorganisms using a combination of the blue light and the ultra-violet light. Embodiments of the present disclosure may effectively kill the microorganisms using ultra-violet light and still prevent damage caused to people due to exposure to ultraviolet light.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a system for controlling growth of microorganisms in accordance with an embodiment of the present disclosure. The system comprises a lamp assembly 102, a microcontroller 108, a light sensor 110 and a motion sensor 112. The lamp assembly 102 comprises a first light source 104 and a second light source 106. The functions of these parts as have been described above.

FIG. 2 is a schematic illustration of a system that comprises a third light source 208 for controlling growth of microorganisms in accordance with an embodiment of the present disclosure. The system comprises a lamp assembly 202, a microcontroller 210, a light sensor 212, a motion sensor 214, a network 216 and a server 218. The lamp assembly 202 comprises a first light source 204, a second light source 206 and the third light source 208. The functions of these parts as have been described above.

FIG. 3 illustrates an exemplary view that depicts an operation of a system when no moving object is detected in premises 302 in accordance with an embodiment of the present disclosure. The system comprises a lamp assembly 304 and a motion sensor 306. The lamp assembly 304 comprises a first light source to radiate a blue light, the second light source to radiate an ultra-violet light and a third light source to radiate a white light. The system further comprises a microcontroller that is communicatively connected to the lamp assembly 304, a light sensor and the motion sensor 306. The light sensor detects an intensity of a light in the premises 302. The microcontroller increases an intensity of the blue light based on the light sensor data. The microcontroller controls an intensity of the ultra-violet light to kill the microorganisms in the premises 302 when no moving object is detected by the motion sensor 306 in the premises 302.

FIG. 4 illustrates an exemplary view that depicts an operation of a system when a moving object 408 is detected in premises 402 in accordance with an embodiment of the present disclosure. The system comprises a lamp assembly 404, a light sensor and a motion sensor 406. The lamp assembly 404 comprises a first light source to radiate a blue light, the second light source to radiate an ultra-violet light and a third light source to radiate a white light. The light sensor detects an intensity of a light in the premises 402. The system further comprises a microcontroller that is communicatively connected to the lamp assembly 404, the light sensor and the motion sensor 406. The microcontroller adjusts an intensity of the blue light and an intensity of the white light based on the light sensor data for controlling the growth of the microorganisms in the premises 402 when the motion sensor 406 detects the moving object 408 in the premises 402. FIGS. 5A and 5B are flow diagrams illustrating a method of controlling growth of microorganisms in accordance with an embodiment of the present disclosure. At step 502, a blue light at a first wavelength that ranges between 400 to 480 nanometres is radiated by a first light source. At step 504, an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres is radiated by a second light source. At step 506, an intensity of a light is detected using a light sensor. At step 508, a moving object is detected using a motion sensor. At step 510, an intensity of the blue light is adjusted based on the light sensor data using a microcontroller. At step 512, an intensity of the ultra-violet light is controlled using the microcontroller to kill the microorganisms, based on detection of a moving object by the motion sensor.

Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Claims

1. A system for controlling growth of microorganisms, comprising

- a first light source (104, 204) for radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres to control the growth of microorganisms;

- a second light source (106, 206) for radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres to kill the microorganisms;

- a light sensor (110, 212) for detecting an intensity of a light;

- a motion sensor (112, 214, 306, 406) for detecting a moving object (408); and

- a microcontroller (108), communicatively connected to the first light source, the second light source, the light sensor and the motion sensor, configured to

- modify an intensity of the blue light based on the light sensor data; and

2. A system according to claim 1, wherein the system further comprises a third light source (208) communicatively connected to the microcontroller

(108), wherein the third light source is configured to radiate a white light at a third wavelength that ranges between 500 to 700 nanometres.

3. A system according to claim 2, wherein the microcontroller (108) is configured to adjust the intensity of the blue light and an intensity of the white light based on the light sensor (110, 212) data for controlling the growth of the microorganisms, when the motion sensor (112, 214, 306, 406) detects the moving object (408).

4. A system according to claim 3, wherein the microcontroller (108) is configured to determine a colour temperature based on the light sensor (110, 212) data, and the microcontroller is configured to adjust the intensity of the blue light and the intensity of the white light to maintain the colour temperature within a desired range.

5. A system according to any of the claims 2-4, wherein the microcontroller (108) is configured to gradually increase the intensity of the blue light and decrease the intensity of the white light to maintain the overall intensity of light constant, based on a tolerance level of a person exposed to the blue light.

6. A system according to any of the preceding claims, wherein a first fluency of the first light source (104, 204) is more than 0.1 milliwatts per square centimetre and a second fluency of the second light source (106, 206) is more than 0.01 milliwatts per square centimetre. 7. A system according to claim 6, wherein the first fluency of the first light source (104, 204) ranges between 0.1 to 400 milliwatts per square centimetre and the second fluency of the second light source (106, 206) ranges between 0.01 to 10 milliwatts per square centimetre on a surface that is being disinfected. 8. A system according to any of the preceding claims, further comprising a server communicatively connected to the microcontroller (108) for providing a first timing plan for adjusting the intensity of the blue light and for controlling the intensity of the ultra-violet light to kill the microorganisms.

9. A system according to claim 8, wherein the microcontroller (108) is configured to adjust the intensity of the blue light and to control the intensity of the ultra-violet light based on the first timing plan if no moving object (408) is detected by the motion sensor (112, 214, 306, 406).

10. A system according to claim 8 or 9, wherein the server is configured to provide a second timing plan to the microcontroller (108) for adjusting the intensity of the blue light and the intensity of the white light to control the growth of microorganisms.

11. A system according to claim 10, wherein the microcontroller (108) is configured to adjust the intensity of the blue light and the intensity of the white light based on the second timing plan and the light sensor (110, 212) data if the moving object (408) is detected by the motion sensor (112, 214, 306, 406).

12. A method for controlling growth of microorganisms, comprising :

- radiating a blue light at a first wavelength that ranges between 400 to 480 nanometres, using a first light source (104, 204);

- radiating an ultra-violet light at a second wavelength that ranges between 250 to 300 nanometres, using a second light source (106, 206);

- detecting an intensity of a light, using a light sensor (110, 212);

- detecting a moving object (408), using a motion sensor (112, 214, 306, 406);

- adjusting an intensity of the blue light based on the light sensor data, using a microcontroller (108); and

13. A method according to claim 12, wherein the method further comprises - radiating a white light at a third wavelength that ranges between 500 to

700 nanometres, using a third light source; and - adjusting the intensity of the blue light and an intensity of the white light based on the light sensor (110, 212) data using the microcontroller (108), when the moving object (408) is detected by the motion sensor (112, 214, 306, 406). 14. A method according to claim 12 or 13, wherein the first wavelength is optimally selected for killing A-deoxyribonucleic acid microorganisms.

15. A method according to claim 14, wherein a range of the second wavelength is optimally selected for damaging B-deoxyribonucleic acid microorganisms, wherein the blue light at the first wavelength produces reactive oxygen to destroy a cell wall of the microorganisms.