A system and method for detecting ionising radiation propagating gaps in radiation shielding personal protective equipment

Abstract

The described system efficiently detects ionising radiation propagating gaps in radiation shielding personal protective equipment (PPE) using an approach that combines infrared technology with a handheld detection unit. It features an infrared radiator designed to emit infrared through PPE, which are detected by a point sensing infrared sensor within the handheld unit. This sensor may be supported by three key indicators: an infrared radiation detection indicator that alerts to any detected infrared radiation, a received signal strength comparator to ensure signals exceed a certain threshold, and a radiator detection indicator that identifies signals uniquely emitted by the system's radiator, distinguishing them from other sources. These components work together to pinpoint gaps in radiation shielding with high precision, offering a reliable and effective solution for evaluating the safety of ionising radiation shielding protective equipment.

Description

A system and method for detecting ionising radiation propagating gaps in radiation shielding personal protective equipmentField of the Invention

[0001] This invention relates generally to a safe and low-cost system and method for detecting ionising radiation propagating gaps in radiation shielding personal protective equipment.Background of the Invention

[0002] X-ray shielding personal protective equipment serves as a critical barrier to protect users from hazardous ionising radiation emanating from sources such as medical, veterinary, or dental X-ray machines. Typically, this type of protective clothing incorporates layers of lead or similar materials, encased within external fabric layers, to block radiation. Despite their effectiveness, these internal shielding layers can sustain damage over time, leading to the formation of subtle gaps through which ionising radiation can leak, posing a significant risk to users.

[0003] Traditionally, the integrity of these protective garments is assessed using X- ray imaging technology. However, this testing method is not only costly but also diverts X-ray machinery away from its primary function of patient diagnosis and treatment, presenting a logistical and financial challenge.

[0004] Alternative approaches include CN 1 15290682 A (UNIV ZHEJIANG) 4 November 2022 which discloses a detection system specifically designed for evaluating medical X-ray protective clothing using through a combination of infrared thermal imaging and X-ray imaging subsystems. This dual approach allows for an initial screening of protective garments to categorise them based on their condition, followed by a more detailed assessment using X-ray imaging for items with uncertain statuses. This methodology not only aims to reduce unnecessary radiation exposure but also streamlines the detection process, enhancing the efficiency of evaluating protective clothing's quality.

[0005] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.Summary of the Disclosure

[0006] There is provided herein a system designed to identify gaps in ionising radiation shielding within personal protective equipment (PPE) using infrared technology.

[0007] It consists of two primary components: an infrared radiator with a surface that emits infrared radiation, and a handheld detection unit equipped with a point sensing infrared sensor.

[0008] During operation, the PPE is placed over the infrared radiator's emitting surface. The user then moves the handheld detection unit across the PPE, allowing the point sensing infrared sensor to detect infrared radiation that passes through any gaps in the PPE where ionising radiation could potentially propagate.

[0009] By design, the system's infrared radiator functions similarly to an ironing board, allowing PPE to be laid across it for inspection and the handheld detection unit used in a manner akin to moving an iron across fabric enables a thorough and efficient scanning process and is more cost-effective as compared to the prior art thermal imaging systems.

[0010] Furthermore, the point sensing infrared sensor within the handheld detection unit is capable of pinpoint detecting of infrared emitted by the infrared radiator, allowing for the precise identification of even small defects within the protective clothing. This level of granularity in detection ensures that gaps in radiation shielding, which could pose significant risks to users, are identified accurately.

[0011] Additionally, the infrared radiator emits a modulated signal, and the handheld detection unit is specifically configured to detect this modulated signal within the infrared radiation.

[0012] The system may incorporate three distinct indicators. The first indicator may be an infrared radiation detection indicator, which signals the detection of infrared radiation to alert the operator when any source of infrared radiation is detected, whichhelps in identifying and eliminating interference from extraneous infrared sources. A received signal strength comparator may be integrated to ensure that this indicator activates only when the detected infrared radiation exceeds a certain threshold, which can be manually adjusted for sensitivity.

[0013] The second indicator may be a signal characteristic detection indicator, activated upon receiving a specific type of infrared radiation signal, discerned through a signal characteristic comparator. This feature aids in distinguishing between the system's own infrared signals and those from other sources.

[0014] Lastly, a radiator detection indicator may be used to identify infrared radiation uniquely emitted by the system's own infrared radiator, differentiating it from all other infrared sources. An information comparator may detect a code encoded in the modulated infrared radiation, which is specific to the system's radiator. This allows for precise identification of radiation escaping through gaps in the PPE, ensuring that only the system's specific signals trigger this indicator.

[0015] Together, these indicators enable the system to accurately identify gaps in radiation shielding of PPE, offering a sophisticated and reliable means of ensuring safety and compliance with radiation protection standards.

[0016] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0017] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0018] Figure 1 shows an exemplary layout of a system for detecting ionising radiation gaps in personal protective equipment;

[0019] Figure 2 shows an exemplary block level electrical schematic of the system in an embodiment; and

[0020] Figure 3 shows exemplary processing by the system in an embodiment.Description of Embodiments

[0021] Figure 1 shows an exemplary setup of a system 100 for detecting ionising radiation propagating gaps in ionising radiation shielding personal protective equipment. Figure 2 shows a functional block level electrical schematic of the system 100.

[0022] The system 100 comprises an infrared radiator 101 designed to emit infrared (IR) radiation 102 from a surface 103 thereof. Infrared radiation is a form of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves.

[0023] The infrared radiator 101 may comprise a plurality of infrared emitting LED transmitters 104 transmitting infrared radiation 102 through a transparent screen forming the surface 103. The transmitters 104 may be spaced from the transparent screen to ensure that the conical infrared transmission patterns thereof evenly cover the surface 103.

[0024] The system 100 further comprises a handheld detection unit 105 which comprise a point sensing infrared sensor 106. The infrared sensor 106 may be an infrared sensitive photodiode, phototransistor, or PIN diode.

[0025] The detection unit 105 is preferably contained within a small form factor housing to be conveniently handheld, and which may comprise a battery power supply for portability.

[0026] Typically, the personal protective equipment 108 comprise outer fabric layers 109 enclosing radiation shielding layers 1 11 therebetween, such as of lead or similar ionising radiation attenuating material.

[0027] Radiation shielding layers 1 11 may overlap as shown in Figure 1 . As such, in the example shown in Figure 1 , a radiation propagation gap 107 in the lower radiation shield 11 1 may be covered by the upper radiation shield 1 11. However, where both radiation shielding layers 11 1 have a collocating radiation propagation gap 107, ionising radiation may escape through the personal protective equipment 108, exposing the wearer to radiation.

[0028] The present system 100 is premised on the ability of the infrared radiation 102 to penetrate the fabric layers 109 but not the internal shielding layers 11 1 . As such, a radiation propagation gap 107 in a piece of defective personal protective equipment 108 would allow infrared radiation 102 from the infrared radiator 101 to propagate through the personal protective equipment 108 for detection by the detection unit 105.

[0029] In use as shown in Figure 1 , the system 100 is configured for the placement of the personal protective equipment 108 across the infrared radiation emitting surface 103 and the handheld detection unit 108 moved over the personal protective equipment 108 to enable the point sensing infrared sensor 106 to pinpoint any infrared radiation propagating through ionising radiation propagating gaps 107 in the personal protective equipment 108.

[0030] The infrared sensor 106 may be shielded within a conical reflector 1 10 so that the infrared sensor 106 can only receive infrared radiation 102 propagating through the personal protective equipment 108, but not from extraneous sources.

[0031] The point sensing infrared sensor 106 detects infrared radiation at a point of the detection unit 105 so that the detection unit 105 can be used to pinpoint even small ionising radiation propagating gaps therethrough. In this regard, the point sensing infrared sensor 106 typically comprises a single sensor such as a single infrared sensitive photodiode, phototransistor, or PIN diode.

[0032] In the embodiment shown in Figure 1 , the surface 103 of the infrared radiator 101 is flat and may take the size and configuration of an ironing board, for example. The surface 103 is preferably larger than the cross-section of the personal protective equipment 108. However, in alternative embodiments, the surface 103 may be anatomically contoured.

[0033] In embodiments, the surface 103 may be flexible, such as comprising a transparent plastic sheet with strips of the LEDs 104 adhered thereto which may enable it to be configured or shaped depending on the application. For example, in accordance with this embodiment, the surface 103 may be laid flat for placement of the protective equipment 108 across the surface 108 or alternatively rolled up into acylinder to insert within the protective equipment 108, such as a personal protective vest or the like.

[0034] In embodiments, a plurality of infrared radiators 101 may be connected together to increase the effective surface area 103 thereof. As will be described in further detail below, in embodiments where in the infrared radiator 101 modulates infrared radiation for detection by the handheld detection unit 105, data and / or power cabling interconnecting these interconnected infrared radiators 101 may allow synchronisation of such modulation between interconnected infrared radiators 101.

[0035] The detection unit 105 may comprise at least one indicator 1 12 which, in embodiments, is a visual indicator comprises at least one LED.

[0036] According to Figure 2, the infrared radiator 101 comprises a modulator 1 16 which controls the transmitters 104 to modulate infrared radiation as a modulated signal and the handheld detection unit 105 comprises a demodulator 1 17 configured to detect the modulated signal in the infrared radiation 102.

[0037] The detection unit 105 may comprises an infrared radiation detection indicator 1 12A activated when any infrared radiation is detected by the point sensing infrared sensor 106. The infrared radiation detection indicator 1 12A may comprise a yellow LED for example. Activation of the yellow infrared radiation detection indicator 1 12A would indicate to the operator that infrared radiation is being detected by the handheld detector unit 105, but which could be from any infrared radiation source , including the sun. The infrared radiation detection indicator 1 12A may allow the operator to identify extraneous sources of infrared radiation so as to remove interference.

[0038] A received signal strength comparator 1 13 may operably interface the point sensing infrared sensor 106 and the infrared radiation detection indicator 1 12A so that the infrared radiation detection indicator 1 12A only activates when a received signal strength of the infrared radiation exceeds a threshold. The threshold may manually tuneable such as by manually adjusting an analogue potentiometer or using a digital control interface.

[0039] The detection unit 105 may further comprises a signal characteristic detection indicator 1 12B activated when a type of infrared radiation signal is received by the point sensing infrared sensor 106. The signal characteristic detection indicator 1 12B may be used to detect a type of infrared radiation signal emitted by the infrared radiator 101 .

[0040] A signal characteristic comparator 1 14 may operably interface the point sensing infrared sensor 106 and the signal characteristic detection indicator 1 12B.

[0041] In one embodiment, the signal characteristic comparator 1 14 may configured to determine if a frequency of the infrared radiation 1 12 falls within a predefined frequency band. For example, the modulator 1 16 may be configured to control the transmitters 104 to emit a periodic wave having a frequency of 300 Hz and wherein the signal characteristic comparator 140 may be configured to detect whether the frequency falls within a band of 280 - 320 Hz. Preferably, the frequency is chosen to avoid interference from other infrared radiation frequency sources, such as TV monitors or mains power which may operate at frequencies of 50 or 60 Hz.

[0042] In alternative embodiments, the modulator 1 16 comprises a signal encoder 128 configured to encode a code within the modulated signal and the signal characteristic comparator 1 14 comprise a signal decoder 129 configured to detect a code encoded in modulation of the infrared radiation 102 by the signal encoder 128. The signal encoder 128 may encode the code using at least one amplitude modulation, frequency modulation, phase modulation, frequency shift keying, phase-shift keying and pulse width modulation.

[0043] For example, the signal encoder 128 may encode in binary format a unique ID of the infrared radiator 101. The signal character comparator 1 14 may be configured to detect such encoding (but not necessarily just the ID of the infrared radiator 101 ) to operate the signal characteristic detection indicator 1 12B.

[0044] In embodiments, a synchroniser 1 15 may operably interface the modulator 1 16 of the infrared radiator 101 and the signal characteristic comparator 1 14 of the handheld detection unit 105 and which may be configured to synchronise time variation of the signal characteristic. For example, a frequency characteristic variedby the synchroniser 150 may vary between 120 - 320 Hz over time and wherein the synchroniser 1 15 keeps the modulator 1 16 and the demodulator 1 17 synchronised at all times so that the demodulator 1 17 can detect the varying frequency signal characteristic.

[0045] The synchroniser 1 15 may interface the infrared radiator and the detection unit 105 via a wired interface but, preferably via a wireless interface to facilitate ease of manoeuvrability of the handheld detection unit 105.

[0046] In embodiments, the signal characteristic may be programmable. For example, the operational frequency of the transmitters 104 and signal characteristic comparator 1 14 of the infrared radiator 101 may be programmable to minimise interference between adjacent systems 100. For example, a first system 100 may be programmed to operate at a frequency of 80 Hz whereas an adjacent system 100 may be programmed to operate a frequency of 120 Hz to avoid interference with each other.

[0047] The detection unit 105 may comprises a radiator detection indicator 1 12C used to specifically detect the infrared radiator 101 to the exclusion of any other. The radiation detection indicator 1 12C is activated when a specific infrared radiation modulation signal 102 is received by the point sensing infrared sensor 106. The radiator detection indicator 1 12C is used to detect only infrared radiation emitted by the infrared radiator 101 as compared to infrared radiation from any other source or any other infrared radiator 101.

[0048] An information comparator 1 18 may operably interface the point sensing infrared sensor 106 and the signal characteristic detection indicator 1 12C. The signal decoder 129 may detect a code encoded by the signal encoder 128 which is specific to the infrared radiator 101 . For example, the infrared radiator 101 may be allocated unique ID 42987656 which is encoded in binary format and the signal 102 and which is detected by the signal decoder 126 and compared against a corresponding ID stored within memory of the detection unit 105.

[0049] Prior use, the detection unit 105 may be paired with the infrared radiator 101 wherein the signal decoder 129 is configured with the unique ID of the infrared detector 101 . Such may be done by setting DIP switches or, alternatively, transmittedbetween the radiator 101 and the detection unit 105 wirelessly, such as via aBluetooth interface.

[0050] In embodiments, a resettable latch 1 19 operably interfaces the radiator detection indicator 1 12C to keep it operational following even fleeting detection of infrared radiation escaping through the protective equipment 108. For example, even if the detection unit 105 detects infrared radiation 102 specifically emitted by the infrared radiator 101 for a brief period, such as less than 500 ms, the resettable latch 119 may latch the radiator detection indicator 112C to keep it illuminated for the attention of the operator until it is reset.

[0051] Figure 3 shows exemplary processing 120 by the system 100 in accordance with a preferred embodiment wherein the handheld detection unit 105 comprises all three indicators 1 12A-C.

[0052] At step 121 , the handheld detection unit 105 receives an infrared signal via the infrared sensor 106.

[0053] At step 122, the received signal strength comparator 1 13 compares the amplitude of the signal to a threshold. If the amplitude exceeds the threshold, the detection unit 105 activates the infrared radiation detection indicator 112A at step 123. In embodiments, the threshold may be tuneable, such as by using a potentiometer.

[0054] At step 124, the handheld detection unit 105 uses the signal characteristic comparator 1 14 to perform signal comparison on the received signal. As alluded to above, the detection unit 105 may detect if the frequency of the received signal lies within a predetermined frequency band (or a frequency received from the synchroniser 1 15) and if the frequencies match, the detection unit 105 activates the signal characteristic detection indicator 112B at step 125. Alternatively, as also mentioned above, the signal characteristic comparator 1 14 may operably interface the signal decoder 129 to detect the digital encoding of a code or codes within the infrared signal 102.

[0055] At step 126, the detection unit 105 uses the information comparator 118 to detect an infrared signal 102 emitted only by the specific infrared radiator 101 andnot any other infrared radiator or source. As alluded to above, the infrared radiator 101 may use the modulator 116 to digitally encode a unique ID assigned to the infrared radiator 101 which is checked by the signal decoder 129 against the unique ID stored within the memory of the detection unit 105.

[0056] Successful information comparison causes the detection unit 105 to activate the radiator detection indicator 112C at step 127.

[0057] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed as obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilise the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

Claims1 . A system for detecting ionising radiation propagating gaps in radiation shielding personal protective equipment, the system comprising: an infrared radiator having an infrared radiation emitting surface, a handheld detection unit comprising a point sensing infrared sensor, wherein: in use, the system is configured for the placement of the personal protective equipment across the infrared radiation emitting surface and the handheld detection unit moved over the personal protective equipment to enable the point sensing infrared sensor to detect any infrared radiation propagating through ionising radiation propagating gaps in the personal protective equipment; and the infrared radiator emits a modulated signal and the handheld detection unit is configured to detect the modulated signal in the infrared radiation.

2. The system as claimed in claim 1 , wherein the detection unit comprises an infrared radiation detection indicator activated when infrared radiation is detected by the point sensing infrared sensor.

3. The system as claimed in claim 2, wherein a received signal strength comparator operably interfaces the point sensing infrared sensor and the infrared radiation detection indicator and wherein the infrared radiation detection indicator activates when a received signal strength of the infrared radiation exceeds a threshold.

4. The system as claimed in claim 3, wherein the threshold is tuneable.

5. The system as claimed in claim 1 , wherein the detection unit comprises a signal characteristic detection indicator activated when a type of infrared radiation signal is received by the point sensing infrared sensor.

6. The system as claimed in claim 5, wherein a signal characteristic comparator operably interfaces the point sensing infrared sensor and the signal characteristic detection indicator.

7. The system as claimed in claim 5, wherein the signal characteristic comparator is configured to determine if a frequency of the infrared radiation falls within a predefined frequency band.

8. The system as claimed in claim 5, wherein the infrared radiator comprises a signal encoder configured to encode a code by modulation of the infrared radiation and the signal characteristic comparator is configured to detect the code.

9. The system as claimed in claim 8, wherein the signal encoder encodes the code using at least one amplitude modulation, frequency modulation, phase modulation, frequency-shift keying, phase-shift keying and pulse width modulation.

10. The system as claimed in claim 5, wherein a synchroniser operably interfaces a modulator of the infrared radiator and the signal characteristic comparator of the handheld detection unit.1 1 . The system as claimed in claim 10, wherein the synchroniser is configured to synchronise time variation of the signal characteristic.

12. The system as claimed in claim 1 , wherein the detection unit comprises a radiator detection indicator activated when a specific infrared radiation signal emitted by the infrared radiator is received by the point sensing infrared sensor.

13. The system as claimed in claim 12, wherein an information comparator operably interfaces the point sensing infrared sensor and the radiator detection indicator.

14. The system as claimed in claim 13, wherein the infrared radiator comprises a signal encoder which encodes a code which is specific to the infrared radiator within modulations of the infrared radiation and the information comparator comprise a signal decoder configured to detect the code.

15. The system as claimed in claim 14, wherein the infrared radiator encodes the code using at least one amplitude modulation, frequency modulation, phase modulation, frequency shift keying, phase-shift keying and pulse width modulation.

16. The system as claimed in claim 12, wherein a resettable latch operably interfaces the radiator detection indicator.

17. The system as claimed in claim 1 , wherein the system comprises a plurality of infrared radiators able to be connected together to increase the size of the infrared radiation emitting surface.

18. The system as claimed in claim 17, wherein the plurality of infrared radiators modulate infrared radiation and wherein modulation of each of the plurality of infrared radiators is synchronised.

19. The system as claimed in claim 1 , wherein the infrared radiator comprises a plurality of infrared transmitters emitting infrared radiation through a transparent screen.

20. The system as claimed in claim 19, wherein the infrared radiation emitting surface is flexible.

21. A method of detecting ionising radiation propagating gaps in radiation shielding personal protective equipment using the system as claimed in claim 1 , the method comprising placement of the personal protective equipment across the infrared radiation emitting surface and moving the handheld detection unit over the personal protective equipment to enable the point sensing infrared sensor to detect any infrared radiation propagating through ionising radiation propagating gaps in the personal protective equipment.

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