GB2593874A - Portable brain scanner - Google Patents

Abstract

A neuroimaging system comprises an electroencephalography (EEG) and a single-photon emission computed tomography (SPECT) device, which are simultaneously used on a patient. Scan outputs from both EEG and SPECT are processed and displayed to the user, with e.g. EEG packets linked to software analysing gamma camera images. The SPECT device may comprise a collimator, scintillator and gamma camera. A power regulator may feed power to the EEG and SPECT devices at different levels. The neuroimaging system may be portable, i.e. not fixed in a single location and can be moved with minimal set-up. This may allow determination of both functional and structural abnormalities, in a scanner used out of hospital, bringing neuroimaging near to the patient for early intervention.

Description

Portable Brain Scanner [001] The present invention relates to a portable brain scanner. Specifically, the invention relates to a portable brain scanner combining two methods of neuroimaging. I ven more specifically the invention relates to a portable brain scanner combining electroencephalography (EEG) and single-photon emission computed tomography (SPI

Background of the Invention

[002] NeuroimagMg has been an area given keen attention from many researchers. It is an important area of study. So far, the brain is one of if not the most vital organ of the body, and hence, it's imaging as port of the diagnosis is important. In the 211 century, many developments have been made, and sophisticated equipment for neuroim agthg have been developed. Some old methods, such as Computerized Tomography (CT) have been improved. X-rays and Magnetic resonance imaging (MR1) machines have been created and modulated to give precise images. However, most of these machines are not portable due to their size.

[003] Neuroimaging is an essential medical imaging technique that is extensively used in a various preclinical and clinical settings. Structural imaging enables diagnosis of large-scale neural diseases such as tumours, neurodegenerative diseases, and brain injury. Functional imaging, on the other hand, aids in diagnosing metabolic abnormalities and lesions that interfere with cognition and the functions of the brain. The technologies involved and the equipment are quite expensive, and they are brought by just a few people or well-established hospitals. Though the advancements aid in the mitigation of life-threatening neural events, they are largely unavailable to the public for utilization. For instance, Magnetic resonance Imaging (MR1) besides costing millions of dollars, is bulky and cannot be moved from its point of installation, hence its disadvantage to be used in an out of hospital setting where dose monitoring of pharmaceuticals, the effectiveness of therapy and assessment of brain damage can be done.

[0041 In the recent past, the cases of brain injuries have increased, and severe forms called Traumatic brain injury are about 1.5 million per year in the United States alone. Besides these, there are many other minor injuries. (Nelson, Elta, Bannister, Dzandu, Mangram & Zach 2016). Although minor, owing to the functions of the brain, there are significant risks and a need for faster diagnosis and management. According to Coles (2007), direct brain imaging after head injury will aid in preventing severe brain damage, as the action to stop further damage is taken quickly. For instance, intracranial haemorrhage can be well contained if it is discovered early. In areas like sports where life-threatening injuries occur and accident scenes where subtle brain injuries that lead to death due to misdiagnosis or ignorance, could be avoided if the brain could be scanned early on in diagnosis.

Although Near-Infrared spectroscopy (NIRS) and some EEG machines exist, NIRS is weak in imaging due to the weak nature of the rays used and the EEG machines are quite expensive. (Izzetoglu ET AL., 2015). Therefore, there is a need to develop a relatively cheap portable brain scanner that could be used out of the hospital. By so doing it could aid in preventing some deaths as well as monitoring therapy of pharmaceuticals for their efficiency.

[0051 It is an object of the current invention to provide a Portable Brain Cross scanner (PBC) that is to be used in assessing the function of the brain and its structures by combining two neuroimaging methods to give highly efficient results.

Electroencephalography (EEG) and Single-photon emission computed tomography (SP I (1,.'1), are incorporated into a single portable instrument referred to as PBC. To bring neuroirnaging health care service near to the patients for the first diagnosis of various brain pathologies fbr early intervention.

Statement of invention

[ON According to a first aspect of the invention there is provided a portable neuroimaging system comprising: an EEG device; a SPEC! device; and, a data processing and integration system, wherein the EEG device and SPECT device are simultaneously used on a patient, the output from both the EEG and SPECT devices are sent to the data processing and integration system, which process both outputs and displays the results to a user.

[007] An embodiment of the invention wherein the SPECT device comprises: at least one collimator; at least one scintillator; and, at least one photomultiplier.

[008] An embodiment of the invention wherein the SPECT device comprises: at least one gamma camera.

[9] An embodiment of the invention wherein the at least one collimator has an aperture size of approximately 0.2mrn and a septal thickness of 0.05mm.

[10] An embodiment of the invention wherein the EEG device comprises a 20 maxim-um of 10 electrodes.

[11] An embodiment of the invention wherein each electrode has an associated differential amplifier.

[012] An embodiment of the invention further comprising a power source and a power regulator, wherein the power regulator provides power to the I V, device and SPECT device from the power source at different power levels respectively.

[13] An embodiment of the invention wherein the power source is in the form of rechargeable batteries and/or an external power source.

[14] An embodiment of the invention wherein the data processing and integration system has internct access.

Brief Description of the Drawings

[15] Figure 1 depicts a schematic view of the invention, [16] Figure 2 depicts an embodiment of the invention, [17] Figure 3 depicts an embodiment of the invention.

Detailed Description

[18] The PBC scanner is a hybrid between SPECT and EEG In neuroimaghig many hybrids have been done such as SPECT/PET or MM/PET. According to an example embodiment the PBC brain scanner prototcipe will have Collimators of 0.2 mm will be used for increase resolution of the images, with septic of thickness 0.05 mm. The collimators will be made of beryllium. High voltage external power supply and high-resolution gamma camera, for the SPECT part. The EEG component in an example embodiment has a potential of 3v, a powerful filter and amplifiers, as well as 15 electrodes with an allowance of 5 more electrodes. This refers to an example embodiment only.

[019] Throughout this application the term "portable" is used. This is intended to mean that the device is not fixed in a single location for it to remain operable and instead can be moved to a desired location and minimal to zero set up is required after being moved for the device to be operable and functional.

SPECT Instruments Aperiun, [020] The area of the aperture is key in determining the sensitivity, as well as the resolution of the system. 'the areas of the aperture should be keenly considered during the construction of the equipment to ensure high resolution and sensitivity in the portable conditions. Increasing the area of the aperture leads to an increase in sensitivity as more protons are allowed to pass through, as the area is decreased, it leads to a decrease in sensitivity as the number of passing photons decreases. Conversely, for resolution of the small regions of the brain, a smaller aperture is needed to give a clear resolution of the areas emitting radiation in the brain. In this case, then image resolution increase as the area of the aperture decreases. This then follows that the construction will take into account resolution and sensitivity. The weighing of the benefits of one parameter over the other will be utilized. One of the factors must be sacrificed over the other. In the present invention, the coupling with EEG gives the ability to focus more on resolution than sensitivity. According to the nature of the study, resolution is more important, and sensitivity issues will be covered by EEG Collimators of 0.2 mm will be used for increase resolution of the images, with septic of thickness 0.05 mm. The collimators will be made of copper and beryllium glued together Gavunu Caltleta [021] The Gamma-ray camera is the one that collects the images, by detecting the gamma rays emitted by the radioligand. Since its invention in the 1950's it has been used in the detection of photons that are emitted by various radiopharmaccuticals that emit gamma rays, especially Iodine-125. The camera must have quality photo-multiplier tubes, radiation goes through the collimator and interacts first with the crystal scintillator to produce scintillation. The scintillator absorbs the gamma 5 radiation and produces visible photons. The photons emitted by radioactive substances lead to the transfer of energy to scintillator atomic electrons leading to excitation. De-excitation may also produce Ultraviolet rays and/ visible rays. Photomultiplier tubes give information about time and location of the photons through photoelectric effect. (Ryvlin, Philippon, Cinotti, Froment, Le Bars, 8,: Mauguiete, 2012). Due to this, the tubes must be -well shielded for efficient emission and transmission of photons.

[0221 In an example embodiment, three four-inch camera detectors will be used. The cameras will help in determining the depths of the areas assessed as well as 15 providing the three-dimensional images.

Poner Supply [0231 A high voltage power supply will be provided by rechargeable batteries, and 20 external power can be used in places where there is electricity Radiopharmacatlial is [0241 Since the goal of SPECT is to give information on how a given radiopharmaceutical is being distributed in the body. The radiopharmaceutical has a ligand which interacts with the tissues and a radioactive tag that is used in tracing the distribution thereof Some of the common labels used are Radioactive Iodine-125, Iodine 123, Iodine, 131, Xenon-133, thallium-201, Fluorine-18, and Technetium 99. (Ryvlin, Philippon, Cinotti, Froment, Le Bars, & Mauguiere, 2012).

10251 Radiolabelled molecular Imaging Probes (RMIP) aid in giving target molecular therapy or diagnosis. There are general rules for choosing an RMTP. An ideal RMIP has the following characteristics: IIas a high affinity for molecular targets ii) It is highly specific and has does not completely saturate given molecular targets.

Has high membrane permeability with high intracellular trapping, for longer periods to allow focusing.

iv) Rapid clearance from non-specific locations.

v) They are rapidly cleared from plasma and hence preventing their pool in the bloodstream. (Kung, Kung & Choi, 2013).

vi) Its favourable parameters to allow for multiple diagnoses.

[0261 Two radiopharmaceuticals will be used in the Portable Brain Cross scanner. Xenon-133 and Technetium, 99. Radioactive Technetium enters tumour cells preferably and doesn't enter the normal cells. Hence it will be used to in detecting brain tumours and other cerebrovascular disorders such as Huntington's disease, Parkinson's disease, stroke, dementia, and other psychiatric disorders. (Saha, MacIntyre & Cc), 2014). Radioactive xenon will be used to monitor the cerebral blood flow to indicate the metabolism of the brain and hence, its functional viability. Besides these key radiopharmaceuticals, other pharmaceuticals such as Iodine will be used depending on the situation being assessed. (RysTlin, Philippon, Cinotti, Froment, I e Bars, & Mauguiere, 2012).

EEG instruments.

Electrodes [0271 The electrodes are made of small metal discs. The small discs are either of gold, tin or stainless steel overlaid with a coating of silver chloride. Steel is cheaper than gold and tin. Additionally, stainless steel is also durable and strong and hence cost effective. The electrodes will be overlaid with silver chloride. Silver chloride is a common reference electrode in many procedures. In this case it is used to reduce polarization, which presents as a major problem. In order to facilitate creation of an interface between the subject and the electrode i.e. the ionic solution and the metallic conductor. At the application of the electrode gel, it will allow detection of the small electrical potential generated. Electrodes will be labelled according to 10/20 standard system of naming, EEG electrodes.

[0281 The electrodes are placed on specific locations in accordance with the International 10-20 system. For this case, silver-chloride electrodes will be used as they are relatively cheaper and easy to obtain. Additionally, the Silver-Silver chloride electrodes have very low impedance, are highly stable and need only low voltage for offset. The number of electrodes will be flexible as other electrodes can be inserted or removed so as to incorporate the size of the children's scalp.

Additional electrodes can be needed in cases where high resolution is needed for a given area of the brain during diagnoses. So, the number of electrodes can vary according to the prevailing circumstance. However, for the present invention, the limit of the electrodes is ten so as not to compromise portability efficiency. In order to aid the placement of the electrodes the connecting cables have differentiating colours. And arc labelled according to the area of the brain to be attached to. The head of the electrode is a smooth surface that will be easily attached to the scalp.

i'igna/ A/Ephyler [29] Unlike the heart which produces prominent waves when performing electrocardiography, the brain waves have very low amplitude, and thus, it is difficult to detect a measurable wave. The amplifier, in this case, will increase the amplitude to visible levels that can be detected and seen. The choice of an amplifier was done carefully so as to avoid the interruption with the direct current that may induce other signals. The construction of the amplifier is that it needs high input dependence with low offset. The amplification of the signal produced in terms of 101-m.

[30] Every electrode has a differential amplifier for the output of its signal. The amplifier, in this case, amplifies the electrode voltage for the active electrodes, unlike the reference electrodes. The amplifier is digitalized, and its output signal is displayed in a digital monitor.

[31] The amplifier used is bipotential as it is of high quality with high gains and efficient control. The signal consumes very low power of 3 volts and hence is easy to use in settings where electricity is not easily accessible. The Instrument has low drift frequency and has a noise-reducing device known in the art attached to it to filter any noise from the cables that can interfere with the signals. The offset voltage is about 100uV and can be varied Filter [32] The signals obtained from the brain have a frequency of about 1-40T Tz, and in some cases, it can extend to about 1001N in some functional derangement conditions. TTowever, due to connection to the scalp bone, which is connected with other bones on the body, various interferences form other parts of the body will be experienced in the signals. 'the noise from the internal organs can travel across and be recorded as a potential. (Gargiulo, Bifulco, Calvo, Cesarelli, jin & Van Schalk, 2008). Other signals will also be experienced from the electrical equipment, but they are of low frequency. So, the scanner's filter will process and eliminate any interfering wave. Incorporated in the device are three filters, one which is high pass filter, an average filter, and a low pass filter, to pre-process the obtained signal to remove any interfering signal. 'the High pass filters will come in after amplification since amplification brings in some new potential that may be recorded as a wave. For efficiency the filter comes after amplification.

Data cotzvercion and '1)nn/èniig device [33] The Arduino controller aids in the analysis of the signal. The resulting information is processed by computer software. The collection of information in the database enables easy analysis of the data. The output can be in the form of signals at some cases the computerized interface gives a hint concerning the underlying condition.

Data Processing Inteijace [34] EEG packets are linked to a software analysing the gamma camera images to provide a platform of a mixed image output that is assessed for information from both techniques. In some cases, the EEG or SPECT can be used on its own without the other. Data packets arc offered according to the hardware arrangement, and single packets are sent in recording filtering the signals and constructing three dimensions output. Various data analysis software known in thar art is added to the computer and hence provides a synchronized data output for the PBC scanner. Data classifier, filters, and collecting packets are well arranged in the data processor. The processor has an additional component whereby all the information is converted into a graphical output with high-resolution images for the SPECT side.

Power Regulation.

[0351 Power control in the device is very precise and accurate. There are no rooms for overheating. A plurality of power sinks are inserted in the electronic part. The power supply, whether from electricity or battery, is regulated before it reaches the amplifiers and the integrated circuits. Low voltage will be supplied by portable batten-es that are rechargeable for cost-effectiveness. Additionally, an AC adapter will be used in case an external mains power source is used. The PBC scanner will work with an optimum of about 3 volts. The power level going into a cathode tube of the scintillator is different to the power level going to the EEG The PCB has software known in the art to track voltage supplied into all the parts of the equipment and automatically regulates it. The voltage regulator will have many capacitors coupled to it.

The PCB [061 The PBC scanner incorporates the concepts of I d V, and SPI Cl for brain neuroimaging for determination of both functional and structural abnormalities.

[37] The model of the scanner is as shown in figure 1 with each component, i.e. EEC and SPECT working separately but converging in the Data processing and integration centre. The converging point is provided by a fast laptop computer with pre-installed data processing hardware and software. All the images are displayed and analysed on the computer. The results are recorded and stored in the computer. If the scanning indicated a clinical emergency, the data is sent to the hospital via the internet as the patient is being rushed to the hospital. This saves the time that would be taken for diagnosis and hence, a prompt action that can save a person form a further fatal progression of brain injury effects.

[38] The signal waves are assessed and recorded by the EEG equipment and the images of the various brain parts according to the emission of gamma rays are displayed. The data obtained is then used in assessing if there is any structural aberration or any functional derangement for an action to be taken in time.

[39] The portable brain scanner has combined the two techniques to provide very powerful portable neuroimagthg equipment. The SPECT component is used to give the images of the brain after injection of a radiolig,and that emits gamma rays that are detected by a gamma camera that is attached to a cathode that produces the images. In association with the scin-tillator. The SPECT component is used to assess the functioning of the brain as well as any structural abnormality resulting from brain injury. The EEG component serves to determine the activity of the brain by analysing the brain waves. The electrodes are attached to the scalp and their electrical signals amplified and recorded consequently. The recording is then interpreted. The two components are synchronized by an integrating centre that has a computer laptop which gives one combined output from the two components hence easy for analysis.

[40] Monitoring and management of many brain conditions can also be done by this portable machine efficiently.

Data I landling/Analysis in PBC Scanner.

[41] The data analysis of the EEG implements a platform known as independent component analysis alongside frequency/Time analysis with many modes of visualization. junk data can be grouped easily into individual components using this software. Since much of the data obtained is usually bulky, a data processing tool capable to deal with each individual component is considered. The data handling is majorly based on statistics. The statistical analysis component includes times and frequencies in order to avoid any drift from the result for better interpretation of the result. The electrophysiological data can be turned to smooth signal and the cortical signals can be differentiated from non-brain 11 V, signals.

The graphic user interface for the software can be integrated and any modification are allowed as plug ins are enabled.

[42] Additionally, in the data handling system integrated anatomical and physiolop,ical data (IAPD) software will be available for thtegrated analysis of the data from the EEG waves. Due to advancement in technology, the data can be automatically related and analysed to match the most likely circumstances related to the result. The analysis will provide a gateway to proper diagnosis and may open ways for the use of the equipment without aid form experts. This is an advantage because the PBC brain scanner is meant for use in areas where other machines are not available, hence the possibility to be used in remote places where there are no experts.

[43] 11 V, data contains many irrelevant details. The raw data has then to be analysed to make it in order to make it useful. Some of the data may be identified as noise or disruption and in the real sense it is not noise. In the PBC cross scanner, other sensors may be attached to scalp PEG. For instance, eye trackers. This will aid in data processing because the functional modality of the eye is regulated in the brain and the blinks have a diagnostic indication and is involved in artefact formation. The artefacts may disrupt the data obtained in EEG, apart from blinking, muscle waves or heart waves many be conducted and recorded by EEG as the electrodes are attached to the scalp bone to which other body impulses may reach. In order to deal with the artefacts, the data processing zone will have a relevant tool to exclude all the artefacts. By considering individual components by using Individual component analysis (ICA) tool, the waveforms will be considered singly and blind source separation. The individual analysis of each software will best suit the evaluation for increased accuracy. The PBC brain scanner, alongside eliminating the artefacts, it will analyse them separately to aid in the diagnosis. A software to do the integrated analysis will be included in the Data processing tool box.

[0441 Statistical parametric monitoring (SRM) will be used in analysing the SPECT component data. Tracer interpretation will be key and the 3D localization software will be used in analysis. Principal component analysis (PCA) will be key in analysis.

Change-rate map will be included in the data handling software in order to assist M determining the rate of cerebral blood flow from the gamma camera output. Univariate or multivariate analysis can be involved alongside texture analysis. Overall analysis of the data will be computer aided that is normalized for various radiotracers.

10451 Since the PBC scanner has two components, both components will be optimized for analysis and the output will be integrated in order to be indicative of a given diagnosis. The statistical analysis will be done by one software in order to aid consistence form the two components. The correction factors will be standardized based on the output form the two components. Finally, the data centre will have an allowance to include inputs from other medical databases and software that will aid in integ,rated diagnosis.

ADVANTAGES AND DISADVANTAGES OF PBC SCANNER

AdrantaAes [46] Combination of EEG and SPECT will aid in minimizing diagnostic errors.

The combination of the two will result in high accuracy of brain imaging unlike individual instruments when they are used separately. Hence the its convenience and reliability. Additionally, it will be convenient in that one component can cater for the deficiency of another during imaging, or when one fails.

The SPEC! Co anent [47] Single photon emission computed tomography (SPECT) is a superior diagnostic tool that has turned diagnostic medicine to a higher level. In comparison to other methods such as X-ray or even its counterpart Positron Emission Tomography (PET), SPELT is a relatively safe method as it employs minimal radiation and is associated with higher levels of safety. One of the factors considered before neurohnaging, is safety and this is covered well in SPECT. Other than safety, SPECT is less expensive compared to Magnetic Resonance imaging (MRI) and PET. Due to the relatively affordable cost, it is extensively used by many diagnostic facilities and hence the reason to include it in the PBC scanner. Additionally, the SPECT component on the PBC brain scanner provides for improved resolution and hence helps in making a correct diagnosis. The sensitivity of SPELT is quite high and hence good for use in detecting brain damage and any structural change in the brain.

The PEG Component [048] There is no other safe method of neuroimag,ing better than EEG. In this component, there is no input from the system to the patient, rather the equipment detects the output from the patient only. Due to high sensitivity, it offers better precision time measurements at very high resolutions of a single millisecond. The equipment works at a very high speed in great accuracy. The component is quite cheap and can be acquired by anybody who wants it. Its price cannot be compared with Mkt or PET because it is far cheaper. Finally, it is a non-invasive method as the electrodes are attached to the skull and the activity of the brain is assessed.

Hence it minimizes complications involved with invasive procedures.

DISADVANTAGES OF PBC BRAIN SCANNER

[049] The spatial resolution of EEG may present some disadvantage, but this is compensated by the SPECT component. The specificity of the exact area in the brain where some abnormal activity takes place, cannot be located precisely by EEG component, although it will detect the abnormality on the gross level. Closely adjacent areas present a problem when determining the exact part of activity.

however, these deficiencies can be compensated by SPECT component. One of the main disadvantages of SPECT component is that it has a high risk of radiation. This is because the equipment uses radioisotopes which undergo decay and release radiation. If the radiopharmaceutical and the radiation produced are not handled properly, they may lead to some effects. However, the design of the PBC scanner wIll enhance proper handling of the radiopharmaceuticals. Additionally, the EEG component will be used alone in many instances where handling of the radiopharmaceuticals may be compromised.

APPLICATIONS OF PBC SCANNF,R.

[50] PBC hybrid scanner will only be used in the medical field although it can be adapted for various uses in diverse fields. Neuroimaging-PBC brain scanner can be used in diagnosis. Some neurodegenerative conditions such as Alzheimer's disease and parkinsonism and epilepsy can be diagnosed by the machine. This is because the LEG component can detect dementia and brain structure changes which could help in diagnosis. In cases of brain damage or head injury, the combined component interface will in visualization and determination of the area of the brain that has been injures. Brain dysfunction and encephalopathy can be easily detected. Since only neurons transmit action potential, strokes can be figured out using the scanner as no impulses are recorded in the areas encountering cell death. (Iniewski, 20(39). Additionally, the signals are characteristic of the state of alertness, sleep disorders and even monitoring patients in a comatose can be easily diagnosed by the EEC component The combined methods aid in visualization of brain tumours. Brain tumours have a different metabolic rate in comparison to normal brain areas, as well their electrical conduction is different [51] Apart from neuroimaging, the PBC scanner SPECT component can be used 20 to study myocardial perfusion in the diagnosis of cardiovascular disorders such as Ischerrric heart disease. Additionally, the SPECT component can be used to diagnosis of vertebral fracture. (Halama & Henkin, 2006).

PBC Scanner Embodiment [52] The I d kI component as shown in figure 2 has a SP I (1:1. component head on which scintillator detectors, collimators and Photomultiplier tubes are attached for detection of gamma rays. The Id V] component is set some distance from the head of the SPECT from where it is attached to the SPECT component. As shown in figure 2, the information from both components is analysed in one monitor.

[053] The relative position of SP ECU and PEG component id shown in figure 2. 5 The main things in the PBC scanner prototype arc electrodes of the EEG, and SPECT detectors as shown in figure 3. The whole equipment has one display only to analyse the information from the SPEC: and EEG equipment together.

Claims (10)

1. Claims 1 A neuroimaging system comprising: an EEG device; a SPECT device; and, a data processing and integration system; wherein the LEG device and SPI (1;11 device are simultaneously used to scan a patient, and the scan outputs from both the EEG and SPECT devices are sent to the data processing and integration system, which processes both scan outputs and displays the results to a user.
2. 2 A neuroimaging system according to claim 1 wherein the SPECT device comprises: at least one collimator; at least one scintillator; and, at least one phommultiplier.
3. 3. A neuroimaging system according to claim 1 wherein the SPECT device comprises: at least one gamma camera.
4. 4. A neuroimaging system according to claim 2 wherein the at least one collimator has an aperture size of approximately 0.2mm and a septal thickness of approximately 0.05mm.
5. 5. A neuroimaging system according to any preceding claim wherein the EEG device comprises a maximum of ten electrodes.
6. 6. A neuroimaging system according to claim 5, wherein each electrode has a respective associated differential amplifier.
7. 7 A neuroimaging system according to any preceding claim further comprising a power source and a power regulator, wherein the power regulator provides power from the power source to the LEG-device at a first power level, and to the SPELT device at a second level different from the first level.
8. 8. A neuroimaging system according to claim 7 wherein the power source is in the form of rechargeable batteries and/or an external power source.
9. 9. A neuroimaging system according to any preceding claim wherein the data processing and integration system has Internet access.
10. 10.A neuroimaging system according to any preceding claim wherein the neuroimaging system is portable.