A measurement system with effective atmospheric and environmental control

Abstract

The invention disclosed herein generally concerns a device structured as an enclosure isolated from electromagnetic effects and comprising a measuring unit.

Description

[0001] A MEASUREMENT SYSTEM WITH EFFECTIVE ATMOSPHERIC AND ENVIRONMENTAL CONTROL

[0002] TECHNOLOGICAL FIELD

[0003] The invention generally relates to systems for carrying out detection and analyses of chemical / biochemical interactions.

[0004] BACKGROUND

[0005] Controlled environments are typically spaces with precisely regulated environmental factors. Incubators represent such controlled environments. They are generally designed and used in a variety of fields where constant and predetermined set of conditions are to be maintained. A typical incubator will generally include a chamber defined inside a metal supporting box, externally insulated and provided with an adjustable heater to maintain the chamber at an optimal or a desired temperature. It is known that environmental conditions (temperature and humidity) and electrical noises can influence the quality of sample and sample measurement, especially where maintaining predetermined and constant set of conditions is required. This is even more acute when rapid and drastic fluctuations of temperature and humidity during measurements influence the quality of samples and / or the measurement and analysis process and unity of such conditions is required along the measurement process, or between different samples or between different days different places etc as they influence the samples or the measurement system outcomes.

[0006] SUMMARY OF THE INVENTION

[0007] The inventors of the technology disclosed herein have developed a light-weight portable device that may be configured as a hand-held device for measuring a change in at least one measurable electrical parameter over time. The device is structured as an enclosure or a housing that comprises a measuring unit configured to receive at least one sensor member or an electronic member for measuring said change. The measuring unit is isolated from electromagnetic influences and from changes in external electronic fluctuations, ambient conditions and illumination. This isolation permits increased signal sensitivity, a better signal reproducibility and reduced noise, as compared to other systems known. The ability to isolate the measuring unit from electronic and ambient fluctuations as well as from light, is due to the enclosure or housing that reduces or diminishes or inhibits electromagnetic field effects. One such implementation is in a form of a Faraday enclosure.

[0008] The uniqueness of the device also resides in its small dimensions, rendering the device portable and operable under any thermal or humidity conditions, even under extremely low or high temperatures and humidity levels. The ability to maintain optimal isolation from ambient conditions and background noises, and to maintain constant or minimally variable conditions within the device enclosure during measurement or sample handling, and the ability of reestablish such conditions immediately following opening of the device enclosure permits sub-ppm or sub-ppb detection of analytes. The device ability to detect small changes in an electric field resulting from interactions between ppb or higher concentrations of analyte materials with a sensor member of the measuring unit, permits overall high sensitivity detection and improved selectivity, as well as high consistency within the measurement process even in short measurement periods and between different measurements for similar samples, as further explained herein.

[0009] Thus, a device of the invention may be characterized as unique for at least the following reasons, as further detailed herein:

[0010] 1. The device is small and portable, having a volume of 2-5 liters and a weight ranging between 1 and 3 kg;

[0011] 2. Measurements are carried out under controlled conditions, and thus measurements may be carried out in environments with high environmental noise, high or low temperatures and humidities, without such conditions affecting the sensitivity of the measurements;

[0012] 3. Measurements are carried out without the influence of electromagnetic field noises;

[0013] 4. Measurements are carried out under stable conditions, exhibiting limited or no fluctuations in the measurement conditions;

[0014] 5. The device is capable of detecting small changes in electrical properties due to interaction between analytes and sensors implemented in the device;

[0015] 6. The device can implement any sensor type and is not limited in this regard; and

[0016] 7. The device is capable of measuring ppm and ppb levels of analytes, being as low as 25 ppb and even lower. A device of the invention is a portable EMI shielded enclosure arranged to maintain a stable measurement profile (i.e., a stable or constant predetermined electromagnetic field, illumination, temperature and / or humidity) throughout the measurement period and comprises a sensor unit (comprising one or a plurality of sensor members) configured to detect a change in at least one measurable electronic parameter due to a chemical change in a vicinity of a sensor member or due to an interaction with a sensor member. The device may also be used to determine a change in the stability or function of an electronic element, such as a resistor.

[0017] In a first of its aspects, the invention provides a portable device for detecting at least one chemical interaction between an analyte and a sensor member, the device comprising a port configured for receiving therein a detachable measurement unit and is arranged as an isolated interaction enclosure capable of reducing or diminishing electromagnetic interference (EMI) and background noises and generally maintaining a stable measurement profile (i.e., a stable or constant predetermined electromagnetic field, illumination, temperature and / or humidity).

[0018] The invention further provides a portable device for detecting at least one chemical interaction between an analyte and a sensor member, the device being arranged as an isolated enclosure for maintaining a stable measurement profile (i.e., a stable or constant predetermined electromagnetic field, illumination, temperature and / or humidity and / or room volatile compounds; or one or more of temperature, thermal uniformity, humidity, electric or magnetic noise); said device comprising a port configured for receiving therein a detachable measurement unit comprising a sensor unit and a sample unit.

[0019] In some embodiments, the enclosure is an isolated interaction Faraday enclosure or an EMI shielded.

[0020] The invention further provides a device for detecting presence of an analyte in a sample, the device being arranged as an isolated interaction Faraday or shielded EMI enclosure, the enclosure comprising a heating array (comprising at least one heating element) and a port configured to receive therein a measuring unit comprising a sensor unit and a sample unit, wherein said sensor unit comprises one or a plurality of sensor members selected to undergo a chemical interaction with the analyte provided in the sample unit and changing at least one electrical property thereof in response to said interaction. Also provided a device arranged as an isolated interaction Faraday or shielded EMI enclosure, the enclosure comprising a heating array and a port configured to receive therein a measuring unit comprising a sensor unit and a sample unit, wherein said sensor unit comprises one or a plurality of sensor members selected to undergo a chemical interaction with an analyte provided in the sample unit and changing at least one electrical property thereof in response to said interaction.

[0021] The invention further provides a device arranged as an isolated interaction enclosure, the enclosure comprising a heating array, and a measuring unit comprising a sensor unit and a sample unit, the measuring unit being positioned in a port of said enclosure; wherein said sensor unit comprises one or a plurality of sensor members selected to undergo a chemical interaction with an analyte provided in the sample unit and changing at least one electrical property thereof in response to said interaction.

[0022] The device of the invention is configured and arranged to permit detection by a sensor member and / or detector presence of a chemical material, i.e., an analyte in a gaseous sample. The interaction between the measurement system and analyte occurs in the device under stable conditions, i.e., a stable measurement profile that is predetermined or preset. The measurement profile dictates operation conditions that are substantially constant and continuous for at least the length of the period of measurement. The measurement profile may include one or more of a predetermined electromagnetic field, a predetermined illumination, a predetermined temperature and a predetermined humidity.

[0023] The device is arranged as an enclosure or a housing defining an enclosed internal chamber that is an isolated interaction Faraday or shielded EMI enclosure, containing all elements and features enabling measurement and a measurement profile required for carrying out the measurement, i.e., detection or analytical steps. Without limitation, the device comprises a heating array enabling a stable and uniform temperature distribution within the device and a port for receiving therein a detachable measurement unit. The device further comprises one or a plurality of temperature and / or humidity sensors, a controller, a fan module, and a power supply unit.

[0024] The heating array present within the internal chamber of the device is configured to maintain a constant and uniform temperature, e.g., air temperature, throughout the enclosed chamber over a period of operation. Proper thermal distribution within the internal chamber may be achieved by a thermo-conductive surface, such as an aluminum surface or a different metallic surface, that is associated with one or more thin-film heating elements and help to distribute the heat in an even manner. Alternatively, one or more heating elements may be distributed within the internal chamber. Each of the heating elements, i.e., those associated with a surface of the thermo-conductive surface and / or those positioned within the chamber, may be individually and independently addressed and controlled. One or more of the heating elements may be turned on or turned off to ensure continuous thermal stability and proper heat distribution in the internal chamber.

[0025] The management of conditions internal to the device, temperature included, may be measurement-dependent or may depend on any variable known to the user.

[0026] A fan assembly or module may also be present. The fan assembly may comprise one or more fan members positioned within the internal chamber to better distribute the heat within the space. In some embodiments, each of the fan units may be positioned on a shock and noise absorber limiting or eliminating vibrations and electric noise within the device.

[0027] The device may comprise a plurality of different sensors, including for example temperature sensors, humidity sensors and sensors for detecting other volatile materials. The sensors are arranged to ensure that a constant measurement profile is maintained. These sensors are provided within the enclosure but outside of the sensor unit and are therefore distinguished from sensor members provided in the sensor unit for detecting a chemical interaction with an analyte. The sensors monitoring changes in temperature, humidity or presence of volatiles may be positioned at any part within the internal chamber of the device, outside of the sensor unit. The sensors used for monitoring changes in temperature, humidity, pressure or presence of volatiles may be selected amongst photoionization detectors (PID), thermal transducers, thermocouples, resistance temperature devices (RTD), thermocouples, thermistors, infrared sensors and others.

[0028] A control unit may be present and may include any physical or virtual processing elements comprising a processor configured to control the operation of the heating elements, the fans, the measurement unit, the sample flow, etc, in a way that is based on a preset protocol and at least one determined feature relating to a tested sample, received temperature data from each of the sensors and control the operation thereof throughout the operation of the device. The enclosure or housing of the device is provided with an opening or a door that enables direct access to the internal chamber of the device. When the device internal chamber is accessed, the detachable measurement unit including one or both of the sensing unit and the sample unit may be inserted, removed, replaced or serviced. When in operation (with its door in a closed position), the device is configured as an “isolated interaction enclosure , whereby detection of a chemical interaction between an analyte in a sample present in the sample unit and a sensor member of the sensor unit is substantially unaffected by events occurring and conditions characterizing the environment external to the device. The enclosure substantially blocks electromagnetic fields and thus may be alternatively regarded as an EMI shielded enclosure. For example, the device may be used to carry out measurements at ambient temperatures ranging from sub-zero to 40-50°C, while maintaining the temperature within the enclosure stable at or near room temperature. Similarly, the device may be used to carry out measurements in a laboratory set up or a medical set up or outdoors with variable electric noise, while maintaining the electromagnetic effects on the measurements minimal.

[0029] The enclosure may be formed by formed of a continuous material sheet of a conductive material, a paint or a covering of a suitable material, as known in the art. In some embodiments, the EMI shield is a conductive metal such as aluminum, which may be provided as a sheet or a shield material. Alternatively, the EMI shield may be provided in a form of a conductive paint or ink, containing metallic fillers (such as silver, copper, nickel, aluminum). The coating of the paint may be formed internally or externally to the enclosure. Electroplated coatings and thin metal layers (nickel, copper, gold, etc.) deposited on a plastic or a metal enclosure may also be used. Also, the enclosure of the device may be formed of a conductive polymer, or polymer composites such as polymer matrices containing carbon, graphene, or metal particles.

[0030] The system is an isolated system whereby additionally the internal chamber is not internally illuminated or is shielded from ambient light. The internal air temperature and humidity fluctuations influencing a signal generated due to a change in the vicinity of or on the surface of the sensor member are dramatically reduced or diminished. Noise affecting the signal / noise ratio is also dramatically diminished by having the internal chamber configured as an EMI enclosure. The isolated interaction enclosure is thus unique not only in permitting substantially (isolated) unaffected detection of chemical interactions within the measurement unit, but also in dramatically reducing light and unwanted noise or electric noise that interferes with signals generated by the chemical interactions with the sensor member.

[0031] The substantially unaffected" interaction that is said to be isolated from external effects is reflected in a comparative signal-to-noise ratio, a detection limit of the chemical interactions, reproducibility of the signals, possible signal selectivity due to much improved signal to noise ratio, and stability of the measurement profile (preset air temperature in the device internal space and optionally a preset humidity level). When measured in a system that is not an ‘isolated interaction enclosure’ or a ‘shielded EMI unit’, e.g., a controlled environment such as a chemical hood operated under ambient conditions or a commercial incubator operated under controlled conditions, each of the aforementioned parameters were much inferior, i.e., exhibiting reduced stability and higher noise levels. For example, in an isolated interaction enclosure according to the invention, the signal-to-noise ratio was at least 8 to 10 times better as compared to the bit noise generated in a commercial incubator device. Temperature stability within the device and within the detachable measurement unit was maintained within a stability of ±0.15°C over time and accuracy of ±0.2°C from a given temperature preset and was maintained uniform throughout the device. Temperature uniformity within the device was also maintained within a range of ±0.15°C or lower. Despite the fact that exposing the internal space of the device by opening of the device door to its environment was expected to affect an immediate temperature change (increase or decrease depending on the temperature of the environment)- this being expected mainly in view of the small volume of the device- the temperature within the device was reset back to its preset temperature rather immediately, or within 1 minute.

[0032] As stated herein, the device comprises a measurement unit that includes a sensor unit and a sample unit. The sensor unit comprises a sensor member, a sensor array or a sensor assembly. The sensor array or sensor assembly may comprise one or a plurality of sensor members or sensing regions capable of interactions with an analyte present in a sample to be analyzed. The interaction between the sensor member(s) and the analyte causes a measurable electrical change in the vicinity of the sensor member(s) or on its surface. This change may be in the resistance measured for the sensor member, its conductivity, capacitance etc. The change may be detected as a change in an electric signal generated by the sensor unit. To ensure limited device and sample contamination, the measurement unit, including the sensor unit and the sample unit are detachable and optionally disposable.

[0033] The senor unit and the sample unit are reversibly associable to each other. The association between the two units permits flow of a sample contained in the sample unit to reach a sensor member in the sensor unit. When the device is operated to allow sample analysis, the sensor unit is plugged into or attached to or positioned within a suitable sensor port integrally provided in the device internal chamber. The port is designed to receive an end of the sensor unit, for example, in a way that permits contact between a sensor electronic pad to pins of an electronic board is enabled, or by any alternative way, to thereby allow measurement of the electric signal. The attachment to the port does not substantially permit sample flow outside of the sensor unit during the time of measurement. The port permits operative connection to an electric source and a means for permitting sample flow over the sensor in the sensor unit.

[0034] The sensor unit comprises a receiving port configured to receive therein an end of the sample unit. The connection between the receiving port of the sensor unit and the sample unit allows flow of the sample from the sample unit into the sensor unit. The sample unit additionally comprises an inlet for collecting a gaseous sample into the sample unit. The collection means may vary as further disclosed herein. In some configurations, the sample unit may be formed of a flexible material and arranged as a bag or a container (petri dish etc.). Similarly, the collection means may be a structured solid member that is configured to receive therein a sample to be tested. Notwithstanding, the sample unit may have a sampling end or a sampling element through which a gaseous sample may be collected or flown into.

[0035] In some embodiments, the measurement unit (comprising the sensor unit and the sample unit) may be described as an integrated measuring unit comprising a member configured to be positioned in the port, as described herein, an inlet sampling element for receiving the sample into the sample unit, a channel assembly configured to direct said sample from the sample unit into the sensor unit and a pump unit that is optionally positioned internal to the device and configured for continuously flowing the sample in a closed loop fashion from the sample unit over the sensor member(s) in the sensor unit, back into the sample unit and over the sensor member(s) again. In other words, the measurement unit could comprise a closed loop channel assembly that is configured to direct the sample from the sample unit to the sensor member(s) and to circulate said sample from the sample unit over the sensor member(s) over a period of time.

[0036] The sensor unit comprises one or more, or an array of sensor members for measuring / detecting components of a gaseous sample, for determining a similarity or an identity between samples or for determining a change between any two samples. The sensor member is typically a sensor capable of undergoing a change in at least one electrical property in response to interaction with a component of the sample, or the sample as a whole. Such sensors may be functionalized surface regions (wherein such surfaces are functionalized with metal nanoparticles, functional molecules, hollow fibers and others), sensors having a functionalized nanowire or a nanotube, a polymer-coated surface acoustic wave (SAW) sensors, sensors employing a semiconductor gas sensor technology, aptamer biosensors, amplifying fluorescent polymer (AFP) sensors and others.

[0037] In some embodiments, the sensor unit comprises one or more (or an array) of chemically sensitive sensor members and the device comprises a processing unit comprising a learning and pattern recognition classifier configured for receiving sensor output signals and comparing the signals to a stored data, by utilizing a pattern recognition algorithm.

[0038] In some embodiments, the sensor member is provided in a form of surface associated plurality of nanoparticles. The surface may comprise one or more sensing regions, each of the regions being associated with same or a different population of nanoparticles, such that a signal may be independently derived from each of the sensing areas, and be indicative of an interaction (or lack thereof) between components present in the sample and the nanoparticles on the sensing regions. In such or similar configurations, each of the sensing regions may comprise a plurality of nanoparticles of a particular population, wherein each population differs from another in at least one of particle size, particle morphology (e.g., core / shell particles, non-core / shell particles, spherical, cubic, tetrahedral, triangular, dumbbell, elongated, multiparticles or fused particles, etc), particle composition (e.g., doping, metallic particles, non-metallic particles, conductive particles, novel metal particles, hybrid materials, etc), surface decoration (e.g., presence of material islands, association with ligand groups, etc) and others.

[0039] In some cases, the sensor member(s), the nanoparticles, and / or the sensing region(s) may be chemically associated with ligand molecules that are selected to further distinguish between the sensing regions or particles. The ligand molecules may be selected amongst small organics, peptides, aptamers, antibodies, etc. that attach to the surface of the nanoparticles or sensing regions. They may be selected to prevent aggregation of nanoparticles on the sensor member or the sensing region, e.g., by providing steric or electrostatic repulsion, and / or to afford selective binding sites for the analytes.

[0040] In some embodiments of a device of the invention, the device provided in an enclosure of an EMI material enabling isolation from electromagnetic effects, the device comprising a heating surface, a fan for circulating heat within the enclosure, a port configured to receive a measuring unit comprising a sensor unit and a sample unit, a pump for circulating a sample from said sample unit over the one or more sensor members in said sensor unit, and one or more sensors provided outside of the measuring unit.

[0041] A sample analyzed by a device of the invention may be any gaseous sample obtained from an environment (e.g., for detection of contaminants, toxic materials, to determine leaks, etc), breath samples (e.g., for determining presence of a volatile indicative of a disease state), headspace samples obtained from a liquid sample, tissues, cells or any other sample that emits VOCS (such as a biological sample) or from any other type of sample, and others. The sample may be received into the sample unit by any means available, including suction, pumping or by any other means.

[0042] The device may comprise a pattern recognition algorithm to determine presence and / or amount of said a gaseous component in the sample. The algorithm may be, but not limited to, artificial neural networks, multi-layer perception (MLP), generalized regression neural network (GRNN), fuzzy inference systems (FIS), self-organizing map (SOM), radial bias function (RBF), genetic algorithms (GAS), neuro-fuzzy systems (NFS), adaptive resonance theory (ART) and statistical methods including, but not limited to, principal component analysis (PCA), partial least squares (PLS), multiple linear regression (MLR), principal component regression (PCR), discriminant function analysis (DFA) including linear discriminant analysis (LDA) or cluster analysis including nearest neighbor.

[0043] The device is configured as a portable device that permits immediate or on-the- spot real-time detection and analysis of a gaseous sample. Due to its small size, low weight and the provision of an isolated interaction enclosure, the device may be carried to any location and used to analyze a chemical interaction under any climate or otherwise changing conditions.

[0044] The device of the invention may be a standalone device used and operated for detection of analytes as disclosed herein, or may be incorporated into spectrometric devices, wherein the detector or sensor used for the detection is a detector or sensor of the spectrometric device. The spectrometric device may be an infra-red (IR) device, an ultraviolet (UV) device, a mass spectroscopy (MS) device, a Raman device etc.

[0045] The invention further provides a portable device for measuring or determining proper function of an electronic element, the device being arranged as an isolated interaction Faraday or shielded EMI enclosure maintaining a stable measurement profile, as defined herein, wherein the device comprises a port for receiving therein a detachable measurement unit configured to electronically receive the electronic element.

[0046] The electronic element to be tested for determining its function over time may be selected amongst any electronic element which function may have an effect on proper operation of an electronic device. The electronic element may be a resistor, an inducer, a capacitor, a diode, a coil, and others. The measurement unit may include a pair of connectors suitable for connecting to the element leads to pass current therethrough. The stability of the element during the testing time may be recorded to determine element suitability.

[0047] The invention further provides a method for measuring a change in an electronic signal due to a chemical interaction between a sensor member and an analyte, the method comprising

[0048] -permitting flow of a gaseous sample onto a sensor member provided in a portable device comprising a detachable measurement unit having a sensor unit and a sample unit, wherein said sensor unit comprising one or a plurality of sensor members; the device being arranged as an isolated interaction enclosure maintaining a stable measurement profile as the gaseous sample is flown over the sensor member;

[0049] -detecting an electronic signal from the sensor member; and

[0050] -comparing the signal to a signal obtained for the sensor member prior to contacting thereof with the sample.

[0051] The invention further provides:

[0052] A portable device for detecting at least one chemical interaction between an analyte and a sensor member, the device comprising a port configured for receiving therein a detachable measurement unit comprising an analyte sample; the device is arranged as an isolated interaction enclosure for reducing or diminishing electromagnetic interference (EMI) during measurement of the at least one chemical interaction to maintain a stable measurement profile.

[0053] In some configurations of a device of the invention, the device is arranged as an isolated interaction Faraday or shielded EMI enclosure, the enclosure comprising a heating array and a port configured to receive therein a measuring unit comprising a sensor unit and a sample unit, wherein said sensor unit comprises one or a plurality of sensor members selected to undergo a chemical interaction with the analyte provided in the sample unit and changing at least one electrical property thereof in response to said interaction.

[0054] In some configurations of a device of the invention, said detachable measurement unit comprises a sensor unit and a sample unit.

[0055] In some configurations of a device of the invention, the sensor member is implemented in a sensor unit.

[0056] In some configurations of a device of the invention, the device further comprising one or a plurality of temperature and / or humidity sensors, a controller, a fan module, and a power supply unit.

[0057] In some configurations of a device of the invention, the heating array is configured to maintain a constant and uniform temperature in the enclosure.

[0058] In some configurations of a device of the invention, the heating array comprises one or more thin-film heating elements associated to a thermo-conductive surface.

[0059] In some configurations of a device of the invention, the heating array comprises one or more heating elements being optionally individually and independently addressed and controlled.

[0060] In some configurations of a device of the invention, the sensor unit comprises a sensor array of sensor members or an assembly of sensor members, each comprising one or a plurality of sensor members or sensing regions capable of undergoing interactions with the analyte present in a sample to be analyzed.

[0061] In some configurations of a device of the invention, an interaction between any one sensor member and the analyte causes a measurable electrical change in a vicinity of the sensor member or on its surface. In some configurations of a device of the invention, the change is a change in resistance, conductivity, or capacitance.

[0062] In some configurations of a device of the invention, the device comprising a plurality of sensors external to said detachable measurement unit or sample unit, for detecting presence of volatile materials present external to said detachable measurement unit or sample unit.

[0063] In some configurations of a device of the invention, the senor unit and the sample unit are reversibly associable to each other.

[0064] In some configurations of a device of the invention, the association between the sensor unit and sample unit permits flow of a sample contained in the sample unit to a sensor member in the sensor unit.

[0065] In some configurations of a device of the invention, the sensor unit is detachably attachable to a sensor port integrally provided in the device internal chamber, wherein the port is designed to receive an end of the sensor unit.

[0066] In some configurations of a device of the invention, attachment to the sensor port does not substantially permit sample flow outside of the sensor unit during a time of measurement.

[0067] In some configurations of a device of the invention, the sensor port permits operative connection to an electric source and a means for permitting sample flow over the sensor in the sensor unit.

[0068] In some configurations of a device of the invention, the sensor unit comprises a receiving port configured to receive therein an end of the sample unit, wherein connection between the receiving port of the sensor unit and the sample unit allows flow of the sample from the sample unit into the sensor unit.

[0069] In some configurations of a device of the invention, the sample unit comprises an inlet for collecting a gaseous sample into the sample unit.

[0070] In some configurations of a device of the invention, the measurement unit comprises a closed loop channel assembly configured to direct the sample from the sample unit to the sensor unit comprising the one or more sensor member(s) and to circulate and re-circulate said sample from the sample unit over the sensor member(s) over a period of time. In some configurations of a device of the invention, said circulating comprises a pump unit positioned internal to the device and configured for continuously flowing the sample.

[0071] In some configurations of a device of the invention, the device comprising a control unit.

[0072] In some configurations of a device of the invention, the device provided in a continuous shield or covering formed of a conductive material, thereby permitting an isolated interaction enclosure for reducing or diminishing electromagnetic interference (EMI).

[0073] In some configurations of a device of the invention, the shield or covering is formed of a sheet of aluminum metal.

[0074] In some configurations of a device of the invention, the device provided in an enclosure of an EMI material.

[0075] In some configurations of a device of the invention, the EMI material is a conductive paint.

[0076] In some configurations of a device of the invention, the conductive paint comprises metallic fillers.

[0077] In some configurations of a device of the invention, the EMI material is a conductive polymer, or a polymer composite.

[0078] In some configurations of a device of the invention, the device provided in an enclosure of an EMI material enabling isolation from electromagnetic effects, the device comprising a heating surface, a fan for circulating heat within the enclosure, a port configured to receive a measuring unit comprising a sensor unit and a sample unit, a pump for circulating a sample from said sample unit over the one or more sensor members in said sensor unit, and one or more sensors provided outside of the measuring unit.

[0079] The invention further provides a method for measuring a change in an electronic signal due to a chemical interaction between a sensor member and an analyte, the method comprising

[0080] -permitting flow of a gaseous sample onto a sensor member provided in a portable device comprising a detachable measurement unit having a sensor unit and a sample unit, wherein said sensor unit comprising one or a plurality of sensor members; the device being arranged as an isolated interaction Faraday or shielded EMI enclosure;

[0081] -detecting an electronic signal from the sensor member; and -comparing the signal to a signal obtained for the sensor member prior to contacting thereof with the sample.

[0082] In some configurations of a method of the invention, the portable device is a device according to any embodiment disclosed herein.

[0083] In some configurations of the device and method of the invention, the sensor unit comprises a plurality of different sensor members.

[0084] BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0086] Fig. 1 demonstrates different sensors response to specific analyte added in different concentrations to breath samples. Each line represents an average and STD response of 5 sensors (from the same type).

[0087] Fig. 2 presents the results of Fig. 1 when presented for multiple experiments with multiple sensors using same device of the invention.

[0088] Figs. 3A-B show temperature stability measurements over 30 minutes (A) and 16 hours (B).

[0089] Fig- 4 shows comparative temperature stability tests in an incubator.

[0090] Fig. 5A shows an exemplary portable device according to some embodiments of the invention. Fig. 5B shows the device with door in the open position.

[0091] Fig- 6 shows a device according to some embodiments of the invention, having a shield of an EMI material.

[0092] Figs. 7A-B represent a striped down depiction of an internal chamber of device according to the invention.

[0093] Figs. 8A-C show a device of the invention comprising a port in which a sensor unit is positioned. (A) an exemplary sensor array. (B) an exemplary measurement unit before positioning in the senor port. (C) an exemplary measurement unit. DETAILED DESCRIPTION OF EMBODIMENTS

[0094] The abilities of a device of the invention to detect analytes in a gaseous sample were compared to an identical sensor device (a sensor array of gold nanoparticles) which was placed in a small lab incubator (Incubator: mrc Air forced laboratory incubator 36 litters, Max. 80°C) maintaining substantially similar testing conditions.

[0095] Samples containing different concentrations of analytes were prepared and tested.

[0096] Example 1: Detection of Sub-ppm concentrations of analytes

[0097] Breath samples were obtained from a single individual and enriched with a known analyte (Limonene) at different concentrations. The concentrations tested were 25, 50 and 100 ppb. Each sample was exposed to a sensor assembly of a device of the invention and the signals reflecting interactions between the analyte and the sensors were recorded.

[0098] Fig. 1A demonstrates different sensors response to specific analyte added in different concentrations to breath samples. Each line represents an average and STD response of 5 sensors (from the same type). As shown, the device of the invention was able to detect sub-ppm concentrations of an analyte in a gaseous medium.

[0099] Example 2: Stability and repeatability of results

[0100] The results presented for Example 1 were analyzed and grouped in multiple experiments with multiple sensors. As shown in Fig. 2, in each group of experiments, the results were quite identical, demonstrating repeatability and stability of the measurements.

[0101] Example 3: Measurements isolated from external noise or environmental changes

[0102] A device according to the invention, utilizing an array of gold nanoparticles, and operated under ambient conditions or room temperature and humidity, was used to measure samples of breath analytes comprising different concentrations of Limonene. The signal -to-noise ratio was observed to be at least 8 to 10 times better than a bit noise generated in a commercial incubator device.

[0103] Temperature stability within the device and within the detachable measurement unit was maintained within a range of ±0.15 and ±0.2°C from a given temperature preset and was maintained uniform throughout the device. The stability in the incubator was much more limited, as shown in the continued increase in the temperature over time. The Alpha device in incubator showed significantly less stability over 30 min comparing to the two beta devices with the stability system integrated. As shown in Fig. 3, during 16h- measurements, the device showed stability of ±0.15 comparing to the device with the incubator as shown in Fig. 4.

[0104] Temperature uniformity (Fig 4) within the device was also maintained within a ±0.15°C or lower, measured at 37°C. The uniformity in the incubator was inferior, maintained at ±1°C, when measured at 37°C.

[0105] Example 4: Exemplary device of the invention

[0106] Fig. 5A shows an exemplary portable device 100 according to some embodiments of the invention. The device 100 comprises an outer enclosure or a housing 10 and a top door 20 in a closed position. The shape of the device is of no functional importance. The volume of the device may range from 2 to 5 liters. The length of the device may be about 20 cm, width of about 10 cm, and height of about 10-15 cm. Fig. 5B shows the device 100 with door 20 in the open position. A part of the sample unit 30 is shown.

[0107] As disclosed herein, the device is structured such that detection of a chemical interaction between an analyte of a sample present in the sample unit and a sensor member of the sensor unit is substantially unaffected by events occurring and conditions characterizing the environment external to the device. The system is an isolated system whereby the internal air temperature and humidity fluctuations influencing a signal generated due to a change in the vicinity of or on the surface of the sensor member are dramatically reduced or diminished. Noise affecting the signal / noise ratio is dramatically diminished by having the internal chamber of the device 100 configured as a Faraday enclosure or as an EMI enclosure. As Fig. 6 shows, the internal space or chamber of the device is formed in a metallic cage 40, or a cage of a different material that is coated with a suitable paint reducing electromagnetic interference. In some cases, the cage is an aluminum cage.

[0108] Figs. 7A-C represent a striped down depiction of an internal chamber of device 100 according to the invention. A thermo-conductive plate 50 extending between internal walls 60 of the enclosure or cage 40 forms a base or a surface for positioning of the various modules and elements of the device. In the specific depiction of Fig. 7A, a pair of heating elements 70 are positioned directly on the plate 50. In some other configurations, three or more heating elements may be present. The position of the heating elements is not limited to any one position on the plate 50.

[0109] As shown in Fig. 7A, the device comprises a port 80 in which a sensor unit 90 is positioned. A sample unit 110 is connected on top and into the sensor unit 90. The senor unit 90 and the sample unit 110 together constitute the measuring unit 120. The shapes of the port 80, the sensor unit 90 and the sample unit 110 are not necessarily as depicted and represent only few of the embodiments of the device.

[0110] Position of additional elements 130, 140 and 150 on plate 50 is depicted in Fig. 7B. These include fans that distribute the heat within the device and permit uniform thermal distribution, and a variety of additional elements.

[0111] Reference is now made to Figs. 8A-C. As schematically depicted in Fig. 8A, a sensor unit used in accordance with the invention 200 may be a single sensor member or may be designed as an array or as an assembly of sensor members 210. The sensor member may comprise a layer or a deposition of nanoparticles that may be distributed on the surface of the member. In some cases, each member is a standalone member that is attached to the sensor unit, or may be a sensing region capable of undergoing interactions with an analyte present in a sample to be analyzed. As shown in Fig. 8B, the sensor unit is provided in a specially designated port that can be associated with or which can receive sample unit 110. Fig. 8B depicts a senor unit 310 and the sample unit 320 before associated together to constitute a measuring unit according to the invention. The senor unit 310 and the sample unit 320 are reversibly associable to each other. The association between the two units permits flow of a sample contained in the sample unit to reach a sensor member in the sensor unit. When the device is operated to allow sample analysis, the sensor unit is plugged into or attached to or positioned within a suitable sensor port 330 integrally provided in the device internal chamber. The port 320 is designed to receive an end of the sensor unit, such that a contact between a sensor electronic pad to pins of an electronic board (not shown) is enabled, allowing measurement of the electric signal. The attachment to the port 330 does not substantially permit sample flow outside of the sensor unit during the time of measurement. The port 330 permits operative connection to an electric source and a means for permitting sample flow over the sensor in the sensor unit.

[0112] A sample unit 400 is depicted for the purpose of exemplification in Fig. 8C. The sample unit 300 comprises an inlet 410 for collecting a gaseous sample into the sample unit 400. The collection means may vary as disclosed herein. The sample unit has an opening 420 designed to attach to port 320 shown in Fig. 8B.

Claims

CLAIMS:

1. A portable device for detecting at least one chemical interaction between an analyte and a sensor member, the device comprising a port configured for receiving therein a detachable measurement unit comprising an analyte sample; the device is arranged as an isolated interaction enclosure for reducing or diminishing electromagnetic interference (EMI) during measurement of the at least one chemical interaction to maintain a stable measurement profile.

2. The device according to claim 1, arranged as an isolated interaction Faraday or shielded EMI enclosure, the enclosure comprising a heating array and a port configured to receive therein a measuring unit comprising a sensor unit and a sample unit, wherein said sensor unit comprises one or a plurality of sensor members selected to undergo a chemical interaction with the analyte provided in the sample unit and changing at least one electrical property thereof in response to said interaction.

3. The device according to claim 1, wherein said detachable measurement unit comprises a sensor unit and a sample unit.

4. The device according to claim 1, wherein the sensor member is implemented in a sensor unit.

5. The device according to any one of the preceding claims, further comprising one or a plurality of temperature and / or humidity sensors, a controller, a fan module, and a power supply unit.

6. The device according to any one of the preceding claims, wherein the heating array is configured to maintain a constant and uniform temperature in the enclosure.

7. The device according to claim 6, wherein the heating array comprises one or more thin-film heating elements associated to a thermo-conductive surface.

8. The device according to claim 6, wherein the heating array comprises one or more heating elements being optionally individually and independently addressed and controlled.

9. The device according to any one of the preceding claims, wherein the sensor unit comprises a sensor array of sensor members or an assembly of sensor members, each comprising one or a plurality of sensor members or sensing regions capable of undergoing interactions with the analyte present in a sample to be analyzed.

10. The device according to claim 9, wherein an interaction between any one sensor member and the analyte causes a measurable electrical change in a vicinity of the sensor member or on its surface.

11. The device according to claim 10, wherein the change is a change in resistance, conductivity, or capacitance.

12. The device according to any one of the preceding claims, comprising a plurality of sensors external to said detachable measurement unit or sample unit, for detecting presence of volatile materials present externally to said detachable measurement unit or sample unit.

13. The device according to any one of the preceding claims, wherein the senor unit and the sample unit are reversibly associable to each other.

14. The device according to claim 13, wherein the association between the sensor unit and sample unit permits flow of a sample contained in the sample unit to a sensor member in the sensor unit.

15. The device according to any one of claims 3 to 14, wherein the sensor unit is detachably attachable to a sensor port integrally provided in the device internal chamber, wherein the port is designed to receive an end of the sensor unit.

16. The device according to claim 15, wherein attachment to the sensor port does not substantially permit sample flow outside of the sensor unit during a time of measurement.

17. The device according to claim 15, wherein the sensor port permits operative connection to an electric source and a means for permitting sample flow over the sensor in the sensor unit.

18. The device according to any one of claims 3 to 17, wherein the sensor unit comprises a receiving port configured to receive therein an end of the sample unit, wherein connection between the receiving port of the sensor unit and the sample unit allows flow of the sample from the sample unit into the sensor unit.

19. The device according to any one of claims 3 to 18, wherein the sample unit comprises an inlet for collecting a gaseous sample into the sample unit.

20. The device according to any one of the preceding claims, wherein the measurement unit comprises a closed loop channel assembly configured to direct the sample from the sample unit to the sensor unit comprising the one or more sensor member(s) and to circulate and re-circulate said sample from the sample unit over the sensor member(s) over a period of time.

21. The device according to claim 20, wherein said circulating comprises a pump unit positioned internal to the device and configured for continuously flowing the sample.

22. The device according to any one of the preceding claims, comprising a control unit.

23. The device according to any one of the preceding claims, provided in a continuous shield or covering formed of a conductive material, thereby permitting an isolated interaction enclosure for reducing or diminishing electromagnetic interference (EMI).

24. The device according to claim 23, wherein the shield or covering is formed of a sheet of aluminum metal.

25. The device according to any one of claims 1 to 24, provided in an enclosure of an EMI material.

26. The device according to claim 25, wherein the material reducing or diminishing electromagnetic interference (EMI) is a conductive paint.

27. The device according to claim 26, wherein the conductive paint comprises metallic fillers.

28. The device according to claim 25, wherein the material reducing or diminishing electromagnetic interference (EMI) is a conductive polymer, or a polymer composite.

29. The device according to any one of the preceding claims, provided in an enclosure of an EMI material enabling isolation from electromagnetic effects, the device comprising a heating surface, a fan for circulating heat within the enclosure, a port configured to receive a measuring unit comprising a sensor unit and a sample unit, a pump for circulating a sample from said sample unit over the one or more sensor members in said sensor unit, and one or more sensors provided outside of the measuring unit.

30. A method for measuring a change in an electronic signal due to a chemical interaction between a sensor member and an analyte, the method comprising-permitting flow of a gaseous sample onto a sensor member provided in a portable device comprising a detachable measurement unit having a sensor unit and a sample unit, wherein said sensor unit comprising one or a plurality of sensor members; the device being arranged as an isolated interaction Faraday or shielded EMI enclosure;-detecting an electronic signal from the sensor member; and-comparing the signal to a signal obtained for the sensor member prior to contacting thereof with the sample.

31. The method according to claim 30, wherein the portable device is a device according to any one of claims 1 to 29.

32. The method according to claim 29, wherein the sensor unit comprises a plurality of different sensor members.

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