A portable system with mechanical multilayer structure for measuring human body (forehead) and object temperature

Abstract

A portable infrared thermometer device is disclosed, which plugs into a smartphone to measure temperatures of the human body (forehead) and objects. The device features a multi-layer insulated sensor chamber that thermally isolates the IR sensor from heat sources. An inner and outer plastic shell creates an insulating air gap around the sensor, and a partition separates the sensor from the main electronics. The device has no internal battery or display, drawing power from the smartphone via a USB-C connector and utilizing the smartphone for control and display. A low-power microcontroller on the main printed circuit board reads the IR sensor and transmits data to the phone. The design enables fast (≈330#ms) and accurate temperature measurements in a compact form factor (~49#mm × 26#mm) by maintaining the sensor at ambient temperature and minimizing thermal interference. The invention applies to medical thermometry and general temperature measurements.

Description

A PORTABLE SYSTEM WITH MECHANICAL MULTILAYER STRUCTURE FOR MEASURING HUMAN BODY (FOREHEAD) AND OBJECT TEMPERATURE

[0001] This invention relates to non-contact temperature measurement devices. More particularly, it pertains to a portable infrared thermometer system for measuring human body (forehead) temperature and object surface temperature. The system uses a compact hardware device with a mechanical multi-layer insulation structure to improve thermal stability, designed to interface with a smartphone for power and data.

[0002] Non-contact infrared (IR) thermometers are widely used to measure temperature without physical contact, especially for medical forehead temperature checks and for checking the temperature of objects or surfaces. Traditional handheld IR thermometers are often standalone devices that include internal batteries, displays, and trigger buttons. These conventional devices tend to be relatively bulky because they incorporate all necessary components (power supply, electronics, and user interface) into one unit. They are designed with housings that sometimes include heat sinks or require a period of acclimation to ambient temperature to ensure accurate readings..

[0003] With the increasing use of smartphones, there have been attempts to create small IR thermometer devices and systems that plug into a phone. Some known portable thermometer devices for smartphones include additional features like small displays or require separate batteries, which add to their size and complexity. In many prior designs, the infrared sensor can be influenced by heat from the device’s electronics or the user’s hand, leading to less accurate measurements. For example, if a user holds a small thermometer device, the warmth of their fingers or the heat generated by the device’s microelectronics can raise the sensor’s temperature, causing drift in the measured readings. Small form-factor IR sensors are particularly susceptible to ambient temperature changes; thus, maintaining sensor stability is a challenge.

[0004] Another limitation in existing portable thermometers is the need for frequent battery charging or replacement, and the inclusion of buttons or displays on a tiny device can complicate the user experience. There is a demand for a compact, plug-and-play IR thermometer that can reliably measure human body (forehead) and object temperature using the smartphone for power and display. However,due to thermal interference in such small assemblies, achieving medical-grade accuracy in a tiny device without active cooling or long stabilization times is technically difficult. Therefore, there is a need for an improved portable infrared thermometer design that addresses thermal stability in a compact device. In particular, the challenge is to isolate the IR sensor from internal and external heat influences in a very small form factor, enabling rapid and accurate measurements without using an internal battery or integrated display.

[0005] The present invention provides a compact infrared thermometer device that plugs into a smartphone and measures human body (forehead) or object temperatures with a high accuracy of ±0.2°C. The invention features a mechanical multi-layer insulation capsule around the IR sensor to maintain thermal stability, along with a partitioned design separating the sensor from other electronics. The device contains no internal battery, display, or buttons – it draws power from the smartphone’s USB port and communicates with a smartphone application for control and readout. By utilizing the smartphone as a power source and user interface, the device minimizes its own size and component count. Key innovative aspects include the multi-layer plastic structure (parts 1, 2, 3) that thermally isolates the infrared sensor (10) while still allowing the sensor to receive radiation and equilibrate with ambient air, the separation of the sensor chamber from the main electronics via a partition (1), and the use of low-power electronics (PCBs 8 and 9 with a deep-sleep microcontroller) to reduce heat generation. This combination of features allows this device to perform a temperature measurement in approximately 330 milliseconds with minimal error, despite its small form factor (about 49 mm in length and 26 mm in diameter).

[0006] The technical problem addressed by the invention is how to design an ultra-compact, portable IR thermometer that can quickly and accurately measure body or object temperatures without being affected by heat from the device’s electronics, the user’s hand, or the environment. In small devices, the proximity of the sensor to other components and to the user’s hand can cause the sensor’s temperature to rise, leading to inaccurate readings. Additionally, removing components like batteries and displays (to rely on a smartphone instead) means the device must manage power and user interaction in a new way. The problem can be summarized as achieving thermal stability and accuracy in a small, smartphone-powered thermometer, while maintaining ease of use and rapid responsiveness.

[0007] In order to solve the above problem, the invention employs a mechanical multi-layer structure to thermally isolate the IR sensor. The sensor (10) is housed within a double-layer plastic capsule composed of an inner shell (2) and an outer shell (3). This capsule creates a thermal insulation barrier, with an air gap or insulating material between the shells, drastically reducing heat transfer from external sources or the device’s electronics to the sensor. A thermally insulating partition (1) is positioned between the sensor’s capsule and the main electronics compartment, effectively separating the sensor chamber from the rest of the device. This partition (1) supports the sensor and its small circuit board, while blocking direct conductive heat flow from the main circuit board (8) and other components.

[0008] The electronic solution complements the mechanical design: the device uses a minimalistic electronics setup with two printed circuit boards (8 and 9) to further isolate the sensor. The two printed circuit boards (PCBs 8 and 9) are housed in a separate capsule from the sensor chamber. The lower PCB (9), located closer to the sensor, is dedicated solely to low-power analog amplification. It is designed for minimal power consumption to prevent local heat generated near the sensor interface.

[0009] The upper PCB (8) carries all higher-power components, such as the microcontroller and digital interface circuitry. This board is thermally managed through metal polygons integrated into the PCB, which conduct heat toward the USB port structure. The metal grounded body of the USB connector then acts as a heat sink, efficiently dissipating excess thermal energy to the outside environment and away from the temperature-sensitive components.

[0010] The connection between these boards is made through a small connector, minimizing thermal conduction paths. The microcontroller is programmed to operate in a deep-sleep mode when not taking a measurement, so it generates virtually no heat most of the time. It wakes only briefly (for a few hundred milliseconds) to read the sensor and communicate data, thereby limiting any self-heating of the device. Power is supplied through a USB-C connector (11) that plugs into the smartphone; no internal battery is needed. The absence of an internal battery and display not only reduces heat sources, it also shrinks the device’s size.

[0011] The multi-layer insulation capsule (1, 2, 3) has a front opening (aperture) that allows the IR sensor to “view” the target (forehead or object) and also permits a degree of air ventilation around the sensor. This design ensures that while the sensor is physically shielded from transient thermal influences (like a warm hand nearby or heat from the microcontroller), it can still equilateral with ambient air temperature for accurate compensation. By these means, the invention provides a thermally stable environment for the IR sensor within a very small device, solving the problem of accuracy degradation in compact thermometers.

[0012] Enhanced Accuracy and Stability: The multi-layer insulated sensor capsule keeps the infrared sensor at a stable temperature close to ambient. This dramatically reduces measurement error caused by heat from electronics or the user’s hand. The result is reliable, repeatable temperature readings with minimal drift over successive measurements.

[0013] Fast Response: The thermal isolation and the low-power operation allow the sensor to be ready and accurate almost immediately. A temperature measurement can be completed in about 330 milliseconds (approximately one third of a second). Users do not need to wait long for the device to stabilize, enabling rapid screening of multiple individuals or objects.

[0014] Compact and Portable Design: By eliminating the internal battery, display, and buttons, the device’s form factor is extremely small (around 49 mm × 26 mm). It is lightweight and can be easily carried in a pocket or attached to a smartphone without adding significant bulk. This makes the thermometer highly portable and convenient for on-the-go use.

[0015] No Battery Maintenance: The device draws power directly from the smartphone via the USB-C port. This means there are no batteries to charge or replace, reducing maintenance. It also eliminates the risk of battery leakage or failure, and allows continuous operation as long as it’s connected to a powered phone.

[0016] Smartphone Integration and User Interface: Using the smartphone as the user interface provides a superior experience. The measurement data is displayed on the smartphone’s screen, which is large and user-friendly compared to tiny built-in displays. The smartphone app can also provide additional functionalities such as data logging, unit switching (°C / °F), high-temperature alerts, or even syncing with health records. All control (for example, initiating a measurement or switching between “body” and “object” measurement modes) is done through the app, so no physical buttons on the device are required.

[0017] Reduced Heat Generation: The deep-sleep mode of the microcontroller and the efficient design of the circuitry mean the device consumes very little power and produces negligible heat during operation. This not only preserves accuracy (by not warming the sensor), it also minimizes battery drain on the smartphone.

[0018] Versatility: The thermometer can be used for both medical and non-medical purposes. It accurately measures human body (forehead) temperature, which is useful for fever screening, and can also measure the temperature of objects (such as a baby’s bottle, ambient air, or equipment surfaces) by simply selecting the appropriate mode in the app. Calibration lookup tables and software adjustments ensure that each type of measurement (body or object) is accurate without requiring separate hardware.

[0019] In summary, the invention combines a novel mechanical insulation approach with smart power management and smartphone integration, yielding a portable thermometer that is small yet highly accurate, quick, and convenient to use in a variety of settings.

[0020] Fig.1 is an external view of the portable temperature measuring device according to an embodiment of the invention. It shows the assembled portable device.

[0021] is an exploded view of the device of Fig.1, illustrating the internal components and structure.

[0022] is a cross-sectional side view of the device (for example, taken along a central longitudinal plane).Description of Embodiment

[0023] Hereinafter, a preferred embodiment of present invention will be described with reference to accompanying drawing.

[0024] Referring now to the drawings, and initially to Fig.1, a preferred embodiment of the portable temperature measuring system is shown in assembled form. The device has a generally cylindrical shape with a length of about 49 mm and a diameter of about 26 mm, making it roughly the size of a USB flash drive. One end of the device is equipped with a USB Type-C male connector (11) which protrudes from the housing. This connector (11) allows the device to be plugged into the charging / data port of a smartphone, through which it draws power and communicates data. The opposite end of the device forms the temperature sensing end, where the infrared sensor is located internally and an opening is present to receive infrared radiation from a target.

[0025] Turning to, the internal construction of the device is illustrated in an exploded view. The core sensing component is an infrared temperature sensor (10), which may be a thermopile or pyroelectric IR sensor calibrated for human body temperature range and general surface temperature measurements. This sensor (10) is mounted on a small sensor printed circuit board (PCB) (9). The sensor PCB (9) includes the sensor package and possibly a dedicated analog front-end or amplifier if needed for the sensor’s signal. In the assembled device, sensor PCB (9) resides in a specially designed electronics chamber at the back of the device.

[0026] The sensor chamber is defined by a multi-layer insulation capsule made up of parts 1, 2, and 3. In the illustrated embodiment, part 1 is a thermally insulating partition wall that also serves as a mounting base for the sensor. Partition (1) is a disc or wall made of a plastic material (such as ABS or polycarbonate) with low thermal conductivity. It is positioned transverse to the device’s length, separating the front sensor chamber from the rear electronics chamber. Partition (1) has a central hollow tube that allows the sensor (10) pins to pass through from the sensor chamber to the electronics chamber.

[0027] Part 2 is an inner insulation shell – a generally cup-shaped or cylindrical piece that surrounds the sensor (10) closely. This inner shell (2) is open toward the front (so that IR radiation can enter) and closed at the back by the partition (1) when assembled. It is made of a plastic or polymer with good thermal insulation properties. The inner shell (2) defines a small internal volume in which the IR sensor (10) sits, essentially creating a micro-environment around the sensor.

[0028] Part 3 is an outer insulation shell that surrounds the inner shell (2). The outer shell (3) is also open at the front and mates with the partition (1) at the back when assembled, thus enclosing the inner shell in a double-walled configuration. Between the inner shell (2) and outer shell (3), there is an air gap (or potential space) which acts as an insulating layer. Air is a poor thermal conductor, so this gap further reduces heat transfer. The inner and outer shells (2, 3) are preferably made of plastic (or a similar low-conductivity material) and may be integrated together or held with a snap-fit or adhesive at the partition (1), forming a multi-layer capsule around the sensor.

[0029] These three parts (1, 2, 3) interact to maintain thermal stability for the sensor (10). Partition (1) blocks heat coming from the back (electronics side) via nearby heat conduction. The double-layer shells (2, 3) limit heat exchange from the sides or front. Importantly, the front opening of this capsule allows the sensor to receive infrared rays from the target object or person. That opening also permits a limited airflow into the sensor chamber. This ventilation means that the air immediately around the sensor (10) can equilibrate with the ambient environment’s temperature. By doing so, the sensor’s built-in temperature reference (many IR sensors measure their own temperature for compensation) accurately reflects the true ambient conditions, not an artificially elevated temperature due to internal heating. At the same time, the design and placement of the opening are such that it minimizes direct exposure of the sensor to heat from the user’s hand. In practice, when the device is held or plugged into a smartphone, the user’s hand will mostly contact the smartphone and perhaps the device’s outer housing (4) near the middle or back. The sensor is at the front end, which is typically not touched by the user, and is further protected by the capsule structure. Any heat from the user’s fingers on the outer housing (4) will have a hard time reaching the sensor due to the insulating shells and partition.

[0030] The outer housing of the device is shown as parts 4, 5, 1, 3 in. In this embodiment, part 4 can be considered the main outer casing – for example, a cylindrical body that forms the exterior of the device. This housing (4) is also preferably made of plastic for low heat conductivity and ease of manufacturing. Housing (4) may hold the partition (1) at its front end (the partition might snap or screw into housing 4, sealing off the front chamber except for the IR aperture). Toward the rear end of housing (4), the USB-C connector (11) protrudes. In the exploded diagram, part 5 represent the removable cap for the USB connector (11). Part 6 and part 7 are additional structural elements in this embodiment – they may include spacers, mounting posts, or rings used to secure components. For example, one of these (say part 6) could be a small bracket that helps lock the sensor PCB (9) to the partition (1) or positions it correctly. Another (part 7) could be a supportive piece for the main PCB (8). In summary, parts 4, 6, 7 constitute the mechanical housing and support structure that hold everything together in the electronics chamber. They ensure that the PCBs are secured in place, and the USB connector (11) is properly seated and able to withstand plugging / unplugging forces. All these housing parts are designed to fit together, for example using snap-fit latches or small screws, to create a robust assembly. In the preferred design, no metal screws are used near the sensor to avoid creating thermal bridges; if screws are needed, they might be placed at the rear or made of plastic.

[0031] Inside the main body (defined by housing 4 and related parts), the electronics of the device are arranged primarily on two circuit boards as shown in. The main printed circuit board (PCB) (8) is a board that holds the principal electronics, including a microcontroller (MCU) and associated circuitry. This microcontroller is a low-power device (for example, an ARM Cortex-M series MCU or similar) that is responsible for reading data from the IR sensor (10) and communicating with the smartphone. The main PCB (8) may also carry other components such as: a USB interface chip or simply the USB connector connections (if the MCU has native USB capability), power regulators or voltage translators (since the device may draw 5V from USB and regulate it to lower voltages for the sensor and MCU), and any memory that might store calibration data (like an EEPROM or flash, if not stored on the MCU). The main PCB (8) is positioned in the rear section of the device, roughly perpendicular to the length in some designs or parallel to it in others, depending on form factor. In one embodiment, PCB (8) could be oriented vertically and the USB-C connector (11) is soldered to its edge, protruding out of the housing.

[0032] The sensor PCB (9), as mentioned, carries the IR sensor (10) and possibly a small amplification circuit (some IR sensors come in modules with integrated lenses and amplifiers). PCB (9) is smaller and is located at the front, within the sensor chamber behind the partition (1). Partition (1) may have features (like slots or bosses) that allow mounting of the sensor PCB (9) securely – for example, the sensor board might screw or snap onto the partition so that the sensor (10) is aligned with the aperture. An electrical connector (such as a board-to-board connector or flexible cable) passes through a sealed opening in partition (1) to link the sensor PCB (9) with the main PCB (8). This connection allows the sensor’s signals and power to reach the main board, but the opening around it is small and preferably filled or insulated to limit heat conduction and airflow between chambers. By using two separate boards (8 and 9), the design physically and thermally decouples the sensor (and its tiny board) from the rest of the electronics. The only connections are via the slim connector or a few wires, which conduct minimal heat. This is a deliberate design choice to ensure that even if the main PCB (8) warms slightly (for instance, when the microcontroller is active or from the phone’s heat), the sensor board (9) remains as close to ambient temperature as possible.

[0033] In, the cross-sectional view further clarifies the assembled relationships. The infrared sensor (10) is positioned looking out through the front opening of the inner (2) and outer (3) shells. The partition (1) is seen separating the sensor’s enclosed front chamber from the rear section. The sensor PCB (9) is mounted just behind the sensor and attached to the partition (1). The main PCB (8) lies in the rear housing space, with the connector (11) extending out the back. Any interior support (6, 7) that holds the main PCB (8) or reinforces the connector (11) can be seen bridging between the PCB and housing walls. Notably, there is a gap between the partition (1) and the main PCB (8) so that direct contact is minimized to reduce heat flow.

[0034] Operation: When the device is in use, it is plugged into a smartphone via the USB-C connector (11). The smartphone runs a dedicated application (or uses standard drivers) to interface with the thermometer. The microcontroller on PCB (8) powers on and establishes communication (for example, it could appear as a USB HID or CDC device to the phone, or use another protocol). By default, the microcontroller stays in a low-power sleep mode to conserve energy and avoid self-heating. Through the smartphone app, the user initiates a temperature measurement – for instance, by pressing a “Measure” button on the screen. Upon command (or on a regular interval if set to continuous mode), the microcontroller wakes up and activates the IR sensor (10) to take a reading. The IR sensor (10) measures the infrared radiation from whatever object the sensor is pointed at (for example, a person’s forehead). Typically, the user would hold the smartphone such that the device’s front is about a few centimeters from the center of the forehead (for body temperature) or pointing towards an object surface for object temperature.

[0035] The sensor (10) outputs a signal. The microcontroller reads this sensor output. It also reads the sensor’s internal temperature reading (most IR sensors provide a reading of their own package temperature, which is needed for compensation). Because of the invention’s insulation design, this sensor package temperature should be very close to the true ambient temperature of the room, since the sensor is not significantly heated by the device. The microcontroller sends these measured data to the app. The implemented algorithm in the app then applies a calibration formula to convert the raw sensor data into an actual temperature value. In this embodiment, calibration data in the form of one or more lookup tables (LUTs) and compensation formula are stored on the smartphone app. For example, one LUT may translate the sensor’s reading at a given ambient temperature into a forehead temperature. There may be separate calibration curves or offsets for the outputs of thermopile and thermistor units of the infrared sensor. The device or app can automatically adjust for emissivity differences or other factors: human skin has a certain impassivity and usually forehead thermometers apply an algorithm to estimate core body temperature. In our case, the smartphone app might allow the user to select the measurement mode (body or object). If in body mode, the microcontroller (or app) will apply the appropriate compensation to display a reading that corresponds to body temperature. This could include adding an offset (since forehead skin is slightly cooler than core body temperature) or using a more complex formula. All such processing is done in software and can be kept fairly simple because the device’s stable sensor readings require minimal further correction. The heavy computing can also be offloaded to the smartphone if desired, as the phone has ample processing power.

[0036] Within about 0.33 seconds (330 ms), the device obtains the temperature reading. The microcontroller then sends this data to the smartphone (for instance, via USB communication). The smartphone app receives the temperature value and displays it on screen to the user, possibly along with any indicator (e.g., a color code for normal or fever if measuring a person). If the device is set to make an audible alert for high temperature, the smartphone can play a sound or the device could optionally incorporate a simple buzzer. In this embodiment, no buzzer is included in hardware to keep it simple; instead, the phone itself can generate any alert sounds.

[0037] After transmitting the data, the microcontroller returns to deep sleep mode, drawing minimal current. The overall power consumption of the device is extremely low – it only draws significant power for a fraction of a second during measurements. This means the device’s self-heating is negligible, and the drain on the smartphone’s battery is also very small. Additionally, because the device lacks any radio (no Bluetooth, etc.), it avoids the heat and power draw associated with wireless communication.

[0038] Design Choices and Alternatives: The described embodiment highlights the multi-layer insulation approach and smartphone integration. There are various possible modifications within the scope of the invention. For example, the exact geometry of the inner (2) and outer (3) shells can be adapted – they might be cylindrical as described, or could have more complex shapes to fit a particular sensor shape or to snap into the partition. The gap between them could be a vacuum in some high-end designs to further improve insulation, though an air gap is cost-effective and sufficient for this size device. The materials for parts 1, 2, 3, and the housing are ideally plastics with low thermal conductivity; one could use, for instance, ABS for structural parts and possibly a foam or polyethylene for an inner liner if needed. The IR sensor (10) itself can be any suitable sensor; a common choice is a thermopile sensor calibrated for medical use (measuring 32°C to 42°C for body temperature) that can also measure wider ranges (e.g., 0–100°C) for object mode.

[0039] The partition (1) not only thermally isolates but also mechanically isolates the sensor from stress. If the device is dropped or subject to shock, the partition and capsule protect the sensor from direct impact, which improves durability and calibration stability over time.

[0040] Furthermore, while the preferred embodiment uses a USB-C plug (11) for connecting to smartphones (common on modern Android phones and some other devices), alternate versions could be made with different connectors (such as Lightning for iPhone or Micro-USB for older phones). The internal design would remain largely the same. In all cases, the device relies on the external host for power, so it does not carry a battery. This is a significant simplification over battery-powered designs: by not having a battery, we remove not only the battery itself but also charging circuits, voltage boost converters, and safety concerns, which also contributes to the small size and low heat.

[0041] No display or controls are present on the device. All output is via the smartphone screen, and all user input is via the smartphone touch interface. This “zero-interface” hardware makes the device essentially a plug-and-play sensor module. As soon as it’s connected, the smartphone app can recognize it (for example, through USB device identification) and guide the user. This also means the device’s firmware can be quite simple, mainly focusing on sensor reading and data transmission. Any firmware updates or calibration updates can potentially be delivered via the smartphone connection as well.

[0042] Deep Sleep and Thermal Benefit: It is worth noting how critical the low-power design is for maintaining accuracy. In continuous operation, even a small microcontroller can produce heat that, in a tiny enclosed space, might raise the internal temperature by several degrees. By using deep sleep, the microcontroller (and any other active electronics) remain off most of the time, effectively eliminating continuous heat output. The short active period means the sensor’s own temperature doesn’t have time to drift significantly due to any minor heat from the MCU. In testing of this system, it was found that the sensor temperature stays very close to room ambient—thus the compensation using ambient temperature is accurate and the readings match reference thermometers within a tight tolerance.

[0043] Calibration: The use of LUTs (lookup tables) and software calibration in the device / app ensures that each unit can be factory-calibrated for accuracy. For instance, during manufacturing, the device’s sensor can be calibrated against known temperature sources, and the resulting correction factors are stored. The app can even adjust for ambient conditions – e.g., if a person’s forehead is measured at a certain distance, the app may instruct the user on proper usage (distance and aiming) and then use the sensor data to compute the actual body temperature. By leveraging the smartphone’s computational power, more complex calibration algorithms (like compensating for ambient humidity or leveraging machine learning for improved accuracy) could be implemented without changing the device hardware. This demonstrates the flexibility gained by offloading functions to the phone.

[0044] Overall, the described embodiment of this portable device provides a small, accurate, and user-friendly temperature measurement solution. By focusing on the hardware innovation of the multi-layer thermal isolation structure in combination with smart power management, the invention achieves performance on par with larger infrared thermometers while being far more convenient for modern users. Variations and enhancements can be made (for instance, adding an LED indicator light on the device if desired, or protective caps for the connector when not in use), but the core inventive concepts remain the multi-layer insulated sensor housing and the partitioned, smartphone-powered design.Examples

[0045] A user wishes to measure their child’s fever using this described device. The user opens the companion smartphone application and plugs the device into the phone’s USB-C port. The app indicates that the device is connected and ready. The user holds the phone such that the device’s sensor end is about 3 cm from the child’s forehead, aiming roughly between the eyebrows. On the app, the user selects “Forehead Mode” which is calibrated for human body temperature. They tap the on-screen measure button. The device’s microcontroller wakes and takes a reading in a fraction of a second. The app then displays the child’s temperature, for example “38.2 °C”, along with an indication that this is above normal (fever warning). Thanks to the device’s thermal stability, this reading is accurate without needing the user to hold the device in place for a long time. The user can trust the reading similar to a standard no-contact thermometer. The app may log the reading with a timestamp for record-keeping. Because the reading was fast, the child does not get uncomfortable, and the device did not need any complicated setup or calibration by the user.If the environment were very different in temperature (say the device was brought in from a cold car into a warm house), the user might wait 5-20 minutes for everything to equalize. However, due to the insulating design, the sensor itself is largely protected from abrupt changes, and in practice, the device is ready to use much quicker than traditional infrared thermometers. The example highlights that even in a small form factor, the device can produce medical-grade measurement speed and accuracy.

[0046] In another scenario, the same user wants to check the temperature of baby formula in a bottle to ensure it’s not too hot. They switch the smartphone app to “Object Mode”. This mode uses a different calibration profile, since object surface temperatures do not require the body-temperature algorithm offset. The user points the device at the surface of the milk in the bottle (from a couple of centimeters away) and triggers a measurement. The device reports a temperature, for example “41.5 °C”. The app might note that this is a bit high for feeding a baby (as an informational guideline). The user can then wait for the milk to cool to below ~37 °C and measure again. In this way, the device serves not only medical needs but also general purpose temperature checking. Because it draws power from the phone, it can be used repeatedly without concern of battery depletion. The versatility is achieved with the same hardware simply by applying different software interpretation of the sensor data.

[0047] In an industrial or office setting, a small group needs to perform quick COVID-19 screenings using personal phones. Each staff member has access to this temperature measuring device which they can plug into their phone when they arrive at work. Using the app, they measure their own forehead temperature or that of colleagues. The device’s rapid readout (~0.3 s) means no long lines form and the process is efficient. Since there are no physical buttons, the device is easily disinfected by wiping the exterior before and after use (the housing being smooth plastic). The lack of openings (aside from the sensor aperture) means cleaning is simple. Moreover, since all data goes to the phone, the results can be automatically logged or shared with a central system if desired (with user permission). This example demonstrates the practicality of the invention in a real-world scenario requiring portability, speed, and accuracy.

[0048] The portable thermometer device described in this invention has wide industrial applicability in healthcare, consumer electronics, and beyond. In the medical field, it can be used for fever screening and patient monitoring in hospitals, clinics, pharmacies, or emergency response situations. Its compact nature and integration with smartphones make it ideal for medicine or home health kits, where patients or caregivers can take readings and instantly share them with healthcare providers. Public health screening—for instance at airports, workplaces, or schools—can also benefit from the quick and contactless measurements the device provides.

[0049] In the consumer sector, the device is applicable as a personal health and wellness gadget. Individuals can carry it with them for routine temperature checks (which became common during pandemic times) or use it for child care (checking baby temperature or bottle temperature as shown in the examples). The fact that it has no battery means it’s always ready to use when connected, without worrying about charging, thereby increasing its reliability for consumers.

[0050] Beyond medical and personal use, the industrial and technical applications include using the device to measure equipment or surface temperatures in the field. For example, an HVAC technician could plug the device into a tablet or phone to measure the temperature of air vents, pipes, or machinery surfaces. Similarly, it could be used in food industry (e.g., checking surface temperature of cooking equipment or transported goods) given its ability to measure object temperatures accurately. Researchers and students might use it as a convenient IR sensor for experiments, leveraging the smartphone for data collection.

[0051] Because the invention leverages standard smartphone technology for power and computing, it is very adaptable to different regions and standards. It can be deployed globally (the smartphone app can handle localization, units conversion, etc.), making it suitable for international markets including Canada, Europe (EPO member states), China, India, Japan, Brazil, Australia, the GCC countries, South Africa, Mexico, Turkey, South Korea, Russia and others, as referenced in the PCT context. The design is straightforward to manufacture using common electronics assembly and injection-molded plastic parts, which is advantageous for industrial scalability.

[0052] Following labels are used in the description to clarify the components of the invention.Partition wall / Sensor chamber partition(thermally insulating barrier between sensor chamber and electronics chamber)Inner insulation shell(inner layer of the sensor’s thermal insulation capsule)Outer insulation shell(outer layer of the sensor’s thermal insulation capsule)Main housing body(outer casing of the device, main body portion)Housing rear cover / support cap(component of housing, covering the USB connector)Internal support / spacer(structural support element inside housing, used to mount or position PCBs or other parts)Internal support / spacer(structural support element inside housing, used to mount or position PCBs or other parts)Main printed circuit board (Main PCB)(carries the microcontroller and primary electronics)Sensor printed circuit board (Sensor PCB)(carries the infrared sensor and associated circuit, located in sensor chamber)Infrared sensor(IR temperature sensor element for measuring target temperature)USB-C connector(external interface plug for power and data, connects device to smartphone)

[0053] Citation List follows:

[0054] Patent US11045092B2

[0055] PLT1: Patent US11340117B2

[0056] PLT1: Patent US12259278B2

[0057] Patent CN115752745

[0058] Patent US20230061946

[0059] Patent WO2024060163

[0060] Patent US20220322949

Claims

A portable instrument for measuring forehead and object temperature, comprising:an infrared sensor disposed within the interior space to detect thermal radiation from a target and produce a signal indicative of the target’s temperature;a multi-layer thermal insulation structure surrounding the infrared sensor to thermally isolate said sensor from heat generated by other components of the instrument and from external heat influences, the structure including at least an inner shell and an outer shell of low thermal conductivity material arranged with an air gap in between; anda main body housing containing electronic circuitry including a microcontroller embedded to receive and process the signal from the infrared sensor;anda thermally insulating partition that separates the infrared sensor and the insulation structure from the electronic circuitry in the main body housing, thereby defining a sensor chamber isolated from a main electronics chamber;anda connector configured to pair with an external host device to receive power for the temperature measuring device and to transmit data, wherein an embodiment aforementioned connector is a USB Type-C plug for connecting to a smart phone;The portable instrument of claim 1, wherein the multi-layer thermal insulation structure comprises a first inner shell surrounding the infrared sensor and a second outer shell surrounding the inner shell which an insulating air gap is formed between the inner and outer shells to reduce heat transfer to the infrared sensor.The portable instrument of claims 1, wherein the infrared sensor is positioned within the insulation structure and aligned with an opening to allow infrared radiation to reach the sensor for measurement.The portable instrument of claim 1, wherein the thermally insulating partition is a plastic wall supporting the infrared sensor or a sensor circuit board carrying the infrared sensor and separating the sensor chamber from the main body housing to minimize thermal conduction between the sensor chamber and the electronics chamber.The portable instrument of claim 3, wherein the infrared sensor is mounted on a separate sensor printed circuit board that is located within the thermal insulation structure.The portable instrument of claim 1 , wherein the main body housing comprises a microcontroller, a main printed circuit board configured to be connected to the sensor printed circuit board through the partition ,and an electrical connector to limit thermal coupling between the sensor and the main electronics.The portable instrument of claim 1, wherein the connector is a USB Type-C connector configured to plug into a port of a smartphone and draw power from the smartphone, the connector also enabling digital communication between the microcontroller of the device and the smartphone for control and data transmission.The portable instrument of claim 1, wherein the microcontroller is configured to operate in a low-power or deep-sleep mode during periods when no measurement is being taken, and to wake only when a temperature measurement is initiated, thereby minimizing heat generation inside the device that could affect the infrared sensor.The portable instrument of claim 1 , wherein the device contains no internal battery or display and being entirely powered by the external host device, utilizing the host (smartphone) for user interaction and display of the temperature measurement results.The portable instrument of claim1, wherein the instrument has a length of about 49 mm and a diameter of about 26 mm, resulting in a compact form factor sized for convenient attachment to a mobile phone and portability.The portable instrument of claim 1 , wherein the microcontroller or associated software is programmed with calibration data including lookup tables and algorithms to convert raw sensor readings into accurate temperature values for different target types or measurement modes.

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