Patent ID: 12188887

DESCRIPTION

The determination of a material's thermal resistance is typically made in a laboratory environment using expensive and cumbersome test equipment and lengthy test procedures. However, in some circumstances a consumer or other non-technical person may want to determine or approximate a material's thermal resistance. For example, a person choosing a building material for a home project may be interested in determining the comparative thermal resistance of two different types of wall coverings. A person choosing camping gear may want to know the thermal resistance of a sleeping bag or coat they are considering purchasing. A parent choosing a garment for their baby may want to know the thermal resistance of different garments to maximize the baby's comfort. A person exercising or competing in a sport may want to know whether a garment is suitable for the environmental conditions. There are other properties of materials that may be of interest to users making a material selection such as the present moisture content of the material and/or the compressibility or softness of the material. In the following description, the term “baby” will be used as a shorthand notation to refer to the person who is wearing a garment made of the material under test.

Disclosed herein are measurement systems and methods that facilitate the measurement of various material properties using a measurement device that is suitable for use by a consumer. The measurement device may be handheld or portable and affordable for purchase for household use.

In some instances simply knowing a garment's various properties, such as thermal resistance, is not sufficient to enable a consumer to select a suitable material for a given purpose or application. Thus, assessing the suitability of the material's properties for a given environment or application is another potentially useful feature provided by some examples of the measurement device described herein. It may also be helpful for the measurement device to evaluate and report selected characteristics of the present environment (e.g., temperature, humidity, air quality) that may aid a consumer in selecting a material for use in the environment.

Portions of the following description will be in the context of a measurement device that determines one or more properties, such as thermal resistance, of a garment's fabric. One possible application of the described measurement device and method is to determine the suitability of a given garment for a given environment (e.g., temperature and/or humidity). The measurement device can be used by individuals seeking a garment that will be suitable (e.g., comfortable) for their environment (or predicted environment). The measurement device can be used by caregivers to select garments for babies or adults under their care that may not be able to provide feedback on their comfort. While many specific examples are presented, it is to be understood that the described methods, devices, and circuitries are also applicable to the thermal property measurement of any material.

The disclosed measurement device utilize non-thermal energy sources and sensing technologies to determine a thermal property of a material or garment, thereby facilitating fast, simple evaluation of the thermal property by a consumer. For the purposes of this description, the term “thermal property” is to be broadly construed as including any property that affects a level of comfort in terms of the wearer's body temperature. Examples of thermal properties include breathability, thickness, thermal resistance, thermal conductivity, compressibility, and so on.

The present disclosure will now be described with reference to the attached figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms “module”, “component,” “system,” “circuit,” “element,” “slice,” “circuitry,” and the like are intended to refer to a set of one or more electronic components, a computer-related entity, hardware, software (e.g., in execution), and/or firmware. For example, circuitry or a similar term can be a processor, a process running on a processor, a controller, an object, an executable program, a storage device, and/or a computer with a processing device. By way of illustration, an application running on a server and the server can also be circuitry. One or more circuits can reside within the same circuitry, and circuitry can be localized on one computer and/or distributed between two or more computers. A set of elements or a set of other circuits can be described herein, in which the term “set” can be interpreted as “one or more.”

As another example, circuitry or similar term can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors. The one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, circuitry can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute executable instructions stored in computer readable storage medium and/or firmware that confer(s), at least in part, the functionality of the electronic components.

It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be physically connected or coupled to the other element such that current and/or electromagnetic radiation (e.g., a signal) can flow along a conductive path formed by the elements. Intervening conductive, inductive, or capacitive elements may be present between the element and the other element when the elements are described as being coupled or connected to one another. Further, when coupled or connected to one another, one element may be capable of inducing a voltage or current flow or propagation of an electro-magnetic wave in the other element without physical contact or intervening components. Further, when a voltage, current, or signal is referred to as being “applied” to an element, the voltage, current, or signal may be conducted to the element by way of a physical connection or by way of capacitive, electro-magnetic, or inductive coupling that does not involve a physical connection.

As used herein, a signal that is “indicative of” a value or “corresponding to” other information may be a digital or analog signal that encodes or otherwise communicates the value or other information in a manner that can be decoded by and/or cause a responsive action in a component receiving the signal. The signal may be stored or buffered in computer readable storage medium prior to its receipt by the receiving component and the receiving component may retrieve the signal from the storage medium. Further, a “value” that is “indicative of” some quantity, state, or parameter may be physically embodied as a digital signal, an analog signal, or stored bits that encode or otherwise communicate the value.

As used herein, “determine” or “determining” some quantity or characteristic is to be construed in non-limiting manner to include directly or indirectly measuring, estimating, calculating, reading data from storage medium, approximating, receiving data from another component, identifying, receiving a signal from a measurement device, computing, and so on. The function of determining may be performed by circuitry or hardware components and/or computer-executable instructions in execution by a processor or device.

As used herein, a signal may be transmitted or conducted through a signal chain in which the signal is processed to change characteristics such as phase, amplitude, frequency, and so on. The signal may be referred to as the same signal even as such characteristics are adapted. In general, so long as a signal continues to encode the same information, the signal may be considered as the same signal. For example, a transmit signal may be considered as referring to the transmit signal in baseband, intermediate, and radio frequencies.

Use of the word example is intended to present concepts in a concrete fashion. The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting of examples. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

In the following description, a plurality of details is set forth to provide a more thorough explanation of the embodiments of the present disclosure. However, it will be apparent to one skilled in the art that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form rather than in detail in order to avoid obscuring embodiments of the present disclosure. In addition, features of the different embodiments described hereinafter may be combined with each other, unless specifically noted otherwise.

FIGS.1A-1Eillustrates various aspects of an exemplary thermal property measurement device100configured to be portable, handheld, and suitable for consumer use. InFIG.1A, general components of the device100can be seen, including a portable housing that includes a first member110, a second member120, a clamping mechanism130connecting the first member to the second member, and a handle mechanism140that is operable to move the first member and the second member between an open position and a closed position.

In the open position (not shown), the first member and the second member are positioned relatively widely apart from one another. The clamping mechanism includes a pivot point about which handle members can be moved to open and close the first and second members. As illustrated best inFIG.1Din the closed position an inside surface of the first member110contacts a first side of a material sample and an inside surface of the second member120contacts a second side of the material sample opposite the first side. In one example, the clamping mechanism130is configured to maintain an orientation of the first member normal or perpendicular to the second member as the device is moved between the open position and the closed position. In this example the clamping mechanism may include a linkage arrangement rather than or in addition to a pivot arrangement.

In one example, the clamping mechanism130includes a feature that limits a pressure applied to the material sample when the first member and the second member are in the closed position. For example, the clamping mechanism may include a spring that relieves the clamping pressure beyond some limit. As will describe in more detail inFIG.6C, the clamping mechanism may be a servo motor configured to move the members together until contact with the material is sensed. A separate relief feature may be included that prevents the device100from overly compressing a sample material being measured which may degrade the measurement quality.

Indicia circuitry150disposed in the housing140is configured to communicate information related to a determined material property. The indicia circuitry150may be configured to display indicia indicative of the information and/or generate an audible signal indicative of the information. In one example indicia circuitry150causes a mobile communication device (e.g., cellphone) to display the information. In this example, the indicia circuitry150includes storage medium storing computer-executable instructions that, when executed by a mobile communication device155, cause the mobile communication device to receive the information and display the information on the mobile communication device as illustrated inFIG.1B. These instructions are transmitted to a mobile device during set up.

FIG.10illustrates a functional block diagram of electronic aspects of the thermal property measurement device100. Many of these electronic aspects are not explicitly labeled in other figures for the sake of simplicity. The device100includes a measurement system160that includes a source element163in the first member110and at least one sensor element165. The device100also includes measurement circuitry170configured to control the source element163to apply energy to the sample material and the sensor element165to generate data indicative of the sample material's response to the energy. The measurement circuitry170and/or analysis circuitry180may be embodied as a processor executing instructions for performing the described functions of the measurement circuitry170and/or analysis circuitry180.

An environmental sensor105is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device100. The analysis circuitry180is configured to determine a thermal property of the sample material based on the data from the measurement circuitry and provide information related to the thermal property to the indicia circuitry150. In one example, the analysis circuitry180receives environmental characteristic data from the environmental sensor element105and determines, based on the thermal property, if the material is suitable for the environment. In one example, the analysis circuitry180is configured to combine determined thermal properties for multiple layers (e.g., adding the thermal resistance of a garment and a sleep sack) and provide information related to the combined thermal properties to the indicia circuitry. In one example, the environmental characteristic data is received from an external source by way of interface circuitry141. For example, weather forecast data from a mobile device may be wirelessly transmitted (e.g., Bluetooth) to the analysis circuitry. The determined suitability may be displayed on the indicia circuitry150. Recall that the indicia circuitry150may be integrated with the device as shown inFIG.1Aor at least partially integrated with a mobile communication device155as shown inFIG.1B.

In one example, a base station or docking station101is provided into which the measurement device100may be docked (e.g., by way of wired interface141) to allow for wired communication between the measurement device100and another device and/or to charge the measurement device. In this example, the base station communicates with the measurement device in a same manner as a cellphone may communicate wirelessly with the measurement device. Alternatively, a cellphone or other device may be plugged into the base station to enable communication between the cellphone or other device and the measurement device100when a wireless connection is not available.

In one example, the analysis circuitry180is configured to leverage the processing power of an external device (e.g., a cellphone's image processing capabilities). In this example, the analysis circuitry includes storage medium storing computer-executable instructions that, when executed by the mobile communication device155ofFIG.1B, cause the external device to receive data, process the data, and transmit the data back to the analysis circuitry180for use in determining the thermal property. These instructions may be transmitted to the external device during setup.

The measurement device100may include storage medium135that is configured to store data used by the device in determining the information that is displayed by indicia circuitry150. If the storage medium135is not internal to the measurement device100, the storage medium is accessible to the device by way of a communication link to an external storage medium. Examples of types of data that may be stored in storage medium135(e.g., in the form of lookup tables, databases, and so on) include data mapping non-thermal response (indicative of a material's response to a non-thermal stimulus) to thermal property values and data mapping thermal property values to ranges of environmental characteristics (e.g., thermal resistance values mapped to ranges of temperatures in which material having the thermal resistance will be comfortable). Data encoding external device instructions (that may be transmitted to a user's device during setup to enable communication and/or co-processing of data) may be stored. Environmental acceptability criteria (e.g., acceptable temperature/humidity ranges representing a default set of ranges or a custom set of ranges as determined for a particular user) may be stored.

User specific biometric data may also be stored (e.g. age, gestational age, weight, sex) for use in determining suitable calibration schemes and/or processing algorithms to use when determining recommendations, or to adjust calibration constants ensuring the device operation is tailored to the given application/user. For example, for premature or underweight babies (as determined by the user specific data) the thermal resistance recommended by the device for a given ambient temperature may be slightly increased. Usage data which is collected during use of the device may be stored for use in providing historical feedback and/or adapting the operation of the device to fit a particular user's characteristics.

Data mapping non-thermal response to material type may also be stored for use in identifying a material type in addition to the material's thermal property. Material type parameters that may be identified include material composition (e.g., cotton vs polyester), thread counts, fabric density, spun/weave/stitch construction, and so on. In one example, some of the data in the storage medium135is stored on storage medium in the measurement device100and some of the data in the storage medium135is stored on a remote device.

FIG.1Dillustrates a functional block diagram of the device100that will be used throughout this description to describe various configurations of sources and sensors for measuring different non-thermal (and thermal) properties of a material. The first member110is connected to the second member120with clamping mechanism130. The environmental sensor105is illustrated as being disposed in the first member100, however the sensor105may be in another location (even external to the device100). A source element163is disposed in the first member110. In some examples, multiple source elements, providing different types of stimulus (e.g., electromagnetic radiation, sound, vibration, compression, heat) will be present in an “array” of source elements. A sensor element165is disposed in the second member120. In some examples, multiple sensor elements, capable of detecting different types of stimulus will be present in an “array” of sensor elements.

FIG.1Eillustrates a functional block diagram of an alternative device100′ that is a probe or wand that does not clamp around the material sample, which will also be referred to as the material under test. In this example, the sensor element165′ is disposed in a same member110′ as the source element163. The examples illustrated herein in which the device is embodied as a clamp may be extended to include the modification illustrated inFIG.1Ewherever possible.

Electromagnetic Energy-Based Non-Thermal Material Properties

FIG.2illustrates an exemplary measurement device200that includes first member210, second member220, and clamping mechanism230. A material under test has been positioned between the first member210and the second member220and the members are held in the closed position by the clamping mechanism230exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor205is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device200. The measurement device200utilizes electromagnetic radiation (e.g., visible or non-visible light) to determine a thermal property of the material under test. An electromagnetic radiation source element263is an LED operating in non-visible light spectrum (750 nm to 1100 nm), most likely 850-950 nm. The electromagnetic radiation source element263may be operated at constant power, for brief periods of time, when controlled to do so by measurement circuitry (not shown).

A first electromagnetic radiation sensor element265ais a photodiode placed in axis of the emitted electromagnetic radiation. It is matched (receptive) to the wavelength of electromagnetic radiation emitted by the electromagnetic radiation source element. Other wavelengths of electromagnetic radiation may be excluded. The output of the photodiode may be converted into a voltage drop over it, or it could be a photodiode system with CMOS that outputs a series of pulses having a frequency proportional to the electromagnetic radiation intensity it receives. A second electromagnetic radiation sensor element265bis another photodiode, operating at the same wavelength as electromagnetic radiation sensor element265a. This diode is located off-axis, and so is not a direct measure of transmission/absorption, but rather measures scatter. A third electromagnetic radiation sensor element265cis another photodiode located along side, or behind the electromagnetic radiation source element263, and so that the third electromagnetic radiation sensor element265cmeasures the backscatter from the electromagnetic radiation source and/or material.

The electromagnetic radiation emitted by the electromagnetic radiation source element263is not in the visible wavelength range so it is less influenced by the color of the fabric through which it has to pass. It is operated at constant current and voltage to ensure it emits a consistent amount of electromagnetic radiation (consumes the same power) every time, and operates in the condition under which it was calibrated. In one example a electromagnetic radiation source of broad wavelength could be used that spans visible to non-visible IR electromagnetic radiation (e.g., between about 300-1100 nm). The electromagnetic radiation sensor elements should be configured to be receptive to those emitted wavelengths.

The electromagnetic radiation sensor elements265a-care selected to be receptive to the wavelength of electromagnetic radiation coming from the electromagnetic radiation source element263in order to reduce the effect of other influences. The various outputs of the sensor elements will be recorded synchronously for a period of time of around 5 seconds (to allow for stabilization of readings) as illustrated inFIG.2A. An algorithm combines the response of the three electromagnetic radiation sensor elements to identify to the fabric type and/or thermal resistance the fabric (as measured by an ASTM recognized machine configuration). A correlation will then be made between sensed values and the predicted/approximated thermal resistance of the fabric. Another thermal property that may be determined by analyzing the electromagnetic radiation received by electromagnetic radiation sensor elements is breathability (similar to porosity) of the material under test. Breathability may be one factor used to determine the material's type.

FIG.3illustrates an exemplary measurement device300that includes first member310, second member320, and clamping mechanism330. A material under test has been positioned between the first member310and the second member320and the members are held in the closed position by the clamping mechanism330exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor305is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device300. The measurement device300utilizes electromagnetic radiation to determine a thermal property of the material under test. A electromagnetic radiation source element363is an LED operating in non-visible light spectrum (750 nm to 1100 nm), most likely with a peak wavelength in the range of 850-950 nm. The electromagnetic radiation source element363will be operated at varying powers, such as a power sweep, as shown inFIG.3A, for brief periods of time, as controlled by the measurement circuitry (not shown).

First electromagnetic radiation sensor element365ais a photodiode placed in axis of the emitted electromagnetic radiation. It is receptive to the wavelength of electromagnetic radiation emitted by the electromagnetic radiation source element363. Ideally other wavelengths of electromagnetic radiation will be excluded preferentially. Output of the photodiode may be converted into a voltage drop, or the photodiode could include a CMOS that outputs a sequence of pulses having a frequency that is proportional to the electromagnetic radiation intensity the photodiode receives. Second electromagnetic radiation sensor element365bis another photodiode operating at the same wavelength as the electromagnetic radiation source element363. This photodiode is located off-axis, and so is not a direct measure of transmission/absorption, it measures scatter. Third electromagnetic radiation sensor element365cis another photodiode located along side, or behind the electromagnetic radiation source363, and so measures the backscatter from the material sample.

The electromagnetic radiation emitted by the electromagnetic radiation source element363is not in the visible wavelength range so it is less influenced by the color of the fabric through which it has to pass. The electromagnetic radiation source element begins operation at the lowest possible current to open the diode and increases up to the maximum operating current of the diode over a couple of seconds (light power sweep). The sensor response from the first and second electromagnetic radiation sensor elements365a,365bare monitored throughout to produce two curves that are characteristic of the fabric under different electromagnetic radiation powers as shown inFIG.3B. In one example a electromagnetic radiation source of broad wavelength could be used that spans visible to non-visible IR light (e.g., 300-1100 nm). The electromagnetic radiation sensor elements should be configured to be receptive to those emitted wavelengths.

The sensor elements are selected to be receptive to the wavelength of electromagnetic radiation coming from the emitter in order to minimize the effects of other influences. The various outputs of the sensor elements are recorded synchronously for a period of time of about 5 seconds (to allow for stabilization of readings). An algorithm combines the response of the three electromagnetic radiation sensor elements to identify to the fabric type and/or thermal resistance the fabric (as measured by an ASTM recognized machine configuration). In combination with other techniques taught herein various physical parameters of the material under test can be determined, and related to predicted thermal properties. In a simple example, a correlation is made between the sensed values from the electromagnetic radiation-based system and the thermal resistance of the material.

FIG.4illustrates an exemplary measurement device400that includes first member410, second member420, and clamping mechanism430. A material under test has been positioned between the first member410and the second member420and the members are held in the closed position by the clamping mechanism430exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor405is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device400. The measurement device400utilizes electromagnetic radiation to determine a thermal property of the material under test.

Light source element463is an LED operating in non-visible light spectrum (750 nm to 1100 nm), most likely 850-950 nm. The electromagnetic radiation source element463is operated at constant power, for brief periods of time, as controlled by measurement circuitry (not shown). Instead of using photodiodes as sensor elements as illustrated inFIGS.2and3, sensor element465ais a digital camera matched to the wavelength of the electromagnetic radiation source element463. A second sensor element465b, which may be a photodiode or photodiode array, is included to measures the backscatter from the material sample.

Images of the back side of the material sample are recorded by the camera465aand then passed to analysis circuitry (not shown) that includes vision/image interrogation software (such as National instruments Vision Development Module). As already discussed, the analysis circuitry that executes the vision/image interrogation software may be integrated into the measurement device or resident on a mobile communication device that receives image data (e.g., via a wireless or wired connection) from the measurement device.

The electromagnetic radiation emitted by the electromagnetic radiation source element463is not in the visible wavelength range so it is less influenced by the color of the material through which it has to pass. The electromagnetic radiation source element463is operated at constant current and voltage to ensure it emits a consistent amount of electromagnetic radiation (consumes the same power) every time, and operates in the condition under which it was calibrated. As outlined inFIGS.4A and4B, the image from the camera465amay be analyzed for a number of things, such as the intensity at the center of the image (in axis of the electromagnetic radiation source element), the exact gradient of transmission/adsorption/scatted profile. The pattern of the material structure (seeFIG.4C) will also be visible for matching to stored material patterns (e.g. whether the material is woven or spun, like weaved cotton or fleece, and so on). The absolute intensity of the image can also be measured. The combination of features analyzed by the vision/image software will help to identify the material type, and its thermal resistance (again as measured by an ASTM recognized machine configuration).

Mechanical Vibration-Based Non-Thermal Material Properties

FIG.5illustrates an exemplary measurement device500that includes first member510, second member520, and clamping mechanism530. A material under test has been positioned between the first member510and the second member520and the members are held in the closed position by the clamping mechanism530exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor505is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device500. The measurement device500utilizes mechanical vibration in the form of acoustic energy or sound to determine properties of the material under test that relate to a thermal property of the material under test.

In one example, the sound source element563is a speaker capable of emitting sound from 20 Hz to 20 kHz (audible range). In some examples, the speaker operates above that sound frequency. In this example, the sound sensing element565ais a microphone with suitable response (matched to the speaker emission) placed in axis on the second member520on the other side of the material sample under test. A second sound sensor element565bis an off-axis microphone that is used in collaboration with sound sensor element565a. An optional third sound sensor element565cdetects backscatter sound, and may also be used to verify and validate various properties of the emitted sound and may also be used to allow for determination of phase shift when compared to other data received by the sensor elements565aand565b.

As illustrated inFIG.5Athe speaker563will emit a sweep of frequencies from 20-20000 Hz over a period of about 3 seconds and may use a constant or varying amplitude profile. In other examples, the speaker563emits a “buzz” comprising single tone or chord, at a frequency (e.g., 20 KHz) which may be selected based on a type of material. At the point of emission the microphone system565a-565cis initialized and records sound as it is received after having passed through the material under test. Emission and received sound are recorded synchronously, such that at any given point in time, it is known at what frequency the emitter was resonating, and what the receiver should have registered. From here is it possible to create an approximate frequency/amplitude plot as shown inFIG.5B(similar to the output of a Fast Fourier Transform (FFT) analysis), without having to perform an entire FFT. An FFT analysis of the entire recording may also be done to verify findings, but may not be required ultimately, saving expensive processing power and vital time to execute analysis. In one example, data indicative of the emitted and recorded sound may be “exported” to a mobile communication device having sufficient processing resources to perform an FFT analysis of the sound data.

Data collected from the material under test may be operated on such that the frequency or time domain amplitude result is subtracted from a pre-determined calibration constant. In one example, the thickness of the material sample is used to select the appropriate calibration data from a look-up table or similar regression, containing values of amplitude responses from varying open gap conditions (i.e., without a material under test between the first and second members such that there is open air in the gap). FFT spectra recorded from the material under test may be analyzed for peak and valley amplitudes and for the frequency-based locations of those features and in this manner compared to stored results of similar analysis of FFT spectra recorded for different types of materials to aid in determining a type of the material under test. The FFT spectra recorded from the material under test may be subject to integral analyses, whereby the total value of the energy received by565aand565band/or565cis determined. The FFT spectra recorded from the material under test might be compared to previously recorded FFT spectra and shape and analyzed by checking for a match using comparison techniques.

The sound response of material may be useful in probing the relative porosity of the material (i.e., check that the material is not a continuous plastic sheet, or a foil). The analysis circuitry should correlate the sound response to the breathability of the material, as the material structure will influence the sound transmission, particularly where locally solid barriers are imposed (e.g., solids like foil, plastic, and so on, that aren't breathable).

In one example, the measurement device uses mechanical energy (e.g., vibrations) to determine a non-thermal property of the material under test. In this example, the source element563is a vibrator (e.g., an unbalanced motor vibrator, or electromechanical shaker) capable of imparting physical motion to the material under test. The source element563is capable of creating first harmonic vibrations in the 0 Hz-1 kHz region. To ensure physical motion is adequately transmitted to the material under test, at least a portion of the material contacting surfaces of510and520may include suitable surface roughness, such that the material under test is gripped and unable to move once the clamp is in the closed position. Therefore the clamp surfaces should not be entirely ‘smooth’. The required surface roughness imparts a locally high contact pressure to small elements of the fabric at the tips of asperities, while maintaining the bulk compressing pressure in the range of 0.5 kPa to 1.5 kPa as controlled by the apparent area of contact and the clamping mechanism530. The source element563may also induce other harmonic vibrations at higher frequencies. In this example, the sensing element565a′ is a 3-axis accelerometer with suitable response (e.g., matched to the energy emission) placed in axis on the second member520. An optional third accelerometer element565ccan be operable to synchronously monitor the energy emission of the source element563.

As illustrated inFIG.5Cthe vibrator563may emit a sweep of frequencies from 0-1 KHz over a period of about 3 seconds. In another example, the vibrator563may operate at a single frequency, or discretely step through various frequencies. At the point of emission, the accelerometer system565a-565cis initialized synchronously and records displacement energy both as it is generated (565c) and as it is received after having passed through the material under test (565a,565b). The properties of the material under test may directly influence the emission characteristics of the vibrator563and so recording the emitted energy using565cmay be beneficial. Emission and received sound are recorded synchronously, such that at any given point in time, it is known at what frequency the emitter was resonating, and what the receiver should have registered.

FIG.5Dshows the result of conducting Fast Fourier Transform analysis on the recorded accelerometer data. Comparative differences in data received are related to physical properties of the material under test. For example, phase and frequency shifts relative to the emitted energy can be detected and attribute to properties of the material relating to thermal resistance. Analysis of higher harmonics measured at565amay also help to determine physical properties of the material under test that relate to its thermal resistance. In another example, analysis of the data generated by accelerometers565aand565cmay simply be evaluated for amplitude, and so results are indicative of the bulk attenuation of energy as a result of interactions with the material under test. In another example, accelerometers565aand565cmay be replaced by microphones to achieve a similar functionality.

Physical vibration of the material under test yields knowledge of the microstructure composition under larger scale deformation than is possible using acoustical energy alone. In particular, physical vibration is good for probing vibratory deformation response at lower frequencies and higher amplitudes than acoustical energy alone. The vibratory response of material may be useful in probing structural properties of the material. In one example, the detected responses may relate to stiffness, elasticity and material density which are function of material composition (e.g., polymer, elastomer, cotton, and so on) and the construction type (e.g., weave, spun, infill, and so on) and all have a role in the bulk thermally resistive properties of the material under test.

Coupling the material's vibratory response to electromagnetic radiation, heat, or sound energy with thickness and compressibility data may create a scheme whereby the material's type (e.g., fleece or cotton) can be identified and its thermal resistance can be approximated/determined. Note that the pre-measured response of the system with the measurement device in the closed position may be subtracted from the measured test data to remove background characteristics. The amplitude response measured is both a function of interactions with the material structure and the path length of the sound energy transmission.

Compressibility-Based Non-Thermal Material Properties

FIG.6Aillustrates an exemplary measurement device600that includes first member610, second member620, and clamping mechanism630. A material under test has been positioned between the first member610and the second member620and the members are held in the closed position by the clamping mechanism630exerting sufficient pressure to contact the material under test without significantly compressing the material (e.g., applying a pressure between 0.5 kPa and 1.5 kPa). The clamping mechanism is configured to limit the pressure placed on the material under test to some predetermined amount (e.g., less than approximately 1.5 kPA). The pressure may be controlled by a separate relief feature such as a spring arranged about a pivot point. An environmental sensor605is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device600. The measurement device600utilizes mechanical energy stored in springs to determine the thickness and a thermal property of the material under test.

Mechanical source elements are spring-loaded wide-area contact elements663a,663b. Spring-loaded wide-area contact element663ahas a lower spring constant/surface area combination than spring-loaded wide-area contact element663b. Thus the wide-area contact element663aexerts less pressure on the material under test than the wide-area contact element663b. Spring-loaded wide-area contact elements663a,663bmay have lower spring constants than the clamping mechanism630, but the reduced area of the wide-area contact elements as compared to the area of the members610,620, allows the spring-loaded wide-area contact elements to apply a higher pressure than the clamping pressure in a limited portion of the material under test.

Distance sensor elements665a,665b(e.g., linear variable resistors in some examples) measure the extension of both springs663a,663b. Distance D1is the extension of the spring with low spring constant (or larger contact element area) which exerts lower pressure. Distance D2is the extension of the spring with high spring constant (or smaller contact element area) which exerts higher pressure. A third angle or gap corresponds to the angle between the first member610and the second member620when the measurement device is in the closed position and contacting (without significantly compressing) the sample material. The gap is measured by a variable resistor665cthat is attached to the clamping mechanism. The voltage drop across the resistor is related to the angle.

To correlate the thermal properties of the material sample, the gap is derived from the reading coming from the rotation of the pivot of the clamping mechanism630. Voltage drop across the resistor is measured and correlated to the absolute gap from the material under test.

When the measurement device600is closed around the material sample, the two spring loaded wide-area contact elements663a,663b(note these provide surface areas creating elements of local pressure) are pushed against the material sample applying different pressures. The lower pressure wide-area contact element663acompresses further than the higher pressure wide-area contact element663b, and so the displacement of the two can be correlated to the compression of the material sample (e.g., based on a ratio or similar).

Note that the role of the spring-loaded wide-area contact element663acould be combined with the spring load of the clamping mechanism630—such that the spring load of the clamping mechanism (light load) is the spring load of wide-area contact element663aand so the gap measurement is actually distance D1. Distance D2may be still used to determine compressibility. Essentially, from knowing displacement data from any two locations under different pressures, compressibility can be determined for those prescribed conditions as shown inFIG.6B. The compressibility as measured by the measurement device could be calibrated to a given displacement under a given pressure, or simply use a curve fit, or regression type relationship to help identify the material and its thermal resistance based on displacement data.

Many other mechanical arrangements (e.g., linkages, pivots, slides, and so on) and sensors may be utilized to determine the compressibility profile of the material under test. For example, the reactive force in the spring wide-area contact elements663a,665acould be correlated to the gap. The relative displacement of the wide-area contact elements663a,663bcould also be determined using variable resistors, linear variable differential transformers, hall sensors, eddy currents, laser time-of-flight and/or capacitance based systems.

FIGS.6C and6Dillustrate an alternative example of a measurement device600′ in which the clamping mechanism630′ includes a small servo motor632mounted at the hinge pivot location marked by P. For the purposes of this description, the term servo motor is a shorthand reference for any suitable motor, including position encoded motor, controllable motor with feedback, and so on. The servo motor may be used instead of or in addition to spring mechanisms in the clamping mechanism. The user places the material under test in between first and second members610′ and620′ and the measurement system is activated. The servo motor632closes the device600′ until the servo motor632detects contact with the material under test. Contact with the material sample may be done by sensing electromagnetic radiation. For example, the device600′ includes a electromagnetic radiation source element663′ and electromagnetic radiation sensor element665a′. The measurement circuitry may be configured to determine when the electromagnetic radiation source sensor665a′ is blocked by contact with a solid (near-zero backscatter). The electromagnetic radiation source element663′ and electromagnetic radiation sensor element665′ may also be used to measure the thermal property of the material sample as described inFIGS.2-4, but operated at a low power to detect contact. Contact with the sample could also be determined by mechanical sensor element665b′, which may measure strain, pressure or bending (for example) of the first member610′ which would change with contact. Proper contact with the material sample may be verified throughout the measurement process. There are various possible methods of determining contact.

Once contact with the sample is determined, the thickness can be gauged through knowledge of the servo motor position (pre calibrated, so using a lookup table for servo position vs gap). This is the uncompressed value of thickness. Other measurements from the various sensor arrays could be conducted here, in particular this location would be useful for the thermal system, where contact needs to be light, but definitely in contact. From this ‘first contact’ location, the servo motor could advance a known amount, thus compressing the material. Pressure measured by mechanical sensor element665′ could be used to determine the gap vs. pressure which would equate to compressibility. Measurements at 2 or more locations may be taken, as shown in the example data ofFIG.6D. This technique may provide advantages over the spring method described inFIGS.6A-6Bas it combines a measure of compressibility and thickness into one, and allows for more control over the clamp contact.

In one example, a strain gauge may be used to measure the reactive force across the clamping mechanism between the spring load and the material-spring load. Compressibility can be approximated by determining the reactive force of the material at a given spring rate provided by the clamping mechanism.

Thermal Energy-Based Material Properties

The material property measurement devices illustrated inFIGS.1-6utilize non-thermal energy such as electromagnetic radiation, sound, and mechanical energy, to determine a property of a material sample such as thickness, compressibility, thermal resistance, or material type. Using non-thermal energy to determine a property of a material provides many benefits including reduced power consumption, fairly quick measurement and analysis, and possibly some packaging advantages that make a handheld measurement device more feasible.FIG.7illustrates an exemplary measurement device700that uses thermal energy to determine a thermal property of a material sample. In spite of using heat, the measurement device700is suited for household use, portable, and capable of being held in hand as compared to laboratory thermal resistance measurement systems which are large, expensive, and slow.

FIG.7illustrates an exemplary measurement device700that includes first member710, second member720, and clamping mechanism730. A material under test has been positioned between the first member710and the second member720and the members are held in the closed position by the clamping mechanism730exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor705is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device700. The measurement device700utilizes heat to determine a thermal property of the material under test.

Heat source element763is a heated plate. In one example, the heat source element763is a highly resistive wire that heats quickly when current is applied. The thermal mass of the heat source element763should be small, so it can heat up quickly with little thermal inertia and robust enough such that it operates consistently over repeated use. A heat sensor element765is a thermocouple or other temperature measurement device with suitable response and accuracy precision (such as TMP36, thermocouple, infrared sensor, resistance temperature detector, and so on). The heat source element763and heat sensor element765are loaded against the material with a known and constant pressure coming from the clamping mechanism. Second member720includes insulated backing material indicated by the shading. The insulated backing material could be any insulator, most likely plastic/air that surrounds the heat source element763and should be sufficiently sized to adequately limit the influence of the ambient environment on performance.

During measurement, the heat source element763is fed a controlled burst of energy from a power supply (battery) as shown inFIG.7A. The heat sensor element765is mounted in the first member710and so is spring loaded against the material. The distance between the heat source element763and the spring loaded heat sensor element765is a function of the first compressibility of the material. The clamping mechanism puts the temperature measurement device in contact with the top of the material under test sample. The heat sensor element765should be an area-type sensor (e.g., having sufficient area). The heat sensor element765should not be a point-probe type, as it should be measuring the temperature rise of an area of material, to remove the effect of non-homogeneity in the material. Both heat source element763and heat sensor element765should operate over an area, for example, of 20 mm2min in order to accurately and representatively capture the thermal resistance of the material under test.

Voltage/data from heat sensor element765(seeFIG.7B) is measured and correlated to the thermal resistance of the material under test (calibrated beforehand using an ASTM recognized instrument). Analysis circuitry (not shown) may store and read a look-up table or regression/curve fit that maps the gradient of the temperature data as correlated with thermal resistance (seeFIG.7C). In one example, an amount of time taken to pass a threshold temperature is measured, which approximates a gradient. Note that a measure of thickness and compressibility may help correlate this method to thermal resistance, although thickness and compressibility is not required for a simple approximation.

Using this thermal measurement technique alone or in combination with another non-thermal measurement technique provides several benefits. For example, the thermal measurement technique measures the thermal resistance of the entire insulation layer (not just what the sensor element touches). By having the temperature sensor on the other side of the material (relative to the heated bed), if the material were to be composed of multiple layers, the entire composite thermal resistance is measured. The thermal measurement technique measures more than just conductance, a property that can dominate with reflectance methods like transient hot plate, and other one-sided touch/measure implementations

One sided methods can struggle with thin samples (e.g., clothing) and may produce erroneous results when a foreign object (or a significant air gap) is inadvertently in contact with the sample. However, the described measurement device includes first and second members that contact both sides of the sample, reducing the risk of a foreign object being included in the measurement.

In the device700the heat sensor element765on the other side of the material/heater moves with the thickness and the thickness can be measured. Thus the distance from heated plate to thermocouple will vary due to thickness and the thermal measurement technique will not include an air gap that would have to be calibrated out. With this method acceptable data can be obtained with just one heat burst (note that with transient plane more than three repetitions are recommended).

The thermal measurement technique is easily combined with other absorption/transmission measurements, like electromagnetic radiation and sound. The thermal measurement technique can easily be achieved with a simple heater and temperature measurement device and can be implemented with less expensive, low precision electronics. This is in contrast to transient plane type one-sided methods that are reported to require very high precision resistance measurement devices for temperature measurement and heat control. Because thermal resistance is measured along with thickness and other non-thermal data, partial material identification is possible (unlike transient plane method). For example, a material sample with a certain gradient temperature rise, and known thickness can be correlated to a fleece, or a cotton sack, or differentiated from another material with the same thickness but different gradient for example.

If a thermocouple (or other similar temperature measurement device) is added to the heater plate, the measurement system could double check the amount of energy provided to the heater, and would improve precision for little cost. Data from this sensor could be used in the calibration scheme. The thermocouple could also be used as a temperature probe when the measurement device is fully opened as illustrated inFIG.1E. The first member may be held against a surface to measure a temperature of the surface (e.g., a person's forehead, an outside surface of a sleep sack, and so on).

In a first calibration scheme, gradients of temperature rise are recorded for known thermal resistance materials. Results from materials under test are compared to that data (or a regressed fit of it) and matched to an equivalent thermal resistance value. A database of materials is accessed to identify a material that has that gradient value, and that thickness, and see if a match exists that identifies its probable structure (polyester fleece vs bamboo weave, for example).

In a second calibration scheme a series of calibrations are taken at different device gap settings (a priori), with only air between the heated plate and thermocouple, at a selection of ambient conditions. The temperature reading initially taken prior to the heat burst is used to select a calibration profile, or interpolate between using a fit. The recorded value of temperature rise variation with respect to time (gradient) is subtracted from the calibration gradient to give the thermal resistance gradient of the material under test. This value is then compared to a calibration to determine the absolute thermal resistance of the material.

For example, the thermal resistance of material under test may be determined as TRes(air at same gap)−TResmeasured. This technique is especially useful for thermal resistance values greater than 0.3 (Km2/W). If a higher temperature difference is created by increasing energy burst per unit time data quality will likely improve.

FIG.7Dshows the apparatus700with the clamping mechanism730in the fully open condition. This exposes the temperature measurement sensor765and allows the entire assembly to be held against a material under test (or the skin of a person) by the user, rather. This allows the device to be used as a temperature measurement probe. In one example, the device700is temporarily used in the open-hinge condition to measure the temperature of the exterior surface of a material (sleep sack or similar) while in occupancy. Swiping the temperature measurement device765over an area of the exposed material for a short period of time (1-10 seconds) and collecting various statistical parameters (e.g. maximum, minimum, median, and mean temperatures) allows for accurate determination of the external surface temperature conditions. In one example, instead of a thermocouple, a thermal imaging system is used to determine the temperature of the surface under test and/or the temperature of the occupant.

The external temperature values may be operated on with the current ambient room temperature value, the measured or assumed internal temperature of the material and the predetermined thermal resistance value of the material under test. Algorithms designed to calculate the heat flux conditions may then be used to determine if existing heat-loss condition is within acceptable, predetermined, and preprogrammed limits. The results may be presented to the user along with recommendations suggesting better clothing material, layette, or ambient temperature/condition choices.

In the simplest case, data detailing the temperature condition of the material external to the occupant, or the occupant itself may be used to provide recommendations to the caregiver, in absence of the knowledge of thermal resistance values. In one example, where an occupant is shown to register a body temperature in excess of predetermined limits, recommendations could be made to check the occupant for signs of a fever, or to simply try a less insulative clothing selection.

Conductance-Based Non-Thermal Material Properties

The moisture content of a material sample may significantly impact its thermal properties as well as comfort in wearing the material sample. Therefore, it may be useful for the measurement device to be able to determine the moisture content of the material sample.FIG.8illustrates an exemplary measurement device800that includes first member810, second member820, and clamping mechanism830. A material under test has been positioned between the first member810and the second member820and the members are held in the closed position by the clamping mechanism830exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor805is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device800. The measurement device800utilizes electrical conductance to determine the moisture content of the material under test.

Electrical source elements first and second electrodes863a,863bare disposed in first member810so that the electrodes contact a material sample. An electrical sensor element ohmmeter865measures a conductivity of the material as a function of the resistance between the two electrodes863a,863b, which are held at fixed distance from each other, as current tries to pass in between. As an alternative to electrodes, the electrical source elements863a,863bcould be probes, or a plate type configuration (such as a swirl printed onto a flat). In one example, a capacitance method can be used for measuring moisture content of the material by probing the dielectric properties of the material.

During moisture content measurement, the first and second electrodes863a,863bare put in contact with the material under test by the spring pressure provided by the clamping mechanism830. The resistance of the material is measured by providing constant current to the electrodes. As shown inFIG.8A, the conductance/resistance of the material varies with moisture content.

Different materials inherently have different conductivity/resistivity and so the measured resistance could be used in collaboration/synergy with other measurement techniques discussed herein to help identify a material-type, as well as a material's thermal resistance. Moisture content might influence the electromagnetic radiation and sound propagation and so the resistance measure might be used to correct data collected from those sensor systems. In one example, the moisture content test is used as a pass fail criteria displayed on the measurement device, and not necessarily for precision identification. In this manner the moisture content measurement may be a check that the material is not too wet for use. The material's conductivity may also be used to determine that the material under test does not contain uncomfortable (e.g., metallic, foil) elements and provide an alert when the conductance indicates an uncomfortable material is being tested, regardless of the thermal property that is determined.

In addition to the thermal properties of a garment or blanket worn by a baby during sleep, the hardness of a sleep surface is also an important consideration for a caregiver. When the measurement device is used by a caregiver, it may also be advantageous for the measurement device to also be capable of determining a softness or hardness (in terms of elasticity) of a surface and display information related to the suitability of the surface for sleeping babies.

FIG.9illustrates an exemplary measurement device900that includes first member910, second member920, and clamping mechanism930. A material under test has been positioned between the first member910and the second member920and the members are held in the closed position by the clamping mechanism930exerting sufficient pressure to contact the material under test without significantly compressing the material. An environmental sensor905is configured to measure an environmental characteristic, such as temperature and/or humidity, of the environment surrounding the device900. The measurement device900utilizes one or more source elements963and sensor elements965and measurement techniques described with referenceFIGS.2-7to determine a thermal property of the material under test.

To measure the softness of a surface, the device900includes a durometer mechanism990extending from an outside surface of one of the second member920. The durometer mechanism includes a spring993having a predetermined spring constant and a probe995disposed at a distal end of the spring993. Measurement circuitry (not shown, seeFIG.10) is configured to determine durometer data based on a compression of the spring. Analysis circuitry (not shown, seeFIG.10) is configured to determine a surface suitability based on the durometer data and display information related to the surface suitability.

A spring loaded switch (not shown) in the durometer mechanism is compressed as the probe995is pressed onto the surface. If the probe995is loaded against a surface and the spring993could not be compressed enough to close the switch, the material would be classified as being too soft. If the spring993could be compressed enough to close the switch, the material would be classified as being suitable for sleep.

While the preceding description illustrates various examples of the measurement device including a single thermal property measurement technique (e.g., non-thermal measurement techniques using electromagnetic radiation, sound, mechanical energy, electrical energy as well as thermal energy techniques), in some examples, the measurement device includes source elements and sensor elements for multiple measurement techniques. Data from the various measurement techniques may be combined to determine a thermal property of the material, classify a material type, and/or determine the suitability of material for a given environment. A multi-variate space (e.g., embodied in a lookup table or mathematical correlation expression) may be used to map data values from various measurement techniques to a single thermal resistance and/or material identity type.

While an environmental sensor element is included so that a garment's suitability with respect the present environment, in some situations, a caregiver may want to select a garment that is suitable for a different temperature/humidity. For example, when a caregiver is going to take a baby to a park, the caregiver may use the device to enter a predicted temperature. The analysis circuitry then determines the suitability of the tested garment for the entered temperature and/or displays stored garments having thermal properties mapped to the entered temperature. In another example, the device may access weather information and provide the predicted temperature to a user or automatically use the predicted temperature for the suitability analysis.

The type of material may affect how measured non-thermal or thermal data may map to a thermal resistance. Therefore determining the type of material may be useful in improving the accuracy with which a thermal resistance is determined using the above described techniques. The plot on the left side ofFIG.10illustrates how an electromagnetic radiation profile varies according to material types, meaning that the profiles can be used to classify types of materials. The graph on the rightFIG.10illustrates an example of how a combination of electromagnetic radiation and acoustic measurement data as well as a measured thickness of the material can be used to classify a material type. Other combinations of profiles measurement data could be used to identify material type. At the bottom ofFIG.10, image data taken by a camera as described inFIG.4can be used to identify patterns characteristic of fleece as compared to woven cotton.

For the purposes of this description, the term “material,” “material sample,” “fabric,” “material type,” “fabric type,” or “garment” should be construed as including a single layer of a homogeneous material; a composite material that includes more than one component; a layered article that, as manufactured includes layers of different material types (e.g., nylon shell overlaying a fiber fill); or a collection of layers of materials stacked together by a user of the measurement device. The measurement device may determine the thermal property of any material sample that it contacts, regardless of the layers or differing components of the material. Recall that the measurement device may also be able to combine separate measurements made for different separate layers of a layette or outfit into a composite thermal property value.

FIG.11illustrates a flow diagram outlining an exemplary method1100for determining a thermal property of a material sample with a measurement that includes a first member and a second member. At1130the method includes applying non-thermal energy to a first side the material sample using a source element on the first member. At1140the method includes sensing, with a sensor element on one or both of the first member and the second member, a response of the material sample to the non-thermal energy. At1150the method includes generating, with the measurement device, non-thermal data indicative of the response. At1160the method includes determining a thermal property of the material sample based on the non-thermal data. Examples of non-thermal energy include electromagnetic radiation, sound, mechanical, and electrical.

As discussed above, determining a suitability of a given material for a given environment can be helpful to a caregiver of an infant, baby, child, teen, or adult incapable of providing feedback on their comfort.FIG.12illustrates a flow diagram outlining an exemplary method1200for providing suitability feedback to a user of a device. The method includes, at1210, providing, in a measurement device, a storage medium having thermal property values mapped to ranges of environment characteristic values. At1220the method includes determining, with the measurement device, a sample thermal property value of a material sample. Any combination of the measurement techniques described inFIGS.2-9can be used to determine the thermal property value.

At1230the method includes determining, with the measurement device, a environmental characteristic value (e.g., a temperature and/or humidity of the room in which the device is present). In one example, the device may receive a temperature/humidity entered by way of a user interface displayed on the indicia circuitry (including, optionally, a connected mobile communication device). At1240the method includes reading the storage medium to determine if the environmental characteristic value falls within a range of environmental characteristic values mapped to the sample thermal property value. At1250the method includes displaying a positive suitability result when the environmental characteristic value falls within the range of environmental characteristic values mapped to the sample thermal property value.

FIG.13illustrates a flow diagram of an exemplary method1300that may be performed by a measurement device as described above. At1302the method includes taking benchmark/background measurements. At1304a determination is made as to whether all systems are in good working order. If not, at1308the device displays an indication that the device is not usable. When the device is determined to be functioning properly, at1306the method includes recording environmental data (e.g., temperature/humidity). At1310the method includes displaying saved garment options having thermal resistance values appropriate for the environmental condition. If no garment is appropriate or the user chooses to continue without selecting a saved garment, at1312the method includes prompting the user to place the sample material within the first and second members of the device. At1314, the method includes executing all sensor systems to perform one or more measurement techniques.

At1320a determination is made as to whether the moisture content of the garment is above a specified limit. If so, at1322the method includes reporting (via indicia circuitry) that the material is too damp for comfort. If the material is not too moist, at1324a determination is made as to whether electromagnetic radiation penetrates the sample material. If electromagnetic radiation does not penetrate, meaning it may be non-breathable, at1326the device reports that the material may not be comfortable. At1327, the method includes analyzing the thickness and compressibility of the material to determine whether the material is “thick” or “thin” based on some predetermined limits on thickness. If the material is thick, at1328data from the sound and thermal systems are selected. If the material is thin, at1330data from the electromagnetic radiation and thermal systems are selected. At1332, the selected data is corrected/correlated based on thickness and compressibility. At1334a material type is identified and displayed for the user to confirm. At1336the suitability of the garment is reported and at1340the user is prompted to save the item of clothing, mapped to the determined thermal resistance, for future access. At1338, the method includes other functions such as displaying educational messages or prompting the user to measure the softness of the sleep surface.

FIG.14illustrates an alternative method1400that may be performed by the thermal property measurement device described herein. At1402the method includes taking benchmark/background measurements. At1404a determination is made as to whether all systems are in good working order. If not, at1408the device displays an indication that the device is not usable. A system status check could include an “open air” test of the device (e.g., with no material sample within the members). Sensor values can be compared with stored values to determine that all systems are functioning properly.

When the device is determined to be functioning properly, at1405the method includes recording environmental data (e.g., temperature/humidity). At1410the method includes displaying saved garment options having thermal resistance values appropriate for the environmental condition. If no garment is appropriate or the user chooses to continue without selecting a saved garment, at1406the method includes prompting the user to place the sample material within the first and second members of the device. At1412the method includes taking thickness and compressibility measurements of the material. At1414, the method includes executing remaining sensor systems to perform one or more measurement techniques as determined based on the thickness and compressibility.

At1420a determination is made as to whether the moisture content of the garment is above a specified limit. If so, at1422the method includes reporting (via indicia circuitry) that the material is too damp for comfort. If the material is not too moist, at1424a determination is made as to whether electromagnetic radiation penetrates the sample material. If electromagnetic radiation does not penetrate, meaning it may be non-breathable, at1425the device reports that the material may not be comfortable. At1426the method includes analyzing collected data and determining a calibration scheme to use. At1432the collected data is corrected or correlated based on the calibration scheme determined at1426. At1434a material type is identified and displayed for the user to confirm. At1436the suitability of the garment is reported and at1440the user is prompted to save the item of clothing, mapped to the determined thermal resistance, for future access. At1438, the method includes other functions such as displaying educational messages or prompting the user to measure the softness of the sleep surface.

FIG.15Aillustrates an exemplary measurement device1500that utilizes arrays of source elements and sensor elements to perform several measurements including non-thermal measurements on the material under test. The device1500includes first member1510, second member1520, and clamping mechanism1530. A material under test has been positioned between the first member1510and the second member1520and the members are held in the closed position by the clamping mechanism1530exerting sufficient pressure to contact the material under test without significantly compressing the material. The measurement device1500includes a first array1561of source elements1563a,1563b,1563c1, and1563c2mounted in the first member1510and the second member1520includes a second array1567of sensor elements including1565aand1565b1. The measurement device1500includes an electromagnetic radiation measurement system with electromagnetic radiation source element1563aand electromagnetic radiation sensor element1565a, a vibration measurement system with vibrator element1563band accelerometers1565b1,1565b2, and a compression measurement system with spring-loaded wide-area contact elements1563c1,1563c2and distance sensor elements1565c1,1565c2.

To determine a thermal property of the material under test, as described above in more detail in the separate sections for each measurement technique, the measurement device1500activates electromagnetic radiation source element1563ameasures electromagnetic radiation passing through the material sample with electromagnetic sensor element1565a. The measurement device1500activates vibrator element1563bmeasures a mechanical response of the material sample with accelerometer1565b. The measurement device1500measures the compressibility of the material sample using distance sensor elements1565c1,1565c2. The different measurements may be performed simultaneously or according to some sequence.

In addition to the illustrated combination, the source elements in the array1561may include sources capable of emitting electromagnetic radiations such as infrared, heat and visible light, a speaker configured to emit acoustic radiation such as sound or mechanical vibrations, and mechanical members configured to apply physical pressure (e.g., for measuring compression). The array1561in the first member1510also includes sensor elements1565b2,1565c1, and1565c2.

In addition to the illustrated combination, the sensor elements may include sensors required to measure displacement such as hall effect, capacitance sensors, resistive sensors, lasers or strain gauges. The sensor elements may also include force measuring sensors, accelerometers, microphones, temperature measuring devices, photodiodes, photodiode arrays, photoresistors, capacitance probes, and various spectrum cameras. The arrays1561,1563may be controlled to simultaneously, or according to some predetermined sequence, activate the source elements and the sensor elements. The arrays1561,1563may include source elements and sensor elements associated with any of the measurement techniques described above in addition to or instead of the source elements and sensor elements illustrated inFIG.15A.

FIG.15Billustrates a flow diagram outlining an example method1570that may be used by a measurement device that includes multiple measurement techniques as with the device1500ofFIG.15A. At1572, the method includes attaching the device to the material under test. At1574, the method includes executing non-thermal measurement systems (e.g., electromagnetic radiation, vibration, compression, and so on). At1575, the method includes determining a thermal resistance value and material type based on the measurement data from the various non-thermal measurement systems. At1576, the method includes determining a certainty of the thermal resistance value and material type identification. This may be performed by determining a fit between the measurement data from the different measurement systems and stored measurement data for the determined thermal resistance value and material type (see, e.g.,FIG.10). At1577, a determination is made as to whether the certainty is above a threshold. If not, at1578the method includes executing a thermal measurement system and at1580all data (including thermal data if obtained)) is used to determine thermal resistance and material identification. At1582, the method includes adding the thermal resistance to a thermal resistance of any previously measured layers.

At1583-1585a temperature input is selected for determining the suitability of the material is determined using one or more options in parallel. At1583an external temperature input (not from an onboard sensor) is received for use to determine suitability. At1584the ambient temperature is measured by an onboard sensor. At1585a body temperature or inner sleep sack temperature is either measured or received. At1586, the method includes comparing the selected temperature input with the thermal resistance value. At1592, the method includes providing a recommendation to a user (e.g., whether or not the material layer(s) provide a suitable thermal resistance for the selected temperature input). At1590, the method includes automatically affecting a change to the environment to make the environment more suitable for the thermal resistance (e.g., adjusting thermostat).

FIG.15Bshows that data collected by the device may be operated on simultaneously or synchronously using a variety of algorithms to relate physically measured parameters to thermal resistance approximations. Data from the system in its entirety provides information relating to the physical properties of the material under test such as, fiber type, fiber size, fiber blend, thickness, compression ratio, density, surface impedance, conductance, elasticity, airflow resistance and porosity. Thermal resistance is a function of the physical composition and microstructure of the material(s) under test and so correlating data from various measurements probing these physical properties to thermal resistance is possible using non-thermal techniques. Where determination is not possible, above a previously specified threshold value, a thermal technique is deployed. Data from this system will be noisy as measuring heat-flux in non-laboratory conditions is not ideal. However, this data combined with the data from the other non-thermal inputs allows for the acceptable threshold to be exceeded and determination of the predicted thermal resistance of the material under test to be reported. At this point the predicted thermal resistance values can be added to previously measured thermal resistance values if a layette is being created.

In one example, the system compares the predicted thermal resistance value of the material under test with others stored in a database and provides recommendations of multiple possible layering options that could match the predetermined ambient condition ensuring that the entire clothing ensemble is thermally matched for the ambient conditions in which it is to be deployed. In another example the system operates based on knowledge of environmental conditions alone and does not need to test a material. It compares the predicted, measured or otherwise inputted environmental conditions with a database of clothing detailing recorded thermal resistance values and creates multiple clothing options for the user to choose from. In this way the clothing ensemble can be selected by the user, allowing for style or other preference to be observed, while still optimally matching the thermal resistance of the layette for the environment in which is it will ultimately be deployed.

The device may operate based on temperature measurements taken from the local environment using its onboard systems, or using external inputs regarding predicted weather, or from manual user inputs can be used in the comparison to the measured thermal resistance values. Comparison can also be made from other temperature measurements provided to the system which may be a measured core body temperature, or the current temperature inside a sleep sack, for example. Input values of ambient conditions are ultimately compared with predicted thermal resistance values, and recommendations are provided to the user. In one example, the system automatically updates a thermostatic control system using the result of the comparison to ensure the ambient conditions within the local environment are matched to the thermal resistance of the selected layette. In another example, after the baby is dressed the measurement device may be clipped to a car set or stroller so that the ambient temperature continues to be measured and compared to the last determined thermal resistance. When the ambient temperature falls outside the range mapped to the thermal resistance, a temperature alert may be provided by indicia circuitry.

FIG.16illustrates several examples of displays/user interfaces that may be presented on indicia circuitry (e.g., on the measurement device or on a mobile communication device as illustrated). Example ‘a’ indicates that a caregiver has the room temperature set too cold for comfortable sleep, even though the thermal property of the selecting clothing's material is suitable for the temperature. Example ‘b’ indicates that a caregiver has the room temperature set too hot for comfortable sleep, even though the thermal property of the selecting clothing's material is suitable for the temperature. Example ‘c’ indicates that the caregiver has the room temperature set in an acceptable range and has selected a garment or garments that are suitable for comfortable sleep. Example ‘d’ displays the result of the caregiver selecting clothes that would not provide sufficient thermal resistance for the ambient temperature. A recommendation is given to try something that would make the baby warmer. Example ‘e’ displays the result of a caregiver testing a garment that would overdress the baby for the ambient temperature. The caregiver is advised to try clothing that would make the baby cooler.

In examples ‘c’-‘e’ a “normalized” representation of the thermal suitability of the measured garment for the present environment is displayed as a number in which 1.0 indicates a “perfect” match between the garment and the environment. In example ‘d’ the normalized representation is 0.5 which indicates that the garment is insufficiently warm. Likewise in example ‘e’ the normalized representation is 2.5 which indicates that the garment is significantly too warm for the environment.

FIG.17‘a’ reports a game-based trend of the suitability of clothing selected by the caregiver over a period of time to show improvement and gamify the suitability interaction. This feature records a caregiver's garment suggestions and compares the thermal resistance of the suggested garments to the room temperature. A score is given in relation to how close the thermal resistance of the suggested garment is to an ideal thermal resistance. Scoring trends are determined based on stored usage data and a “ranking” is determined based on the score. Example ‘b’ reports a quantification of the improvement in a baby's sleep obtained by choosing suitable clothing and maintaining optimal room temperature. In order to use this feature, the user may be prompted to quantify the quality of sleep or other parameter on a periodic basis so that the quality quantification may be correlated with the suitability of the selected garment. This will cause recordation of the quantification in usage data as shown inFIG.1C.FIG.17‘c’ displays an example of potential education provided to the user to remind them of the most up to date recommended sleep practices.

In one example education is delivered to the user based on specific learnings made through operation of the device. Where recorded historical data suggests a preference to overdress an infant exists, education would be selected and administered explaining the dangers of overdressing and helping the user to improve their clothing or layette selection skills. In another example, where it is inputted that the device is being used with a premature infant, specific education tailored to those conditions might be administered. If it is determined that the device is constantly being deployed in an environment that is below or above predetermined acceptable environmental limits it may suggest changes need to be made to the sleep environment itself. Education articles may be selected through interrogation of any of the data handled by the device, including ambient conditions, clothing selections, user inputs, external inputs, predictions and forecasts and usage statistics.

An example user interface or display that is not illustrated inFIG.17is a thermal resistance alert feature. This feature provides an alert if the room temperature changes outside of range of temperatures mapped to the most recent thermal resistance and displays an alert message to the user. To support this feature the device continues to measure (or otherwise determine) the ambient temperature around the device without performing thermal property assessments. Each new ambient temperature is compared with the range of temperatures mapped to the last recorded thermal property value (or selected garment's thermal property value). When the new ambient temperature is outside the range, the alert (visual, audio, or both) is provided.

Another user interface or display that is not illustrated inFIG.17is a database of personalized clothing recommendations. This feature prompts the user to capture an image of a measured garment and records the measured thermal resistance mapped to the image of the clothing article in a database. The next time the room temperature is taken or a new temperature is predicted (e.g., from a weather forecast or the user manually inputting the predicted temperature), the database is searched for a garment of acceptable combinations of garments and sleep sacks having a suitable thermal resistance for that temperature. In one example, the database is constructed externally to the user and contains generic material and/or thermal property information relating to potential material and/or clothing choices. Comparison is then made between the material properties remote database and the predicted, measured or otherwise inputted environmental conditions and subsequent recommendations provided to the user.

Another user interface or display that is not illustrated inFIG.17is personalized learning. Personalized learning includes the user recording the thermal resistance of the clothes selected and the room temperature, and then is prompted to enter an experienced quality characteristic (e.g., a rating of the quality of the sleep or perceived comfort, perhaps based on a duration of uninterrupted sleep). A learning algorithm determines correction factors to apply to core the calibration scheme to personalize comfort to baby. This may involve selecting material types that individually captured statistics show result in greater comfort or sleep for the learned baby, or selecting clothing with thermal resistance values that are within safe ranges for the ambient conditions, but tailored to a specific baby. In one example a baby is perceived to sleep better with slightly lower thermal resistance clothing choices and so the system suggests recommendations based on that learning, but still within safe limits. Over time, a new calibration scheme evolves and improves each time used—baby sleep quality is improved and optimized. With more user input the system could also determine sleep clothing type choices, so for example, the baby may typically sleep better in a particular sleep sack, or not like a particular sleep sack (i.e., outliers could be detected and notified to the user). In one example, to effectuate personalized learning, the device's storage medium is adjusted to map the thermal property values to different ranges of environmental characteristic values based on an experienced quality characterization.

Another user interface or display that is not illustrated inFIG.17is personalized learning of the babies sleep environment itself. Over time, the device may characterize temperature trends (based on stored usage data) when operated within a given room and may learn patterns which provide input to clothing choice recommendations. In one example, the caregiver selects exactly the right clothing choices for the current room temperature, but the input from the room temperature trend pattern learning software suggests that the room will likely heat up throughout the duration of sleep-time and so the device suggests a clothing choice with lower thermal resistance.

Another user interface or display that is not illustrated inFIG.17is quantification of time spent in the “thermoneutral” zone. If a caregiver uses the device to perfectly match clothing choices to the ambient conditions, the infant will be in the thermoneutral zone, meaning the baby expends little or no energy maintaining body temperature, and most calories go to growth and development. By constantly comparing the saved current clothing choice with the ambient conditions, a history of the match can be created which will inform the user of the quality of the baby's comfort (i.e, being in the thermoneutral zone) whether awake or asleep. In one example, it may present a chart showing the amount of time the baby spent within the specified thermoneutral zone, and report a score indicating how close the sleep-time was to ‘perfect’ (remaining within the zone of thermoneutrality for the entire duration of sleep).

Service Based Garment Recommendations

In one example, a garment recommendation device may be embodied as a communication device with an installed garment recommendation application. The device is capable of receiving a user input that identifies the temperature for which the baby should be dressed. Alternatively, the device could include a temperature sensor configured to provide temperature data to the communication device (e.g., a thermocouple with a communication adaptor). In this example, many of the functions described as being performed by “onboard” components of the measurement device are performed by an internet-based garment recommendation service (e.g., a subscription service).

The garment recommendation device measure (or otherwise determines using any of the methods described above) an environmental characteristic (e.g., temperature, humidity, and so on (hereinafter “temperature”)) for which the baby should be dressed. The temperature is transmitted, via the internet, to the garment recommendation service. The service would access a database of recommendations for different temperatures and transmit a recommendation back to the device for display by the device. The recommendations could be in terms of thermal resistance values that are suitable for the temperature, a listing of clothing (previously recorded as owned by the user) that would be suitable for the temperature, material types and/or thicknesses that are suitable for that temperature, different manufacturers' listing of garments that are suitable for that temperature, and so on.

It can be seen from the foregoing description that the described methods, circuitries, and devices provide a household suitable handheld and portable measurement device that determines a thermal property of material and, in some examples, determine and display a suitability of the material for the present environment.

Examples can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine cause the machine to perform acts of the method or of an apparatus or system for measuring a thermal property of a material sample according to embodiments and examples described herein.

Various illustrative logics, logical blocks, modules, and circuits described in connection with aspects disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform functions described herein. A general-purpose processor can be a microprocessor, but, in the alternative, processor can be any conventional processor, controller, microcontroller, or state machine. The various illustrative logics, logical blocks, modules, and circuits described in connection with aspects disclosed herein can be implemented or performed with a general purpose processor executing instructions stored in computer readable medium.

While the invention has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the invention. The above description of illustrated embodiments of the subject disclosure is not intended to be exhaustive or to limit the disclosed embodiments to the precise forms disclosed. While specific embodiments and examples are described herein for illustrative purposes, various modifications are possible that are considered within the scope of such embodiments and examples, as those skilled in the relevant art can recognize.

In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding Figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below.

In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. The use of the phrase “one or more of A, B, or C” is intended to include all combinations of A, B, and C, for example A, A and B, A and B and C, B, and so on.