System for mitigating thermal discomfort during a medical imaging procedure

Abstract

The invention provides a method for improving the thermal comfort of a patient during a medical imaging procedure by means of changing a sensory perceptible property of the ambient state, for example a method for improving the thermal comfort of a patient by changing the color temperature and / or the luminance of the lighting output provided in the space in which the scan is performed and which is perceptible to the patient.

Description

Technical Field

[0001] This invention relates to the field of medical imaging, and more specifically to alleviating thermal discomfort in patients during medical imaging procedures. Background Technology

[0002] Some medical imaging procedures require patients to remain still for extended periods, often in unnatural situations or conditions. In some cases, scanning instruments may be placed very close to the patient. Examples include computed tomography (MRI, CT, or PET) and some types of prolonged ultrasound examinations. In addition to radiological imaging, various treatments (such as radiation therapy or intravenous infusions) also require patients to remain still for extended periods in confined spaces.

[0003] During such a process, the patient's body temperature may rise uncomfortably due to energy deposits in the body and the patient's inability to adjust their posture in response.

[0004] For example, during an MRI scan, a patient's perceived body temperature may increase significantly due to the absorption of emitted radiofrequency (RF) fields by the tissues. The amount of heating is typically expressed as specific absorptivity (SAR) and is measured in watts per kilogram (W / kg). The amount of emitted RF depends on the scanner field strength and the type of imaging sequence. Furthermore, factors such as age and heart rate can also affect the degree of MRI-related body temperature changes. See, for example, Myeong Seong Kim's paper "Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging" (Iranian Journal of Radiology).

[0005] Existing MRI scanners can operate at high SAR to obtain higher quality images. Current regulations limit SAR to 4 W / kg to prevent core body temperature from rising more than 1°C. However, even with these measures, patients may still experience thermal discomfort due to radiofrequency absorption by tissues.

[0006] Typical measures to prevent patient discomfort include controlling patient clothing, ensuring patients wear light clothing, and providing orifice ventilation at a sufficiently high rate.

[0007] However, a typical scan consists of multiple scan sequences, and the SAR associated with each scan sequence may vary. Therefore, this can cause patients to feel cold during sequences with relatively low SAR and hot (leading to sweating and discomfort) during sequences with high SAR intensity. Additionally, the cumulative amount of radiofrequency (RF) absorbed by the tissue increases during the scan, resulting in a potential upward linear trend in RF absorption, superimposed with inter-sequence fluctuations. Furthermore, scan sequences are often separated by pauses. During pauses, no new energy deposition causes a decrease in skin temperature. The resulting periodic changes in skin temperature during the scan can exacerbate thermal discomfort or heat unease in patients.

[0008] US2014 / 0055133A1 discloses an MRI system that adaptively and dynamically adjusts the color and brightness of an illuminator (e.g., an LED array) mounted inside a cavity in response to a scan sequence for magnetic resonance imaging or the patient’s condition in order to reduce discomfort during magnetic resonance imaging.

[0009] US7702375B23 discloses a medical imaging examination device with an illumination device for illuminating a large area of ​​the anterior wall to reduce patient anxiety. Summary of the Invention

[0010] This invention is defined by the claims.

[0011] According to an example of one aspect of the invention, an environmental control system for use with a medical imaging scanner is provided, the medical imaging scanner including an imaging device adapted to acquire imaging data of an object located in an imaging area.

[0012] The system includes a sensory output system comprising one or more sensory output devices adapted to generate a set of controllable sensory outputs. The combination of sensory outputs defines the state of the surrounding environment as perceived by a patient located in the imaging area. The sensory output system is operable to alter the state of the surrounding environment by controlling the sensory output devices. For example, the sensory output system is operable to alter the state of the surrounding environment by controlling one or more variable sensory parameters of the sensory outputs. The setting of the variable sensory parameters of the one or more sensory outputs can uniquely define the state of the surrounding environment; that is, the state of the surrounding environment can be characterized by the values ​​of the one or more variable sensory parameters. The combination of sensory outputs preferably includes at least one or more visually perceptible outputs.

[0013] The surrounding environment can be used to influence a patient's thermoregulation.

[0014] The system also includes a controller.

[0015] The controller is adapted to receive scan information indicating one or more medical imaging scan parameters that change over time during a medical imaging scan of a patient. The scan information may include indications reflecting changes over time in energy deposition (or energy deposition rate) acting on the patient during the scan.

[0016] The controller is also suitable for performing thermal sensing compensation operations.

[0017] Thermal sensing compensation operations may include: determining, based on scan information, direct or indirect indications of expected changes in body temperature (e.g., changes in skin temperature) between a first time point in a medical imaging scan and a later time point in the medical imaging scan; and adjusting the ambient conditions at a second time point according to the expected changes in body temperature.

[0018] For example, regulating the ambient state may include estimating changes in the ambient state that will at least partially offset the patient's perception of a change in body temperature. This may be based, for example, on a known or predetermined relationship or correlation between changes in one or more variable sensory parameters of the ambient state and a perceived change in temperature (or vice versa). For example, a known relationship or correlation may be where the perceived body temperature increases in response to a decrease in the color temperature of the light output (i.e., warmer light). Regulating the ambient state may include, for example, decreasing the color temperature of the light at a second time point to compensate for a anticipated decrease in body temperature at that time point, and increasing the color temperature of the light at a second time point to compensate for an anticipated increase in body temperature at that time point. For example, in a simple case, the sensory output device may include an illumination system for generating light output in the ambient environment, and regulating the ambient state may include: increasing the color temperature of the light output at a second time point (a cooler light color) in response to an anticipated increase in body temperature at that time point, and decreasing the color temperature of the light output at a second time point (a warmer light color) in response to an anticipated decrease in body temperature at that time point.

[0019] In some embodiments, the controller may be adapted to retrieve a predefined thermal sensing model that defines the relationship between changes in one or more variable sensory parameters of sensory output and (or vice versa) a predicted change or effect (or vice versa) in perceived temperature of a person exposed to an ambient state including said sensory output. The predicted change or effect in perceived temperature may be qualitative (e.g., merely an indication of whether the change will increase or decrease the (perceived) temperature) or may be an indication of a predicted quantitative change in (perceived) temperature. The controller may be adapted to adjust the ambient state at a second time point based on using the thermal sensing model to estimate changes in the ambient state settings that will at least partially offset the perception of changes in body temperature.

[0020] In some embodiments, the thermal sensing model may implicitly represent relationships. For example, in some embodiments, the thermal sensing model may include a lookup table that defines a mapping between different possible values ​​of (direct or indirect) indications of expected changes in body temperature and settings of ambient environmental states (one or more variable sensory parameters for sensory output) that are predicted to cause a change in temperature perceived by the user that will at least compensate for the expected changes in body temperature.

[0021] In some embodiments, at least one or more visually perceptible outputs have controllable color content and / or controllable brightness.

[0022] Different environmental conditions affect skin temperature through well-established thermoregulatory pathways. These will be explained in more detail below.

[0023] Embodiments of the present invention are based on the concept of influencing a user’s perception of temperature (e.g., thermal perception, thermal comfort, or thermal satisfaction) in a controlled manner by using a controlled combination of sensory outputs, which is related to the user’s physiological state (e.g., skin temperature, skin conductance, sweating, vasoconstriction, vasodilation, heart rate, respiratory rate).

[0024] By estimating the changes in a patient's expected body temperature (e.g., skin surface temperature) due to energy absorption, and further estimating the thermal perception effects of different sensory states on the patient's temperature perception, the changes in temperature perceived by the patient due to energy absorption can be reduced or offset. Therefore, patient thermal comfort can be improved without requiring direct thermal interaction with the patient.

[0025] As described above, in some embodiments, a thermal sensing model is employed. This model may, for example, be stored on a data storage device or memory included in the system.

[0026] Regarding thermal sensing models, this could, for example, define an estimated mapping between different ambient state settings and the predicted changes or effects (or vice versa) on the temperature perceived by a person exposed to those ambient states. As an example, this could take the form of a lookup table in some embodiments, a mathematical function in others, or a machine learning model in still others.

[0027] In a set of advantageous, simple embodiments, a thermal sensing model can simply define a mapping between possible values ​​of an indication of expected changes in body temperature and appropriate settings of corresponding variable parameters of the surrounding environment to achieve at least partial compensation for temperature changes.

[0028] In some embodiments, the value of the indicator information for expected body temperature changes It can be classified into a set of reduced discrete categories (e.g., low, medium, and high). Each category can correspond to a specific range of values ​​for indicative information of expected body temperature changes. The thermal sensing model can define a mapping between each expected body temperature change category and appropriate settings of corresponding variable parameters of the surrounding environmental state to achieve at least partial compensation for temperature changes. Corresponding to each category... The range of values ​​is predefined.

[0029] Direct or indirect indications of expected changes in body temperature can be proxy indications. For example, in some embodiments, it could be a value related to or proportional to the rate of energy deposition exerted on the patient by the imaging scanner at a second time point.

[0030] Medical imaging scanners may include cavities, wherein the imaging area is located inside the cavity.

[0031] Medical imaging scanners can be MRI scanners.

[0032] In some embodiments, a scan consists of a set of individual scan sequences, each associated with a different set of scan parameters, wherein a first time point is the start time of the scan, and wherein a second time point is the start (or end) time of a particular scan sequence. Therefore, here, the estimated body temperature change is the change in body temperature between the start of the scan and the start of one of the scan sequences.

[0033] Alternatively, in some embodiments, the scan consists of a set of individual scan sequences, each associated with a different set of scan parameters, wherein a first time point coincides with a scan sequence, and a second time point coincides with a subsequent scan sequence. Therefore, here, the ambient conditions are adjusted to compensate for anticipated body temperature changes between successive scan sequences, rather than, for example, the total temperature change since the start of the scan. Human thermal comfort is generally more related to short-term relative temperature changes than absolute temperature changes. Therefore, by controlling the ambient conditions based on anticipated body temperature changes between successive scan sequences, the resulting compensation effect will have a greater impact on the user's thermal comfort.

[0034] In some embodiments, the controller may be adapted to perform thermal sensing compensation operations for each scan sequence. For example, this may involve estimating the expected change in body temperature caused by each scan sequence. In some embodiments, it may involve estimating the change in body temperature between a first time point, which is the start of the scan, and a plurality of second time points, each second time point corresponding to the start or end time of a particular scan sequence. In other embodiments, it may involve estimating the expected change in body temperature between a series of pairs of first and second time points, each pair corresponding to a pair of temporally successive scan sequences.

[0035] More generally, the controller can be adapted to perform thermal sensing compensation operations at multiple second time points during the scan duration, for example, performing thermal sensing compensation operations at regular time intervals throughout the scan. For example, the thermal sensing compensation operation can be performed continuously or quasi-continuously. The first time point can always be the same, while the second time points can vary. Alternatively, the first and second time points can be shifted, such that compensation operations are performed on estimated body temperature changes within a shifting time window throughout the scan.

[0036] Regarding sensory output systems, one or more sensory output devices may include an illumination system for generating light output in the surrounding environment. The illumination system can be controlled to change the color temperature of the light output and / or change the illuminance or intensity of the light output. As will be explained in more detail below, both the color temperature and luminance of the light are independently related to changes in the perceived body temperature (e.g., surface temperature, such as skin temperature) of the object exposed to the light. Therefore, by generating a light display and adjusting one or both of these variables of emitted light, the perceived thermal state of the object can be influenced.

[0037] More specifically, in some embodiments, the thermal sensing model may reduce the light color temperature and / or increase the illuminance to raise the temperature perceived by the patient. Conversely, the thermal sensing model may increase the light color temperature and / or decrease the illuminance to lower the temperature perceived by the patient.

[0038] Available research suggests that a decrease in color temperature, measured in Kelvin (meaning a warmer hue), and / or an increase in brightness can lead to an increase in perceived ambient temperature (or vice versa).

[0039] As described above, in some embodiments, the scan may be an MRI scan.

[0040] In this context, scan information may include the expected specific absorptivity (SAR) at one or more time points during the scan. Specific absorptivity (SAR) is a measure of the rate at which the human body absorbs energy when exposed to radio frequency (RF) electromagnetic fields. In MRI, it is used as a measure of the rate at which a patient absorbs energy due to RF radiation emitted by an RF coil. Its unit is energy per unit mass (patient mass) (e.g., watts per kilogram (W / kg) or milliwatts per gram (mW / g)). This energy manifests as heat when absorbed by the body.

[0041] SAR can be used to estimate the amount of energy deposited in a patient's body (per unit of body mass) over a given time period, based on multiplying the SAR of a scanned portion (e.g., a scan sequence) by the duration of that scanned portion. Furthermore, SAR itself is a direct indicator of tissue heating: a higher SAR produces a greater (instantaneous) tissue heating effect. Tissue heating leads to an increase in body temperature. Therefore, it can be seen that SAR can be used as an indicator of an expected increase in body temperature (e.g., an increase in surface body temperature, such as increased skin temperature).

[0042] As described above, in some embodiments, a scan may consist of a set of separate scan sequences. Here, the scan information may include the expected SAR for each scan sequence.

[0043] Regarding the estimated changes in perceived temperature, the perceived temperature of an object at a given time can be correlated with the rate of energy absorption (i.e., with the SAR value of a given scan sequence). As mentioned above, this is because RF energy causes local tissue heating (i.e., local body temperature increase (e.g., surface body temperature increase)).

[0044] To further explain: To maintain a stable core body temperature, the body performs thermoregulation (a steady-state process that keeps the core body temperature within a narrow range (where all bodily processes operate optimally)). One set of thermoreceptors is located centrally (e.g., in the internal organs). These thermoreceptors are used to sense core body temperature. Another set of thermoreceptors is located peripherally (in the skin). These thermoreceptors are used to sense surface temperature (also known as skin temperature). If the thermoreceptors (centrally and / or peripherally) sense a temperature change, a person may exhibit physiological responses (e.g., sweating, vasoconstriction / vasodilation, increased / decreased metabolic rate, shivering, prickly heat, etc.) and / or behavioral responses (e.g., regulating movement, clothing, body posture, or food intake / appetite; moving to another location, etc.). These responses are used to maintain a stable core body temperature. Skin temperature is more variable (changes more rapidly) than core body temperature, and certain thermoregulatory responses (e.g., sweating, regulated blood flow in the skin) are closely related to skin temperature. A person's thermal perception is strongly influenced by skin temperature. MR-induced RF exposure causes a measurable increase in skin temperature (while also affecting core body temperature, albeit less significantly). This can thus influence a person's thermal perception, thermal comfort, and thermal satisfaction.

[0045] Therefore, for simplicity, in some embodiments, based on observations that energy absorption rate is correlated with body temperature rise and thus with perceived temperature, SAR itself can simply be used as a proxy indication of at least one component of expected body temperature changes (e.g., changes in skin temperature or body surface temperature). In this case, for example, the SAR change between a first time point and a second time point can be used as an indication of at least one additional component of the expected body temperature change. For example, the expected SAR of an MR sequence can be used as a proxy for body temperature changes between the time before the scan begins (where SAR is zero) and the time period during which the scan sequence is being performed. Additionally or alternatively, the SAR change between two successive scan sequences can be used as a proxy indication of the expected body temperature change between the two scan sequences.

[0046] In addition, changes in body temperature at a given time point (compared to the first time point) can also be correlated with cumulative energy absorption over the period since the first time point when RF energy was applied.

[0047] Therefore, in some embodiments, the expected SAR of each scan sequence can be used to calculate an indication of the patient’s total energy absorption between a first time point and a second time point, wherein the total energy absorption is used as an indication of at least one component of the expected change in body temperature.

[0048] In some embodiments, the two methods described above can be combined such that the expected change in body temperature is calculated as the sum of (i) a term proportional to the total energy absorption between the first and second time points and (ii) a term proportional to the change in SAR between the first and second time points. The total energy absorption term may represent a trend baseline for the change in body temperature, while SAR may represent a local change. In some embodiments, these two terms may be weighted differently in the sum.

[0049] In some embodiments, the sensory output device includes an illumination system for generating light output in the surrounding environment. A first time point may coincide with a scan sequence, and a second time point coincides with a subsequent scan sequence. The thermal sensing model allows adjusting the ambient state at the second time point based on anticipated changes in body temperature to include changing the color temperature of the light output by a function of the SAR change between the scan sequence and subsequent scan sequences.

[0050] In some embodiments, the thermal sensing model defines a mapping between the SAR of a given scan sequence and the color temperature of the light to be output during the scan sequence, wherein the mapping is such that the color temperature of the light to be applied increases with increasing SAR.

[0051] In some embodiments, the sensory output system may include a display device (e.g., a display panel or projector) for presenting 2D visual output.

[0052] 2D visual output can include visual elements with a perceptible color temperature, wherein the color temperature is adjustable.

[0053] In some embodiments, the 2D visual output may include the presentation of a visual image having perceptible color content, and wherein adjusting the color temperature of the output includes adjusting the visual image.

[0054] For example, images associated with cold (e.g., snow scenes, cold water flowing in a stream) or images associated with warmth (e.g., tropical beaches, crackling fireplaces) can be shown.

[0055] Additionally or alternatively, 2D visual output may include the presentation of visual images conceptually related to a range of thermal temperatures. In this case, the effect is evoked by associating the content of the scene with warmth (a warm sweater, a cup of hot tea, a hot bath, etc.) or cold. This may be associated with a specific color, but it does not necessarily have to be.

[0056] In some embodiments, the sensory output device may include an audio output device. The audio content may be adapted to correspond to a target change in perceived temperature. For example, if warm elements are displayed on a display device, then audio associated with those elements (e.g., crackling flames, flowing cold water, opening a fresh beverage, etc.) may be generated.

[0057] In some embodiments, a display device may be controlled to display a visual representation of transitions between multiple temperature scenes that present contrast.

[0058] Here, the intention is to induce a shift in the patient's perceived thermal state based on contrast. For example, to guide a patient from one perceived thermal state (e.g., feeling hot) to another (e.g., feeling less hot), a scenario depicting the successful resolution of an unpleasant perceived thermal state might be displayed. As an example, when a patient feels cold, the display might show a scene where a person (or cartoon character) is initially shivering and appears cold, then puts on a sweater and sits by a fire drinking hot chocolate. Alternatively, if a person feels hot, the display could show a scene where a person is initially sweating and appears hot, then dives into cold water on a sunny day.

[0059] In some embodiments, the sensory output device may include an olfactory output device. Patients may be exposed to odors associated with warmth (such as the smell of coconut, hot chocolate, or a campfire) or odors associated with cold.

[0060] In some embodiments, the sensory output device may include a tactile stimulation generator. For example, tactile stimulation can be used to distract a patient from their unpleasant thermal sensation. Tactile sensations such as vibration or tapping can alleviate thermal discomfort.

[0061] As described above, in some embodiments, changes in the ambient state may include at least a change in the color temperature of the light output generated by the lighting system. In this case, in some embodiments, the controller may be adapted to control the sensory output system such that the transition from a first ambient state to a second ambient state includes a transition of the light output through a path in the color space. In some embodiments, the transition may be a smooth transition of the light output through the color space.

[0062] A possible example is as follows. A transition in the state of the surrounding environment can at least involve the transformation of the RGB colors of the RGB light output from the lighting system from the first color (A) in the RGB space to the second color (B) in the RGB space. Performing the transformation from color A to color B can include: converting color A and color B to points in the CIELAB color space; determining a continuous line through points A and B in the CIELAB color space; extracting a series of CIELAB color points distributed along the CIELAB line and converting the extracted series of points back to the RGB color space, thereby deriving a series of RGB color points; controlling the lighting system to transition between color A and color B by controlling the lighting system to sequentially traverse the series of RGB color points. RGB is not a perceptually uniform color space, so the transition from color A (R1, G1, B1) to color B (R2, G2, B2) will appear abrupt to a human observer. Therefore, to make the transition smoother, the transformation function can be defined in the CIELAB color space before converting the transformation function back to the RGB color space.

[0063] In some embodiments, to improve the estimation of expected body temperature changes, the system may further include one or more temperature sensors for sensing the patient's body temperature. The controller may be adapted to determine indications of expected body temperature changes based at least on a combination of scan information and measurements of the patient's body temperature at a second time point.

[0064] The system may also include one or more ambient temperature sensors for sensing the temperature of the surrounding environment. The controller may be adapted to determine indications of expected body temperature changes based at least on a combination of scan information and measurements of the ambient temperature at a second time point.

[0065] In some embodiments, a combination of a body temperature sensor and an ambient temperature sensor may be used.

[0066] In some embodiments, the system may further include one or more physiological parameter sensors for sensing one or more physiological parameters of the patient. The controller may be adapted to determine indications of expected body temperature changes based at least on a combination of scan information and measurements of one or more physiological parameters at a second time point.

[0067] These indicators may include, for example, heart rate or sweat rate.

[0068] In some embodiments, the estimated body temperature change may also be determined based on one or more of the patient’s biological parameters, such as any one or more of the following: age, sex, body mass, height, weight, body composition, basal metabolic rate, resting heart rate, average activity level, and sleep pattern.

[0069] In some embodiments, the controller may be adapted to determine indications of expected changes in body temperature based on a predefined thermophysiological model.

[0070] For example, in the case where the scan is an MRI scan and the scan information includes the expected specific absorption rate (SAR) at one or more time points during the scan, the controller may be adapted to determine indications of expected body temperature changes based on a predefined thermophysiological model adapted to estimate the RF-induced increase in body temperature based on the SAR and the duration of exposure.

[0071] Additional factors such as ambient temperature, clothing, patient size and position, coil size and position, patient ventilation information, and / or individual thermoregulation can also be included as variables in the model.

[0072] In some embodiments, the controller may also be adapted to receive patient-specific temperature sensitivity information, and wherein indications of expected body temperature changes are determined in part based on the patient-specific temperature sensitivity information.

[0073] In some embodiments, the controller is also adapted to receive user input at a second time point instructing the patient to report temperature perception, and to adjust the state of the surrounding environment in part based on the user input.

[0074] Another aspect of the present invention is an environmental control method for use with a medical imaging scanner during medical imaging scanning, wherein the medical imaging scanner includes an imaging device adapted to acquire imaging data of an object located in an imaging area.

[0075] This method may involve controlling a sensory output system comprising one or more sensory output devices adapted to generate a controllable set of sensory outputs, the combination of which defines the state of the surrounding environment as perceived by a patient located in an imaging area. The sensory output system is operable to alter the state of the surrounding environment by controlling the sensory output devices. For example, the sensory output system is operable to alter the state of the surrounding environment by controlling one or more variable sensory parameters of the sensory outputs. The setting of the variable sensory parameters of the one or more sensory outputs can uniquely define the state of the surrounding environment (i.e., the state of the surrounding environment can be characterized by the values ​​of one or more variable sensory parameters). The combination of sensory outputs preferably includes at least one or more visually perceptible outputs.

[0076] The surrounding environment can be used to influence a patient's thermoregulation.

[0077] The method may include the following steps: receiving scan information indicating medical imaging scan parameters that change over time during a medical imaging scan of a patient. The scan information may include indications reflecting changes over time in energy deposition (or energy deposition rate) acting on the patient during the scan.

[0078] The method may also include performing thermal sensing compensation operations.

[0079] Thermal sensing compensation operations may include: determining, based on scan information, direct or indirect indications of expected body temperature changes between a first time point in a medical imaging scan and a later second time point in the medical imaging scan, and adjusting the ambient conditions at the second time point according to the expected body temperature changes.

[0080] For example, modulating the ambient state may include estimating changes in the ambient state that will at least partially offset the patient's perception of temperature changes. This may be based, for example, on a known or predetermined relationship or correlation between changes in one or more variable sensory parameters of the ambient state and perceived temperature changes.

[0081] In some embodiments, the method may include retrieving a predefined thermal sensing model that defines a relationship between changes in one or more variable sensory parameters of sensory output and a predicted change or effect on the perceived temperature of a person exposed to an ambient state including said sensory output. The predicted change or effect may be qualitative, such as merely an indication of whether the change will increase or decrease the perceived temperature, or it may be an indication of a predicted quantitative change in the perceived temperature. The controller may be adapted to adjust the ambient state at a second time point based on using the thermal sensing model to estimate changes in the ambient state settings that will at least partially offset the patient's perception of a change in expected body temperature.

[0082] Any features or embodiments described with respect to the first (apparatus) aspect of the invention may also be applied as or incorporated as embodiments of the method aspect of the invention.

[0083] Another aspect of the invention is a computer program product comprising computer program code configured to, when executed by a processor, cause the processor to perform any of the examples or embodiments described herein or any of the claims of this application. For example, the processor may be coupled to a data storage device storing a representation of a thermal sensing model.

[0084] These and other aspects of the invention will become apparent and elucidated with reference to one or more embodiments described below. Attached Figure Description

[0085] To better understand the invention and to more clearly illustrate how the invention can be implemented, reference will now be made to the accompanying drawings by way of example only, in which: Figure 1 The steps of an example method according to one or more embodiments of the present invention are summarized; Figure 2 This is a block diagram of an example controller and system according to one or more embodiments of the present invention; Figure 3 The illustration shows an example of the modulation of the surrounding environment for each scan sequence in a series of scan sequences for medical imaging; and Figure 4 The illustration shows an example of the modulation of the surrounding environment for each of a series of scan sequences in a medical imaging scan, which are separated by time delays. Detailed Implementation

[0086] The invention will be described with reference to the accompanying drawings.

[0087] It should be understood that while the detailed description and specific examples indicate exemplary embodiments of the apparatus, system, and method, they are intended for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are merely schematic and not drawn to scale. It should also be understood that the same reference numerals are used in all the drawings to indicate the same or similar parts.

[0088] The present invention provides a method for improving thermal comfort of a patient during a medical imaging procedure by means of sensory perceptible characteristics of altering the state of the surrounding environment (e.g., by changing the color and / or brightness of the illumination output provided in a space that is being scanned and is perceptible to the patient).

[0089] One advantageous application is during MRI examinations, as will be explained below. However, the same principle can be applied to any type of medical imaging examination.

[0090] As background, during an MRI examination, the patient's body temperature rises significantly because the emitted radiofrequency (RF) field is absorbed by the patient's tissues. The amount of heating can be quantitatively expressed by specific absorptivity (SAR). Specific absorptivity (SAR) is a measure of the rate at which the human body absorbs energy when exposed to a radiofrequency (RF) electromagnetic field. In MRI, it is used as a measure of the rate at which a patient absorbs energy due to RF radiation emitted by an RF coil. Its unit is energy per unit mass (patient mass) (e.g., watts per kilogram (W / kg) or milliwatts per gram (mW / g)).

[0091] The amount of RF energy emitted depends on the scanner field strength and the type of imaging sequence. Furthermore, patient-related factors such as age and body size can also influence MR-related body temperature changes. This is referenced in Myeong Seong Kim's paper, "Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging" (Iranian Journal of Radiology).

[0092] Existing MRI scanners operate at high SAR (Self-Range Thermometry) to achieve higher image quality. Current regulations limit SAR to a maximum of 4 W / kg in certain areas to prevent core body temperature from rising more than 1°C. However, even with these measures, patients may still experience thermal discomfort due to radiofrequency absorption by tissues.

[0093] MR-induced RF exposure primarily causes an increase in temperature at the body surface. For example, referencing the literature by ADAIR, ER, and BERGLUND, LG, "Predicted Thermophysiological Responses of Humans to MRI Fields" (Annals of the New York Academy of Sciences, Vol. 649, pp. 188-200, 1992), this indicates that, for instance, after three consecutive 20-minute MRI scans with high SAR, an increase in skin temperature of 3.5°C and a slight increase in core body temperature of 0.3°C could be observed. In this study, the increase in skin temperature was accompanied by an increase or improvement in perceived temperature, sweating, and skin blood flow.

[0094] The study also referenced the following literature: Schlader et al., “Human temperature regulation when given the opportunity to behave” (Eur J Appl Physiol, Vol. 113, pp. 1291-1301, 2013). This study found that changes in skin temperature have a significant impact on thermal comfort.

[0095] Previous studies have found that sensory perceptibility characteristics of the surrounding environment (sometimes referred to as the surrounding experience or the surrounding environment) can affect perceived temperature changes.

[0096] For example, the following literature was referenced: Hoffman, HG; Richards, TL; Coda, B.; Bills, AR; Blough, D.; Richards, AL; and Sharar, SR, “Modulation of thermal pain-related brain activity with virtual reality: evidence from fMRI” (Neuroreport, 15(8), pp. 1245-1248, 2004). This study found that thermal discomfort could be partially compensated by modulating lighting or visual effects (e.g., by playing a VR game (Snow World) that displays a snow scene).

[0097] The following literature was also referenced: Mogensen, MF and English, HB, “The apparent warmth of colors” (The American Journal of Psychology, 1926). This literature elaborates on the so-called “hue-thermal effect,” which shows that perceived temperature is affected by color.

[0098] For example, further research has found that even when the objective temperatures of two rooms are the same, people feel warmer in spaces illuminated with warm ambient colors (i.e., lower color temperatures (e.g., 3000 K)) and / or high illuminance (e.g., 800 lx) compared to spaces illuminated with cool ambient colors (i.e., higher color temperatures (e.g., 5500 K)) and lower illuminance (e.g., 300 lx). This research is therefore detailed in the following literature: “Effect of illumination on perceived temperature” by Tsushima, Y., Okada, S., Kawai, Y., Sumita, A., Ando, ​​H., and Miki, M. (PLoSone, 15(8), e0236321, 2020).

[0099] A review summarizing 31 experiments is presented in the following literature: "The effects of manipulating the visual environment on thermal perception: A structured narrative review" by Harry S. Mayes, Martina Navarro, Liam P. Satchell, Michael J. Tipton, Soichi Ando, ​​and Joseph T. Costello (hereinafter referred to as "Mayes et al."). This review shows that thermal perception and thermal comfort are affected by changes in illumination.

[0100] There are two main theories, both of which indicate that light color is related to changes in perceived temperature and thermal comfort.

[0101] According to the hue-thermal hypothesis, people associate red (and reddish colors) with warmth and blue (and bluish colors) with coolness; seeing "warm" colors makes people feel warmer, while seeing "cool" colors makes people feel cooler. The hue-thermal hypothesis is further described in the following literature: Kulve et al., "The influence of light on thermal responses" (Acta Physiol., 216(2), pp. 163-185, 2015).

[0102] Correlated color temperature theory assumes the same assumptions, but specifically relates to light; color temperature is measured in Kelvin (K). For this reason, light with a lower Kelvin is redder and therefore associated with warmth. Similarly, light with a higher Kelvin is bluer and therefore associated with coolness. Correlated color temperature theory is further outlined in the following literature: Golasi et al., “Influence of lighting color temperature on indoor thermal perception: astrategy to save energy from the HVAC installations” (Energy Build., 185, pp. 112-122, 2019). As detailed in the aforementioned paper published in 2023 by Mayes et al., the color temperature of light has been found to affect heat perception, thermal comfort, skin temperature, and thermoregulatory responses. The color of light has been found to influence physiological thermoregulatory responses (e.g., heart rate, skin blood flow, sweating, shivering) as well as behavioral responses (e.g., moving from one room to another; adding or removing clothing).

[0103] Therefore, the effect of light on perceived temperature is mediated at least in part through the non-autonomous influence of light on the thermoregulatory system of the object (i.e., light stimulates the patient's autonomous response, which affects skin temperature and / or core body temperature. In this regard, see section 3.7 of the aforementioned paper by Mayes et al., published in 2023).

[0104] The above discussion leads to the conclusion that light and visual effects can significantly influence perceived temperature, and that adjusting light (e.g., color, brightness) can be used to alleviate thermal discomfort. For example, increasing the color temperature of light (making the light "cooler") has the effect of lowering the perceived body temperature of an object, while decreasing the color temperature of light (making the light "warmer") has the effect of increasing the perceived body temperature of an object.

[0105] Accordingly, the inventors of this invention propose the use of controlled modulation of sensory-perceptible characteristics of the surrounding environment (sometimes referred to as ambient experience (AE)) to help patients better manage temperature-related discomfort by adapting the AE to anticipated, measured, or perceived temperature changes.

[0106] For example, considering the specific applications of MRI imaging, the surrounding experience can be modulated as a means of influencing how a patient perceives the temperature inside the scanner's aperture. Based on this, according to a set of embodiments, it is proposed to adapt surrounding experience settings (e.g., light, and optionally video and sound) based on MRI scan sequence information and more specifically on expected body temperature changes for each particular MR sequence.

[0107] According to a specific set of embodiments, it is proposed to use the expected specific absorptivity (SAR) as a proxy for changes in the perceived temperature of a patient undergoing a scan, and to adjust the ambient light conditions (e.g., adapting the brightness and color of the light according to the SAR deposited during a specific scan sequence and / or throughout the examination) based on the expected changes in body temperature, thereby compensating for, eliminating, or counteracting changes in the patient's perceived temperature.

[0108] Figure 1 The steps of an example method according to one or more embodiments are outlined in block diagram form. These steps will be briefly summarized below, followed by further description through specific embodiments.

[0109] Method 10 is an environmental control method for use with a medical imaging scanner during medical imaging scanning. For example, the medical imaging scanner may include an imaging device adapted to acquire imaging data of an object located in the imaging area.

[0110] Method 10 includes a sensory output system comprising one or more sensory output devices adapted to generate a set of controllable sensory outputs, and the combination of sensory outputs defines an ambient environment (“AE”) state that can be perceived by a patient located in the imaging area. The sensory output system is operable to alter the ambient environment state by controlling the sensory output devices. For example, the sensory output system is operable to alter the ambient environment state by controlling one or more variable sensory parameters of the sensory outputs. The setting of the variable sensory parameters of the one or more sensory outputs can uniquely define the ambient environment state, i.e., the ambient environment state can be characterized by the values ​​of the one or more variable sensory parameters.

[0111] The state of the surrounding environment can be used to influence a patient’s thermoregulatory state and / or the patient’s thermal perception state.

[0112] The combination of sensory outputs preferably includes at least one or more visually perceptible outputs.

[0113] Method 10 includes receiving 12 scan information, the scan information indicating medical imaging scan parameters that change over time during a medical imaging scan of a patient. The scan information includes indications reflecting changes over time in energy deposition (or energy deposition rate) acting on the patient during the scan.

[0114] The method may optionally further include retrieving a thermal sensing model that defines a relationship between changes in the ambient state and a predicted change or effect on the perceived temperature of a person exposed to the ambient state. For example, the thermal sensing model may define a relationship between changes in one or more variable sensory parameters of the sensory output and a predicted change or effect on the perceived temperature of a person exposed to the ambient state including the sensory output. The predicted change or effect may be qualitative, such as merely an indication of whether the change will increase or decrease the perceived temperature, or it may be an indication of a predicted quantitative change in the perceived temperature.

[0115] In some embodiments, the thermal sensing model can define an estimated mapping between different ambient environmental state settings and changes in temperature perceived by a person exposed to those ambient environmental states (e.g., quantitative effects).

[0116] In some embodiments, a thermal sensing model can be configured to output an estimate of one or more ambient state settings that will cause a change in temperature perceived by the user and thus compensate for a given expected change in actual body temperature (e.g., actual skin temperature). Such a thermal sensing model can be implemented using a simple lookup table, wherein the lookup table allows mapping from values ​​indicating expected changes in body temperature to a specific set of settings for ambient states (e.g., settings that include at least the color temperature of the lighting output) to compensate for that change.

[0117] The method may further include performing a thermal sensing compensation operation 14. The thermal sensing compensation operation 14 includes determining, based on the scan information, direct or indirect indications of a expected change in body temperature between a first time point in the medical imaging scan and a later second time point in the medical imaging scan.

[0118] The thermal sensing compensation operation 14 also includes adjusting the surrounding environmental state at a second time point 18 based on the expected change in body temperature.

[0119] For example, adjusting the ambient conditions of 18 may include estimating changes in the ambient conditions that will at least partially offset the patient's perception of the change in body temperature. This may be based, for example, on a known or predetermined relationship or correlation between changes in one or more variable sensory parameters of the ambient conditions and changes in perceived temperature.

[0120] For example, in some embodiments, adjusting the ambient state may include (e.g., at a second time point) decreasing the color temperature of light to compensate for a anticipated decrease in body temperature at the second time point, and (e.g., at a second time point) increasing the color temperature of light to compensate for a anticipated increase in body temperature at the second time point. For example, in a simple case, the sensory output device may include an illumination system for generating light output in the ambient environment, and adjusting the ambient state may include: increasing the color temperature of the light output at the second time point (a cooler light color) in response to a anticipated increase in body temperature at the second time point, and decreasing the color temperature of the light output at the second time point (a warmer light color) in response to a anticipated decrease in body temperature at the second time point.

[0121] When using a thermal sensing model, the controller can be adapted to adjust the ambient state at a second time point based on the use of the thermal sensing model to estimate changes in the ambient state settings that will at least partially offset the patient's perception of changes in body temperature.

[0122] As described above, the method can also be embodied in hardware, for example, in the form of a processing device configured to perform the method according to any example or embodiment described herein or according to any claim of this application.

[0123] To further aid understanding, Figure 2 A schematic diagram of an example controller 32 configured to perform methods according to one or more embodiments of the present invention is presented. The controller is shown in the context of a system 30 including the controller. The controller alone represents one aspect of the invention. System 30 is another aspect of the invention. The provided system does not need to include all the hardware components shown; the system may include only a subset of these hardware components.

[0124] The controller 32 includes one or more processors 36 configured to perform the methods described above or according to any embodiment described herein or any claim of this application. In the illustrated example, the controller also includes an input / output (I / O) unit 34 or a communication interface.

[0125] exist Figure 2 In the illustrated example, system 30 includes a sensory output system 52. Sensory output system 52 includes one or more sensory output devices adapted to generate a set of controllable sensory outputs, the combination of which defines a state of the surrounding environment (AE) that can be perceived by a patient located in the imaging area. The sensory output system is operable to alter the state of the surrounding environment by controlling the sensory output devices. For example, the sensory output system is operable to alter the state of the surrounding environment by controlling one or more variable sensory parameters of the sensory outputs. The combination of sensory outputs includes at least one or more visually perceptible outputs.

[0126] exist Figure 2 In the illustrated example, system 30 also includes (optionally) a thermal sensing model 54 adapted to define the relationship between changes in one or more variable sensory parameters of the sensory output and the resulting predicted changes or effects of temperature perceived by a person exposed to the ambient state including the sensory output.

[0127] For example, in some embodiments, the thermal sensing model 54 can define an estimated mapping between different ambient environmental state settings and changes in temperature perceived by a person exposed to those states. The thermal sensing model can, for example, be stored or embodied in a memory or data storage device.

[0128] exist Figure 2 In the illustrated example, the system also includes a medical imaging scanner 56, which comprises imaging devices adapted to acquire imaging data of an object located in the imaging area. For example, this could be an MRI scanner. However, the scanner is not an essential component of the system.

[0129] System 30 may also include memory 38 for storing computer program code (i.e., computer executable code) configured to cause one or more processors 36 of controller 32 to perform the methods outlined above, or any of the embodiments described in this disclosure or the methods described in any claim.

[0130] As previously stated, the present invention can also be embodied in software form. Therefore, another aspect of the present invention is a computer program product comprising computer program code configured to, when run on a processor, cause the processor to perform any example or embodiment of the invention described herein or any method described according to any claim of this patent application.

[0131] Example embodiments of the method according to a specific set of embodiments will now be described by way of illustration, summarizing the above-described inventive concept. It should be understood that not all features of this specific set of embodiments are necessary for the inventive concept, and all such features are described in order to aid understanding and provide examples to illustrate the inventive concept.

[0132] According to this set of specific embodiments, an imaging scan may consist of multiple scanning sections, wherein the scanning parameters associated with each section may be different.

[0133] Specifically, as an example, a scan can consist of a set of individual scan sequences, each associated with a different set of scan parameters. For instance, in MRI imaging, an MRI examination (planned as an "examination card") typically consists of multiple scan sequences. In particular, the specific absorption rate (SAR) of these different sequences varies from sequence to sequence. Additionally, the cumulative amount of RF energy absorbed by the tissue increases during examination card processing. Therefore, there is an upward linear trend in the deposited RF energy, superimposed on this trend by temporal local fluctuations between sequences.

[0134] Therefore, the inventors recognized that it could be valuable to alter the state of the surrounding environment throughout the scan, as this allows for the specific adjustment of the state of the surrounding environment during each scan sequence to compensate for the estimated perceived thermal load on the patient during that scan sequence.

[0135] For example, referring to thermal sensing compensation operations, it is proposed that the first time point can be the start time of a scan, and the second time point can be the start or end time of a specific scan sequence. Alternatively, the first time point can be a time point that coincides with a scan sequence, and the second time point can be a time point that coincides with a later scan sequence (e.g., the next scan sequence in time).

[0136] According to this set of embodiments, preferably, the controller is adapted to perform the thermal sensing compensation operation for each scan sequence of the scan based on an estimated expected change in body temperature caused by each scan sequence compared to the start of the scan or a previous scan sequence. To this end, the controller may be adapted to perform the thermal sensing compensation operation at multiple second time points within the duration of the scan (e.g., one second time point for each scan sequence). Additionally or alternatively, the thermal sensing compensation operation may be performed at regular time intervals throughout the scan, wherein the time intervals may be shorter than the total duration of any single scan sequence. In this way, for example, the temperature compensation may be updated continuously or quasi-continuously.

[0137] Figure 3 The proposed implementation of a set of embodiments described herein is illustrated schematically.

[0138] Figure 3 The illustration depicts an exemplary MRI scan consisting of an ordered series of eight scan sequences. In medical imaging, such as MRI or CT, scans typically consist of an ordered series of different scan sequences, each with adjusted scan parameters to acquire images of different contrasts or resolutions, or to highlight different types of tissue or pathology. In the specific context of MRI, the term "scan sequence" refers to a specific series of magnetic pulses and gradients applied to the patient's body to acquire images of a target type. Examples of different scan sequences in the context of MRI include, for example, T1-weighted images, T2-weighted images, proton density images, and diffusion-weighted images.

[0139] A series of scan sequences forming a scan are composed of Figure 3 Arrow 62 indicates and is labeled S1-S8. Each scan sequence is labeled as low SAR, medium SAR, or high SAR based on its SAR. S1 is low SAR, S2 is medium SAR, S3 is high SAR, S4 is low SAR, S5 is low SAR, S6 is high SAR, S7 is medium SAR, and S8 is medium SAR. As an example, high SAR may correspond to SAR between 2-4 W / kg, medium SAR may correspond to SAR between 0.5-2 W / kg, and low SAR may correspond to SAR less than 0.5 W / kg. The duration ΔT of each scan sequence is further indicated for each sequence.

[0140] exist Figure 3 Above the outline of the scan sequence is a schematic bar chart 64, which illustrates the rate of energy deposition (SAR) acting on the patient during each scan. The height of each bar represents the rate of energy deposition acting on the patient during a specific scan sequence in the scan sequence 62 aligned with that bar.

[0141] Figure 3 The diagram also illustrates line 66, which indicates the predicted perceived temperature increase of the patient relative to the first time point corresponding to the start time of the scan (i.e., t=0) at each of a series of (second) time points throughout the scan. It can be seen that the perceived temperature increase gradually increases throughout the scan as energy is cumulatively deposited in the patient's body via RF emission, and simultaneously, during each individual scan sequence, there are local fluctuations in the magnitude of the perceived temperature increase that are correlated with, related to, or proportional to the SAR. For example, during sequence 1 (S1), the SAR is low and there is a relatively small upward fluctuation in the perceived temperature increase, while during, for example, sequence 2 (S2), the SAR is moderate and there is a large upward fluctuation in the perceived temperature increase.

[0142] like Figure 3 The illustration shows pauses or delays that may exist between successive scan sequences. During these delays, the patient remains within the scanner's imaging area, but the next scan does not begin immediately. This is because technicians and radiologists typically review the data acquired in previous scan sequences before starting the next sequence to determine if the data is of sufficient quality. During pauses, there is no active RF energy deposition in the body. Consequently, the patient's skin temperature may begin to drop. This, in turn, affects the patient's thermal comfort. Specifically, this will make the patient feel less warm or cold.

[0143] The decrease in skin temperature between scan sequences is indicated by line 66, which shows the predicted decrease in body temperature between scan sequences, followed by a rise again at the start of the next scan sequence.

[0144] Figure 3 The diagram also illustrates a calculated sequence or procedure 72 of ambient state states executed throughout the entire scan duration, wherein the sensory characteristics of the ambient state are controlled to be different during each scan sequence, and the sensory characteristics of the ambient state are adjusted according to SAR during each scan sequence. An ambient state setting exists for each scan sequence. The ambient state setting is labeled AE1-AEB.

[0145] Each ambient state setting is determined by performing thermal sensing compensation operations. Each ambient state setting can be predetermined before the scan begins or calculated in real-time during setup. Real-time calculation allows for the consideration of additional real-time data variables, which will be explained later. These variables can include, for example, measured physiological signals such as skin temperature, heart rate, respiratory rate, sweating, skin conductance, vasoconstriction, vasodilation, and / or patient movement. Additionally, real-time calculation allows for the consideration of real-time changes in the scan examination card. For example, scan sequences can be added or removed, and / or the inter-scan delay / pause can be adjusted to be shorter or longer.

[0146] Thermal sensing compensation operations first involve determining, based on scan information, direct or indirect indications of the expected change in body temperature (e.g., skin temperature) between a first time point in the medical imaging scan and a later (second) time point in the medical imaging scan. In this case, the second time point could be the start of the scan sequence, during the scan sequence, or at the end of the scan sequence, in order to calculate each environmental state setting for each scan sequence. In this example, for simplicity, the SAR of a particular scan sequence is used as indirect indication information of at least one component of the expected change in body temperature.

[0147] Regarding changes in body temperature, it can be assumed that the body temperature of an object at a given time is related to the rate of energy absorption (i.e., related to the SAR value of a given scan sequence). This can be understood from the fact that deposited RF energy causes local tissue warming, and therefore the energy deposition rate will be related to changes in body temperature.

[0148] Therefore, based on observations of the correlation between energy absorption rate and body temperature changes, SAR itself can simply be used as a proxy indicator of at least one component of the expected sensed temperature. In this case, for example, the SAR change between a first time point and a second time point can be used as an indicator of at least one additional component of the expected sensed temperature change. For example, the expected SAR of an MR sequence can be used as a proxy for body temperature changes between the time before the scan begins (where SAR is zero) and the time period during which the scan sequence is being performed.

[0149] Therefore, in the simplest case, for each scan sequence, the indirect indication of the estimated body temperature change between the start time of the scan and time t at or during that scan sequence can be estimated as follows: in, It is an indirect indication of the estimated change in body temperature at time t, while It is the SAR at time t.

[0150] In more complex examples, in addition to the rate of energy deposition acting on the patient at any given time, the cumulative energy deposition acting on the patient can also be considered. This factor is generally smaller than the real-time energy deposition rate because the body's homeostatic processes are used to dissipate excess heat from the body, resulting in only a relatively small offset between the rate of heat deposition and the rate of heat expulsion, leading to only a relatively small cumulative accumulation of heat energy in the body. Nevertheless, in Figure 3 The gradual accumulation of thermal energy can also be seen in the estimated perceived temperature rise graph 66, where local (relatively large) fluctuations are superimposed on the underlying gradual upward trend, which represents the cumulative energy absorption over time.

[0151] Therefore, in some embodiments, for each scan sequence, the indirect indication of the estimated body temperature change between the start time of the scan and time t at or during that scan sequence can be estimated as (i) a term proportional to the total energy absorption or cumulative energy absorption between the start time of the scan and time at or during the relevant scan sequence, and (ii) a term proportional to the SAR of the relevant scan sequence. These two terms can be weighted differently. To calculate the cumulative energy absorption at the time window corresponding to each scan sequence, SAR information for the entire scan (at least up to the relevant scan sequence) may be required so that the indication of the cumulative amount can be calculated or estimated.

[0152] For example, according to one example, for each scan sequence, the start time of the scan is related to the time t at or during that scan sequence. n Indirect indicative information about estimated changes in body temperature may be estimated as follows: in, It is time t n Indirect indications of changes in estimated body temperature, while At time t n The SAR at the location. Weights α and β can be adjusted as needed to adjust the cumulative energy deposition relative to the real-time energy deposition rate (e.g., SAR). The importance of the energy deposits is weighted differently. The weight α can be less than the weight β. It should be noted that cumulative energy deposits do not reflect the cumulative energy retained in the patient's body, as most energy is excreted through steady-state processes. Therefore, cumulative energy deposits are an indirect indicator of the patient's cumulative energy retention. A lower weight α can be used to reflect this compared to β.

[0153] Return to Figure 3An example has now been described of how an indication of the estimated body temperature change at the time window corresponding to each scan sequence can be calculated. The second step of the thermal sensing compensation operation for each scan sequence is to determine the settings of the ambient conditions during that scan sequence based on the expected body temperature change, so as to at least partially offset or compensate for the patient's perceived body temperature change (i.e., reduce the change in perceived temperature) to make the perceived temperature more uniform throughout the scan.

[0154] This determination of the state of the surrounding environment can be achieved using a predefined thermal sensing model, which defines an estimated mapping between different possible environmental state settings and changes in temperature perceived by a person exposed to the relevant environmental state.

[0155] In its simplest form, the model may consist of a lookup table that associates different ranges of values ​​for direct or indirect indications of changes in perceived temperature with different specific settings of the surrounding environment. When referring to settings of the surrounding environment, this means the setting of one or more variable sensory parameters of the surrounding environment. Examples of variable sensory parameters include the intensity, luminance, or illuminance of the light output of the lighting system, and / or the color temperature of the light output. Another possible variable is the timing of the sensory output (e.g., the timing of light output). Other sensory modalities are also possible, which will be explained further below.

[0156] exist Figure 3 In the current example, for simplicity, it is assumed that the sensory output system 52 includes only an illumination system for generating light output in the surrounding environment, and wherein the illumination system can be controlled to change the color temperature of the light output.

[0157] As mentioned above, to induce an increase in the patient's perceived temperature (the patient feels warmer), the light color temperature can be decreased (to create a warmer hue). Similarly, to induce a decrease in the patient's perceived temperature, the light color temperature can be increased (to create a cooler hue).

[0158] For the sake of simplicity, in Figure 3 In the example, only the color temperature is adjusted as a variable setting for the ambient state of each scan sequence. Specifically, during low SAR sequences, the ambient state is set to illumination with a warm color temperature (e.g., about 1200K); during medium SAR sequences, the ambient state is set to illumination with a moderately warm color temperature (e.g., about 5500K); and during high SAR sequences, the ambient state is set to illumination with a cool color temperature (e.g., about 11000K).

[0159] Therefore, in this example, the thermal sensing model can define a mapping between different ranges of the SAR for a given scan sequence and corresponding appropriate settings of variable parameters of the surrounding environment state to achieve at least partial compensation for temperature variations. Then, based on the known SAR of the scan sequence, the variable parameters of the surrounding environment state can be simply set to the settings defined by the thermal sensing model mapping.

[0160] More preferably, the thermal sensing model can define indications of estimated body temperature changes 66 calculated for specific time points during the scan. The mapping relationship between different ranges and the corresponding appropriate settings of variable parameters of the surrounding environment is used to achieve at least partial compensation for temperature changes.

[0161] Purely for illustration, applied to Figure 3 For example, a simple heat sensing model can be presented in the form of a lookup table, such as the form shown in Table 1 below:

[0162] Table 1 Therefore, in this simple example, the value of the indicator information for the expected change in body temperature... The reduced set is categorized into discrete classes (e.g., low, medium, and high), and the thermal sensing model defines a mapping between each expected body temperature change class and corresponding appropriate settings of variable parameters of the surrounding environmental state to achieve at least partial compensation for temperature changes. Corresponding to each class... The range of values ​​is predefined.

[0163] However, more refined models can also be used, where a larger number of... The different ranges are associated with specific settings for illuminance and color temperature.

[0164] Regarding For the specific color temperature settings corresponding to each range of values, please refer to the previously mentioned literature. The results of these studies are summarized in Table 2 below regarding the color temperature range and its corresponding impact on perceived temperature:

[0165] Table 2 Based on these literature results, the inventors propose the following suitable ranges for light color temperature values ​​corresponding to different classifications of expected body temperature changes:

[0166] Table 3 Values ​​of indicative information regarding expected body temperature changes corresponding to different classifications The range of values ​​can be selected as needed. As an example, in a scan sequence SAR used to measure body temperature changes... In the case of indirect indication information, for different scan sequences Suitable ranges could be, for example: high SAR: 2-4 W / kg; medium SAR: 0.5-2 W / kg; low SAR: less than 0.5 W / kg.

[0167] Therefore, in this specific example, the mapping relationship defined by the thermal sensing model can be summarized as follows:

[0168] Table 4 Therefore, in this example, the value of the indicator information for expected body temperature changes... Reduced sets classified into discrete categories (e.g., low, medium, and high, e.g., with) (corresponding to different value ranges), and wherein the thermal sensing model defines a mapping relationship between each expected body temperature change category and a corresponding appropriate setting of variable parameters of the surrounding environment state to achieve at least partial compensation for temperature changes. More specifically, in this example, the thermal sensing model defines a mapping relationship between the SAR of a given scan sequence and the color temperature of the light to be output during the scan sequence, and wherein the mapping relationship causes the color temperature of the light to be applied to increase as the SAR increases.

[0169] Figure 3 Line 68 illustrates a schematic representation of how patient-perceived temperature changes over time throughout the scan when a compensatory ambient state is activated during the scan. Therefore, line 68 represents the patient's corrected or compensated temperature perception.

[0170] It should be noted that the patient's perceived temperature 68 continued to rise to some extent throughout the scan, but the total change in perceived temperature was significantly lower than the expected (true) body temperature change 66, and the local variability of the perceived temperature change was less than that of the actual body temperature change. These effects improved the patient's thermal comfort and thermal satisfaction.

[0171] Although Figure 3 In the examples above, each scan sequence has an ambient experience (AE) state setting. However, in other examples, the AE state setting can be adjusted to change at different times during a single scan sequence. For example, there may be one AE setting for the first half and a second AE setting for the second half, or three different settings, each lasting one-third of the scan sequence duration. Additionally or alternatively, in some embodiments, some AE settings may span more than one scan sequence.

[0172] In addition, Figure 3 In one example, there is an AE setting that is maintained throughout the entire duration of each scan sequence and during the delay period following the scan sequence. However, in another example, a separate AE setting may exist for the inter-scan delay period. For example, the system could be configured to modify the light color temperature to a warmer color temperature after a predefined threshold delay period (when no RF emission is generated) has elapsed. This helps to prevent the patient from feeling cold between scan sequences.

[0173] Figure 4 Another example is shown of a calculated sequence or procedure 72 of ambient state executed throughout the entire scan duration, wherein the sensory characteristics of the ambient state are controlled to be different during each scan sequence, and the sensory characteristics of the ambient state are adjusted according to SAR during each scan sequence. For each of the first three scan sequences, there is a corresponding ambient state setting (AE1, AE2, AE3), an additional ambient state setting (AE4) spanning a delay period between the third and fourth ambient state settings, and a final ambient state setting (AE5) spanning the last two scan sequences and the delay period separating the last two scan sequences.

[0174] A series of scan sequences forming a scan are composed of Figure 4 Arrow 62 indicates and is labeled S1-S5. Each scan sequence is labeled as low SAR, medium SAR, or high SAR based on its SAR. S1 is low SAR, S2 is medium SAR, S3 is high SAR, S4 is low SAR, and S5 is low SAR. As an example, high SAR may correspond to SAR between 2-4 W / kg, medium SAR may correspond to SAR between 0.5-2 W / kg, and low SAR may correspond to SAR less than 0.5 W / kg. The duration ΔT of each scan sequence is further indicated for each sequence. Between each successive scan sequence pair is a corresponding delay period. The duration ΔT of each delay period is indicated.

[0175] exist Figure 4 Above the outline of the scan sequence is a schematic bar chart 64, which illustrates the rate of energy deposition (SAR) acting on the patient during each scan. The height of each bar represents the rate of energy deposition acting on the patient during a specific scan sequence of the scan sequence 62 aligned with that bar.

[0176] It can be seen that during the low SAR scan sequences (S1, S4, S5), the light output of the illumination system, including the sensor output system, was set to a warm color temperature of 1200K. During the medium SAR sequences, the color temperature of the light output was set to a medium warm color temperature of 5500K. During the high SAR sequences, the light output of the illumination system was set to a cool color temperature of 11000K.

[0177] The delay periods between S1 and S2 and between S2 and S3 are relatively short, at 20 seconds and 15 seconds respectively. In contrast, the delay period between S3 and S4 is much longer, at 4 minutes and 30 seconds. During such a long delay period, following the high SAR sequence (which warms the patient), the patient's expected body temperature drops and the patient may begin to feel cold. Therefore, an AE setting with a moderately warm light output of 5500K is applied during the delay period between S3 and S4. Sequences S4 and S5 both involve low SAR, and the delay time between them is short, at 10 seconds. Therefore, for this pair of sequences, a single continuous ambient setting with warm light (1200K) is applied across S4 and S5 and the delay period between them.

[0178] Regarding the lighting system of sensory output system 52, the lighting system may include one or more light output devices that may be arranged in a room containing an imaging scanner and / or on the scanner itself. For example, illumination mounted on a wall or ceiling may be provided to provide light output in the surrounding space of the room, which is also at least partially visible inside the aperture of, for example, an MRI scanner. Additionally or alternatively, one or more light sources may be provided on or around the scanner, arranged to provide light output directed into the aperture so that it is visible to a patient inside the aperture. The lighting system may also include a display device (e.g., a display panel or projector) for presenting 2D visual output. For example, the display panel may be located inside the aperture of the scanner and visible to the patient while the scan is in progress. The display panel may present visual output (e.g., 2D or 3D visual output). The visual output may have controllable color content and optionally controllable brightness. For example, the visual output may include visual elements with a perceptible color temperature, wherein the color temperature is adjustable. A single uniform color block may be presented, or alternatively, a color pattern may be presented. Alternatively or additionally, one or more images containing color content may be presented.

[0179] In more advanced implementations, one or more other sensory aspects of the surrounding environmental state can be adapted, and / or other characteristics or statistics calculated from sequence SAR can be used. For example, standard deviation, minimum, maximum, range, and difference between successive sequences can be calculated, and these characteristics or statistics can be used to drive the adaptation of the surrounding experience.

[0180] In other words, in some embodiments, the ambient conditions during each scan sequence can be adjusted not only based on the use of a thermal sensing model but also based on one or more additional rules or conditions. For example, in some embodiments, the thermal sensing compensation operation can be configured such that during the scan sequence with the highest SAR, the AE is configured to have the coolest light color compared to the AE of each other scan sequence of the imaging scan. In some embodiments, the AE setting for the entire scan sequence set can be configured such that a warmer setting is applied to enhance the effect of the cool light setting before adjusting the AE to the cool light color setting. In some embodiments, the AE setting for the entire scan sequence set can be configured such that the color temperature difference between two successive scan sequences is proportional to the difference in SAR between the two scan sequences.

[0181] In some embodiments, estimates of body temperature changes may be calculated based on additional factors, such as the level of orifice ventilation provided, the type of coil used, the duration of the examination, and the ambient temperature of the patient's clothing and / or the room.

[0182] Additional optional features that are relevant to determining the characteristics of estimated body temperature changes and are compatible with any embodiment of the invention will now be described.

[0183] According to some embodiments, to improve the accuracy of estimating changes in body temperature, measurements of the patient's actual temperature can be acquired during the scan. Non-metallic and non-magnetic temperature sensors can be used to measure the actual changes in the patient's temperature. Some examples are fiber optic temperature sensors, infrared thermometers, non-invasive sensors (thermostats or thermocouples placed on the skin or in the ear), and temperature-sensitive patches (placed on the skin whose color changes according to changes in the patient's temperature).

[0184] Therefore, in some embodiments, the system may further include one or more temperature sensors for sensing the patient's body temperature during scanning. The controller may be adapted to determine indications of expected temperature changes based at least on a combination of scan information (e.g., SAR, such as during each scan sequence) and measurements of the patient's body temperature at a second time point.

[0185] For example, in some embodiments, the ambient (AE) state settings for each scan sequence can be predetermined based on the patient's expected body temperature change between the start of the scan and the time point corresponding to the relevant scan sequence. Then, during the scan, a skin temperature sensor can be used to acquire measurements of the actual body temperature, and the AE state settings can be adjusted based on any difference between the expected body temperature change and the actual body temperature. For example, in the case of using a thermal sensing model that provides a mapping between body temperature changes and AE state settings, the actual body temperature settings can be acquired and used to find the appropriate AE state settings corresponding to the body temperature changes and adjust the AE state settings accordingly. In some embodiments, both the expected body temperature change and the actual body temperature change can be considered when determining the AE state settings, optionally assigning them different weights; for example, the expected body temperature change is assigned a lower weight than the actual body temperature change.

[0186] In some embodiments, body temperature measurements may be used additionally or alternatively to control cooling equipment in the scanning chamber (e.g., to control ventilation levels). In some embodiments, body temperature measurements may be used additionally or alternatively to modify the sequence order of scan sequences and / or to control the pausing and / or termination of scans. For example, if the rate of temperature rise exceeds a threshold amount more than expected, the system may be configured to pause or terminate the scan.

[0187] In some embodiments, the thermal sensing model may include a machine learning model trained to receive a target change in temperature perceived by a patient as input and to generate settings of one or more sensory parameters (e.g., changes in color temperature) of a sensory output system predicted to cause the perceived temperature change as output.

[0188] Machine learning models can be, for example, artificial neural networks (such as convolutional neural networks).

[0189] In other examples, the machine learning model can be a trained regression model.

[0190] Other types of machine learning algorithms or models can also be considered.

[0191] Regarding the training model, training data may include data compiled from historical MRI scan sessions of one or more different patients, during which the AE state was changed in a defined manner, and patients were surveyed after each change to assess changes in their perceived temperature. More specifically, training data may include training input data values ​​indicating changes in a patient's perceived body temperature and training output data values ​​(benchmark values) indicating quantitative changes in color temperature. During training, the model is trained to infer predicted changes in color temperature (output data values) that would cause changes in the patient's perceived temperature to the input target changes (input data values).

[0192] In some embodiments, the model can be trained to receive multi-parameter inputs, wherein, in addition to one or more other characteristics of the patient or scanning room or surrounding environment state (e.g., physiological measurements (heart rate, respiratory rate, sweating, skin conductance, vasodilation, vasoconstriction), ambient room temperature, and / or data representing the SAR and cumulative scan duration of the current scan sequence), multiple parameters also include sensing temperature changes.

[0193] To transmit measured body temperature information in real time, a wireless communication device can be provided for wireless communication of sensor data from one or more temperature sensors to the controller. Alternatively, a wired connection is also possible.

[0194] In addition to measuring changes in patient body temperature, or as a substitute for measuring changes in patient body temperature, in some embodiments, measurements of ambient temperature in the environment of the medical imaging scanner can be acquired and used to calculate indications of expected changes in body temperature. In other words, the system may also include one or more ambient temperature sensors for sensing the temperature of the surrounding environment, and the controller may be adapted to determine indications of expected changes in body temperature based at least on a combination of scan information and measurements of ambient temperature at a second time point.

[0195] For example, in the case of MRI imaging, an MR-compatible temperature sensor (such as an infrared thermometer) can be used. In some examples, the infrared thermometer can be portable, and the temperature of a corresponding object or area can be measured by moving and pointing the infrared thermometer at different objects or areas.

[0196] In some embodiments, in addition to measuring the temperature in the room where the imaging scanner is located, or instead of measuring the temperature in the room where the imaging scanner is located, the controller may be adapted to retrieve real-time local weather information and use that information to calculate an estimated change in the perceived temperature.

[0197] In some embodiments, additional physiological signals (such as heart rate, skin blood flow, respiratory rate, or ECG) may be used to estimate thermal discomfort. In other words, the system may also include one or more physiological parameter sensors for sensing one or more physiological parameters of the patient, and wherein the controller is adapted to determine indications of expected changes in body temperature based at least on a combination of scan information and measurements of one or more physiological parameters at a second time point.

[0198] Additionally or alternatively, in some embodiments, user input can be used to determine changes in perceived temperature. Users may indicate that they feel heat discomfort via manual control or via eye movements (using gaze tracking technology).

[0199] The above description presents a relatively simple method for determining the estimated changes in a patient's perceived temperature, particularly using SAR and / or cumulative energy deposition as proxy indicators of these changes. However, more sophisticated methods can also be used.

[0200] In particular, according to one set of embodiments, a thermophysiological model can be predefined, which allows for the simulation of different perceived temperature variations based on multiple independent variables.

[0201] Specifically, reference was made to van den Brink and Johan S.'s "Thermal Effects Associated with RF Exposures in Diagnostic MRI: Overview of Existing and Emerging Concepts of Protection" (hindawi.com). This literature details a quantitative method for estimating induced body temperature changes based on SAR and exposure duration. See Section 4 of this literature, particularly its section on... Figure 3 .

[0202] Other example thermophysiological models can take into account additional factors such as ambient temperature, clothing, and the individual's thermoregulation ability.

[0203] In some embodiments, one or more of the patient's biological parameters, such as any one or more of the following, may be considered in the modeling or simulation: age, sex, body mass, height, weight, body composition, basal metabolic rate, resting heart rate, average activity level, and / or sleep pattern. This information may be obtained, for example, from a patient medical record system and / or from a medical scanner console.

[0204] In addition to these parameters, modeling or simulation may also receive scan information (e.g., information about the imaging protocol, such as scan sequence parameters, SAR, and / or process length) as input. Optionally, instrument details and environmental data may also be incorporated as input. Regarding environmental data, this may include indications of season, external temperature, and / or internal temperature. Regarding instrument details, this may include details about the available variable sensory parameters of the sensory output system (e.g., the types of available sensory output devices and the variable parameters of each sensory output device, such as the brightness and color temperature of the lighting system)).

[0205] A suitable example of modeling human body temperature in response to changing conditions and capable of considering multiple factors is the Stolwijk method. Here, inputs such as whole-body SAR, skin blood flow impairment, ambient temperature, relative humidity, and insulation (clothing) information are used as inputs. The original Stolwijk model can be found in the following literature: Stolwijk JAJ, “Amathematical model of physiological temperature regulation in man” (Washington, D.C., 1971, NASA CR-1855).

[0206] Various improvements to the model have been proposed. For example, one improvement is detailed in Roelofsen, C. and Vink, Peter, “Improvement of the Stolwijk model with regard to clothing, thermal sensation and skin temperature” (Work, Vol. 54, pp. 1009-1024, 2016).

[0207] Also referenced is Eleanor R. Adair and Larry G. Berglund, “On thethermoregulatory consequences of NMR imaging” (Magnetic Resonance Imaging, Vol. 4, No. 4, pp. 321-333, 1986). This paper describes a thermal regulation model that can predict physiological heat dissipation responses during MRI scans in real time based on selected ambient temperature (Ta), air motion (V), and whole-body radiofrequency (RF) energy deposition rate (SAR).

[0208] It is possible to use the various additional parameters mentioned above to create more accurate and refined thermal discomfort estimates than those achievable using SAR alone.

[0209] As described above, some embodiments of the present invention utilize thermal sensing models to determine changes in the surrounding environment to be performed in response to specific predicted changes in body temperature during a scan. The thermal sensing model can be configured to output estimates of changes in the surrounding environment that will cause a change in the user's perceived temperature and thus compensate for a given expected change in actual body temperature (e.g., actual skin temperature).

[0210] This thermal sensing model can be implemented using a simple lookup table, which allows mapping from values ​​indicating expected changes in body temperature to a specific set of settings for the state of the surrounding environment (e.g., settings that include at least the color temperature of the lighting output) to compensate for that change.

[0211] This thermal sensing model can alternatively be implemented using a trained artificial neural network. The artificial neural network can be trained using training data, which includes the temperature sensing reports in conjunction with ambient environmental settings concurrent with the patient's temperature sensing reports.

[0212] In summary, according to a set of embodiments, the medical imaging scan may be an MRI scan, and wherein the scan information includes the expected specific absorbance (SAR) at one or more time points during the scan; and wherein the controller is adapted to determine indications of expected body temperature changes based on a predefined thermophysiological model adapted to estimate the RF-induced increase in body temperature based on SAR and exposure duration. Additional factors, such as ambient temperature, clothing, and the individual's thermoregulation capacity, may also be incorporated into the model.

[0213] In some embodiments, the controller may also be adapted to receive patient-specific temperature sensitivity information, and wherein indications of expected changes in perceived temperature are determined in part based on the patient-specific temperature sensitivity information.

[0214] For example, prior to the scan, patients can provide input that can be used to further modulate anticipated thermal discomfort. The patient information collected may include, for example, sensitivity to temperature changes and aspects of emotional, anxiety, and other psychological, physical, or demographic characteristics known to affect temperature and / or thermal perception.

[0215] In addition, patient interaction mechanisms (such as audio input, audio output, handheld control, or eye tracking) can be used to collect patient input during the scan.

[0216] Based on patient input, the patient's temperature regulation preferences can be determined and the surrounding experience can be altered accordingly. This can be done automatically or manually (e.g., manually by MR technicians who may receive prompts instructing them to make adjustments).

[0217] Various additional optional details relating to the sensory output system and compatible with any embodiment of the present invention will now be described.

[0218] As described above, a sensory output system may include a lighting system comprising one or more light sources for generating light output in the surrounding environment. Ambient lighting can be adapted, for example, by changing the color (or color temperature; K) of the light, so that cooler light makes people feel less hot.

[0219] Additionally or alternatively, the sensory output system may include a display device for presenting 2D or 3D visual output. This display device may take the form of a display panel or a projector, for example. For instance, a display panel may be provided inside the aperture of a scanner. The 2D or 3D visual output may include visual elements that can be adjusted to modify their color or content.

[0220] Regarding color adjustment, 2D or 3D visual output may include visual elements with a perceptible color temperature, wherein the color temperature is adjustable. For example, 2D or 3D visual output may include the presentation of visual images with perceptible color content, and wherein adjusting the color temperature of the output includes adjusting the visual images.

[0221] Regarding content adjustment, 2D or 3D visual output can include the presentation of visual images that are conceptually associated with a certain thermal temperature range.

[0222] For example, images associated with cold (e.g., snow scenes, cold water flowing in a stream) or with warmth (e.g., tropical beaches, crackling fireplaces) may be shown.

[0223] Audio can be adapted to images and light. For example, if warm elements are displayed, audio associated with those elements can be generated (e.g., crackling flames, flowing cold water, opening a fresh beverage, etc.). In this case, the sensory output device can include an audio output device.

[0224] To help patients transition from one state (e.g., feeling hot) to another (e.g., feeling less hot), scenarios depicting the successful resolution of unpleasant heat perception can also be displayed. As an example, when a patient feels cold, the intracavitary display of the device could be controlled to show a person (or an anthropomorphic figure (e.g., a cartoon character)) initially shivering and appearing cold, then putting on a sweater and sitting by a fire drinking hot chocolate. As another example, if a person feels hot, the intracavitary screen could display a scene where the person initially sweats and appears hot, then dives into cold water on a sunny day, then emerges from the water and drinks an ice-cold beverage.

[0225] In other words, it is possible to control the display device to show a visual representation of the transition between contrasting temperature scenes.

[0226] In addition to visually perceptible outputs, sensory output systems can also be configured to generate sensory outputs of other sensory modalities.

[0227] One example is the use of odors, such as by exposing the patient to odors associated with warmth (e.g., the smell of coconut, hot chocolate, or a campfire). For this purpose, the sensory output devices of a sensory output system may include olfactory output devices.

[0228] Another example is the use of tactile stimulation. For instance, tactile stimulation can be applied to a patient to distract them from an unpleasant state of heat perception. Tactile sensations such as vibration or tapping can alleviate heat discomfort. Therefore, in some embodiments, the sensory output device of a sensory output system may include a tactile stimulation generator.

[0229] As described above, in a preferred embodiment, the ambient conditions vary throughout the scan to provide optimal thermal sensing compensation for variations in perceived temperature at different points throughout the scan. Therefore, this involves changes in the ambient conditions at various points throughout the scan. Sudden changes may surprise the patient and may disrupt the effectiveness of sensory output.

[0230] Therefore, according to at least one set of embodiments of the present invention, it is proposed to implement functions for further optimizing the transitions between surrounding environmental states to make the transitions smoother and / or more gradual.

[0231] For example, in cases where changes in the ambient state include at least a change in the color temperature of the light output generated by the lighting system, the controller may be adapted to control the sensory output system such that the transition from the first ambient state to the second ambient state includes a smooth transition of the light output through the color space.

[0232] From a technical perspective, most existing lighting fixtures operate and / or are controlled in the RGB color space, where each color is represented by a vector of three color values ​​(red, green, and blue). However, RGB is not a perceptually uniform color space. Therefore, a transition from color A (R1, G1, B1) to color B (R2, G2, B2) may appear abrupt to the observer.

[0233] Accordingly, according to at least one set of embodiments, it is proposed to convert color points A and B in the RGB color space into equivalent colors in the CIELAB color space, thereby converting them into A(L1, a1, b1) and B(L2, a2, b2), i.e. A further method is proposed to define a continuous line between points A and B in CIELAB space, whereby points on this line will define the transition color values ​​in CIELAB to be implemented during the transition from A to B.

[0234] Extract multiple values ​​of the identified line distribution along the CIELAB color space and convert them back to the RGB color space.

[0235] When moving between color A and color B in the RGB color space, the lighting system is controlled to transition between color A and color B by sequentially traversing the transformed RGB points (which correspond to points along the line in the CIELAB space). This allows for a perceptibly smooth color transition from any first color to any other second color.

[0236] The conversion from CIELAB color space to RGB color space is a known process, and the conversion formula is well-known.

[0237] It should be noted that thermal discomfort is unpleasant for most patient groups, and at least one objective of the system described herein is to alleviate this discomfort. However, the risk of overheating in the scanner is greater for certain patient groups (e.g., pregnant women or patients using medications that may affect thermoregulation). Therefore, for these patient groups, controlling the ambient conditions to increase the perceived temperature during high SAR sequences may be beneficial. In other words: for sensitive patient groups (e.g., patients with thermoregulation deficiencies), it may be beneficial not to use ambient conditions that have the effect of making the patient feel colder; instead, ambient conditions that signal high temperatures to staff and patients can be used. This can help patients and staff be more aware of the potential risk of overheating.

[0238] The embodiments of the invention described above employ a controller comprising one or more processors. The controller typically includes a single processor or multiple processors. The controller may be located in a single housing device, structure, or unit, or it may be distributed among multiple different devices, structures, or units. Therefore, references to a controller adapted or configured to perform a specific step or task may correspond to that step or task performed individually or in combination by any one or more of the multiple processing components. Those skilled in the art will understand how such a distributed processing device can be implemented. The controller may include a communication module or input / output unit for receiving data and outputting data to other components.

[0239] One or more processors of the controller can be implemented in a variety of ways using software and / or hardware to perform a variety of required functions. Processors typically employ one or more microprocessors that can be programmed using software (e.g., microcode) to perform the required functions. A processor can be implemented as a combination of dedicated hardware for performing some functions and one or more programmed microprocessors and associated circuitry for performing other functions.

[0240] Examples of circuits that may be used in various embodiments of this disclosure include, but are not limited to, conventional microprocessors, application-specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0241] In various implementations, the processor may be associated with one or more storage media, such as volatile and non-volatile computer memories (e.g., RAM, PROM, EPROM, and EEPROM). The storage media may be encoded with one or more programs that perform desired functions when executed on one or more processors and / or controllers. The various storage media may be fixed within the processor or controller, or may be portable, such that one or more programs stored thereon can be loaded into the processor.

[0242] Based on a study of the accompanying drawings, the disclosure, and the appended claims, those skilled in the art will be able to understand and implement variations of the disclosed embodiments. In the claims, the word "comprising" does not exclude other elements or steps, and the quantifiers "a" or "an" do not exclude a plurality.

[0243] A single processor or other unit may perform the functions of several items as described in the claims.

[0244] The mere fact that certain measures are described in different dependent claims does not imply that combinations of these measures cannot be used advantageously.

[0245] Computer programs can be stored / distributed on suitable media (such as optical storage media or solid-state media supplied together with or as part of other hardware), but can also be distributed in other forms (such as via the Internet or other wired or wireless telecommunications systems).

[0246] If the term “suitable” is used in the claims or description, it should be noted that the term “suitable” is intended to be equivalent to the term “configured as”.

[0247] No reference numerals in the claims should be construed as limiting the scope.

Claims

1. An environmental control system for use with a medical imaging scanner, the medical imaging scanner including an imaging device adapted to acquire imaging data of an object located in an imaging area, the system comprising: A sensory output system comprising one or more sensory output devices adapted to generate a set of controllable sensory outputs, the combination of sensory outputs defining a state of the surrounding environment perceptible by a patient located in the imaging area, wherein the sensory output system is operable to alter the state of the surrounding environment by controlling one or more variable sensory parameters of the sensory outputs, and wherein the combination of sensory outputs includes at least one or more visually perceptible outputs; and Controller, which is suitable for: Retrieve the thermal sensing model, which defines the relationship between changes in one or more variable sensory parameters of the sensory output and the resulting predicted changes in temperature perceived by a person exposed to the ambient state including the sensory output; and Receive scan information indicating medical imaging scan parameters that change over time during a medical imaging scan of a patient, wherein the scan information includes indications reflecting changes in energy deposition acting on the patient over time during the scan; and Perform a thermal sensing compensation operation, the thermal sensing compensation operation including: Based on the scan information, determine direct or indirect indications of the patient's expected body temperature change between a first time point in the medical imaging scan and a later second time point in the medical imaging scan; and Based on the use of the thermal sensing model to estimate changes in the ambient environment settings that will at least partially offset the patient's perception of the temperature change, the ambient environment settings at the second time point are adjusted according to the expected body temperature change.

2. The system according to claim 1, wherein, The scan consists of a set of individual scan sequences, each associated with a different set of scan parameters. Wherein, the first time point is the start time of the scan, and the second time point is the start time of a specific scan sequence of the scan; or Wherein, the first time point is the time point that coincides with a scan sequence, and the second time point is the time point that coincides with a subsequent scan sequence.

3. The system according to claim 2, wherein, The controller is adapted to perform the thermal sensing compensation operation on each scan sequence of the scan based on an estimated expected change in body temperature caused by each scan sequence.

4. The system according to any of the preceding claims, wherein, The controller is adapted to perform the thermal sensing compensation operation at multiple second time points during the duration of the scan, for example, by performing the thermal sensing compensation operation at regular time intervals throughout the scan.

5. The system according to any of the preceding claims, wherein, The sensory output device includes an illumination system for generating light output in the surrounding environment, and wherein the illumination system can be controlled to change the color temperature of the light output and / or change the illuminance or intensity of the light output.

6. The system according to claim 5, wherein, The thermal sensing model enables: The color temperature (K) is decreased and / or the illuminance (lux) is increased to raise the temperature perceived by the patient; and The color temperature (K) is increased and / or the illuminance (lux) is decreased in order to reduce the temperature perceived by the patient.

7. The system according to any of the preceding claims, in, The scan is an MRI scan, and the scan information includes the expected specific absorption (SAR) at one or more time points during the scan. Optionally, the scan consists of a set of individual scan sequences, and the scan information includes the expected SAR for each scan sequence of the scan.

8. The system according to claim 5, wherein, The SAR change between the first time point and the second time point is used as at least one component of the information indicating expected changes in body temperature.

9. The system according to claim 8, in, The sensory output device includes an illumination system for generating light output in the surrounding environment; and The thermal sensing model defines a mapping relationship between the SAR of a given scan sequence and the color temperature of the light to be output during the scan sequence, wherein the mapping relationship causes the color temperature of the light to be output to increase with the increase of the SAR.

10. The system according to claim 8 or 9, in, The sensory output device includes an illumination system for generating light output in the surrounding environment; Wherein, the first time point is the time point that coincides with a scan sequence, and the second time point is the time point that coincides with a subsequent scan sequence; and The thermal sensing model enables the adjustment of the surrounding environment at the second time point based on the expected change in body temperature by changing the color temperature of the light output by a certain amount, which is a function of the SAR change between a scan sequence and the subsequent scan sequence.

11. The system according to any of the preceding claims, in, The sensory output system includes a display device for presenting visual output, such as a display panel or a projector, and wherein the visual output includes visual elements with a perceptible color temperature, wherein the color temperature is adjustable; and Optionally, the visual output includes the presentation of a visual image having perceptible color content, and adjusting the color temperature of the output includes adjusting the visual image.

12. The system according to any of the preceding claims, in, The changes in the surrounding environment include at least changes in the color temperature of the light output generated by the lighting system, and The controller is adapted to control the sensory output system such that the transition from a first ambient state to a second ambient state includes a transition of the light output through a path in the color space.

13. The system according to claim 12, in, The change in the surrounding environment state includes at least the change in the RGB color of the RGB light output of the lighting system from the first color (A) in the RGB space to the second color (B) in the RGB space; The process of performing the transformation from color A to color B includes: Convert color A and color B to points in the CIELAB color space; Determine a continuous line between point A and point B in the CIELAB color space; Extract a series of CIELAB color points distributed along the CIELAB line, and convert the extracted series of points to the RGB color space to derive a series of RGB color points; The lighting system is controlled to switch between color A and color B by sequentially traversing the series of RGB color points.

14. An environmental control method for use with a medical imaging scanner during medical imaging scanning, The medical imaging scanner includes an imaging device adapted to acquire imaging data of an object located in the imaging area, and The method includes controlling a sensory output system, the sensory output system comprising one or more sensory output devices adapted to generate a set of controllable sensory outputs, the combination of sensory outputs defining a state of the surrounding environment that can be perceived by a patient located in the imaging area, wherein... The sensory output system is operable to alter the state of the surrounding environment by controlling one or more variable sensory parameters of the sensory output, and wherein the combination of the sensory outputs includes at least one or more visually perceptible outputs; The method includes: Receive scan information indicating medical imaging scan parameters that change over time during a medical imaging scan of a patient, wherein the scan information includes indication information reflecting changes over time in energy deposition acting on the patient during the scan; Retrieve the thermal sensing model, which defines the relationship between changes in one or more variable sensory parameters of the sensory output and the resulting predicted changes in temperature perceived by a person exposed to the ambient state including the sensory output; and Perform a thermal sensing compensation operation, the thermal sensing compensation operation including: Based on the scan information, determine direct or indirect indications of the patient's expected body temperature change between a first time point in the medical imaging scan and a later second time point in the medical imaging scan; and Based on the use of the thermal sensing model to estimate changes in the ambient environment settings that will at least partially offset the patient's perception of the temperature change, the ambient environment settings at the second time point are adjusted according to the expected body temperature change.

15. A computer program product comprising computer program code configured to, when executed by a processor, cause a system according to any one of claims 1-13 to perform the method according to claim 14.

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