Imaging-based reflectometry for sedation depth monitoring

Abstract

The present invention relates to sedation assessment. To facilitate sedation depth monitoring in a self-imaging environment, it is proposed to use the imaging modality itself to measure responses to appropriate reflexes, including but not limited to the pupillary reflex, the so-called superficial reflexes, and the withdrawal reflex, to determine sedation depth. In one embodiment, the pupillary reflex can be measured in an MRI system by dedicated iris MR imaging interleaved with the regular scanning protocol. In another embodiment, the superficial reflexes in response to touching the skin can be measured. This can involve a dedicated actuator that can be tightly integrated with the imaging modality, for example an MR receive coil applied to the patient. Alternatively, a remote haptic system can also be used. The reflex is then acquired with appropriate diagnostic imaging methods. In another embodiment, the withdrawal reflex in response to pain can be measured. This can involve an actuator that induces sudden suture pain or very localized temperature-induced pain and is tightly integrated with the imaging modality, for example a pinch device integrated with the patient support or an MR receive coil applied to the patient. The reflex is then acquired with appropriate diagnostic imaging methods.

Description

Technical Field

[0001] This invention relates to sedation assessment, and more particularly to a medical imaging system and a method for assessing sedation levels. Background Technology

[0002] Patients under sedation need to be monitored to determine their depth of sedation, which is usually done manually by healthcare professionals. The classic method for monitoring the depth of sedation and general anesthesia (GA) involves repeated manual monitoring by staff against clinical criteria such as responsiveness to verbal and tactile stimuli.

[0003] In autonomous imaging environments, automated monitoring of sedation depth is desirable. Various attempts have been made to find new forms of monitoring that are less manual, more objective, and meet the standards required in autonomous imaging. One such method is to replace the classic manual examination of pupillary reflexes with video pupillography with the camera close to the patient's eyes. Pupilography is a quantitative measurement of pupil size and its dynamic changes. However, this requires the patient to keep their eyes open, or to keep them open by some mechanical means. Both are highly inconvenient during extended imaging processes. Due to strong scattering in the eyelids, any optical or infrared (IR) measurement using devices compatible with autonomous imaging is not expected to achieve the accuracy required to measure pupil diameter through closed eyelids. Generally, any sensor that must be correctly applied to the patient can complicate the workflow and potentially complicate reliability in autonomous imaging. Summary of the Invention

[0004] It may be necessary to make sedation depth monitoring in autonomous imaging more convenient.

[0005] The object of the invention is achieved through the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the following aspects of the invention are also applicable to medical imaging systems and methods for assessing sedation levels.

[0006] A first aspect of the invention relates to a medical imaging system. The medical imaging system includes a medical imaging device and a sedation assessment device. The medical imaging device is configured to acquire a series of images of a patient's body parts to detect a response to at least one reflex of the patient. The at least one reflex is selected from reflexes having a response dependent on the depth of sedation. The sedation assessment device is configured to determine the patient's level of sedation based on the detected response.

[0007] In other words, it is proposed to use the imaging modality itself to measure the response to a suitable reflection in order to determine the depth of sedation. As mentioned earlier, if an additional sensor is used to measure the response to a suitable reflection, that sensor may have to be correctly applied to the patient. This can complicate the workflow and potentially complicate reliability in autonomous imaging. Therefore, using the imaging modality itself, without using an additional sensor, to measure the response to a suitable reflection may streamline the workflow and improve reliability in autonomous imaging.

[0008] The medical imaging equipment used in this article refers to a device for acquiring images of the internal structure of an object. A medical imaging device is a non-invasive examination device that can capture and process structural details, internal tissues, and / or fluid flow within the body. Users (such as doctors) can diagnose a patient's health condition and diseases by using the medical images output from the medical imaging device. Medical imaging devices can include, for example, magnetic resonance imaging (MRI) devices, computed tomography (CT) devices, and X-ray devices.

[0009] The human body has approximately fifty reflexes, covering a wide range of bodily systems, but only a few are suitable for sedation monitoring in an autonomous imaging environment because they must meet at least two criteria: (1) the reflex response must be dependent on the depth of sedation; and (2) the response must be measurable in a clinical setting, allowing for easy integration with diagnostic imaging. In other words, for diagnostic purposes, medical imaging devices (such as MRI, CT, or X-ray devices) are used to image the body to obtain an accurate diagnosis and determine future care. Reflexes should be selected to have patient responses that can be measured by the medical imaging device in a clinical setting. Therefore, during diagnostic medical imaging, the imaging modality itself, i.e., the medical imaging device, can be used directly to measure the response to a suitable reflex without the use of additional sensors.

[0010] Many reflexes, such as the well-known patellar or knee-jerk reflex, are monosynaptic, meaning their reflex arcs involve only two neurons: a sensory neuron connected by a single synapse, typically located in the spine, and a reactive motor neuron. Because this pathway does not involve the central nervous system (CNS), the response is independent of the state of the CNS and therefore independent of the depth of sedation. Other monosynaptic reflexes are the biceps reflex, brachioradialis reflex, extensor digitorum reflex, triceps reflex, and Achilles tendon reflex. All of these motor reflexes protect muscles or tendons from overstretching. Other reflexes are not suitable because they involve stimuli or responses that are inconvenient for the patient, or involve major bodily movements, such as the cough, sneeze, or blink reflex in response to eye touch. Still other reflexes are not suitable because they target internal physiological quantities that are not easily measured, such as the barotragic reflex, the Bainbridge reflex, and the Bezold-Jarisch reflex.

[0011] The following reflections may be suitable for use in autonomous imaging for sedation monitoring.

[0012] The pupillary reflex, responding to changes in retinal illumination, can be used to measure sedation depth, as detailed below. The pupillary reflex can also be suitable for monitoring sedation depth in magnetic resonance imaging (MRI) systems. For example, the pupillary reflex can be measured in an MRI system by alternating between dedicated iris MR imaging and conventional scanning protocols.

[0013] Another suitable set of reflexes includes superficial reflexes, which respond to the scraping of the skin with a motor response. Examples include the abdominal wall reflex, cremasteric reflex, glabellar reflex, and normal plantar response. The latter involves the flexion of the big toe when the sole of the foot is touched and can be particularly useful because it involves a mild stimulus and a response with slight localized movement. The glabellar reflex, also known as the "glabellar tapping sign," involves blinking when the forehead is repeatedly tapped and appears to be useful as well. Superficial reflexes can be suitable for monitoring sedation depth in MRI, X-ray imaging, or computed tomography (CT) systems. MR, X-ray, or CT imaging devices can acquire a series of images of the body part to detect responses such as slight localized movements, blinking, etc.

[0014] Another suitable group includes withdrawal reflexes of the limbs or fingers, because they can be readily stimulated and measured during diagnostic imaging if the induced movement does not interfere with imaging. Withdrawal reflexes are suitable for use in MRI, X-ray imaging, or CT systems for monitoring sedation depth. These systems can acquire a series of images of the body part to detect the response, i.e., the induced movement of the limbs or fingers.

[0015] According to one embodiment of the present invention, the at least one reflection includes the pupillary reflex.

[0016] Several different types of measurements can be used to determine pupillary reflexes, including but not limited to resting pupil size (MAX), minimum pupil size after light stimulation (MIN), pupil size reduction rate (expressed as a percentage of [MAX-MIN] / MAX), delay duration (i.e., the time between the onset of retinal light stimulation and the onset of pupillary constriction), constriction velocity (i.e., the degree of constriction / duration of constriction), maximum constriction velocity, and dilation velocity (i.e., the degree of pupillary size recovery / duration of recovery).

[0017] According to one embodiment of the present invention, a medical imaging device is configured to detect the stationary size of a patient's iris for measuring pupillary reflex.

[0018] Resting pupil size (MAX) correlates well with the depth of sedation of commonly used medications, such as sevoflurane-remifentanil (SEV / REM), sevoflurane (SEV), desflurane-remifentanil (DES / REM), and propofol-remifentanil (PRO / REM). Resting pupil size (MAX) shows a large response and does not require any stimulation. The typical timescale for changes in sedation depth is approximately several minutes. High-resolution MR imaging can be used to measure the resting size of the iris to provide a measurement of the depth of sedation. Changes in pupil size are approximately several millimeters, which can be addressed using MR imaging methods.

[0019] According to one embodiment of the present invention, the medical imaging device includes a magnetic resonance imaging (MRI) device.

[0020] According to one embodiment of the present invention, the MR imaging device is configured to apply a dedicated sequence for performing pupil measurements.

[0021] Routine MR imaging of the eye performed for oncology can be used to measure pupillary reflexes, providing high-resolution detail. However, this method can take several minutes to image. In this case, a dedicated sequence, specifically designed for pupillary measurements, is preferable and is therefore much faster.

[0022] According to one embodiment of the present invention, the dedicated sequence is a T2w fast spin echo sequence, which uses slice-selective refocusing pulses along the phase encoding direction.

[0023] A variant of the T2w fast spin echo sequence can be applied, which uses slice-selective refocusing pulses along the phase-encoding direction. This confines the field of view to the eye region, thus enabling in-plane resolution of 1 mm in less than one minute of imaging time. A fixed field of view size is available for all patients because the variation in human eye size between subjects is very small. Eye movement can complicate the imaging process, but many motion reduction and motion compensation techniques are known in MRI and can be applied to mitigate this effect.

[0024] According to one embodiment of the present invention, the at least one reflection includes at least one of shallow reflection and receding reflection.

[0025] According to one embodiment of the present invention, the medical imaging system further includes at least one stimulus generator. The at least one stimulus generator is configured to generate at least one stimulus at an impact area on the patient's skin to stimulate a response to the at least one reflex.

[0026] In one example, the at least one stimulus generator may include a remote tactile device configured to stimulate a patient's response from a distance without physical contact.

[0027] In another example, the at least one stimulus generator may include a wearable device, such as a heating device that can be attached to the patient, to stimulate the patient's response.

[0028] In another example, the at least one stimulation generator may include an actuator that can be tightly integrated with the imaging modality, such as a pinch device integrated with a patient stent or an MR receiving coil applied to the patient.

[0029] The at least one stimulus generator can be controlled by a control device to stimulate the response of the at least one reflex at a desired intensity, repetition rate, and / or duration. The control device can send control signals to the at least one stimulus generator to control the intensity, repetition rate, and / or duration of the stimulus. The control signals can be transmitted via physical cables, such as Universal Serial Bus (USB) cables, or wirelessly, such as Bluetooth or Wireless LAN (WiFi). In one example, the control signals can be generated in response to commands from a user interface. In another example, the control signals can be automatically generated using machine learning and statistical techniques on historical data from multiple patients.

[0030] According to one embodiment of the present invention, the superficial reflex includes at least one of the normal plantar response and the glabella reflex.

[0031] According to one embodiment of the invention, the at least one stimulation generator includes at least one of the following means for stimulating a normal plantar response: a stroking device that can be attached to the patient's sole, and a remote tactile device configured to induce tactile sensation from a distance at an impact area on the patient's sole.

[0032] Figure 1 shows an exemplary example of a remote haptic device, namely remote haptic device 130a.

[0033] According to one embodiment of the invention, the at least one stimulation generator includes at least one of the following means for stimulating the glabella reflex: a means configured to repeatedly tap the patient's forehead, and a remote tactile means configured to induce tactile sensation from a distance at an impact area on the patient's forehead.

[0034] For example, such as Figure 1B As shown, the device can be integrated with the MR head coil 70.

[0035] According to an embodiment of the present invention, the remote haptic device includes at least one of the following transmitters:

[0036] i) Airborne acoustic transmitter;

[0037] ii) Aerial ultrasonic tactile transmitter;

[0038] iii) Air nozzle;

[0039] iv) Electromagnetic wave transmitter;

[0040] v) Electrical transmitter;

[0041] vi) Magnetic emitter; and

[0042] vii) Radio frequency transmitter.

[0043] Airborne acoustic transmitters use sound waves to generate acoustic radiation pressure, which can induce tactile sensations at any desired intensity, frequency, and / or duration. For example, sound is perceived as vibration by modulating a sound field within a range of tactile sensitivity (e.g., 10-200 Hz).

[0044] An airborne ultrasonic tactile transmitter can form an ultrasonic beam at a specific focal point and generate acoustic radiation pressure. The focused ultrasound waves result in a tactile sensation of any desired intensity, frequency, and / or duration at a distance in a non-invasive manner.

[0045] Air nozzles can generate airflow patterns that result in a directional jet of air that can induce tactile sensations on the patient's skin at the impact site. Both direct compressed air methods and vortex-based methods can be used to simulate tactile sensations.

[0046] Electromagnetic wave emitters, such as lasers, can be used to generate tactile effects at a distance from the excitation source. Electromagnetic wave emitters can be pulsed laser-based systems, such as nanosecond lasers, which evoke tactile sensations when applied to the skin. For example, electromagnetic radiation can be configured to excite mechanoreceptors embedded in a patient's skin. For instance, a nudging emitter can be arranged as a laser emitter capable of operating at an appropriate frequency.

[0047] The transmitters described above can be used individually or in combination. For example, the push signal can be pulsed. In any of the above embodiments, the individual frequency, the frequency of the pulse, and / or the intensity of the push signal can remain constant throughout the push operation, but may vary in other embodiments. More specifically, the intensity of the push signal can decrease as the region of interest gets closer to the target region. Proximity information can be additionally or alternatively modulated by changing the pulse frequency of the push signal. In a similar manner, the frequency of the ultrasound signal itself can also be changed.

[0048] According to one embodiment of the invention, the at least one stimulator is configured to induce sudden suture pain and / or localized temperature-induced pain at the impact area on the patient's skin to stimulate a withdrawal reflex.

[0049] In one example, the at least one stimulation generator may include an actuator that can be tightly integrated with the imaging modality, such as a pinch device integrated with a patient stent or an MR receiving coil applied to the patient.

[0050] In another example, the at least one stimulation generator may include a heating and / or cooling device that may be attached to the impact area on the patient's skin and configured to heat or cool the impact area to induce a pain sensation. Figure 5 An exemplary example of a heating and / or cooling device, namely device 130c, is shown.

[0051] According to an embodiment of the present invention, the medical imaging device includes at least one of the following: MR imaging device, X-ray imaging device, and computed tomography (CT) imaging device.

[0052] MR imaging equipment can be configured to apply a specific sequence to acquire images of a patient's body parts in order to detect the patient's response to at least one reflective reflex. This will be explained below, particularly regarding... Figure 1A An exemplary example is provided.

[0053] X-ray imaging equipment and CT imaging equipment can be configured to acquire a series of low-resolution reconnaissance images of a patient's body parts to detect at least one reflective response from the patient. CT imaging equipment may also include positron emission tomography-computed tomography (PET-CT) imaging equipment or single-photon emission computed tomography-computed tomography (SPET-CT) imaging equipment. This will be explained below, particularly regarding... Figure 5 An exemplary example is provided.

[0054] A second aspect of the invention relates to a method for assessing sedation levels. The method includes...

[0055] A series of images of a patient's body parts are acquired using medical imaging equipment in order to detect the patient's response to at least one reflex.

[0056] Wherein, the at least one reflection is selected from reflections having a response that depends on the depth of sedation; and

[0057] The patient's sedation level is determined based on the detected response.

[0058] A third aspect of the invention relates to a computer program unit that, when executed by at least one processing unit, is adapted to cause the processing unit to perform the methods described above and below.

[0059] A fourth aspect of the invention relates to a computer-readable medium on which the program unit is stored.

[0060] These and other aspects of the invention will become apparent and will be illustrated from the embodiments described below.

[0061] definition

[0062] The term “user” as used in this article should be understood as a medical professional who participates in the imaging procedure in at least a managerial or organizational manner.

[0063] The term “patient” as used in this article should be considered as the person being imaged, or the animal (especially a mammal) being imaged in a veterinary setting. Attached Figure Description

[0064] These and other aspects of the invention will become apparent and further elucidated by referring to the embodiments described by way of example in the following description and by referring to the accompanying drawings, wherein

[0065] Figure 1A A medical imaging system according to some embodiments of the present disclosure is illustrated schematically.

[0066] Figure 1B An example of an MR head coil is shown schematically.

[0067] Figure 2 A through 2C show the responses of three different pupillary measurements to the administration of different sedatives (including SEV / REM, SEV, DES / REM, and PRO / REM).

[0068] Figure 3 An example of a low-resolution reconnaissance image used for automated scan planning is shown.

[0069] Figure 4 A and 4B show high-resolution MR imaging of the human eye.

[0070] Figure 5 Another medical imaging system according to some embodiments of the present disclosure is illustrated schematically.

[0071] Figure 6 A flowchart of a method for assessing sedation levels is shown.

[0072] It should be noted that these figures are purely schematic and not drawn to scale. In these figures, elements corresponding to those already described may have the same reference numerals. Examples, embodiments, or optional features, whether or not marked as non-limiting, should not be construed as limiting the claimed invention. Detailed Implementation

[0073] Figure 1A An embodiment of a medical imaging system 100 is illustrated schematically and exemplary. The medical imaging system 100 includes a medical imaging device 110, such as... Figure 1A MR imaging equipment 110a and Figure 5 The medical imaging equipment 110b and sedation assessment equipment 120 are included. The medical imaging equipment can be any of the following: i) MR imaging equipment, ii) X-ray imaging equipment, and iii) CT imaging equipment. The CT imaging equipment can be a PET-CT imaging equipment or a SPET-CT imaging equipment.

[0074] exist Figure 1A In this exemplary embodiment, the medical imaging device 10 is an MR imaging device 110a, which has an MR port 10 and a patient support stage 20. Figure 1A Patient PAT, which can be Figure 1A The human patient or animal (not shown) is placed on top of the patient support table 20, which is positioned within the MR hole 10 in the operable state of the system 100.

[0075] Sedation quantification is a crucial area in scanning for disruptive events. It requires delivering optimized sedation doses to the patient. To determine the level of sedation in a patient's paresthesia (PAT) located within the MR aperture 10, the medical imaging device 110 is configured to acquire a series of images of the body parts of the patient's PAT to detect the patient's response to at least one reflex.

[0076] As previously mentioned, the human body has approximately fifty reflexes, covering a wide range of bodily systems, but only a few reflexes are suitable for use in an autonomous imaging environment for sedation monitoring because they must meet at least two criteria: (i) the at least one reflex is selected from responses that are dependent on the depth of sedation; and (ii) the response is measurable in a clinical setting, allowing it to be integrated with diagnostic imaging.

[0077] exist Figure 1A In exemplary MR imaging systems, reflections suitable for sedation monitoring include at least one of pupillary reflection, superficial reflection, and withdrawal reflection.

[0078] In the first example, pupillary reflexes can be measured in an MRI system based on at least one of the following: resting pupil size (MAX), minimum pupil size after light stimulation (MIN), pupil size reduction rate ([MAX-MIN] / MAX), delay duration, constriction velocity, maximum constriction velocity, and dilation velocity. For some of the measurements listed, the temporal resolution of MR imaging may be insufficient to address dynamic quantities.

[0079] It is well known and demonstrated that, for video pupillography, the resting pupil size (MAX) correlates well with the depth of sedation of commonly used drugs, such as SEV / REM, SEV, DES / REM, and PRO / REM. For example, Figure 2 A through 2C show the responses of three different pupillary measurements to the administration of different sedatives (including SEV / REM, SEV, DES / REM, and PRO / REM). In particular, Figure 2 A shows the resting pupil size (MAX) compared to the unsedated control group. Figure 2 B shows the decrease in pupil size after light stimulation. Figure 2 C shows an increased delay in pupillary reflex compared to the unsedated patient group. It should be noted that the resting pupillary size (MAX) exhibits a large response and requires no stimulation. The typical timescale for changes in sedation depth is approximately several minutes. Therefore, it is proposed to apply high-resolution MR imaging to measure the resting size of the iris to provide a measurement of sedation depth. Changes in pupillary size are approximately several millimeters, which can be addressed using MR imaging methods.

[0080] For automated scan planning, the position of the eye and the approximate position of the lens can be determined from the reconnaissance MR image used at the beginning of each imaging session. It is proposed to utilize such a scan to automatically determine the positions of the eye and lens before planning a higher-resolution iris scan. Preferably, the iris scan is planned to be coplanar with the iris in the coronal direction, as the iris is known to be located in front of the lens. Automated planning can be performed using known automated planning concepts, similar to Philips SmartExam in the brain. TM This involves acquiring low-resolution reconnaissance images, automatically identifying patient-specific anatomical landmarks, and estimating slice orientation in diagnostic scans based on the identified landmarks. Regarding the aforementioned Philips SmartExam in the brain... TM For a detailed discussion of the automatic planning concept, see the following patent US 9,724,538 B2. Figure 3 An example of a low-resolution reconnaissance image used for automated scan planning is shown. Figure 3 The image shown is a transverse T1w MR reconnaissance image across the eye, typically acquired within 2 seconds. The lens of the eye is depicted as a white dot within the black frontal portion of the eyeball. Such a scan can be used to determine the approximate location of the lens and to plan a coronal scan coplanar with the iris, which lies in front of the lens.

[0081] Routine ocular MR imaging performed for oncology can be used to measure pupillary reflexes, providing high-resolution detail. However, this method can take several minutes of imaging time. Here, a dedicated sequence, solely for the purpose of performing pupillary measurements, is preferred and therefore much faster. Preferably, a variant of the T2w fast spin echo sequence can be used, employing slice-selective refocusing pulses along the phase-encoding direction. This confines the field of view to the eye region and thus achieves a planar resolution of 1 mm in less than one minute of imaging time. A fixed field of view size is available for all patients because the variation in human eye size between subjects is very small. Eye movement can complicate the imaging process, but numerous motion reduction and motion compensation techniques are known in MRI to mitigate this effect.

[0082] Figure 4 A and 4B show high-resolution MR images of the human eye. In particular, Figure 4 Image A shows a T2w image of a slice oriented coplanar with the iris. It contains a lesion located at the 2 o'clock position. Figure 4 B shows a T1w image oriented perpendicular to this view, again showing the vitreous body (black), the lens of the eye (gray), and the lobes of the iris located at the top of the lens.

[0083] Once a pupillary reflex response is detected, the sedation assessment device 120 is configured to determine the patient's level of sedation (PAT) based on the detected response. The sedation assessment device 120 may include an application-specific integrated circuit (ASIC), electronic circuitry, a processor (shared, dedicated, or grouped) and / or memory (shared, dedicated, or grouped) executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components or parts thereof that provide the aforementioned functionality. In one example, the sedation assessment device 120 may use any set of appropriate image processing methods to assess the pupil diameter. The basic task is to find a circle with approximately constant image intensity and approximately centered in the image, and to determine its radius. This can be achieved using a model-based segmentation method, for example, modeling the pupil as a circle with the following fitting parameters: the x and y positions of the pupil center in the iris image, the pupil radius, and the average image intensity of the pupil. The parameters of this model can be constrained to common dimensions and image intensities.

[0084] In the second example, superficial reflexes in response to touching the skin can be measured. Superficial reflexes include at least one of the normal plantar response and the glabella reflex.

[0085] To stimulate a response to a superficial reflex, the medical imaging system may also include at least one stimulus generator 130, such as the remote tactile device 130a shown in FIG1. ​​The at least one stimulus generator 130 is configured to generate at least one stimulus at an impact area on the patient's skin to stimulate a response to the at least one reflex.

[0086] At least one stimulation generator 130 may include at least one of the following means for stimulating a normal plantar response: a stroking device that can be attached to the patient's foot and a remote tactile device configured to induce tactile sensation from a distance at an impact area on the patient's foot.

[0087] exist Figure 1A In an exemplary example, the remote tactile device 130a is configured to induce tactile sensation from a distance at an impact area on the sole 40 of the patient's foot 40 without physical contact with the patient's PAT, thereby stimulating a normal plantar response. The remote tactile device 130a may be mounted in or within the imaging chamber or MR aperture 10. Examples of devices that induce such tactile sensation may include i) an airborne acoustic transmitter, ii) an airborne ultrasonic tactile transmitter, iii) an air nozzle, iv) an electromagnetic wave transmitter, v) an electrical transmitter, vi) a magnetic transmitter, and vii) a radio frequency transmitter.

[0088] The remote tactile device 130a can utilize one or more transmitters to generate single or multiple remote tactile taps at different intensities, repetition rates, and / or durations to evoke one or more distinct tactile sensations. The patient's response to one or more distinct tactile sensations can be any known response of a sedated patient to a routine physical tap, such as toe flexion, which can be detected by an MR imaging system.

[0089] Taking an ultrasound-based tactile system as an example, a remote tactile device 130a may include one or more airborne ultrasound tactile transmitters (not shown) configured to generate a directional or focused ultrasound beam that can be directed to a desired impact area on a patient's body. The airborne ultrasound tactile transmitters may generate an acoustic interference pattern that results in the generation of a directional ultrasound beam capable of inducing tactile sensation at the impact area on the patient's skin. The focused ultrasound waves, at a distance, non-invasively produce a tactile sensation of any desired intensity, frequency, and / or duration. In some embodiments, the sound field generated by a phased array may allow the formation of a volumetric sound field, such as a tactile sphere or other geometric construct. The direction of the ultrasound beam can be adjusted automatically or manually to impact the desired impact area. When applied to the patient at the impact area, the patient experiences a sensation similar to that of a physical object of a specified shape contacting the skin. The patient does not need to expose bare skin for this, as the ultrasound waves can couple to the skin through suitable thin clothing (such as a hospital gown typically worn by patients).

[0090] Of course, other types of transmitters can be used instead of or in addition to the airborne ultrasonic tactile transmitter. For example, in some embodiments, one or more air nozzles can be used to generate an airflow pattern that produces a directional jet of air capable of inducing tactile sensation on the patient's skin at the impact area. Methods involving direct compressed air or vortex-based methods can be used to simulate tactile sensation. In another example, one or more electromagnetic wave transmitters, such as lasers, can be used to generate a tactile effect at a distance from the excitation source. The electromagnetic wave transmitter can be a pulsed laser-based system, such as a nanosecond laser, which evokes tactile sensation when applied to the skin. In some embodiments, thermal radiation can be used because certain receptors in human skin, such as TRPV1, respond not only to heat but also to pain. By sequentially stimulating these two responses, a tactile sensation can be induced. This can be achieved by controlling a heat source, such as a halogen lamp or others. The heat source is properly focused using one or more reflectors and the focus is rapidly switched. The transmitter embodiments described above can be used alone or in combination, or in any sub-combination.

[0091] Patient responses, such as toe flexion, can be detected by an MR imaging device by capturing a series of images of the toes. Sedation assessment devices can use any appropriate set of image processing methods to assess the response, such as induced movement of the stimulated body part, and determine the patient's level of sedation based on the detected response.

[0092] Alternatively or additionally, at least one stimulator 130 may be a stroking device (not shown) that can be attached to the sole of the patient's foot to stimulate a normal foot response.

[0093] Similarly, at least one stimulation generator 130 may include at least one of the following means for stimulating the glabella reflex: a means configured to repeatedly tap the patient’s forehead and a remote tactile means configured to induce tactile sensation from a distance at the impact area on the patient’s forehead.

[0094] exist Figure 1A In an exemplary example, the glabella reflex can be stimulated by a dedicated device (not shown), which can be integrated with the MR head coil 70. Figure 1B An example of an MR head coil 70 is shown. The MR head coil 70 can be integrated into the patient support 20 and attached to the patient's head. Alternatively or additionally, a telehaptic device (not shown) can be provided to induce tactile sensation from a distance at the impact area on the forehead 50 of the patient's PAT without physical contact with the PAT. The telehaptic device can be mounted in or within the imaging chamber or MR aperture 10. In some examples, the telehaptic device, such as an air nozzle, can be integrated with the MR head coil 70, such as... Figure 1B As shown, an airflow pattern is generated that produces a directional jet of air capable of inducing tactile sensation on the patient's forehead.

[0095] In the third example, a withdrawal reflex in response to pain can be measured. This may involve at least one stimulator that induces sudden suture pain or very localized temperature-induced pain at the impact site on the patient's skin to stimulate the withdrawal reflex. Preferably, the at least one stimulator can be tightly integrated with an imaging modality, such as a pinch device integrated with a patient support or an MR receiving coil applied to the patient. The reflection is then acquired using magnetic resonance imaging equipment 110a.

[0096] Optionally, the medical imaging system 100 may also include a control device 140. The control device 140 may be configured to generate a control signal to control at least one stimulus generator, thereby stimulating a response of at least one reflex. The control signal may be transmitted via physical cable or wirelessly.

[0097] exist Figure 1AIn an exemplary example, control device 140 is configured to generate a control signal to control the remote tactile device 130a to induce a desired tactile sensation. For example, the control signal may be used to control the intensity, repetition rate, and / or duration of the tactile sensation at a specific impact area on the patient's skin. In some examples, control device 140 may be configured to generate the control signal in response to an input request received from a user interface (UI). For example, at least one or a combination of intensity, repetition rate, and / or duration may be configured in response to a command received from the user interface (UI). Examples of the user interface (UI) may include, but are not limited to, touchscreens, button-based interfaces, and joystick devices. The user interface (UI) is preferably arranged remotely from the imaging equipment, e.g., outside the imaging room. Alternatively, the user interface (UI) may be arranged indoors. The user interface may be configured to allow remote control of the control device and / or remote monitoring of detected patient responses and / or determined levels of sedation. For example, some information may be transmitted remotely for further evaluation by an anesthesiologist. The information shared with remote personnel may be tactile touch or an assessment of the patient's response. If the stimulation generator includes multiple emitters, such as multiple airborne ultrasonic emitters, the user interface (UI) may include multiple user interface elements that allow the user to select and switch different emitters to induce tactile / painful sensations at different impact zones, thereby inducing superficial reflexes and / or withdrawal reflexes. For example, in Figure 1A In an exemplary example, a user can choose to switch between a remote haptic device 130a and a dedicated device to stimulate a normal plantar response or a glabella reflex.

[0098] However, in other embodiments, the control device can automatically control at least one stimulation generator. In particular, the control device 140 can be configured to change any or all of the direction and modulation of the push signal based on the patient's historical data. For example, by using machine learning and statistical techniques on historical data from multiple patients, a series of push intensities with different gradients can be defined for sensitivity control.

[0099] exist Figure 1A In the exemplary example, the sedation assessment device 120 is a separate computing device. However, in some examples, the sedation assessment device 120 may be part of a user interface (UI), for example... Figure 5 An exemplary example is shown in the figure.

[0100] Figure 5Another embodiment of the medical imaging system 100 is illustrated schematically and exemplary. In this exemplary embodiment, the medical imaging device 110 is a CT scanner 110b. The CT scanner 110b includes a gantry 112 rotatable about a rotation axis R extending parallel to the z-direction. A radiation source 114, in this embodiment an X-ray tube, is mounted on the gantry 112 and is provided with a collimator 116 that forms a conical radiation beam 118 from the radiation generated by the radiation source 114. The radiation passes through a human patient PAT located within a cylindrical examination area 122. After passing through the examination area 122 and thus through the patient PAT, the radiation beam 118 is incident on a detection device 124, which includes a two-dimensional detection surface. Furthermore, the detection device 124 is mounted on the gantry 112. Control logic CL is configured to generate a scanning scheme that induces the medical imaging device 110b (in this embodiment, a CT scanner) to perform a medical scan of the body parts of the patient PAT. Further examples of CT scanners include PET-CT scanners and SPECT-CT scanners.

[0101] exist Figure 5 In exemplary CT scanners, reflections suitable for sedation monitoring include at least one of superficial reflections and withdrawal reflections.

[0102] In the first example, superficial reflexes in response to touching the skin can be measured. Superficial reflexes include at least one of the normal plantar response and the glabella reflex.

[0103] To stimulate a response to superficial reflexes, the medical imaging system 100 may further include at least one stimulus generator 130, for example... Figure 5 The remote tactile device 130b is shown. At least one stimulation generator 130 is configured to generate at least one stimulus at an impact area 60a on the patient's skin to stimulate a response of at least one reflex. The remote tactile device 130b may be mounted in or within an imaging chamber or a cylindrical examination area 122. Examples of devices that can induce such tactile sensation may include i) an airborne acoustic transmitter, ii) an airborne ultrasonic tactile transmitter, iii) an air nozzle, iv) an electromagnetic wave transmitter, v) an electrical transmitter, vi) a magnetic transmitter, and vii) a radio frequency transmitter. In one example, the remote tactile device 130b may be arranged and configured to induce tactile sensation from a distance at an impact area on the sole of the patient's foot (PAT) without physical contact with the patient to stimulate a plantar response. In another example, the remote tactile device 130b may be arranged and configured to induce tactile sensation from a distance at an impact area on the patient's forehead (PAT) without physical contact with the patient to stimulate a glabellar reflex.

[0104] Alternatively or additionally, a stroking device that can be attached to the patient's foot can be used to stimulate normal plantar responses. A device configured to repeatedly tap the patient's forehead can be used to stimulate the glabella reflex.

[0105] In the second example, a withdrawal reflex in response to pain can be measured. This may involve at least one stimulator that induces sudden suture pain or very localized temperature-induced pain at the site of impact on the patient's skin to stimulate the withdrawal reflex. For example, at least one stimulator may be tightly integrated with an imaging modality, such as a pinch device integrated with a patient support or an MR receiving coil applied to the patient. Figure 5 In an exemplary example, at least one stimulation generator 130 may include a heating and / or cooling device 130c, which may be attached to the impact area 60b on the patient's skin and configured to heat or cool the impact area 60b to induce a pain sensation. In other words, at least one stimulation generator may be a wearable device.

[0106] Superficial reflexes and withdrawal reflexes can elicit movement in one or more body parts of a patient. For example, in a healthy adult, the plantar reflex elicits a downward response in the toes. Withdrawal reflexes, for example, elicit movement in the limbs or fingers. Therefore, the CT scanner 110b can be configured to acquire a series of images of at least one of these body parts to detect induced movement. The sedation assessment device 120 then determines the patient's level of sedation based on the detected responses, such as the induced movement in the patient's body parts.

[0107] Optionally, the medical imaging system 100 may further include a control device 140, which can be configured to generate a control signal to control the at least one stimulus generator to stimulate a response of at least one reflex. The control signal can be transmitted via physical cable or wirelessly.

[0108] exist Figure 5 In an exemplary example, control device 140 is configured to generate a control signal to control remote tactile device 130b to induce a desired tactile sensation. Control device 140 may also be configured to generate a control signal to control heating and / or cooling device 130c to stimulate a withdrawal reflex response.

[0109] The control device 140 can be controlled by a user interface (UI). For example, control signals can be generated in response to commands received from the user interface (UI). In some examples, the user interface (UI) can be a computing device, such as a personal computer (PC). The sedation assessment device 120 can be part of the user interface (UI).

[0110] Now for reference Figure 6The figure illustrates a flowchart of a method 200 for assessing sedation levels. Although the steps described below relate to the system described above, these steps are not necessarily limited to the system described, and the method for assessing sedation levels described below can also be understood as its own teaching.

[0111] In step 210, the medical imaging device acquires a series of images of the patient's body parts to detect the patient's response to at least one reflex. This at least one reflex is selected from reflexes that have a response dependent on the depth of sedation. The medical imaging device may be at least one of an MR imaging device, an X-ray imaging device, and a CT imaging device.

[0112] For example, a medical imaging device is an MR imaging device. Reflections suitable for MR imaging may include, but are not limited to, pupillary reflexes, superficial reflexes, and withdrawal reflexes. In one example, the pupillary reflex can be measured in an MRI system by repeatedly alternating between dedicated iris MR imaging and conventional scanning protocols. In another example, superficial reflexes in response to touching the skin can be measured. This may involve a dedicated actuator that can be tightly integrated with the imaging modality, such as an MR receiver coil applied to the patient. Alternatively, a remote tactile system can also be used. The reflex is then acquired using a suitable diagnostic imaging method. In yet another example, withdrawal reflexes in response to pain can be measured. This may involve an actuator that induces sudden suture pain or very localized temperature-induced pain and is tightly integrated with the imaging modality, such as a pinch device integrated with a patient support or an MR receiver coil applied to the patient. The reflex is then acquired using MR imaging.

[0113] For example, medical imaging equipment is X-ray imaging equipment or CT imaging equipment. Reflections suitable for X-ray or CT imaging can include, but are not limited to, superficial reflections and withdrawal reflections, which can be stimulated using methods similar to those used in MR imaging. X-ray or CT imaging equipment can acquire a series of low-resolution reconnaissance images of induced movements of a patient's body parts to detect the response of superficial reflections and / or withdrawal reflections.

[0114] It should be understood that measuring the resting pupil size (MAX) of the pupillary reflex does not require any stimulation. However, for other reflexes, such as the superficial reflex and the withdrawal reflex, the method may involve additional steps (not shown) of activating at least one stimulus generator to stimulate the response of these reflexes.

[0115] In step 220, the patient's sedation level is determined based on the detected response. Any set of appropriate image processing methods can be used to assess the response, such as pupil diameter and / or induced movement of the stimulated body part, and to determine the patient's sedation level based on the detected response.

[0116] In another exemplary embodiment of the present invention, a computer program or computer program unit is provided, characterized in that it is adapted to perform the method steps of the method according to one of the foregoing embodiments on a suitable system.

[0117] Therefore, a computer program unit can be stored on a computer unit, which can also be part of an embodiment of the present invention. The computing unit can be adapted to perform or induce the execution of the steps of the above-described method. Furthermore, it can be adapted to operate components of the above-described device. The computing unit can be adapted to automatically operate and / or execute user commands. The computer program can be loaded into the working memory of a data processor. Therefore, the data processor can be configured to execute the method of the present invention.

[0118] This exemplary embodiment of the invention covers both computer programs that use the invention from the outset and computer programs that convert existing programs into programs that use the invention through updates.

[0119] Furthermore, the computer program unit is capable of providing all the necessary steps to complete the operation of the exemplary embodiments of the method described above.

[0120] According to another exemplary embodiment of the present invention, a computer-readable medium, such as a CD-ROM, is provided, wherein the computer-readable medium has computer program units stored thereon, which are described in the foregoing portion.

[0121] Computer programs may be stored and / or distributed on suitable media, such as optical storage media or solid-state media provided together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0122] However, computer programs can also be provided via networks like the World Wide Web and can be downloaded from such networks to the working memory of a data processor. According to another exemplary embodiment of the invention, a medium is provided for making a computer program unit downloadable, the computer program unit being arranged to perform the method described in one of the foregoing embodiments of the invention.

[0123] It should be noted that embodiments of the invention have been described with reference to different subjects. In particular, some embodiments are described with reference to method-type claims, while other embodiments are described with reference to apparatus-type claims. However, those skilled in the art will understand from the foregoing and hereinafter description that, unless otherwise indicated, any combination of features related to different subjects, in addition to any combination of features belonging to one type of subject, is also considered to be disclosed in this application. However, all features can be combined to provide a synergistic effect that is more than the simple sum of the features.

[0124] Although the invention has been illustrated and described in the accompanying drawings and the foregoing description, such illustrations and descriptions are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. By studying the drawings, the disclosure, and the dependent claims, those skilled in the art will be able to understand and implement other variations of the disclosed embodiments in practicing the claimed invention.

[0125] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. A single processor or other unit can perform the functions of several items recited in the claims. The recitation of certain measures only in mutually different dependent claims does not imply that combinations of these measures cannot be advantageously used. Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A medical imaging system (100), comprising: Medical imaging equipment (110, 110a, 110b); and Sedation assessment equipment (120); The medical imaging device is configured to acquire a series of images of the internal structure of a patient’s body parts in order to detect the patient’s response to at least one reflective response during diagnostic imaging performed by the medical imaging device. Wherein, the at least one reflection is selected from reflections having a response that depends on the depth of sedation; and The sedation assessment device is configured to determine the patient's sedation level based on the detected response; and The medical imaging device includes at least one of the following: Magnetic resonance imaging equipment; X-ray imaging equipment; and Computed tomography (CT) imaging equipment.

2. The medical imaging system (100) according to claim 1, wherein, The at least one reflex includes the pupillary reflex.

3. The medical imaging system (100) according to claim 2, wherein, The medical imaging device is configured to detect the stationary size of the patient's iris in order to measure the pupillary reflex.

4. The medical imaging system (100) according to claim 2 or 3, wherein, The medical imaging equipment includes magnetic resonance imaging (MRI) equipment.

5. The medical imaging system (100) according to claim 4, wherein, The MR imaging device is configured to apply a dedicated sequence for performing pupil measurements.

6. The medical imaging system (100) according to claim 5, wherein, The dedicated sequence is the T2w fast spin echo sequence, which uses slice-selective refocusing pulses along the phase encoding direction.

7. The medical imaging system (100) according to any one of claims 1 to 3, wherein, The at least one reflection includes at least one of shallow reflection and receding reflection.

8. The medical imaging system (100) according to claim 7, wherein, The medical imaging system also includes: At least one stimulus generator (130, 130a, 130b, 130c); The at least one stimulation generator is configured to generate at least one stimulus at impact areas (60a, 60b) on the patient's skin to stimulate a response to the at least one reflex.

9. The medical imaging system (100) according to claim 8, wherein, The superficial reflexes include at least one of the normal plantar response and the glabella reflex.

10. The medical imaging system (100) according to claim 9, wherein, The at least one stimulation generator includes at least one of the following devices for stimulating the normal plantar response: A stroking device that can be attached to the sole of the patient's foot; and A remote tactile device (130a) configured to induce tactile sensation from a distance at an impact area on the sole of the patient's foot.

11. The medical imaging system (100) according to claim 9 or 10, wherein, The at least one stimulation generator includes at least one of the following devices for stimulating the glabella reflex: A device configured to repeatedly tap the patient's forehead; and A remote tactile device configured to induce tactile sensation from a distance at an impact area on the patient's forehead.

12. The medical imaging system (100) according to claim 11, wherein, The remote haptic device includes at least one of the following transmitters: i) Airborne acoustic transmitter; ii) Aerial ultrasonic tactile transmitter; iii) Air nozzle; iv) Electromagnetic wave transmitter; v) Electrical transmitter; vi) Magnetic emitter; and vii) Radio frequency transmitter.

13. The medical imaging system (100) according to any one of claims 8 to 10, wherein, The at least one stimulator is configured to induce sudden suture pain and / or localized temperature-induced pain at the impact area on the patient's skin to stimulate the withdrawal reflex.

14. A method for assessing sedation levels (200), comprising: A series of images of the internal structures of a patient's body parts are acquired using a medical imaging device in order to detect the patient's response to at least one reflective reaction during diagnostic imaging performed by the medical imaging device. Wherein, the at least one reflection is selected from reflections having a response that depends on the depth of sedation; and The patient's sedation level is determined based on the detected response. The medical imaging device includes at least one of the following: MR imaging equipment; X-ray imaging equipment; and Computed tomography (CT) imaging equipment.

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