Motion detection system and image system

Abstract

The utility model discloses a motion detection system and an image system, the motion detection system includes: a plurality of sensors, including a reference arm sensor configured to measure an environmental reference signal and a measurement arm sensor configured to measure a motion signal of an examined part of a patient; the signal processing device is connected with the sensors, the signal processing device is configured to receive the environment reference signal and the motion signal and obtain a target motion signal based on the environment reference signal and the motion signal, and the target motion signal represents real motion information of the patient. According to the utility model, the reference arm sensor is provided, and the measurement deviation caused by the image equipment is eliminated according to the environment reference signal of the reference arm sensor, so that the quality of the obtained motion information is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical equipment and other technical field, especially, a kind of motion detection system and image system. BACKGROUND

[0002] In medical scanning process, if scanning site is affected by patient motion activity, it is extremely easy to produce motion artifact on scanning image. Especially in some scanning time is relatively long occasion, because the artifact produced by motion activity is more serious, for example, in magnetic resonance heart and abdominal scanning, the artifact produced by the motion of tissue and chest cavity caused by patient's heartbeat, breathing can even interfere with the diagnosis of disease. In order to weaken motion artifact, motion gating technology arises at the historic moment. Motion gating technology can collect the motion activity state of patient, such as the abdominal motion caused by the beating of heart, breathing, and through the triggered mode to adapt to the motion activity process of patient in scanning process, so as to weaken the influence of motion on image, and obtain clear medical image.

[0003] In related art, motion gating technology is divided into two categories, one is contact type or interventional room motion gating detection technology, such as traditional monitoring instrument through electrode patch to collect ECG signal of heartbeat. Another is non-contact measurement, for example, through radio frequency, laser or millimeter wave radar to collect heartbeat or breathing motion of patient, and obtain breathing or heartbeat information of patient. However, in non-contact measurement, radar sensing technology is a kind of indiscriminate measurement, which cannot distinguish whether it is vibration of sensor itself or motion of detection object, resulting in inaccurate detection result. UTILITARY MODEL

[0004] Therefore, the purpose of the utility model embodiment is to provide a kind of motion detection system, reference arm sensor is proposed, and measurement deviation caused by image device is eliminated according to environmental reference signal of reference arm sensor, so that the quality of motion information obtained is higher.

[0005] The utility model embodiment provides a kind of motion detection system, the system includes: multiple sensors, the multiple sensors include reference arm sensor and measurement arm sensor, the reference arm sensor is configured to measure environmental reference signal, and the measurement arm sensor is configured to measure the motion signal of patient examination site;Signal processing device, the signal processing device is connected with the multiple sensors, the signal processing device is configured to receive the environmental reference signal and the motion signal, and obtains target motion signal based on the environmental reference signal and the motion signal, wherein the target motion signal represents the real motion information of patient.

[0006] Exemplarily, the motion detection system is applicable to an imaging device, the imaging device comprising a scanning cavity and the patient bearing device, the scanning cavity and the patient bearing device being arranged along a preset direction, and the plurality of sensors being arranged in the scanning cavity along the preset direction.

[0007] Exemplarily, the scanning cavity comprises a plurality of windows on the shell of the scanning cavity, the windows being configured to fix the sensors, the plurality of sensors being at the same distance from the patient bearing device, and the plurality of windows corresponding to the plurality of sensors one by one.

[0008] Exemplarily, the sensor comprises an external interface, a main control board and a substrate, the signal processing device being connected to the plurality of sensors through the external interface, the external interface being connected to the main control board through a lead wire, the main control board being fixed on the substrate, and the main control board comprising a transceiving array antenna.

[0009] Exemplarily, the main control board is further configured to adjust the emission angle of the transceiving array antenna of the main control board by adjusting the inclination angle of the substrate.

[0010] Exemplarily, the sensor further comprises a shielding shell and an antenna cover, the shielding shell being connected to the antenna cover, the shielding shell being configured to shield external interference signals, the antenna cover being arranged in an arc shape, the antenna cover being arranged at the transceiving array antenna and protruding outward relative to the sensor.

[0011] Exemplarily, the environmental reference signal comprises at least one of a first environmental reference signal caused by the sensor and a second environmental reference signal caused by the patient bearing device, and the first environmental reference signal is caused by sensor vibration due to gradient coil gradient climbing.

[0012] Exemplarily, the measurement arm sensor comprises a first sensor and a second sensor, the first sensor being configured to measure a chest motion signal of a patient's chest, and the second sensor being configured to measure an abdominal motion signal of a patient's abdomen.

[0013] Exemplarily, the signal processing device is a filter, the filter being connected to the plurality of sensors, the filter being configured to receive the environmental reference signal and the motion signal, and filtering the motion signal based on the environmental reference signal to obtain the target motion signal.

[0014] Exemplarily, the sensor is a millimeter wave radar sensor.

[0015] Another embodiment of the utility model provides an imaging system, the imaging system comprises an imaging device and the motion detection system.

[0016] In the above embodiment, the motion detection system comprises: a plurality of sensors, including a reference arm sensor and a measurement arm sensor, the reference arm sensor is configured to measure an environmental reference signal, and the measurement arm sensor is configured to measure a motion signal of a patient examination site; a signal processing device connected with the plurality of sensors, the signal processing device is configured to receive the environmental reference signal and the motion signal, and obtain a target motion signal based on the environmental reference signal and the motion signal, wherein the target motion signal represents the real motion information of the patient. The reference arm sensor is provided, and the measurement deviation caused by the imaging equipment is eliminated according to the environmental reference signal of the reference arm sensor, so that the quality of the obtained motion information is higher. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A schematic diagram of a motion detection system provided by the embodiment of the present application is shown in the figure;

[0018] Figure 2 A schematic diagram of a medical imaging equipment provided by the embodiment of the present application is shown in the figure;

[0019] Figure 3 A schematic diagram of a sensor provided by the embodiment of the present application is shown in the figure;

[0020] Figure 4 A schematic diagram of an imaging system provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0022] In some examples, the motion detection technology can be detected by contact or interventional room gating, such as the ECG signal collected by the electrode patch of the traditional monitoring instrument, the motion of the fixed air bag through abdominal respiration compression, etc. Such technology has high precision and good real-time performance, but the doctor needs to spend extra time to wear the sensor equipment for the patient, the overall scanning time is long, and the efficiency is low.

[0023] In some examples, non-contact measurements can be used, such as acquiring a patient's heartbeat or respiratory movements via radio frequency, laser, or millimeter-wave radar to obtain respiratory or heartbeat information. Non-contact measurement methods improve patient comfort and reduce total scan time. However, radar sensing technology in non-contact measurements is indiscriminate and cannot distinguish between sensor vibration and the movement of the object being measured, leading to inaccurate results. For example, in MRI (Magnetic Resonance Imaging), the current rise of the gradient system in the magnetic field causes widespread scanning cavity vibration due to the Ampere force. Similarly, in CT (Computed Tomography), gantry rotation inevitably causes scanning cavity sway. Millimeter-wave radar sensors are mounted on top of the scanning cavity; the displacement information acquired during scanning is actually a superposition of the patient's motion and the scanning cavity displacement.

[0024] Based on this, the present invention innovatively proposes the concept of a reference arm, using at least one channel as a reference measurement, and forming a correlated radar sensor structure with the sensors of other measurement arms. This correlated mechanism can filter out the vibration interference of the scanning cavity from the measurement signal through a post-correlation processing algorithm, and finally obtain a motion signal with a high signal-to-noise ratio.

[0025] Figure 1 This is a schematic diagram of a motion detection system according to an embodiment of the present invention.

[0026] As an example, such as Figure 1 As shown, the motion detection system includes multiple sensors, including a reference arm sensor and a measuring arm sensor. The reference arm sensor is configured to measure an environmental reference signal, and the measuring arm sensor is configured to measure motion signals at the patient's examination site. A signal processing device is connected to the multiple sensors and is configured to receive the environmental reference signal and the motion signal, and obtain a target motion signal based on the environmental reference signal and the motion signal, wherein the target motion signal represents the patient's actual motion information.

[0027] For example, such as Figure 1As shown, the number of the plurality of sensors (S1, S2, S3) is not limited to three, and can be other numbers. At least one of the sensors is a reference arm sensor, and at least one of the sensors is a measurement arm sensor. For example, S1 can be a reference arm sensor, and S2 and S3 can be measurement arm sensors. The beam focusing position of the reference arm sensor is a scanning device, such as a patient bed or a scanning cavity, for measuring an environmental reference signal. The beam focusing position of the measurement arm sensor is a patient examination site, such as an abdomen or a chest cavity, for measuring a motion signal of the patient examination site. It can be understood that the measurement value of the measurement arm sensor is an original motion signal, which is actually a superposition of a patient motion motion and a scanning cavity vibration. The plurality of sensors are connected to a signal processing device, which is configured to receive the environmental reference signal and the motion signal, and obtain a target motion signal based on the environmental reference signal and the motion signal, wherein the target motion signal represents the true motion information of the patient. It can be understood that the target motion signal is a signal after eliminating the measurement deviation caused by the scanning cavity vibration, for example, breathing or heartbeat information. In other examples, the target motion signal includes a motion signal of the examination site caused by patient movement.

[0028] The target motion signal obtained by the utility model can more accurately reflect the true motion information of the patient, and obtain high-quality motion information of the detected object, to facilitate the doctor to make a medical judgment.

[0029] As an example, the motion detection system is applicable to an imaging device, the imaging device includes a scanning cavity and a patient carrying device, the scanning cavity and the patient carrying device are arranged along a preset direction, and a plurality of sensors are arranged on the scanning cavity along the preset direction.

[0030] Exemplarily, the imaging device includes a scanning cavity and a patient carrying device, such as Figure 1 As shown, the imaging device can be an MRI (medical magnetic resonance imaging device), of course, the imaging device can also be a computer tomography device CT, or a positron scanning device PET, or a PET-C, a PET-MR, and the like. The plurality of sensors can be arranged on the scanning cavity, and the patient carrying device can be a patient bed for carrying a patient. The plurality of sensors are arranged on the scanning cavity along a preset direction, and the preset direction can be a transverse direction as shown in Figure 1 The beam focusing position of the reference arm sensor can be the patient carrying device, for measuring an environmental reference signal.

[0031] Exemplarily, of course, the plurality of sensors can also not be arranged on the scanning cavity, but can be erected at a certain position through a support device, for example, erected on the patient bed of the carrying device through the support device.

[0032] As an example, the environmental reference signal includes at least one of a first environmental reference signal caused by a sensor and a second environmental reference signal caused by a patient-carrying device, wherein the first environmental reference signal is caused by sensor vibration due to gradient coil gradient ascent.

[0033] For example, during the scanning of a patient, the patient support device vibrates, and a reference arm sensor acquires a second environmental reference signal caused by the patient support device. The sensor vibration is caused by the vibration of the gradient coil during gradient ascent. The reference arm sensor also acquires a first environmental reference signal caused by the sensor. It can be understood that this invention acquires the environmental reference signal and combines it with the motion signal to eliminate the influence of the scanning cavity vibration or the patient support device vibration in the original motion signal.

[0034] As an example, the outer shell of the scanning cavity includes multiple windows configured to hold sensors, and the multiple sensors are equidistant from the patient-carrying device, wherein each window corresponds to one of the multiple sensors.

[0035] For example, multiple windows can be provided on the top of the scanning cavity of a medical imaging device. These windows are used to house multiple radar sensors, with at least one sensor serving as a reference arm and at least one sensor as a measuring arm. The radar sensors are positioned along the longitudinal axis of the scanning cavity and mounted at the same height relative to the patient bed surface. Each window corresponds one-to-one with a different sensor.

[0036] As an example, the measuring arm sensor includes a first sensor and a second sensor, the first sensor being configured to measure chest movement signals of the patient's chest cavity and the second sensor being configured to measure abdominal movement signals of the patient's abdomen.

[0037] For example, such as Figure 2As shown, three radar sensors are used as an implementation example, and these sensors are millimeter-wave radar sensors. 101 is a reference arm sensor, with its beam focused on the bed surface. 102 is the first sensor, with its beam focused on the patient's chest cavity, used to measure chest cavity motion signals. 103 is the second sensor, with its beam focused on the patient's abdomen, used to measure abdominal motion signals. The signal processing unit 201 can be an embedded device containing an embedded processor such as a microcontroller (MCU), a signal processor chip (DSP), or a programmable logic array (FPGA), or a commercial computer containing multiple digital serial data interfaces. 201 interconnects with all millimeter-wave sensors via a common serial data bus, typically including USB, RS232, RS485, or TCPIP. The communication media that can be used between the signal processing unit 201 and the multiple sensors include at least one of cable, fiber optic, Bluetooth, or Wi-Fi. Optionally, the signal processing unit 201 outputs a digital signal representing a heartbeat or respiratory gating signal.

[0038] As an example, such as Figure 3 As shown, the sensor includes an external interface 122, a main control board 123, and a base plate 124. The signal processing device 201 is connected to multiple sensors through the external interface 122. The external interface 122 is connected to the main control board 123 through leads. The main control board 123 is fixed on the base plate 124. The main control board 123 includes a transceiver array antenna.

[0039] For example, such as Figure 3 As shown, the sensor includes a main control board 123, a base plate 124, and an external interface 122. The main control board 123 includes at least one pair of transmitting and receiving antennas, a programmable dedicated millimeter-wave radar processing chip, and an external serial data interface. The main control board 123 is connected to the external interface 122 via leads. The main control board 123 includes a transceiver array antenna. The main control board 123 transmits carrier signals through the transceiver array antenna and receives environmental reference signals and / or motion signals through the transceiver array antenna.

[0040] For example, for the reference arm sensor, a carrier signal is transmitted via the transceiver array antenna of the main control board 123, and an ambient reference signal is received via the transceiver array antenna. For the measurement arm sensor, a carrier signal is transmitted via the transceiver array antenna of the main control board 123, and an ambient reference signal is received via the transceiver array antenna.

[0041] For example, the signal processing device 201 is connected to multiple sensors through the external interface 122 to obtain the environmental reference signal of the reference arm sensor and the motion signal of the measuring arm sensor, and processes the environmental reference signal and the motion signal to obtain the target motion signal.

[0042] As an example, such as Figure 3 As shown, the main control board 123 is also configured to adjust the transmission angle of the transceiver array antenna of the main control board 123 by adjusting the tilt angle of the substrate 124.

[0043] For example, the main control board 123 is fixed on the substrate 124, which may be an acrylic plastic substrate. The antenna transmission angle can be adjusted by adjusting the tilt angle of the plastic substrate.

[0044] As an example, such as Figure 3 As shown, the sensor also includes a shielding housing 121 and an antenna cover 125. The shielding housing 121 is connected to the antenna cover 125. The shielding housing 121 is configured to shield external interference signals. The antenna cover 125 is arc-shaped and is located at the transceiver array antenna, protruding outward relative to the sensor.

[0045] For example, the shielding shell 121 may be a plastic shielding shell with silver powder plating on the surface, and the antenna cover 125 may be a PBT (polybutylene terephthalate) arc-shaped antenna cover, with an arc-shaped antenna cover provided at the antenna array of the main control board 123.

[0046] For example, such as Figure 3 As shown, 100 is the outer shell of the scanning cavity. A window is made in the outer shell of cavity 100 to install a radar sensor. The radar sensor is fixed to the outer shell by screws at the front and back.

[0047] As an example, the sensor is a millimeter-wave radar sensor.

[0048] For example, the sensor transmits signals with wavelengths on the order of millimeters, ranging from 0.1 mm to 10 mm, and the radar sensor can transmit carrier signals modulated by linear frequency.

[0049] As an example, the signal processing device is a filter connected to multiple sensors. The filter is configured to receive an environmental reference signal and a motion signal, and filter the motion signal based on the environmental reference signal to obtain the target motion signal.

[0050] For example, the signal processing device 201 includes a signal processing algorithm, which can be implemented by an embedded program, firmware, or computer software. Since the reference arm signal represents the vibration of the sensor itself or the patient bed itself during the scanning process, and is not related to the patient's motion signal, the signal processing device performs correlation operations to filter out the related vibration signals, and finally recovers the patient's true breathing or heartbeat information.

[0051] The specific process of a typical filter filtering algorithm is as follows:

[0052] byFigure 2 The three sensors shown are examples. Let the signal of the reference arm sensor 101 be s(n), the signal of the first measuring arm sensor 102 be x1(n), and the signal of the second measuring arm sensor 103 be x2(n). The mathematical model can be established as follows:

[0053] x1(n) = h(t) + s(n) * a;

[0054] x2(n)=r(t)+s(n)*b;

[0055] Where a and b are linear coefficients, h(t) is the body surface motion signal caused by the actual heartbeat, and r(t) is the chest cavity displacement signal caused by the actual respiration. The initial adaptive digital filter parameters p(n) and the target value m0 of the normalized correlation coefficient are defined.

[0056] For each measurement terminal signal, calculate the filter output y1=x1-s(n)*p(n);

[0057] For each measurement terminal signal, calculate the normalized correlation coefficient m=y1.*s(n) / |y1||s(n)|;

[0058] For each measurement terminal signal, adjust the digital filter parameter coefficients p(n) until the normalized correlation coefficient approaches m0. Repeat the above process, using y1 as the output. The output y1 is the target motion signal of this invention.

[0059] In this embodiment, the output signal of the first sensor 102 is processed by an algorithm to recover the body surface motion signal caused by the heartbeat, and the output signal of the second sensor 103 is processed by an algorithm to output the chest cavity displacement signal caused by breathing.

[0060] This invention adds a reference arm to independently collect environmental reference signals caused by the vibration of the scanning cavity housing or the patient bed, and associates them with the back-end algorithm to eliminate measurement deviations caused by the vibration of the scanning cavity housing or the overall vibration of the patient bed in the measuring arm, making the detected motion signals more accurate.

[0061] This utility model also discloses an imaging system.

[0062] As an example, such as Figure 4 As shown, the imaging system 400 includes an imaging device 401 and the motion detection system 402 described above.

Claims

1. A motion detection system, characterized in that The system comprises: a plurality of sensors, the plurality of sensors comprising a reference arm sensor configured to measure an environmental reference signal and a measurement arm sensor configured to measure a motion signal of a patient examination site; a signal processing device connected to the plurality of sensors, the signal processing device configured to receive the environmental reference signal and the motion signal and derive a target motion signal based on the environmental reference signal and the motion signal, wherein the target motion signal represents true motion information of the patient.

2. The motion detection system of claim 1, wherein, The motion detection system is applicable to an imaging device, the imaging device comprising a scanning cavity and a patient support device, the scanning cavity and the patient support device being arranged along a predetermined direction, the plurality of sensors being arranged in the scanning cavity along the predetermined direction.

3. The motion detection system of claim 2, wherein, The scanning cavity comprises a plurality of windows configured to fix the sensors, the plurality of sensors being at the same distance from the patient support device, wherein the plurality of windows correspond one-to-one to the plurality of sensors.

4. The motion detection system of claim 1, wherein, The sensor comprises an external interface, a main control board and a substrate, the signal processing device being connected to the plurality of sensors through the external interface, the external interface being connected to the main control board through a lead, the main control board being fixed on the substrate, the main control board comprising a transceiving array antenna.

5. The motion detection system of claim 4, wherein, The main control board is further configured to adjust the emission angle of the transceiving array antenna of the main control board by adjusting the inclination angle of the substrate.

6. The motion detection system of claim 4, wherein, The sensor further comprises a shielding shell and an antenna cover, the shielding shell being connected to the antenna cover, the shielding shell being configured to shield external interference signals, the antenna cover being arranged in an arc shape, the antenna cover being arranged at the transceiving array antenna and protruding outward relative to the sensor.

7. The motion detection system of claim 2, wherein, The environmental reference signal comprises at least one of a first environmental reference signal caused by the sensor and a second environmental reference signal caused by the patient support device, wherein the first environmental reference signal is caused by sensor vibration due to gradient coil gradient climbing.

8. The motion detection system of claim 1, wherein, The measurement arm sensor comprises a first sensor configured to measure a chest motion signal of a chest of the patient and a second sensor configured to measure an abdominal motion signal of an abdomen of the patient.

9. The motion detection system of claim 1, wherein, The signal processing device is a filter connected to the plurality of sensors, the filter being configured to receive the environmental reference signal and the motion signal and filter the motion signal based on the environmental reference signal to derive the target motion signal.

10. The motion detection system of any of claims 1-9, wherein, The sensor is a millimeter wave radar sensor.

11. An imaging system, characterized by The imaging system comprises an imaging device and the motion detection system according to any one of claims 1-10.

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