Hybrid continuous positive pressure and surface imaging system and method

Abstract

The present application discloses a hybrid continuous positive pressure and surface imaging system and method wherein the hybrid continuous positive pressure and surface imaging system comprises: a positive pressure unit adapted to apply a continuous positive pressure to a lung of a patient during radiotherapy; a surface camera system configured to capture body surface images of the patient continuously or at intervals; and a processing unit configured to model thoracic and / or abdominal movement of the patient in response to the applied continuous positive pressure continuously or at intervals based on the body surface image.

Description

Technical Field

[0001] The present invention relates to a hybrid continuous positive pressure and surface imaging system for use in a radiation therapy system. The present invention also relates to a computer implemented method for providing real-time feedback to a positive pressure unit. Background Art

[0002] Radiation therapy is a treatment modality that uses ionizing radiation, usually provided as part of tumor treatment to control or kill malignant cells, and is usually delivered by a linear accelerator. Radiation therapy is effective against many types of tumors if they are localized to one area of ​​the body. The radiation in the radiation beam does not distinguish between healthy and malignant cells and therefore can damage healthy cells as well as malignant cells. For this reason, the radiation beam must usually be precisely configured and targeted to the malignant target site to concentrate the radiation energy at the malignant site and minimize the radiation energy deposited into surrounding healthy tissue.

[0003] Conventional methods of depositing radiation energy via a therapeutic radiation beam to a malignant site that exhibits motion during irradiation may include forming a radiation beam large enough so that the malignant site remains within the cross-section of the radiation beam during the entire irradiation process. Respiration-induced tumor motion is a challenge for radiation therapy of tumors in the chest. One strategy to address this challenge is to model the tumor trajectory and generate an internal target volume (ITV), which allows the patient to breathe freely during treatment. However, this approach is associated with a larger amount of normal lung tissue receiving an ablative dose of radiation than other motion management strategies.

[0004] Recently, Continuous Positive Airway Pressure (CPAP) has been studied as an alternative strategy to reduce tumor motion during radiation therapy. CPAP was initially developed for other purposes, such as the treatment of obstructive sleep apnea, intubation, and a non-invasive alternative to other non-invasive techniques used in situations such as pulmonary edema, but has been shown to be effective in reducing tumor motion during radiation therapy. It can be used in conjunction with other techniques that address tumor motion caused by breathing. It has a particularly strong effect in heavy particle radiation of thoracic tumors, where motion may cause inappropriate dose deposition. However, there are also multiple associated difficulties with the use of this technology. One example is determining the optimal CPAP pressure for a specific patient, which is a difficult and time-consuming task. Anxiety may also have a significant impact on breathing patterns. Summary of the invention

[0005] The present invention relates to a hybrid continuous positive pressure and surface imaging system used in a radiotherapy system, the hybrid continuous positive pressure and surface imaging system comprising:

[0006] a positive pressure unit (PPU) adapted to apply continuous positive pressure to the patient's lungs during radiation therapy;

[0007] a surface camera system configured to capture images of the patient's body surface continuously or at regular intervals; and

[0008] A processing unit is configured to model the patient's chest and / or abdominal movement in response to the applied continuous positive pressure continuously or at certain intervals based on the body surface image.

[0009] The inventors have realized that by using a surface camera system to capture images of the patient's body surface continuously or at intervals and to model chest and / or abdominal movements continuously or at intervals, preferably substantially real-time feedback is provided to the PPU. This has several advantages and possible applications. Determining the optimal CPAP pressure for a specific patient can be a difficult and time consuming task. The system of the present invention can enable a CPAP training process to be performed outside of a radiation therapy room prior to radiation therapy, where only the PPU, the surface camera system, and the processing unit are required.

[0010] Radiation therapy typically involves a planning or simulation process. The simulation may be performed in a simulation room, which may be the same as the treatment room. The simulation may include, for example, scanning, positioning the patient and aligning the radiation therapy beam, and preparing for a complete radiation therapy session, wherein doses are calculated and modeling of targets and organs at risk is performed. The hybrid continuous positive pressure and surface imaging system of the present invention may be used as an integral part of a radiation therapy system, but may also be used independently outside of a radiation therapy room prior to a radiation therapy session.

[0011] A surface camera system and a processing unit configured to model the patient's chest and / or abdominal movement, either continuously or at intervals, provides a system that can be used to train a patient to reliably reproduce a stable, shallow breathing pattern with limited ventilation and limited chest wall and / or abdominal movement, thereby achieving the same conditions during simulation and treatment. The system can provide a signal representing chest wall / abdomen movement that is sensitive to small changes in CPAP pressure. The effectiveness of the PPU in maintaining chest position throughout the respiratory cycle can be determined by a hybrid continuous positive pressure and surface imaging system. A feedback mechanism, preferably substantially real time, can enable the operator to adjust the positive pressure (force) to the point where chest movement is within predetermined limits. According to one embodiment, this can be done by automatically increasing the pressure in a controlled manner across a determined variable speed time period until the chest movement is within predetermined limits or the pressure reaches a predetermined limit.

[0012] The system may also be used to detect and monitor abnormal and unpredictable increases in chest wall and abdominal motion in anxious patients. Another application of the hybrid continuous positive pressure and surface imaging system may be a configuration in which the system provides synchronized feedback of the radiation beam and / or terminates operation of the radiation beam when there is a deviation in height, shape, or motion of the patient's chest and / or abdomen from the expected height, shape, or motion of the patient's chest and / or abdomen or when there is a surface deviation caused by changes in lung volume.

[0013] The positive pressure unit may typically include an air pump unit, a flow tube, and a control unit configured to control the positive pressure unit. The positive pressure unit may also include a power source such as a rechargeable battery and a wireless communication unit for communicating with the surface camera system directly or through another unit. The processing unit may be located in any one of the positive pressure unit and the surface camera system or in another unit. The positive pressure unit may be configured to slow down and reduce the movement of the diaphragm during breathing and expand the lungs and chest cavity.

[0014] A surface camera system configured to capture body surface images of a patient continuously or at intervals may include one or more three-dimensional cameras and / or one or more two-dimensional cameras. The processing unit may be configured to model the patient's chest and / or abdominal movements continuously or at intervals based on the body surface images from the camera. There are several possible technologies and camera systems that can be used as surface camera systems, including systems provided by Vision RT and described in multiple earlier patents and patent applications, including US7889906, US7348974, US8135201, US2015 / 062303, US2015 / 0265852, US2020 / 0184625, US10,441,818, US2016 / 0256710, the disclosures of which are incorporated herein by reference.

[0015] In a non-limiting example, a three-dimensional model of a patient's surface is generated using a plurality of stereoscopic video images of at least a thorax and / or an abdominal region of the patient. The video images are processed to generate a three-dimensional model of the thorax and / or the abdominal region that is rapidly updated to reflect changes in movement of the thorax and / or the abdominal region.

[0016] In order to update the surface model of the patient as quickly as possible, a variety of techniques can be used. In one embodiment, an image processing method is provided, comprising the following steps: acquiring a stereoscopic image of an individual; generating a surface model of the individual using the stereoscopic image; receiving another stereoscopic image of the individual and generating another model of the individual from the other stereoscopic image and the previous model of the individual.

[0017] According to one non-limiting embodiment, a speckle pattern of light is projected onto a surface of a chest and / or abdominal region of a patient to facilitate identification of corresponding portions of the patient's surface captured from different angles. An image of the patient is obtained and processed along with data determining the relative position of a camera that captured the image to determine the 3D positions of a large number of points corresponding to points on the patient's surface. Another example of a surface camera system monitors the position of a patient undergoing radiation therapy by projecting structured light (e.g., laser) in the form of straight lines or a grid pattern or other predetermined pattern onto the patient's surface and generating a model of the surface of the monitored patient based on the appearance of the projected pattern in the captured images. Based on the model of the surface, which may be the surface of the patient's chest and / or abdominal region, the movement of the patient's chest and / or abdominal region may be continuously modeled.

[0018] The present invention also relates to a computer-implemented method for providing real-time feedback to a positive pressure unit. The method comprises the steps of:

[0019] Continuous positive pressure data are obtained from the continuous positive pressure applied to the patient's lungs during radiation therapy;

[0020] Using a surface camera system to capture images of the patient's body surface continuously or at regular intervals; and

[0021] The patient's chest and / or abdominal movements in response to the applied continuous positive pressure are modeled continuously or at intervals based on the body surface image.

[0022] As will be appreciated by those skilled in the art, the computer-implemented method of providing real-time feedback to a positive pressure unit disclosed herein may be performed using the hybrid continuous positive pressure and surface imaging system of any embodiment disclosed herein, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described below with reference to the accompanying drawings, which are provided only as examples of implementation, but not limitation, of the hybrid continuous positive pressure and surface imaging system and computer-implemented method for providing real-time feedback to a positive pressure unit disclosed herein.

[0024] Figure 1 An embodiment of a hybrid continuous positive pressure and surface imaging system disclosed herein for use in a radiation therapy system is shown;

[0025] Figure 2 A flow chart showing a computer-implemented method for providing real-time feedback to a positive pressure unit according to the disclosure herein;

[0026] Figure 3 shows a front perspective view of an embodiment of a surface camera system;

[0027] Figure 4A schematic block diagram of an embodiment of a processing unit of a hybrid continuous positive pressure and surface imaging system disclosed herein is shown. DETAILED DESCRIPTION

[0028] The present invention relates to a hybrid continuous positive pressure and surface imaging system used in a radiotherapy system, the hybrid continuous positive pressure and surface imaging system comprising:

[0029] a positive pressure unit (PPU) adapted to apply continuous positive pressure to the patient's lungs during radiation therapy;

[0030] a surface camera system configured to continuously capture images of a body surface of a patient; and

[0031] A processing unit is configured to continuously model the patient's chest and / or abdominal movement in response to the applied continuous positive pressure based on the body surface image.

[0032] The description of the implementation of the hybrid continuous positive pressure and surface imaging system disclosed herein is provided by way of example, but is not intended to limit the scope of the invention. The described embodiments include different features, not all of which are necessarily required in all implementations of the invention. Some implementations utilize only some of the features or possible combinations of features. For those skilled in the art, changes to the described implementation of the present invention and implementations that include different combinations of the features mentioned in the described implementations can be made.

[0033] By using a surface camera system to continuously capture images of the patient's body surface and to continuously model chest and / or abdominal movements, a system with real-time feedback to the PPU can be obtained. This has several advantages and possible applications. For example, it enables the use of a portable PPU. Determining the optimal CPAP pressure for a specific patient can be a difficult and time-consuming task. The system of the present invention can enable a CPAP training or preparation process to be performed outside the radiotherapy room before radiotherapy, where only the PPU, the surface camera system and the processing unit are required. The portable PPU can remain in use after the CPAP training or preparation process so that controlled breathing is maintained. The device can be carried or pushed between the radiotherapy room and a second location or room.

[0034] The inventors have realised that by using a surface camera system to continuously capture images of the patient's body surface and to continuously model chest and / or abdominal movements, a system with preferably substantially real-time feedback to the PPU is provided. This has several advantages and possible applications. Determining the optimal CPAP pressure for a particular patient can be a difficult and time consuming task. The inventive system can enable a CPAP training process to be performed outside of a radiotherapy room prior to radiotherapy treatment, where only a PPU, a surface camera system and a processing unit are required.

[0035] "Continuous" should be interpreted broadly to include receiving a sequence of images and modeling at any appropriate rate. In this regard, as an example, it is well known that a sequence of static images at a given rate creates the illusion of moving images. This can be transferred to the hybrid continuous positive pressure and surface imaging system and method disclosed herein, where the surface camera system can be configured to capture images of the patient's body surface at a certain rate.

[0036] Figure 1 A non-limiting example of a hybrid continuous positive pressure and surface imaging system 100 for use in a radiotherapy system 200 is shown. The radiotherapy system 200 can be any suitable radiotherapy system and can typically include a radiation beam generator such as a gated radiation beam generator, which typically includes a linear particle accelerator suitable for generating a radiation beam for irradiating a target. The gated radiation beam generator is typically an external device or system. The radiotherapy system can also include a controller for controlling the radiation beam generator. The radiotherapy system can be a conventional two-dimensional radiation beam system, but can also be, for example, a three-dimensional radiation beam system, an intensity modulated radiation therapy (IMRT) system, a volume modulated arc therapy (VMAT) system, or a heavy particle radiation beam system, such as a proton or carbon ion beam based system. In Figure 1 In the example of , a radiation beam 210 is generated toward a target 320, which may be a tumor in a patient 300 located on an examination table 150. The positive pressure unit 110 is configured to apply continuous positive pressure to the lungs of the patient 300 during radiation therapy. The positive pressure unit 110 includes an air pump unit 111 and a flow tube 112 connected to the airway of the patient 300 via a mask 113. The surface camera system 120 is configured to continuously capture body surface images of the patient 300, in particular, surface images of the chest and / or abdominal region 310 of the patient 300. The processing unit 130 is configured to continuously model the chest and / or abdominal movements of the patient 300 in response to the applied continuous positive pressure based on the body surface images from the surface camera system 120. The control unit 140 is configured to control the positive pressure unit 110 and / or the radiation therapy system 200.

[0037] The processing unit is configured to continuously extract a magnitude metric that can be converted into chest and / or abdominal movement. The magnitude metric can be any suitable metric, such as a change in the height of the patient's chest wall or abdomen. The height of the chest wall can be understood as a quantity perpendicular to the surface of the patient's chest. Figure 1 The height of the abdomen is defined as the height perpendicular to the patient's abdominal surface.

[0038] The processing unit may be configured to continuously model chest and / or abdominal motions with six degrees of freedom (6DOF) based on images from a surface camera system. "6DOF" generally refers to the degrees of freedom of motion of a rigid body in three-dimensional space. Specifically, the rigid body is free to change position by forward / backward (swing), up / down (heave), left / right (swing) transformations in the directions of three perpendicular axes, combined with changes in direction achieved by rotation around three perpendicular axes, commonly referred to as pitch (vertical axis), pitch (lateral axis), and roll (longitudinal axis). The processing unit may be configured to continuously model chest and / or abdominal motions based on body surface images obtained from a surface camera system.

[0039] In an embodiment, the processing unit is configured to continuously extract the amplitude of the chest height movement during the breathing cycle. Alternatively or additionally, the processing unit may be configured to detect deviations in the height, shape or movement of the patient's chest and / or abdomen. The extraction of the height, shape or movement of the patient's chest may be extracted from a model of the chest and / or abdomen movement, for example from a continuously modeled six degrees of freedom (6DOF) chest and / or abdomen movement.

[0040] In an embodiment, the processing unit is configured to distinguish patient movement from chest and / or abdominal movement. Based on a surface model, which surface may be a surface of a chest and / or abdominal region of the patient, or based on, for example, a comparison with other modeled references of the patient, the system may distinguish total patient movement from local chest and / or abdominal movement. The processing unit may be configured to distinguish patient movement from chest and / or abdominal movement based on modeled chest and / or abdominal movement of the patient. The processing unit may be configured to distinguish patient movement from chest and / or abdominal movement based on a body surface image.

[0041] Feedback from the surface camera system can be used in multiple applications. In one embodiment, the control unit is configured to optimize continuous positive pressure based on the patient's chest and / or abdominal movement of continuous modeling to minimize the patient's chest and / or abdominal movement. As those skilled in the art will appreciate, the control unit and the processing unit may be provided as separate devices or may be provided as one unit. The control unit and the processing unit may form a part of any other part of the system such as a surface camera system, a radiotherapy system or a positive pressure unit. The control unit may be configured to optimize continuous positive pressure based on body surface images to minimize the patient's chest and / or abdominal movement. The control unit may be configured to optimize continuous positive pressure based on modeled patient's chest and / or abdominal movement to minimize the patient's chest and / or abdominal movement.

[0042] The hybrid continuous positive pressure and surface imaging system can be configured to continuously model the patient's chest and / or abdominal motion in substantially real time. For example, this can be performed by acquiring a body surface image of the patient, particularly a body surface image of the patient's chest and / or abdominal region, and using the body surface image in a physiological model of the patient to model the chest and / or abdominal motion. The body surface image can then be converted into a model of the chest and / or abdomen using the patient's physiological model.

[0043] The hybrid continuous positive pressure and surface imaging system disclosed herein may also include a control unit configured to control continuous positive pressure to keep chest and / or abdominal movement within predetermined limits. The monitoring feedback mechanism thus enables the operator to adjust the positive pressure to a point where chest movement is within predetermined limits or minimized. The monitoring feedback mechanism enables automatic adjustment of positive pressure to a point where chest movement is within predetermined limits or minimized. This is usually done in a built environment, but if excessive chest movement is detected in the treatment room, the pressure can be adjusted to the correct pressure for the situation. In one embodiment, the continuous positive pressure is gradually increased until the chest and / or abdominal movement is within predetermined limits. For example, the positive pressure can be automatically increased in a controlled manner across a determined variable speed time period until a consistent chest position is obtained or the positive pressure reaches a predetermined limit. The control unit may be configured to control continuous positive pressure based on a body surface image to keep chest and / or abdominal movement within predetermined limits. The control unit may be configured to control continuous positive pressure based on modeled patient chest and / or abdominal movement to keep chest and / or abdominal movement within predetermined limits.

[0044] The positive pressure unit preferably includes an air pump unit and a flow tube. The air pump unit may include a blower. In one embodiment, the positive pressure unit includes an air duct connected to a blower having an integrated attachment for pressure and volume measurement and a nozzle for connecting a hose. The PPU may also include a control unit configured to control the positive pressure unit. In one embodiment, the control unit provides a signal for adjusting the continuous positive pressure provided by the positive pressure unit. For example, the speed of the blower can be controlled by pulse width modulation (PWM), which allows fine speed regulation and provides a signal proportional to the fan speed. Other suitable methods for controlling the positive pressure unit are also possible. The PPU can detect changes in pressure and adjust the fan speed accordingly to maintain the required pressure.

[0045] The positive pressure unit may be configured to apply air pressure to the patient's airway to expand the lungs and elevate the chest and minimize chest movement during the course of radiation therapy. This provides the benefit of stabilizing the chest position while moving the heart away from the left chest. This also increases lung volume thereby redistributing dose away from normal lung tissue and reducing tumor movement in the lungs. This has the advantage of reducing unplanned lung and heart doses during radiation therapy.

[0046] The positive pressure unit may be configured to perform surgery at a target site in the chest or abdominal region of the patient's body and to limit movement of the target site due to respiratory motion during the surgery. The positive pressure unit may be configured to provide continuous positive ventilation pressure to the patient's lungs during and / or prior to a radiation therapy procedure to limit movement of the target site, expand the chest cavity and lungs, and / or displace organs and tissues in the chest cavity to a distance from the target site.

[0047] The hybrid continuous positive pressure and surface imaging system may also include a pressure measurement unit for measuring lung pressure. The processing unit may be configured to compare the measured lung pressure with the desired lung pressure. The processing unit may also be configured to verify the mismatch between the measured lung pressure and the desired lung pressure based on continuously modeled chest and / or abdominal movements. If there is a mismatch between the measured lung pressure and the desired lung pressure, an error condition may be marked. This may signal the control unit, which may notify the operator. Similarly, radiation beam retention may signal the radiotherapy system. The measurement unit may also be suitable for measuring lung capacity and / or measuring from around the mask or in a connection to the mask. The positive pressure unit may also include a power source such as a rechargeable battery and a wireless communication unit for communicating directly or via another unit with the surface camera system. The PPU may be a portable PPU.

[0048] The hybrid continuous positive pressure and surface imaging system disclosed herein may be configured to store patient-specific pressure settings for individual patients. This may allow for reproducibility of breathing patterns. The disclosed hybrid continuous positive pressure and surface imaging system may continuously measure and / or monitor multiple parameters. For example, if the measured pressure exceeds a predetermined tolerance, or the tidal volume exceeds a determined tolerance, an error condition may be marked. The hybrid continuous positive pressure and surface imaging system may include a monitoring system, such as in the form of an application running on a processing unit that checks the pressure of the PPU or error conditions from the PPU at certain intervals. When transitioning between the preparation room and the treatment room, the monitoring system may be deactivated for a preset period of time.

[0049] CPAP can be configured to slow down and reduce the movement of the diaphragm during breathing and to expand the lungs and chest. CPAP can thereby reduce the movement of tissues and organs in the chest and abdominal regions caused by the patient's breathing, thereby reducing the movement of the target of the radiotherapy system during irradiation. The expansion of the lungs and chest tends to reposition and increase the spacing between the organs in the chest and abdomen. The reduction in the movement of the target site and other organs and tissues in the chest and abdominal regions of the patient is conducive to the delivery of medical devices or agents to the target site and contributes to reducing the possible collateral damage to tissues outside the target site that originates from the delivery of medical devices or agents. The expansion of the lungs and chest and the resulting repositioning and separation of organs in the chest and abdomen can also be conducive to the delivery of medical devices or agents to the target site and reduce the possible collateral damage to tissues outside the target site that originates from the delivery of medical devices or agents.

[0050] The surface camera system configured to continuously capture body surface images of the patient may include one or more three-dimensional cameras and / or one or more two-dimensional cameras. The processing unit may be configured to continuously model the patient's chest and / or abdominal movements based on the body surface images from the cameras. There are several possible technologies and camera systems that can be used as the surface camera system, including the system provided by Vision RT.

[0051] According to a non-limiting example, the surface camera system may be adapted to provide a stereoscopic body surface image of a patient. Stereoscopic images of the patient may be acquired and processed to generate data defining the 3D positions of a large number of points corresponding to points on the imaged patient surface.

[0052] One embodiment of a surface camera system is Figure 3 Shown in. Figure 3 1 is a front perspective view of an exemplary surface camera system 120. In this example, the surface camera system 120 includes a housing 123 connected to a support 121 via a hinge 122. The support 121 enables the surface camera system 120 to be connected to the ceiling of the treatment room in a fixed position, while the hinge 122 allows the direction of the surface camera system 120 to be oriented relative to the support 121 so that the surface camera system 120 can be arranged to see the patient 300 on the examination table 150. A pair of lenses 125L / 125R are mounted at both ends of the front surface 124 of the housing of the surface camera system 120. These lenses 125L / 125R can be located in front of an image capture device / camera contained in the housing 123, such as a CMOS active pixel sensor or a charge coupled device. The camera / image detector is preferably arranged behind the lenses 125L / 125R to capture an image of the patient 300 through the lenses 125L / 125R.

[0053] In this example, the speckle projector 126 is provided in the middle of the front surface 124 of the housing 123 and is located between the two lenses 125L / 125R in the surface camera system 120, as shown in FIG. Figure 3 . In this example, the speckle projector 126 is arranged to illuminate the patient 300 with a non-repeating speckle pattern of light, such as red light, so that when an image of the patient 300 is captured by two image detectors installed in the surface camera system 120, corresponding parts of the captured image can be more easily distinguished. To this end, the speckle projector includes a light source, such as an LED, and a film on which a random speckle pattern is printed. In use, light from the light source is projected through the film so that a pattern composed of light and dark areas is projected onto the surface of the patient 300. In some monitoring systems, the speckle projector 126 can be replaced by a projector arranged to project structured light (such as a laser) in the form of a straight line or grid pattern onto the surface of the patient 300.

[0054] Figure 4 A schematic block diagram of an embodiment of a processing unit is shown. To enable the processing unit 130 to process images received from the surface camera system 120, the processing unit 130 is configured into a plurality of functional modules 131-135, either by software configuration provided on a disk or by receiving electrical signals via a communications network. In this example, the functional modules 131-135 include: a 3D position determination module for processing images received from the surface camera system 120; a model generation module 132 for processing data generated by the 3D position determination module 131 and converting the data into a 3D screen model of the imaged computer surface; a generated model memory 133 for storing a 3D screen model of the imaged surface; a target model memory 134 for storing previously generated 3D screen models; and a matching module 135 for determining the rotation and translation required to match the generated model to the target model. In use, images are obtained by the surface camera system 120 and these images are processed by the 3D position determination module 131. This processing enables the 3D position determination module 131 to determine the 3D positions of corresponding points in the multiple pairs of images on the surface of the patient 300. In the exemplary system, this is achieved by the 3D position determination module 131 determining corresponding points in the multiple pairs of images obtained by the surface camera system and then determining the 3D positions of those points based on the relative positions of the corresponding points in the multiple pairs of images obtained and the stored camera parameters of the surface camera system 120.

[0055] The hybrid continuous positive pressure and surface imaging system disclosed herein is not limited to the surface camera system 120 and processing unit 130 of the above example. Another example of a surface camera system includes a sheet that can be placed on a patient, for example, on the surface of the patient's chest and / or abdomen. Preferably, at least a portion of the sheet is colored. The surface camera system can be used to obtain an image of the patient and the sheet. The model generation module can be used to process the image obtained by the surface camera system to generate a model of the surface of a portion of the patient that appears in the image. In some embodiments, the system may further include a projector that can be used to project a light pattern onto the patient. In such an embodiment, preferably, the colored portion of the sheet is configured to absorb a considerable proportion of the projection light projected by the projector, so that the projected pattern is not easily visible (clearly visible) in the portion of the image corresponding to the sheet. This can be achieved by the color of the sheet being substantially black to absorb a considerable proportion of the projection light. In other embodiments, the color of the sheet can be selected to correspond to a color associated with the wavelength of the projection light, so that the light projected onto the surface of the sheet is not easily visible. In some embodiments, the sheet can be colored black.

[0056] The surface camera system may be adapted to provide a stereoscopic body surface image of the patient. The processing unit may accordingly be configured to process the stereoscopic body surface image and generate a model of the patient's chest surface.

[0057] The radiotherapy system can be a conventional two-dimensional radiation beam system, but can also be, for example, a three-dimensional radiation beam system, an intensity modulated radiation therapy (IMRT) system, or a volumetric modulated arc therapy (VMAT) system. The radiotherapy system can be an external radiation beam therapy system. There are a variety of techniques available, including conventional external radiation beam therapy using a medical linear accelerator. Typically, the treatment is simulated before treatment. The purpose of the simulation is to accurately aim or locate the mass to be treated. The technology has been confirmed and is generally fast and reliable. The difficulty is that some high-dose treatments may be limited by the radiation toxicity capacity of healthy tissue located near the target tumor mass. Other types of feedback control systems are stereotactic radiation, intensity modulated radiation therapy, and volumetric modulated arc therapy. The hybrid continuous positive pressure and surface imaging system disclosed herein is not limited to any particular type of radiotherapy system. The radiotherapy system may typically include a radiation beam generator suitable for generating a radiation beam for irradiating the target mass.

[0058] It may be possible to use additional systems such as fluoroscopy-based systems to track tumor motion.

[0059] The control unit may be configured to terminate the operation of the radiation beam when the height or shape of the extracted patient's chest and / or abdomen deviates from the desired height or shape of the patient's chest and / or abdomen. In another embodiment, the control unit is configured to synchronize the radiation beam with the height or shape of the extracted patient's chest.

[0060] The present invention also relates to a computer-implemented method for providing real-time feedback to a positive pressure unit. The method comprises the steps of:

[0061] obtaining continuous positive pressure data from continuous positive pressure applied to the patient's lungs during radiation therapy; continuously capturing body surface images of the patient using a surface camera system; and continuously modeling chest and / or abdominal movement of the patient in response to the applied continuous positive pressure based on the body surface images.

[0062] Figure 2 A flow chart is shown for an embodiment of a computer-implemented method (400) for providing real-time feedback to a positive pressure unit according to the disclosure herein. The method includes the steps of obtaining continuous positive pressure data from continuous positive pressure applied to a patient's lungs during radiation therapy (410); continuously capturing a body surface image of the patient using a surface camera system (420); and continuously modeling a chest and / or abdominal movement of the patient in response to the applied continuous positive pressure based on the body surface image (430). The method may also include the step of applying continuous positive pressure to the patient's lungs during radiation therapy. The method may also include the steps of optimizing the continuous positive pressure to minimize chest and / or abdominal movement of the patient and / or controlling the continuous positive pressure to keep chest and / or abdominal movement within predetermined limits.

[0063] The method may be implemented as a computer program having instructions that, when executed by a computing device or computing system, cause the computing device or computing system to perform the method of providing real-time feedback to a positive pressure unit. A non-transitory storage medium may include a computer program product having instructions embodied thereon that, when executed by a computing device or system, cause the computing device or system to provide real-time feedback to a positive pressure unit.

Claims

1. A hybrid continuous positive pressure and surface imaging system for use in a radiotherapy system, include: a positive pressure unit adapted to apply continuous positive pressure to the patient's lungs during radiation therapy; a surface camera system configured to capture images of a patient's body surface continuously or at intervals; and A processing unit is configured to model the patient's chest and / or abdominal movement in response to the applied continuous positive pressure continuously or at certain intervals based on the body surface image.

2. The hybrid continuous positive pressure and surface imaging system according to claim 1, in, The processing unit is configured to extract, continuously or at intervals, amplitude measures convertible to chest and / or abdominal movements.

3. The hybrid continuous positive pressure and surface imaging system according to claim 1, in, The processing unit is configured to extract the height of the patient's chest wall or abdomen continuously or at certain intervals.

4. The hybrid continuous positive pressure and surface imaging system according to claim 1, in, The processing unit is configured to model chest and / or abdominal motion in six degrees of freedom, either continuously or at certain intervals.

5. The hybrid continuous positive pressure and surface imaging system according to claim 1, in, The processing unit is configured to extract the amplitude variation of the chest and / or abdomen height direction movement during the breathing cycle.

6. The hybrid continuous positive pressure and surface imaging system of claim 1, in, The processing unit is configured to detect deviations in height, shape or movement of the patient's chest and / or abdomen.

7. The hybrid continuous positive pressure and surface imaging system of claim 1, in, The processing unit is configured to differentiate between patient movement and chest and / or abdominal motion based on the body surface image.

8. The hybrid continuous positive pressure and surface imaging system of claim 1, further comprising a control unit configured to optimize the continuous positive pressure based on the body surface image to minimize chest and / or abdominal movement of the patient.

9. The hybrid continuous positive pressure and surface imaging system of claim 1, in, The processing unit is configured to model the patient's chest and / or abdominal movements continuously or at intervals in substantially real time.

10. The hybrid continuous positive pressure and surface imaging system of claim 1, further comprising a control unit configured to control continuous positive pressure based on the body surface image to keep chest and / or abdominal motion within predetermined limits.

11. The hybrid continuous positive pressure and surface imaging system of claim 10, in, The continuous positive pressure is gradually increased until chest and / or abdominal movement is within predetermined limits.

12. The hybrid continuous positive pressure and surface imaging system of claim 1, in, The positive pressure unit includes an air pump unit and a flow tube.

13. The hybrid continuous positive pressure and surface imaging system of claim 12, in, The air pump unit includes a blower.

14. The hybrid continuous positive pressure and surface imaging system of claim 1, further comprising a control unit configured to control the positive pressure unit based on the body surface image.

15. The hybrid continuous positive pressure and surface imaging system of claim 14, in, The control unit provides a signal for adjusting the continuous positive pressure provided by the positive pressure unit.

16. The hybrid continuous positive pressure and surface imaging system of claim 1, further comprising a pressure measurement unit for measuring lung pressure.

17. The hybrid continuous positive pressure and surface imaging system of claim 16, in, The processing unit is configured to compare the measured lung pressure with the desired lung pressure, wherein the processing unit is further configured to verify a mismatch between the measured lung pressure and the desired lung pressure with reference to continuously modeled chest and / or abdominal movements.

18. The hybrid continuous positive pressure and surface imaging system of claim 1, in, The surface camera system is adapted to provide a stereoscopic body surface image of a patient.

19. The hybrid continuous positive pressure and surface imaging system of claim 18, in, The processing unit is configured to process the stereoscopic body surface image and generate a model of the patient's chest and / or abdominal surface.

20. The hybrid continuous positive pressure and surface imaging system of claim 1, further comprising a radiation beam generator adapted to generate a radiation beam for irradiating a target mass.

21. The hybrid continuous positive pressure and surface imaging system of claim 20, in, The control unit is configured to terminate operation of the radiation beam when the height, shape or motion of the patient's chest and / or abdomen deviates from an expected height, shape or motion of the patient's chest and / or abdomen or when a surface deviation occurs due to changes in lung volume.

22. The hybrid continuous positive pressure and surface imaging system of claim 20, in, The control unit is configured to synchronize the radiation beam with the extracted height or shape of the patient's chest and / or abdomen.

23. The hybrid continuous positive pressure and surface imaging system of claim 17, in, The control unit is configured to terminate operation of the radiation beam when a mismatch occurs.

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