System and method for assessing pulmonary function based on surface topographic measurements

Abstract

A surface topographic scanner is configured to capture surface topography images of a patient. Surface topography image data of the patient is received from the surface topographic scanner. Inhalation image data relating to the patient performing an inhalation is determined based on the received surface topography images data. Exhalation image data relating to the patient performing an exhalation is determined based on the received surface topography image data. A patient surface volume differential of the patient is determined based on the determined inhalation image data and the determined exhalation image data. A pulmonary function of the patient is determined based on the patient surface volume differential.

Description

SYSTEM AND METHOD FOR ASSESSING PULMONARY FUNCTION BASED ON SURFACE TOPOGRAPHIC MEASUREMENTSField of the Invention

[0001] The present invention relates to systems and methods for assessing a patient’s pulmonary function utilizing surface topographic measurements.Background

[0002] Spirometry, gas dilution, and body plethysmography are the gold standards for pulmonary function tests (PFTs). However, many patients struggle to complete these tests, or suboptimal results are obtained, because of a patient’s inability to follow directions, wear the required nose or mouthpiece, or endure prolonged periods of deep breathing.Brief Summary of the Invention

[0003] A system for determining pulmonary function of a patient is disclosed including a surface topographic scanner and a processor. The surface topographic scanner is configured to capture surface topography images of a patient. The processor configured to receive surface topography image data of the patient from the surface topographic scanner, determine, based on the received surface topography image data, inhalation image data relating to the patient performing an inhalation, determine, based on the received surface topography image data, exhalation image data relating to the patient performing an exhalation, determine a patient surface volume differential of the patient based on the determined inhalation image data and the determined exhalation image data, and determine a pulmonary function of the patient based on the determined patient surface volume differential.

[0004] In an aspect, the processor is configured to determine at least one template body surface model; perform a fitting of the at least one template body surface model with the inhalation image data and a fitting of the at least one template body surface model with the exhalation image data; and determine an inhalation volume of a portion of the patient based on the fitting of the at least one template body surface model with the inhalation image data and an exhalation volume of the portion of the patient based on the fitting of the at least one template body surface model with the exhalation image data.

[0005] In an aspect, the processor is configured to determine the patient surface volume differential based on the determined inhalation volume and the determined exhalation volume. In an aspect, the processor is configured to determine a surface geometry of the subject via the inhalation image data and the exhalation image data. In an aspect, the processor is configured to use the template body surface model as a starting point to fit one or more portions of the template body surface model with one or more portions of the surface geometry.

[0006] In an aspect, the inhalation image data relates to at least one image of the patient performing a normal inhalation and the exhalation image data relates to at least one image of the patient performing a normal exhalation. In an aspect, inhalation image data relates to at least one image of the patient performing a maximum inhalation and the exhalation image data relates to at least one image of the patient performing a maximum exhalation. In an aspect, the inhalation image data relates to a plurality of images over a predetermined time period. In an aspect, the received inhalation image data and the received exhalation image data relates to an image of the torso of the patient, and the determined patient surface volume differential is a torso volume differential of the patient.

[0007] In an aspect, the processor is configured to generate 3D reconstructions based on the received surface topography image data. In an aspect, the processor is configured to determine the patient surface volume differential based on the generated 3D reconstructions.

[0008] In an aspect, the inhalation image data relates to a plurality of images over a predetermined time period, and wherein the processor is configured to determine the pulmonary function based on a plot of the patient surface volume differential over the predetermined time period.

[0009] In an aspect, the determined pulmonary function comprises at least one of a Forced Vital Capacity, Vital Capacity, Tidal Volume, Forced Expiratory Volume at 1 second, and / or Flow Volume Loop values.

[0010] In an aspect, the processor is configured to generate 3D reconstructions based on the received surface topography image data. In an aspect, the processor is configured to determine the patient surface volume differential based on the generated 3D reconstructions.

[0011] In an aspect, the step of determining a patient surface volume differential includes generating 3D reconstructions based on the obtained surface topography images; and determining a surface volume differential of the subject based on the generated 3D reconstructions.

[0012] In an aspect, the processor is configured to identify a localized portion of the patient based on the received inhalation image data and the received exhalation image data, wherein the determined patient surface volume differential relates to the localized portion of the patient.Brief Description of the Drawing

[0013] The foregoing summary, as well as the following detailed description of the exemplary embodiments of the subject disclosure, will be better understood when read in conjunction with the appended drawing.

[0014] FIG. 1 is a schematic diagram of a system for measuring pulmonary function of a subject in accordance with an exemplary embodiment of the subject disclosure;

[0015] FIG. 2 is a schematic diagram of image data received and determined by the system of FIG. 1 ;

[0016] FIG. 3 is a schematic diagram of a surface topographic scanner in accordance with an exemplary embodiment of the subject disclosure;

[0017] FIG. 4 is an exemplary graph showing conventional measurements of pulmonary function in a subject;

[0018] FIG. 5 is an exemplary graph showing correlation measurements of conventional pulmonary function test values versus surface topography values determined in accordance with an exemplary embodiment of the subject disclosure;

[0019] FIGS. 6A and 6B are volume surface meshes representing maximum inhalations and exhalations, respectively, of a subject in which the surface meshes are generated by the exemplary system applicable to the subject disclosure;

[0020] FIGS. 7A, 7B are flowcharts of methods for measuring pulmonary function in accordance with exemplary embodiments of the subject disclosure;

[0021] FIG. 8 is a graph showing correlation measurements of spirometer test values versus surface topography values determined in accordance with an exemplary embodiment of the subject disclosure; and

[0022] FIG. 9 is a graph of flow-volume loop data in accordance with an exemplary embodiment of the subject disclosure.Detailed Description

[0023] Reference will now be made in detail to the various exemplary examples of the subject disclosure illustrated in the accompanying drawings. Wherever possible, the same or like reference numbers will be used throughout the drawings to refer to the same or like features. It should be noted that the drawings are in simplified form and are not drawn to precise scale. Certain terminology is used in the following description for convenience only and is not limiting. Directional terms such as top, bottom, left, right, above, below and diagonal, are used with respect to the accompanying drawings. The term “distal” shall mean away from the center of a body. The term “proximal” shall mean closer towards the center of a body and / or away from the “distal” end. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the identified element and designated parts thereof. Such directional terms used in conjunction with the following description of the drawings should not be construed to limit the scope of the subject disclosure in any manner not explicitly set forth. Additionally, the term “a,” as used in the specification, means “at least one.” The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.

[0024] “About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, or ±0.1% from the specified value, as such variations are appropriate.

[0025] “Substantially” as used herein shall mean considerable in extent, largely but not wholly that which is specified, or an appropriate variation therefrom as is acceptable within the field of art. “Exemplary” as used herein shall mean serving as an example.

[0026] Throughout this disclosure, various aspects of the subject disclosure can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the subject disclosure. Accordingly, thedescription of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1 , 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.

[0027] Furthermore, the described features, advantages, and characteristics of the exemplary embodiments of the subject disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the present disclosure can be practiced without one or more of the specific features or advantages of a particular exemplary embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all exemplary embodiments of the subject disclosure.

[0028] Definitions

[0029] “Forced Vital Capacity” (FVC) can be defined as the volume of gas (e.g., air) that can be forcibly exhaled from a subject’s lungs after taking a maximal inhalation.

[0030] “Vital Capacity” (VC) can be defined as the volume of gas (e.g., air) resulting from a maximal exhalation after a maximal inhalation while breathing normally.

[0031] “Total Lung Capacity” (TLC) can be defined as the volume of gas (e.g., air) in the lungs after a maximal inhalation.

[0032] “Forced Expiratory Volume” (FEV) can be defined as the volume of gas (e.g., air) resulting from a subject exhaling as forcibly as possible after a normal inhalation. FEV is measured after a predetermined time, e.g., FEV1 is the FEV after one second.

[0033] “Tidal Volume” (TV) can be defined as the difference in the volume of gas (e.g., air) between a normal inhalation and a normal exhalation.

[0034] “Body Volume Difference” (BVD) can be defined as Body Volume Inhalation minus Body Volume Exhalation.

[0035] “Torso Volume Difference” (TVD) can be defined as Torso Volume Inhalation minus Torso Volume Exhalation.

[0036] The terms “subject” and “patient” may be used interchangeably throughout the disclosure.

[0037] Surface topography (ST) scanning of a subject is a rapid, non-contact, and reproducible method of scanning a subject. Although surface topography scanning can be useful for scanning any subject, surface topography scanning may be particularly useful for patients who are unable to undergo traditional pulmonary function tests (PFTs), such as patients with spinal deformities or learning disabilities. Other imaging modalities exist, such as MRI and CT scans, that can accurately determine lung volumes of subjects, however, such modalities may require sedation of the patient in order to perform lung volume studies. Further, other imaging modalities, such as CT scans, may present radiation upon the patient.

[0038] Non-imaging methods for performing pulmonary function testing exist that do not present radiation upon the patient. Such methods include spirometry and body plethysmography. Although such methods do not present radiation, performing pulmonary function testing via spirometry and body plethysmography is often timeconsuming, uncomfortable for patients, and requires patient compliance. In addition, many patient populations, such as young patients or patients with developmental disabilities (e.g., patients with onset scoliosis), have difficulty performing spirometry due to an inability to follow directions, wear the nose or mouth apparatus, or tolerate the prolonged periods of deep breathing required for the spirometry tests.

[0039] Surface topography, in contrast, is a non-invasive method for evaluating a patient’s body morphology that poses no known risks (e.g., such as ionizing radiation) and does not make physical contact with the patient. Further, with surface scans, such as full body surface scans or torso scans, localized anatomic outputs can be determined. For example, via surface scans the system 100 (described herein) can determine how a portion of a subject deforms during inhalations and / or exhalations, and where the deformities occur. As a result, the surface scanning techniques described herein provide an ability for identifyingspecific portions of the body in which a subject breaths, such as the volume that a subject breaths using their diaphragm versus their rib cage. Further, the surface scanning techniques described herein can be used to diagnose certain diseases (e.g. by paradoxical breathing, and so on). Accordingly, surface topography scanning to determine pulmonary function, as described herein, is an advantageous method of performing pulmonary function testing over methods known in the art.

[0040] In accordance with an exemplary embodiment as shown in FIG. 1 , there is provided a system 100 for measuring pulmonary function using surface topography scanning. The system 100 can measure one or more attributes relating to pulmonary function. For example, the system 100 can measure the volume and / or flow of gas (e.g., air) in which a subject can inhale and / or exhale. Volume and flow measurements can provide information relating to the pulmonary function of the subject, such as resistance and / or constriction information relating to the pulmonary function of the patient. In exemplary embodiments, the system 100 can measure one or more values of a subject including a Forced Vital Capacity of the subject, a Vital Capacity of the subject, a Tidal Volume of the subject, a Forced Expiratory Volume at 1 second of the subject, and so on.

[0041] The system 100 can measure flow volume loop values relating to the subject. FIG. 9 shows a graph of flow volume loop data in accordance with an exemplary embodiment of systems and methods described herein. In particular, FIG. 9 shows how flow volume loop data generated via a spirometry technique relates to flow-volume loop data generated via topography scanning, as described herein. Flow volume loop graph data can be determined based on body volume differences. For example, surface changes of a subject (e.g., surface changes of a subject over time) can be determined via body surface data, which can result in an ease in computing differences in volume.

[0042] The system 100 can be a computerized system having one or more processors 112 or other logic controllers, memories 114, surface topographic scanners 116, displays 118, input devices 120, networks 122, and mobile devices 124. The system 100 can be a fully integrated system or a modular system, e.g., wherein the surface topographic scanner 116 can be modularly integrated thereto. The system 100 is configured via the processor 112 to determine or assess pulmonary function(s) of a patient, as further discussed herein.

[0043] The processor 112 is a programmable control device or processing device that is operatively coupled to one or more memories 114. The processor 112 is configured to access data and process data, and execute computer-readable code. The processor 112 can be a microprocessor, a computer processing unit (CPU), a graphics processing unit (GPU), a neural processing unit, a digital signal processor, a multi-core processor, and so forth. As used herein, “processor,” “processing component,” “processing device,” and / or “processing unit” can be used generically to refer to any or all of the aforementioned specific devices, elements, and / or features of the processing device.

[0044] The memory 114 can be any memory device and / or include a computer processing unit register, a cache memory, a magnetic disk, an optical disk, a solid-state drive, and so forth. The memory 114 can be configured with random access memory (RAM), read-only memory (ROM), static RAM, dynamic RAM, masked ROM, programmable ROM, erasable and programmable ROM, electrically erasable and programmable ROM, and so forth. As used herein, “memory,” “memory component,” “memory device,” and / or “memory unit” can be used generically to refer to any or all of the aforementioned specific devices, elements, and / or features of a memory device. The memory 114 can be a local memory device physically located with the system 100 or a remote memory such as computer data stored on remote or off-site servers and accessible via the internet. In an exemplary embodiment the processor 112 and the memory 114 are operatively in communication. For example, the memory 114 can include computer readable code executable by the processor 112 such that the processor is configured to perform the functions as further described herein.

[0045] The system 100 may communicate with one or more devices such as an input device 120 (e.g., a keyboard, or a pointing device), the display 118, the surface topographic scanner 116, a network 122, and a mobile device 124. The display 118 can be any display known in the art and operatively connected to the system 100 for displaying an output to the user.

[0046] The network 122 can include one or more of a direct or indirect physical communication connection, a mobile communication network, a wireless network, the Internet, the intranet, a Local Area Network, a Wide Area Network (WAN), a Storage Area Network (SAN), and the like. The network 122can include any wired, wireless, or software data communication used to connect two or more components of system 100. For example, the network 122 can be used to connect one or more of the components shown in FIG. 1 with one or more of the other components shown in FIG. 1 , such as the processor 112 being connected to input device 120, display 118, surface topographic scanner 116, network 122, and mobile device 124.

[0047] The mobile device 124 can include one or more of a smartphone, tablet computer, mobile phone, personal digital assistant (PDA), media player, portable multimedia player (PMP), e-book terminal, digital broadcasting terminal, electronic bulletin board, personal computer (PC), laptop computer, television, and the like. The mobile device 124 can receive one or more pieces of data, such as surface topographic image data, from the surface topographic scanner 116 and display such data to a user.

[0048] In an embodiment the mobile device 124 may include one or more of the processor 112, the memory 114, the input device 120, the display 118, and the like. In such embodiments the mobile device 124 can process and determine data, such as the inhalation image data, the exhalation image data, the patient surface volume differential, and the pulmonary function of the patient, as described herein. In other embodiments one or more of the processor 112, the memory 114, the input device 120, the display 118, and the like may be external to the mobile device 124. For example, in an embodiment in which the processor 112 is external from the mobile device 124, the processor 112 can process and determine one or more of the inhalation image data, the exhalation image data, the patient surface volume differential, and the pulmonary function of the patient, and the mobile device 124 can receive such data from the processor 112 via the network 122.

[0049] The processor 112 may be configured to determine a volume of a subject based on reconstructions (e.g., three dimensional (3D) reconstructions). In an exemplary embodiment the volume of the subject may be based on reconstructions of one or more template body surface models and / or surface scans (e.g., 3D surface scans) of the subject. The volume of the subject may include a portion of the subject (e.g., a torso of the subject) or the total body of the subject. That is, in an exemplary embodiment, the processor 112 is configured to determine a volume of a subject’s torso based on reconstructions (e.g., 3D reconstructions) ofone or more template body surface models of a torso and / or surface scans (e.g., 3D surface scans) of the torso of the subject, although in other embodiments the processor 112 can be configured to determine a total body volume of a subject based on reconstructions (e.g., 3D reconstructions) of one or more template body surface models of a total body and / or surface scans (e.g., 3D surface scans) of the total body of the subject.

[0050] In an exemplary embodiment the processor 112 may be configured to determine a volume based on a fitted model surface. In such embodiments the fitted model surface can be based on a template body surface model and a surface geometry and / or surface mesh of the subject derived from a surface scan, as described herein. The template body surface model may be a generic, or template, body surface model 3D mesh model. In an embodiment the template body surface model may be fitted to the surface geometry and / or surface mesh by adjusting parameters of the template body surface model, such as the body shape and pose of the subject.

[0051] FIG. 3 shows an example surface topographic scanner 1 16. The surface topographic scanner 116 may be a scanner capable of measuring the surface topography of a subject in one or more (e.g., three) dimensions. The surface topographic scanner 116 can include a 360 degree camera system and an automated data processing pipeline. In an embodiment the surface topographic scanner 1 16 described in this disclosure may be the 3dMD body system, which is a photogrammetric scanner composed of 30 cameras that may capture full body scans at ten frames per second, although in other embodiments the surface topographic scanner 1 16 can be a different scanner having different components and capabilities useful for measuring the surface topography of a patient.

[0052] In an exemplary embodiment and as described herein, the surface topographic scanner 116 can include one or more processors 302, memories 304, cameras 306, modular camera units 308, input devices 314, output devices 316, and / or laser scanners 318. The one or more cameras 306 may be used to generate a surface mesh of a patient for a given scan of the patient. As used herein, a surface mesh may be one or more data structures that represent a surface (e.g., geometric surface) of the patient, such as a surface of the torso of the patient, the surface of total body of the patient, or the surface of one or more other portions ofthe patient such as the chest, back, and / or abdomen of the subject. In an embodiment, the surface mesh may be a collection of vertices, edges, and faces. The surface mesh representing the surface of the patient may consist of one or more polygonal faces, such as triangles, that cover the patient. In exemplary embodiments and described herein, FIG. 6A shows an example surface mesh of a torso of a patient during a maximum inhalation, and FIG. 6B shows an example surface mesh of a torso of a patient during a maximum exhalation.

[0053] The processor 302 may be a programmable control device or processing device that is operatively coupled to one or more memories 304. The processor 302 may be configured to access data and process data, and execute computer-readable code. The processor 302 can be a microprocessor, a computer processing unit (CPU), a graphics processing unit (GPU), a neural processing unit, a digital signal processor, a multi-core processor, and so forth.

[0054] The memory 304 can be any memory device and / or include a computer processing unit register, a cache memory, a magnetic disk, an optical disk, a solid-state drive, and so forth. The memory 304 can be configured with random access memory (RAM), read-only memory (ROM), static RAM, dynamic RAM, masked ROM, programmable ROM, erasable and programmable ROM, electrically erasable and programmable ROM, and so forth. The input device 314 may include a keyboard, a pointing device, and the like, and the output device 316 may be any device known in the art for displaying an output to the user.

[0055] The camera 306, 310 may include any device useful for capturing images and / or video. The cameras 306, 310 may be a single camera in an embodiment, although in other embodiments 306, 310 may be separate and distinct cameras. In an exemplary embodiment the camera 306, 310 may be an industrial grade machine vision camera, although in other embodiments the camera 306, 310 may include one or more other types of cameras known in the art for capturing images useful for surface topographic images. The projector 312 may include one or more projectors known in the art useful for surface topographic imaging. For example, projector 312 may be a speckle projector that uses laser speckle to measure the surface topography of an object. In such embodiments, variations in the intensity of a projected speckle pattern or other forms of structured light, which may be caused by roughness of the surface, may be analyzed to determine detailedheight variations across the surface of the patient. The detailed height variations may create a 3D map of the topography of the patient.

[0056] In embodiments the surface topographic scanner 1 16 may include one or more lasers or laser components, such as the laser scanner 318. The laser scanner 318 may be used to create a reconstruction (e.g., 3D reconstruction) of surfaces of the patient, such as the surface of the total body of the subject or the torso of the patient. In an embodiment, the processor 1 12 may be configured to determine a volume of a subject’s torso based on the reconstructions (e.g., 3D reconstructions) of the patient as a result of laser scans, although in other embodiments the processor 1 12 may be configured to determine a total body volume of a subject based on reconstructions (e.g., 3D reconstructions) of laser scans of the total body of the subject.

[0057] The surface topographic scanner 1 16 may include one or more modular camera units (MCUs) 308 that may contain one or more (e.g., three) cameras, such as cameras 310. In an embodiment the cameras 310 may include one or more color cameras and one or more black and white cameras. In an exemplary embodiment, a color camera may be configured to generate texture images and one or more (e.g., two) black and white cameras may be configured to generate surface information relating to the patient. The MCU 308 may contain one or more projectors, such as projector 312. As described herein, in an embodiment the projector 312 may be a speckle projector that assists in the creation of digital image correlations between in plane and out of plane displacements, although in other embodiments the projector 312 may be any projector known in the art that is useful in the creation of surface topographic images.

[0058] In accordance with an embodiment, the processor 112 is configured to receive scans (e.g., 3D surface scans) of the subject. The scans (e.g., 3D surface scans) of the subject may be taken during and / or after the subject has performed at least one normal inhalation, at least one normal exhalation, at least one maximal inhalation, at least one maximal exhalation, tidal breathing, and / or at least one maximal exhalation following a maximal inhalation (or vice-versa). The scans may be taken at predefined frame rates, such as 1 , 2, 4, 5, 10, 20, 30, 40, 50, 100 frames per second, for example. The processor 112 receives the scan data (e.g., 3D surface scan data) from the surface topographic scanner 1 16 after the surfacetopographic scanner 116 performs one or more surface scans of the subject. The surface topographic scanner 116 may perform the surface scans in accordance with predetermined protocols, such as a defined positioning of the subject, clothing requirements for the subject, angles in which the subject is scanned by the surface topographic scanner 116, reference points relating to the subject, data acquisition settings (e.g., resolution, scan speed) of the surface topographic scanner 116, postprocessing procedures, and so on.

[0059] Reconstructions (e.g., 3D reconstructions) may be generated. In an exemplary embodiment the reconstructions may be generated based on a template body surface model and / or the scan data (e.g., the 3D surface scan data) provided by the topographic scanner 116. The 3D surface scan data may be based on image data of the subject as described herein. For example, the 3D surface scan data may be based on image data of the subject during and / or after the subject inhaling, exhaling, and so on. In an exemplary embodiment the 3D surface scan data may relate to surface meshes of the subject, such as those shown in FIGS. 6A and 6B and described herein.

[0060] The processor 112 may receive or generate a template body surface model. The template body surface model may be a template body surface model 3D mesh model. The template body surface model can be a template (e.g., generic, pre-designed) 3D mesh representing a surface of the subject, such as the full body surface of the subject or the torso of the subject. The template body surface model can be a generic representation of a subject, although in embodiments the template body surface model can be configured based on patient-specific characteristics of the subject, such as the height of the subject, weight of the subject, gender of the subject, and so on.

[0061] In an exemplary embodiment, the processor 1 12 can use the template body surface model as a starting point to fit one or more portions of the template body surface model with one or more portions of the surface geometry and / or surface mesh of the subject. In an embodiment the processor 112 can fit one or more portions of the template body surface model with one or more portions of the surface mesh of the subject by adjusting the vertices and polygons of the template body surface model to fit the surface geometry and / or surface mesh of the subject.

[0062] In an exemplary embodiment the template body surface model can include a 3D mesh model of one or more portions of a body, such as a 3D mesh model of the torso of the body or a 3D mesh model of the full body. The template body surface model can include an atlas of points defining one or more portions of the surface of the body. A registered mesh may be generated based on fitting the template body surface model to the surface geometry and / or surface mesh of the subject provided by the 3D surface scan. The registered mesh may be generated on one or more (e.g., each) frame in which a 3D surface scan has been generated or provided. For example, in an example in which 3D surface scans are generated at ten frames per second, a registered mesh may be generated at one frame per second, two frames per second, ten frames per second, and so on.

[0063] Each point on the registered mesh may correspond to a point on one or more other scans of the subject. In an exemplary embodiment, each point on the registered mesh may correspond to an anatomical location (e.g., the same anatomical location) on one or more scans of the subject. As a result of the registered mesh, the points (e.g., all of the points) in one or more other 3D surface scans of the patient may have a mapping in which measurements can be defined. For example, as a result of the registered mesh, all points of a 3D surface scan can be mapped to determine volumes (e.g., torso volumes, total body volumes) of the subject during and / or after the subject inhales, exhales, tidal breathes, exhales after inhaling (and vice-versa), and so on. Volumes (e.g., torso volumes, total body volumes) of the patient can be used to determine one or more of the following pulmonary functions of the subject: Forced Vital Capacity, Vital Capacity, Tidal Volume, Forced Expiratory Volume at a predetermined period of time (e.g., 1 second), and / or flow volume loop data.

[0064] The processor 112 is configured to receive scan data (e.g., 3D surface topographic scan data) taken over a predetermined period of time to generate a reconstruction (e.g., 3D reconstruction). As described herein, the reconstruction can be based on the template body surface model and / or the scan data (e.g., 3D surface topographic scan data) over the predetermined period of time. The predetermined period of time can be e.g., .1 , .2, .5, 1 , 1 .5, 2, 2.5, 3, 3.5, 4, 4.5, 5+ seconds, for example.

[0065] FIGS. 7A and 7B show exemplary methods 700, 750, respectively, used to determine a pulmonary function of a patient using a surface topographic scanner, such as the surface topographic scanner 116. In accordance with an exemplary operation, a subject is positioned (e.g., stands or sits) in the center of the scanning system field of view of the surface topographic scanner 116. The subject can be positioned in an ‘A’ pose, which is a position in which the subject stands with feet shoulder width apart and arms abducted about 30 degrees from the sides of the subject. The surface topographic scanner 116 can perform a scan of the subject while the subject performs breaths in different cadences and in different depths. For example, the surface topographic scanner 116 can perform a scan of the subject while the subject breathes normally for a period of time, such as for two seconds, three seconds, four seconds, and so on. The surface topographic scanner 116 can scan the subject while the subject performs inhale and exhale cycles (tidal breathing). The surface topographic scanner 116 can scan the subject while the subject inhales as deeply as possible and / or while the subject exhales as deeply as possible. In embodiments the surface topographic scanner 116 can scan the subject while the subject inhales as deeply as possible and then the subject exhales all air as fast as possible, and vice-versa.

[0066] The scan of the subject is processed to generate reconstructions (e.g., 3D reconstructions) for each frame of the scans. In an exemplary embodiment a frame can include a scan at 0.1 second intervals, although other embodiments may include the frame including a scan at other intervals, such as 0.2, 0.3, 0.4, 0.5, 1 , 1 .5, 2, 3 second intervals, and so on. The volume of the patient, such as the total body volume and / or the torso volume of the patient, can be measured at each frame. Pulmonary function test measurements, such as tidal volume (TV) and forced expiratory volume (FEV) measurements may be estimated.

[0067] In embodiments, one or more regression techniques including linear regression, nonlinear regression, univariate regression, multivariate regression, and machine learning (e.g., neural network) regression can be used to evaluate the relationship between body volume difference (BVD) and standard pulmonary function test (PFT) values. Correlations between body volume difference (BVD) and standard pulmonary function test (PFT) values indicate that BVD techniques, such as the surface topography scanning described herein, can be used to effectively determine pulmonary functions of a subject.

[0068] As shown in FIG. 7A, method 700 shows steps used in accordance with an exemplary embodiment of determining the pulmonary function of a patient using a surface topographic scanner 116. As described herein, the surface topographic scanner 116 scans a subject and generates a surface topographic image of the subject. The surface topographic scanner 116 can scan the subject while the subject is performing one or more types of inhalations. For example, the surface topographic scanner 116 can scan the subject while the subject is performing a normal inhalation and exhalation, a maximum inhalation and exhalation, tidal inhalations and exhalations, as well as one or more combinations of such inhalations and exhalations. In an embodiment, the surface topographic scanner 1 16 can scan the subject while the subject is performing a maximum inhalation followed by a maximum exhalation, and vice-versa. As described herein, tidal inhalations and exhalations can refer to inhalations and exhalations during restful breathing of the subject. The surface topographic scanner 116 produces data, such as surface topographic image data and the like, as a result of the scan of the subject.

[0069] At Step 702, the processor 1 12 receives image data from the surface topographic image, such as the surface topographic image data 202 shown in FIG.2. The surface topographic image data 202 can include digital data representing one or more surface topographic images of a subject. In an embodiment, the digital data includes a collection of numbers that represent colors and locations of pixels of the surface topographic image (e.g., matrices of data relating to pixels of the surface topographic image) of the subject, and the like.

[0070] At Step 704, the processor 1 12 can determine data relating to the patient performing an inhalation, such as the inhalation image data 204 shown on FIG. 2. The inhalation image data 204 can be based on the surface topographic image data 202 received from the surface topographic image and can include a surface volume (e.g., a torso surface volume or total surface volume) of the subject based on the subject performing an inhalation. The inhalation image data 204 can include a mesh (e.g., a geometry mesh, a surface mesh), such as the mesh representation of a subject shown in FIG. 6A. The mesh may include a 3D reconstruction and / or representation of the subject performing an inhalation. In an exemplary embodiment the volume of the subject’s torso during inhalation (e.g., amaximum inhalation) can be determined based on a reconstructed surface mesh of the subject’s torso while inhaling (e.g., performing a maximum inhalation).

[0071] At Step 706, the processor 1 12 determines data relating to the patient performing an exhalation, such as the exhalation image data 206 shown in FIG. 2. The exhalation image data 206 can be based on the surface topographic image data 202 received from the surface topographic image and can include a surface volume (e.g., torso surface volume or total surface volume) of the subject based on the subject performing an exhalation. The exhalation image data 206 can include a mesh (e.g., a geometry mesh, a surface mesh), such as the mesh representation of a subject shown in FIG. 6B. The mesh may include a 3D reconstruction and / or representation of the subject performing an exhalation. In an exemplary embodiment the volume of the subject’s torso during exhalation (e.g., a maximum exhalation) will be determined based on a reconstructed surface mesh of the subject’s torso while inhaling (e.g., performing a maximum exhalation).

[0072] The processor 112 may generate and / or receive a template body surface model. As described herein, the template body surface model may be a template body surface model 3D mesh model. In an embodiment an inhalation template body surface model may relate to the subject in an inhaling state, and an exhalation template body surface model may relate to the subject in an exhaling state. The template body surface model can be a template (e.g., generic, predesigned) 3D mesh representing a surface of the subject, such as the full body surface of the subject or the torso of the subject. The template body surface model can be a generic representation of a subject, although in embodiments the template body surface model can be configured based on patient-specific characteristics of the subject, such as the height of the subject, weight of the subject, gender of the subject, and so on. In an exemplary embodiment the template body surface model can include a 3D mesh model of one or more portions of a body, such as a 3D mesh model of the torso of the body or a 3D mesh model of the full body. The template body surface model can include an atlas of points defining one or more portions of the surface of the body.

[0073] In an exemplary embodiment, the processor 1 12 can use the template body surface model as a starting point to fit one or more portions of the template body surface model with one or more portions of the surface geometry and / orsurface mesh of the subject. A registered mesh may be generated based on fitting the template body surface model to the surface geometry and / or surface mesh of the subject provided by the 3D surface scan. A registered mesh based on a subject performing an inhalation may be generated, a registered mesh based on the subject performing an inhalation may be generated, a registered mesh based on the subject performing tidal breathing may be generated, and so on.

[0074] The registered mesh may be generated on one or more (e.g., each) frame in which a 3D surface scan has been generated or provided. If a frame is missing data (e.g. an arm) relating to a scan of the subject, the template body surface model may contain that data. For example, if a frame is missing data relating to an arm of a subject, the template body surface model may contain data relating to that particular portion of the subject. In another embodiment, if a patch is missing in a surface scan of the subject, the template body surface model can estimate what that region should look like based on statistical training or neighboring frames that do have the region, for example. In a further embodiment, noisy data can be ignored by the processor if the data is beyond a predefined statistical model space.

[0075] Each point on the registered mesh may correspond to a point on one or more scans of the subject. In an exemplary embodiment, each point on the registered mesh may correspond to an anatomical location (e.g., the same anatomical location) on one or more scans of the subject. As a result of the registered mesh, the points (e.g., all of the points) in one or more other 3D surface scans of the patient may have a mapping in which measurements can be defined. For example, as a result of the registered mesh, all points of a 3D surface scan can be mapped to determine one or more volumes (e.g., torso volumes, total body volumes) of the subject during and / or after the subject inhales, exhales, tidal breathes, exhales after inhaling (and vice-versa), and so on.

[0076] At 708, the processor 1 12 determines a patient surface volume differential (i.e. , difference). In an embodiment the processor 112 may determine the patient surface volume differential based on one or more of the template body surface model, the determined inhalation image data 204, and the determined exhalation image data 206, as described herein. In an exemplary embodiment the surface volume differential of the patient can be determined based on a differential ofthe registered meshes and / or reconstructed surface meshes of the subject during inhalation (e.g., maximum inhalation, tidal inhalation, etc.) and the registered meshes and / or reconstructed surface meshes of the subject during exhalation (e.g., maximum exhalation, tidal exhalation, etc.). The surface volume differential of the patient can be determined based on a differential of the subject during a frame in which the smallest surface volume of the subject is achieved during inhalation and a frame in which the largest surface volume of the subject is achieved during exhalation.

[0077] At 710, the processor 1 12 determines a pulmonary function of the subject based on the patient surface volume differential determined in step 708. The determined pulmonary functions may include one or more of the following pulmonary functions, although such listing of pulmonary functions is for illustration purposes and the other pulmonary functions may be determined in other embodiments: Forced Vital Capacity of the subject; Vital Capacity of the subject; Tidal Volume of the subject; Forced Expiratory Volume of the subject at predetermined interval of time; and / or flow volume loop data. The predetermined interval of time for the pulmonary functions can be 1 , 1 .5, 1 .8, 2, 2.5, 2.8, 3, 3.5, 3.8, 4, 5, 5+ seconds, and the like.

[0078] As shown in FIG. 7B, method 750 shows steps used in accordance with another exemplary embodiment of determining the pulmonary function of a patient using a surface topographic scanner 116. Step 752 includes obtaining surface scans (e.g., 3D surface scans) of the subject taken after the subject has taken at least one inhalation or exhalation. For example, step 752 includes obtaining surface scans of the subject taken after the subject has taken at least one normal inhalation; at least one normal exhalation; at least one maximal inhalation; at least one maximal exhalation following a normal inhalation; at least one tidal inhalation and / or exhalation; and / or at least one maximal exhalation following a maximal inhalation. Step 754 includes generating reconstructions (e.g., 3D reconstructions) based on the surface scans (e.g., 3D surface scans).

[0079] Step 756 includes determining a volume (e.g., a torso volume or total body volume) of the subject based on the generated reconstructions (e.g., 3D reconstructions). Step 758 includes determining a pulmonary function of the subject based on the volume of the subject determined in step 756. The determined pulmonary functions may include one or more of the following pulmonary functions,although such listing of pulmonary functions is for illustration purposes and the other pulmonary functions may be determined in other embodiments: Forced Vital Capacity of the subject; Vital Capacity of the subject; Tidal Volume of the subject; and / or Forced Expiratory Volume of the subject at predetermined interval of time. The predetermined interval of time for the pulmonary functions can be 1 , 1 .5, 1 .8, 2, 2.5, 2.8, 3, 3.5, 3.8, 4, 5, 5+ seconds, and the like.

[0080] The following are exemplary examples of the system for measuring pulmonary function of a patient in accordance with the subject disclosure. Such examples are for illustrative purposes only and are not intended to limit the inventive concepts as described herein.EXAMPLES

[0081] Example 1 - Correlation of surface topographic measurements of chest volumes to pulmonary function tests in patients with spinal deformity.

[0082] This study focused on using surface topographic (ST) measurements of body volume difference (BVD) and torso volume difference (TVD) between maximum inhale and exhale to assess forced vital capacity (FVC), vital capacity (VC) and total lung capacity (TLC) as measured by PFTs.

[0083] Materials and Methods

[0084] Patient characteristics

[0085] Patients were retrospectively evaluated from the Spinal AlignmentRegistry (SAR), which is a prospectively collected registry of patients with scoliosis at a single institution. Once enrolled, pediatric patients (age 10-21 years) with scoliosis received surface topographic scans, standard-of-care clinical examinations and EOS biplanar radiographs, all on the same day.

[0086] Patient data including age, specific scoliosis diagnosis, body mass index (BMI), and radiographic measurements were collected. This study included all patients who had surface topographic evaluation and pulmonary function tests within three months of one another. Patients were included if they had thoracic or thoracolumbar curves of at least 40 degrees. Patients were excluded if they had prior chest wall or spinal surgery, a primary deformity of Scheuermann's kyphosis, and orthopedic deformities other than scoliosis.

[0087] Pulmonary Function Tests (PFTs)

[0088] Standard PFTs were performed at pulmonary function testing centers within 3 months of surface topographic scans, and the results were collected. Patients were either in a seated or standing position, with a nose clip in place to occlude the nostrils. With a mouthpiece in place, the patients were instructed to inhale “as deeply as possible” until they felt uncomfortable. The patients were then instructed to “blast” the air from their lungs, exhaling until uncomfortable once again, at which point they were instructed to inspire fully once again. Each test required three trials with the best-effort recorded, with arm-span used in lieu of standing height. As shown in FIG. 4, the following variables were measured and assessed by a respiratory physician: forced vital capacity (FVC), tidal volume (TV), forced expiratory volume in first second (FEV1), vital capacity (VC), total lung capacity (TLC), and residual volume (RV).

[0089] Surface Topographic (ST) scans

[0090] Surface topographic imaging data was compiled using the 3dMD body system, which is a photogrammetric scanner composed of 30 cameras. Full body scans were captured at ten frames per second. All patients changed into compression shorts and hairnets, and female subjects also wore custom halter tops with full back exposure. Patients stood in the center of the surface topographic scanner. For the pose of interest, patients first walked in place before assuming a natural stance with arms abducted at 45° with palms down (in an ‘A’ pose). Patients were instructed to inhale to the fullest extent, at which point they supinated their arms such that their palms faced upwards. The patients exhaled as much as possible, at which point they pronated their palms back towards the floor to indicate they completed exhalation.

[0091] Upon completion of surface topographic scans, the frames at maximum inhalation and maximum exhalation were reconstructed into 3D volumetric meshes. 3D meshes are processed (e.g., processed via an algorithm) to produce registered reconstructions as previously described. The volume of the 3D mesh (e.g., the entire 3D mesh) of the patient’s body (including head, arms, torso, and legs) was computed to determine full body volume. The difference between the full body volume of the maximum inhalation and the maximum exhalation scans wascomputed and defined as the body volume difference (BVD). The torso volume was defined as being bound by a plane defined by the pelvis posterior superior iliac spine and anterior superior iliac spine landmarks and a plane defined by the acromioclavicular joints, jugular notch and C7 at the neck. The difference in torso volume between the maximum inhalation and maximum exhalation frames was computed and defined as torso volume difference (TVD).

[0092] Statistical analysis

[0093] Univariate linear regression analysis was used to investigate relationships between PFT parameters and the following: ST-based BVD, ST-based TVD, and thoracic / thoracolumbar curve magnitude. The statistical analyses were conducted using the Statistical Package for the Social Sciences (SPSS) software (version 22, IBM, Armonk, NY).

[0094] Results

[0095] Eighteen patients met inclusion criteria for this study, 13 (72.2%) of which were female. The mean age of the population was 14.0 ± 2 years (10-18), mean BMI 21 .4 ± 4.5 kg / m2, and mean thoracic / thoracolumbar curve magnitude 61.5° ± 13.9° (45.1 °-92.6°). Seven (38.9%) had an underlying diagnosis of asthma. Fourteen patients had adolescent idiopathic scoliosis, 2 had juvenile idiopathic scoliosis, 1 had thoracogenic scoliosis, and 1 had neuromuscular scoliosis. There was an average of 37 days (range 0-79) between the surface topographic scan and the PFTs.

[0096] Mean PFT values and surface topographic measurements are detailed in Table 1 . The correlations between BVD, TVD and the pulmonary function measurements are shown in Table 2.

[0097] Table 1

[0098] SD: Standard deviation

[0099] 1 N=17 for VC, TLC, RV due to 1 patient missing this data.[000100] Table 2root mean squared error; FVC: forced vital capacity; FEV1 : forced expiratory volume; VC: vital capacity; TLC: total lung capacity; RV: residual volume*Sign if icant at p <0.05[000102] Significant positive correlations were found between BVD and FVC (R = 0.874, p <0.0001 ), FEV1 (R = 0.886, p < 0.0001 ), VC (R = 0.831 , p < 0.0001 ) and TLC (R = 0.768, p <0.0001 ). Significant correlations also emerged between TVD and FVC (R = 0.863, p < 0.0001 ), FEV1 (R = 0.844, p < 0.0001 ), VC (R = 0.824, p < 0.0001 ), and TLC (R = 0.747, p = 0.001 ).[000103] This study described in Example 1 demonstrates excellent correlations between body and torso volume differences with FVC, FEV1 , VC and TLC.[000104] FIG. 5 shows the correlations of surface topographic values (i.e., Body Volume Difference (L)) versus Forced Vital Capacity (FVC) and Vital Capacity (VC) values. In particular, the R-value, or Pearson correlation coefficient, was calculated and is shown in FIG. 5. As known in the art, the R-value measures the strength of the linear relationship between two variables in a scatterplot, such as the surface topographic values and FVC values, and the surface topography values and VC values shown in FIG. 5. As shown in FIG. 5, (1 ) the R-value for the surface topographic values versus Forced Vital Capacity (FVC) values was determined to be 0.874, and (2) the R-value for the surface topographic values versus the Vital Capacity (VC) values was determined to be 0.831 . As such, the positive R-values indicates a positive correlation between the surface topographic values and the PFT values.[000105] Example 2 - Correlation of surface topographic volume to co-current handheld spirometry[000106] This study focused on performing a concurrent validity of pulmonary volumes and function by using a 3D surface topography system to measure volume differences (e.g., body volume difference (BVD) versus spirometry in a reliable and accurate manner.[000107] Materials and Methods[000108] Patient characteristics -[000109] Healthy subjects were recruited with the following criteria: age 18+; volunteers; able to stand for 15+ minutes; able to comply with instructions; no respiratory conditions (e.g., asthma, COPD, etc.)[000110] Patient data including age, sex, race, height, and body mass index was recorded. The patients and controls underwent a surface topographic scan wearing a custom-made halter top and compression shorts (females) or compression shorts (males) with hair net.[000111] Spirometer measurements[000112] Participants performed maximal inspiration and forced expiration following spirometry protocols, for a total of 3 acceptable trials. This was repeated 3 times (twice with the first rater and once with a second rater).[000113] Surface Topographic scans[000114] Surface topographic measurements were conducted substantially simultaneously with the spirometer measures. Subjects stood centered in the surface topographic scanning field of view with one arm elevated to hold the spirometer while leaving their torso visible to the surface topographic camera system.[000115] Reliability protocol:[000116] In trial 1 , rater A brought subject into a 3dMD scanner and conducted PFTs with the subject until the subject performed three acceptable PFTs. Rater A removed patient from 3dMD. Subject rested 1 minute.[000117] In trial 2, rater A brought subject back into the 3dMD scanner and repeated trial 1 , which established intra-rater reliability. Subject rested 1 minute.[000118] In trial 3, rater B brought subject back into the 3dMD scanner and repeated trial 1 . This establishes inter-rater reliability. The subject rested 1 minute.[000119] All trials involved simultaneous 3dMD and spirometry measurements so both system measured the same breathing maneuver. The best of the three trials was used for further reliability analysis.[000120] Reconstructed surface meshes were processed through a data analysis pipeline and volumes (e.g., body volumes and torso volumes) were extracted, such as the torso surface meshes shown in FIGS. 6A, 6B. The surface volumes were acquired from the 3dMD surface topographic scanner. The difference between body volume at inhalation and exhalation scans were computed.[000121] Statistical analysis[000122] Forced Vital Capacity (FVC) was determined from the spirometer measurements and body volume difference (BVD) was determined from the surface topographic scans. The correlation between FVC and BVD was computed.Intraclass Correlation Coefficients were computed for both systems to measure how reliable each system is.[000123] FIG. 8 shows the correlations of spirometry FVC values and topographic body volume difference (BVD) values provided via surface topography for different subjects, wherein each subject is differentiated by a different symbol in FIG. 8. In the study, the R-value was calculated as r = 0.96, which indicates a positive correlation between the FVC values provided via spirometry and body volume difference values provided via surface topography.[000124] Reliability between spirometry FVC values and body volume difference values[000125] Reliability is high and comparable between the spirometry FVC values and the surface topographic BVD. Intraclass Correlation Coefficients:[000126] Example 3 - Volume differential via template body surface model[000127] Start: Data capture[000128] A topographic scanner (e.g., 3dMD scanner) can output triangulated meshes with RGB texture, for example, at 10 fps. The topographic scans can be full-body of the subject, covering 360 degrees of the patient, although in other examples the topographic scans can be of one or more portions of the body. The scanning protocol requires skin-tight clothing upon the subject.[000129] Step 1 : Per-frame network inference[000130] Input: Triangulated mesh of the body surface[000131] Description: The surface of the subject can be down-sampled and converted to a point cloud representation. The point cloud can be fed into a 3D U-net neural network. The output of the 3D U-net neural network includes a predicted coordinate of the matching anatomical point on a template body surface model.[000132] Output: Predicted template coordinate for each vertex in the scan mesh[000133] Step 2: Multi-frame initial template alignment[000134] Input A: Triangulated mesh of the body surface[000135] Input B: Predicted template coordinates[000136] Description: The template body surface model is parameterized by (1 ) body shape and (2) anatomical joint angles. Anatomic landmarks of the subject (e.g., the posterior superior iliac spine, the acromioclavicular (AC) joint, and so on) may be defined on the template body surface model. An optimization algorithm may be applied to the parameters to align the template body surface model to the scan data of the subject. Optimization is performed (e.g., simultaneously performed) over the entire scan sequence. The optimization can attempt to minimize a cost function using two criteria: (1 ) proximity of the scan data to the aligned template surface, and (2) proximity of corresponding anatomical surface points, as predicted in Step 1.[000137] Output: Aligned template model parameters for each frame[000138] Step 3: Iterative model fitting[000139] Input A: Triangulated mesh of body surface[000140] Input B: Initial template parameters[000141] Description: Final registration of the template mesh can be performed iteratively by repeating two steps: (1 ) performing (e.g., performing on each frame separately) registration of the template mesh to the scan data by warping the template surface to align with the geometric scan data in an as-rigid-as-possible deformation, and (2) optimizing model parameters to align the template body surface with the warped model surface from above. This step can be performed across all frames simultaneously, with a regularization term to ensure that joint angles change smoothly across time.[000142] Output: Registered template model surface for each frame[000143] Step 4: Template refinement[000144] Input: Registered template body surface model for each frame.[000145] Description: To reduce the influence of noise in the appendages of the subject, the mesh can be modified to ensure that the appendages of the subject do not change volume over time. The torso region of the subject can be modified to use a high-resolution mesh to enable more precise fitting to the original scan data.[000146] Output: A more accurate template fitting[000147] Step 5: Volume calculation[000148] Input: Registered template body surface models[000149] Description: The volume can be computed for each frame using Stokes’ theorem, for example. Temporal smoothing can be applied.[000150] Output: Body volume measurements for each frame[000151] Step 6: compute vital capacity[000152] Input: Body volume measurements[000153] Description: Find the frames with maximal and minimal body volume; subtract.[000154] Output: Body Volume Difference[000155] It will be appreciated by those skilled in the art that changes could be made to the various aspects described above without departing from the broad inventive concept thereof. It is to be understood, therefore, that the subject application is not limited to the particular aspects disclosed, but it is intended to cover modifications within the spirit and scope of the subject application as defined by the appended claims

Claims

We claim:1 . A system for determining pulmonary function of a patient, characterized by: a surface topographic scanner (116) for capturing surface topography images of a patient; and a processor (112) configured to: receive surface topography image data (202) of the patient from the surface topographic scanner (116), determine, based on the received surface topography image data (202), inhalation image data (204) relating to the patient performing an inhalation, determine, based on the received surface topography image data (202), exhalation image data (206) relating to the patient performing an exhalation, determine a patient surface volume differential of the patient based on the determined inhalation image data (204) and the determined exhalation image data (206), and determine a pulmonary function of the patient based on the determined patient surface volume differential.

2. The system of claim 1 , wherein the processor (112) is further configured to: determine at least one template body surface model; perform a fitting of the at least one template body surface model with the inhalation image data and a fitting of the at least one template body surface model with the exhalation image data; and determine an inhalation volume of a portion of the patient based on the fitting of the at least one template body surface model with the inhalation image data and an exhalation volume of the portion of the patient based on the fitting of the at least one template body surface model with the exhalation image data.

3. The system of claim 2, wherein the processor (112) is further configured to determine the patient surface volume differential based on the determined inhalation volume and the determined exhalation volume.

4. The system of any of the preceding claims, wherein the processor (112) is configured to determine a surface geometry of the subject via the inhalation image data (204) and the exhalation image data (206).

5. The system of claim 4, wherein the processor (112) is configured to use the template body surface model as a starting point to fit one or more portions of the template body surface model with one or more portions of the surface geometry.

6. The system of any of the preceding claims, wherein the inhalation image data (204) relates to at least one image of the patient performing a normal inhalation and the exhalation image data (206) relates to at least one image of the patient performing a normal exhalation.

7. The system of any of the preceding claims, wherein the inhalation image data (204) relates to at least one image of the patient performing a maximum inhalation and the exhalation image data (206) relates to at least one image of the patient performing a maximum exhalation.

8. The system of any of the preceding claims, wherein the inhalation image data (204) relates to a plurality of images of the patient over a predetermined time period.

9. The system of any of the preceding claims, wherein the received inhalation image data (204) and the received exhalation image data (206) relates to an image of the torso of the patient, and the determined patient surface volume differential is a torso volume differential of the patient.

10. The system of any of the preceding claims, wherein the processor (112) is further configured to generate 3D reconstructions based on the received surface topography image data.11.The system of claim 10, wherein the processor (112) is further configured to determine the patient surface volume differential based on the generated 3D reconstructions.

12. The system of any of the preceding claims, wherein the inhalation image data (204) relates to a plurality of images over a predetermined time period, and wherein the processor (1 12) is further configured to determine the pulmonary function based on a plot of the patient surface volume differential over the predetermined time period.

13. The system of any of the preceding claims, wherein the determined pulmonary function comprises at least one of a Forced Vital Capacity, Vital Capacity, Tidal Volume, Forced Expiratory Volume at 1 second, and / or Flow Volume Loop values.

14. The system of any of the preceding claims, wherein the processor (1 12) is further configured to identify a localized portion of the patient based on the received inhalation image data (204) and the received exhalation image data (206), wherein the determined patient surface volume differential relates to the localized portion of the patient.

15. A computer implemented method for determining pulmonary function of a patient, characterized by: obtaining surface topography images of a patient during tidal breathing and maximum inhalation and exhalation; receiving surface topography image data (202) based on the obtained surface topography images; determining inhalation image data (204) relating to the patient performing an inhalation based on the received surface topography image data (202); determining exhalation image data (206) relating to the patient performing an exhalation based on the received surface topography image data (202); determining a patient surface volume differential of the patient based on the determined inhalation image data (204) and the determined exhalation image data (206); and determining a pulmonary function of the patient based on the determined patient surface volume differential.

16. The computer implemented method of claim 15, further comprising: determining at least one template body surface model; performing a fitting of the at least one template body surface model with the inhalation image data and a fitting of the at least one template body surface model with the exhalation image data; and determining an inhalation volume of a portion of the patient based on the fitting of the at least one template body surface model with the inhalation image data and an exhalation volume of the portion of the patient based on the fitting of the at least one template body surface model with the exhalation image data.

17. The computer implemented method of claim 16, further comprising determining the patient surface volume differential based on the determined inhalation volume and the determined exhalation volume.

18. The computer implemented method of any of claims 15-17, further comprising determining a surface geometry of the subject via the inhalation image data (204) and the exhalation image data (206).

19. The computer implemented method of claim 18, further comprising using the template body surface model as a starting point to fit one or more portions of the template body surface model with one or more portions of the surface geometry.

20. The computer implemented method of any of claims 15-19, wherein the inhalation image data (204) relates to at least one image of the patient performing a normal inhalation and the exhalation image data (206) relates to at least one image of the patient performing a normal exhalation, or wherein the inhalation image data (204) relates to at least one image of the patient performing a maximum inhalation and the exhalation image data (206) relates to at least one image of the patient performing a maximum exhalation.21 . The computer implemented method of any of claims 15-20, wherein the inhalation image data (204) relates to a plurality of images over a predetermined time period.

22. The computer implemented method of any of claims 15-21 , wherein the received inhalation image data (204) and the received exhalation data (206) relates to an image of the torso of the patient, and the determined patient surface volume differential is a torso volume differential of the patient.

23. The computer implemented method of any of claims 15-22, further comprising generating 3D reconstructions based on the received surface topography image data.

24. The computer implemented method of claim 23, further comprising determining the patient surface volume differential based on the generated 3D reconstructions.

25. The computer implemented method of any of claims 15-24, wherein the inhalation image data (204) relates to a plurality of images over a predetermined time period, and the pulmonary function is determined based on a plot of the patient surface volume differential over the predetermined time period.

26. The computer implemented method of any of claims 15-25, wherein the determined pulmonary function comprises at least one of a Forced Vital Capacity, Vital Capacity, Tidal Volume, Forced Expiratory Volume at 1 second, and / or Flow Volume Loop values.

27. The computer implemented method of any of claims 15-26, wherein the step of determining a patient surface volume differential comprises: generating 3D reconstructions based on the obtained surface topography images; and determining a surface volume differential of the subject based on the generated 3D reconstructions.

28. The computer implemented method of any of claims 15-27, further comprising identifying a localized portion of the patient based on the received inhalation image data (204) and the received exhalation image data (206), wherein the determined patient surface volume differential relates to the localized portion of the patient.

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