US-12618775-B2 - Testing of luminescence imaging apparatus with automatic detection of a testing device

US12618775B2US 12618775 B2US12618775 B2US 12618775B2US-12618775-B2

Abstract

A solution is proposed for testing a luminescence imaging apparatus ( 105 ). A corresponding method ( 700 ) comprises acquiring ( 706 ) a photograph image and finding ( 708 ) a position of the testing device ( 110 ) in the photograph image. The 5method further comprises acquiring ( 706 ) a luminescence image and determining ( 734 - 736 ) a representation of sites of the testing device ( 110 ), each comprising at least one luminescence substance, in the luminescence image according to the position of the testing device ( 110 ) in the photograph image. The luminescence imaging apparatus ( 105 ) is then tested ( 754 - 772 ) according to the representation of the sites ( 330 ) in the 0luminescence image. A corresponding computer program ( 600 ) and a computer program product for implementing the method ( 700 ) are also proposed. Moreover, a testing device ( 110 ) for use in the method ( 700 ) is proposed.

Inventors

Dmitry Bozhko
Maximilian Koch
Adrian Taruttis
Christian Aichinger
Jurek Nordmeyer-Massner

Assignees

SURGVISION GMBH

Dates

Publication Date: 20260505
Application Date: 20201119
Priority Date: 20191125

Claims (20)

1 . A method for testing a luminescence imaging apparatus with a testing device placed within a field of view of an imaging head of the luminescence imaging apparatus, the testing device having an imaging surface for imaging the testing device with one or more sites each comprising at least one luminescence substance, wherein the method comprises, under the control of a control unit of the luminescence imaging apparatus: acquiring, with a photograph camera of the imaging head, a photograph image of the field of view representative of a reflected light being reflected by the field of view, retrieving a descriptor of the testing device comprising an indication of a geometry of the testing device and of a position of the sites in the testing device, the indication of the geometry of the testing device comprising real-world coordinates of geometry indicators indicative of a position of the geometry indicators in the testing device, finding a position of the testing device in the photograph image according to the geometry of the testing device being indicated in the descriptor, calculating a transformation between the real-world coordinates of the geometry indicators being indicated in the descriptor and corresponding image coordinates of the geometry indicators being found in the photograph image, acquiring, with a luminescence camera of the imaging head, a luminescence image of the field of view representative of a luminescence light being emitted by the luminescence substance of the sites in response to an excitation light thereof provided by an excitation light source of the imaging head, determining a representation of the sites in the luminescence image according to an application of the transformation to the position of the sites in the testing device being indicated in the descriptor, and testing the luminescence imaging apparatus by verifying a specification of the luminescence light defined by the representation of the sites in the luminescence image.
2 . The method according to claim 1 , wherein the geometry indicators comprise one or more optically machine-readable positional markers at the imaging surface of the testing device.
3 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: testing the luminescence imaging apparatus according to a comparison of the specification of the luminescence light defined by the representation of each of the sites in the luminescence image with at least one corresponding nominal value.
4 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: testing the luminescence imaging apparatus according to a comparison of the specification of the luminescence light defined by the representation of each of the sites in the luminescence image with the specification of the luminescence light defined by the representation of at least another one of the sites in the luminescence image.
5 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: determining a representation of a background area, different from the representations of the sites, in the luminescence image, and testing the luminescence imaging apparatus according to a comparison of the specification of the luminescence light defined by the representation of each of the sites in the luminescence image with a specification of the luminescence light defined by the representation of the background area in the luminescence image.
6 . The method according to claim 1 , wherein the testing device comprises one or more containers corresponding to the sites each filled with a liquid comprising the corresponding luminescence substance, the method comprising, under the control of the control unit: estimating expected types of the containers according to a comparison of the representations of the containers in the photograph image with a plurality of pre-defined specifications of possible types of the containers, the types of the containers being defined by nature and/or concentration of the corresponding luminescence substances.
7 . The method according to claim 6 , wherein the method comprises, under the control of the control unit: testing the luminescence imaging apparatus according to pre-defined specifications of the expected types of the containers.
8 . The method according to claim 6 , wherein the method comprises, under the control of the control unit: determining a representation of corresponding end portions, of the containers projecting from corresponding seats of the testing device, in the photograph image, and verifying a configuration of the testing device according to a matching of a color of the representation of the end portions in the photograph image with pre-defined color definitions of the corresponding expected types of the containers.
9 . The method according to claim 1 , wherein the testing device has one or more optically machine-readable informative markers at the imaging surface and comprises one or more containers corresponding to the sites each filled with a liquid comprising the corresponding luminescence substance, the method comprising, under the control of the control unit: determining a representation of the informative markers in the photograph image, determining device information relating to the testing device according to the representation of the informative markers, and determining expected types of the containers according to the device information, the types of the containers being defined by nature and/or concentration of the corresponding luminescence substances.
10 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: finding a position of the testing device in the luminescence image, and testing the luminescence imaging apparatus according to an alignment between the photograph image and the luminescence image determined according to the position of the testing device in the photograph image and the position of the testing device in the luminescence image.
11 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: retrieving one or more usage rules of the testing device, and enabling said testing the luminescence imaging apparatus according to the usage rules.
12 . The method according to claim 11 , wherein the testing device has one or more optically machine-readable informative markers at the imaging surface, the method comprising, under the control of the control unit: determining a representation of the informative markers in the photograph image, determining device information relating to the testing device according to the representation of the informative markers, and retrieving the usage rules according to the device information.
13 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: retrieving usage information of one or more previous executions of said testing the luminescence imaging apparatus, enabling said testing the luminescence imaging apparatus according to the usage information, and saving the usage information of said testing the luminescence imaging apparatus.
14 . The method according to claim 13 , wherein the testing device has one or more optically machine-readable informative markers at the imaging surface, the method comprising, under the control of the control unit: determining a representation of the informative markers in the photograph image, determining device information relating to the testing device according to the representation of the informative markers, and retrieving the usage information according to the device information.
15 . The method according to claim 1 , wherein the testing device comprises a testing light source at the imaging surface for generating a testing light corresponding to the luminescence light, the method comprising, under the control of the control unit: acquiring a further luminescence image of the field of view with the luminescence camera while the excitation light source is turned off and the testing light source is turned on, and testing an acquisition unit of the imaging head for acquiring the luminescence images according to the further luminescence image and predefined characteristics of the testing light source.
16 . The method according to claim 15 , wherein the method comprises: testing an illumination unit of the imaging head for generating the excitation light according to a result of said testing the luminescence imaging apparatus and a result of said testing the acquisition unit.
17 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: determining a displacement of the testing device and/or the imaging head from a target position according to the position of the testing device in the photograph image, and outputting an indication of a movement of the testing device and/or the imaging head for reaching the target position according to the displacement thereof on an output unit of the luminescence imaging apparatus.
18 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: outputting an indication of a result of said testing the luminescence imaging apparatus on an output unit of the luminescence imaging apparatus.
19 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: transmitting an indication of a result of said testing the luminescence imaging apparatus to a remote computing system over a telecommunication network.
20 . The method according to claim 1 , wherein the method comprises, under the control of the control unit: repeating in a non-operative condition of the luminescence imaging apparatus: acquiring a further photograph image of the field of view with the photograph camera, and searching a representation of the testing device in the further photograph image according to the geometry of the testing device, until the representation of the testing device in the further photograph image has been found; and triggering said testing the luminescence imaging apparatus in response to the representation of the testing device in the further photograph image being found.

Description

This application claims priority to International Patent Application No. PCT/EP2020/082669 filed on Nov. 19, 2020 which claims priority to European Patent Application No. 19211287.8 filed on Nov. 25, 2019, which applications are incorporated by reference herein. TECHNICAL FIELD The present disclosure relates to imaging applications. More specifically, this disclosure relates to luminescence imaging. BACKGROUND ART The background of the present disclosure is hereinafter introduced with the discussion of techniques relating to its context. However, even when this discussion refers to documents, acts, artifacts and the like, it does not suggest or represent that the discussed techniques are part of the prior art or are common general knowledge in the field relevant to the present disclosure. Imaging generally relates to a number of techniques that allow acquiring images of objects (typically, not visible directly) in a substantially non-invasive manner. For example, imaging techniques are routinely exploited in equipment for medical applications to inspect (inner) body-parts of patients for diagnostic, therapeutic and/or surgical purposes. A specific imaging technique increasingly considered is luminescence imaging, and especially fluorescence imaging. Luminescence imaging is based on a luminescence phenomenon, consisting of the emission of light by luminescence substances when subject to any excitation different from heating; particularly, a fluorescence phenomenon occurs in fluorescence substances (called fluorophores), which emit light when they are illuminated (with an intensity depending on an amount of the fluorophores that are illuminated). For example, this phenomenon is leveraged in medical applications by administering fluorescence agents to the patients, and especially targeted fluorescence agents adapted to reaching a specific molecule of a desired target and then to remaining immobilized thereon (for example, thanks to a specific interaction with tumoral tissues). For this purpose, (fluorescence) imaging apparatuses are used; the imaging apparatuses allow illuminating each object to be imaged (with an excitation light suitable to excite the fluorophores) and to acquire corresponding (fluorescence) images representing the fluorophores present in the object, often together with (photograph) images simply representing the object; particularly, in medical applications the fluorescence images represent the fluorescent agent immobilized on the corresponding target and the photograph images represent the body-parts under analysis. The imaging apparatuses should be tested to verify their performance. This is especially important in medical applications, wherein the performance of the imagining apparatuses affects corresponding diagnostic, therapeutic and/or surgical results. The test of the imaging apparatuses may be carried out with specific metering instruments. However, this does not allow verifying an illumination unit and an acquisition unit of the imaging apparatuses simultaneously. Another possibility is of using a curable polyurethane matrix or a composite phantom embedding quantum dots (small particles manufactured in a semiconductor process) in different concentrations, for example, as described in U.S. Pat. No. 9,167,240. However, the quantum dots exhibit a very high absorption of visible light (particularly, far higher than the one of the fluorescence agents typically used in medical applications), so that they may be used to verify the performance of the imaging apparatuses only in environments with controlled illumination. In order to test the imaging apparatuses in a close simulation of their actual usage, it is instead possible to use samples of the same fluorophores to be imaged, i.e., the fluorescence agents in medical applications. Several testing devices are available for this purpose. For example, it is possible to use well plates (commonly used in laboratories for other purposes), loosely arranged tubes or capillary tubes being filled with different concentrations of the fluorescence agent. However, these testing devices require manual interventions (for example, on-site preparations and selections of regions of interest in the images), which are inconvenient and error-prone. Moreover, “Setting Standard for Reporting and Quantification in Fluorescence-Guided Surgery” by Hoogstings et al., Mol Imaging Biol (2019) 21:11-18 proposes the use of a testing device by SurgVision called CalibrationDisk (trademarks thereof). This testing device is formed by an upper disk (holding eight tubes filled with different concentration of a fluorescence agent) and a base on which the upper disk may rotate. US-A-2003/146663 discloses a light calibration device, which comprises an array of low-power light supplies each having a known emission. US-A-2008080781 discloses a fluorescence standard, which has at least two areas with different fluorescent response. US-A-2007/200058 discloses a phantom device, w