Determining a unique spatial relationship of a medical device to a further object

Abstract

The present embodiments relate to a method for determining a unique spatial relation of a medical device to an object. The medical device includes a registration mechanism with a first determination of the spatial relation of the medical device to the object by the registration mechanism by a first method for determining a relation of this kind, and with a second determination of the spatial relation of the medical device to the object by the registration mechanism by a second method for determining a relation of this kind. The second method is based on a physical principle of action different from that of the first method, with an evaluation of the results of the first and second determinations with respect to conformance by the registration mechanism, and, on the determination of a prespecified degree of conformance between the results, with a final determination of the spatial relation from the results of the first and second determinations by the registration mechanism to increase the safety of the medical device during operation in spatial interaction with a object.

Claims

1. A method for determining a unique spatial relation of a medical device to an object, wherein the medical device comprises a registration mechanism, the method comprising: determining a first determination of the spatial relation of the medical device to the object by the registration mechanism by a first method for determining a spatial relation; determining a second determination of the spatial relation of the medical device to the object by the registration mechanism by a second method for determining a spatial relation, wherein the second method is based on a physical principle of action different from that of the first method; evaluating results of the first and second determinations with respect to a conformance by the registration mechanism, wherein the conformance represents a similarity between the results of the first and second determinations of the spatial relation; determining, based on determining that the conformance is above a prespecified degree of conformance between the results, a final determination of the spatial relation from the results of the first and second determinations by the registration mechanism; and signaling, based on determining that the conformance is below the prespecified degree of conformance, a low degree of conformance, wherein the signaling comprises display of an error message, a prompt that the method is to be performed again, or the error message and the prompt that the method is to be performed again.

2. The method of claim 1, wherein a prespecified functionality of the medical device is configured to be activated only when the prespecified degree of conformance has been established.

3. The method of claim 2, wherein: the medical device is a robotic device; and the prespecified functionality comprises a mobility, an autonomous movement, or both the mobility and the autonomous movement of the robotic device or a component of the robotic device.

4. The method of claim 3, wherein the first method is a contact-free method.

5. The method of claim 4, wherein the first method is an image-based method based on visible light, X-rays, infrared light, or a combination thereof.

6. The method of claim 5, wherein the second method is a haptic method with that the robotic device approaches at least one predetermined position or pose on the object to determine the spatial relation of the medical device to the object.

7. The method of claim 6, wherein the robotic device approaches the predetermined position or pose with guidance from an operator.

8. The method of claim 6, wherein the robotic device approaches two, three, or four predetermined positions depending on a number of degrees of freedom of the robotic device.

9. The method of claim 7, wherein the robotic device approaches two, three, or four predetermined positions depending on a number of degrees of freedom of the robotic device.

10. The method of claim 1, wherein the medical device is a robotic device and the second method is a haptic method with that the end effector of the robotic device approaches at least one predetermined position or pose on the object to determine the spatial relation of the medical device to the object.

11. A medical device comprising: a registration mechanism configured to: determine a spatial relation of the medical device to an object by a first method for determining a spatial relation; determine the spatial relation of the medical device to the object by a second method for determining a spatial relation, wherein the second method is based on a physical principle of action different from that of the first method; and evaluate the results of the first and second determinations with respect to conformance, wherein the conformance represents how similar the spatial relation of the medical device to an object by a first method is to the spatial relation of the medical device to the object by a second method; determine, when the conformance meets a prespecified degree of conformance between the results of the first and second determinations by the registration mechanism, the spatial relation from the results of the first and second determinations; and signal, when the conformance fails to meet the prespecified degree of conformance between the results of the first and second determinations by the registration mechanism, a low degree of conformance by marking a result of the evaluation as faulty.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a schematic representation of a method for determining a unique spatial relation with reference to a medical device in a first exemplary embodiment.

(2) FIG. 2 depicts a schematic flow diagram of a further exemplary embodiment of a method for determining a unique spatial relation.

DETAILED DESCRIPTION

(3) FIG. 1 is a schematic representation of a method for determining a unique spatial relation with reference to a medical device in a first exemplary embodiment.

(4) The medical device 1 is provided as a robotic medical device 1 and includes an end effector 2. A registration mechanism 3 (e.g., a camera 4 and a control mechanism 5) is also included in the medical device 1. The medical device ay be registered to an object 6. A unique spatial relation R of the medical device 1 (e.g., a base of the medical device 1) to the object 6 is determined. As depicted in FIG. 1, two reference positions 7 and 8 are used, which are in known spatial relations r.sub.76 and r.sub.86 to the object 6.

(5) As depicted in FIG. 1, first a dotted line symbolizes the acquisition of the optical reference position 7 and the spatial relation r.sub.47 of the camera 4 to the reference position 7. Because the spatial relation r.sub.14 between the camera 4 and medical device 1 (e.g., the base of the medical device 1) is known, it is possible to determine the spatial relation R of the medical device 1 (and in derivation therefrom, also of the end effector 2 and an end point E of the end effector) to the object 6. In the example shown, the first determination act 10 (FIG. 2) of the spatial relation R of the medical device 1 to the object 6 by the registration mechanism 3 is determined (e.g., with a contactless image-based method).

(6) In the example shown, a second determination act 11 (FIG. 2) of the spatial relation R of the medical device 1 to the object 6 is performed using a haptic method. For example, the end point E of the end effector 2 is guided by an operator ne or more reference positions (e.g., the one second reference position 8). The spatial elation R of the medical device 1 to the further object 6 may be determined again independently of the camera 4 and the first method from the known spatial relations r.sub.12 of the robotic device 1 to the end effector 2, the known spatial relation r.sub.2E of the end effector 2 to the end point E, and the known spatial relation r.sub.86 of the second reference point 8 to the object 6.

(7) The results of the first and second determinations may be evaluated. If a prespecified degree of conformance between the results is determined, a final determination of the spatial relation R may be performed because the relation R in all probability reflects reality with sufficient accuracy. If however, the prespecified degree of conformance may not be determined, at least one of the two registrations is faulty and the use of the medical device 1 or the end effector 2 may have serious consequences, and use may be avoided by blocking a functionality of the medical device 1 or the end effector 2.

(8) FIG. 2 is a schematic flow diagram of an exemplary embodiment of a method for determining a unique spatial relation.

(9) In the example shown, the first act is a first determination 10 of the spatial relation R (FIG. 1) of the medical device 1 (FIG. 1) to the object 6 (FIG. 1) by the registration mechanism 3 (FIG. 1) by a first method for the registration or determination of a spatial relation. For example, the medical device 1 may be provided as a lightweight robot and registered via an image-based method as shown in FIG 1 to a C-Arm system as the object 6.

(10) A second determination 11 of the spatial relation R (FIG. 1) of the medical device 1 (FIG. 1) to the object 6 (FIG. 1) by the registration mechanism 3 (FIG. 1) by a second method for determining a spatial relation or for the registration. For example, the second method may be a haptic method. For example, the lightweight robot may approach different predetermined reference positions 7 and 8 (FIG. 1) on a component of the C-Arm system.

(11) Accordingly, both methods provide a registration. This is represented mathematically by a transformation matrix with that may include six degrees of freedom between two coordinate systems. In the method shown, evaluation 12 of the respective results of the first and second determinations 10 and 11 with respect to conformance by the registration mechanism 3 (FIG. 1) is performed. If a prespecified degree of conformance between the results is established, there is a final determination 13 of the spatial relation R (FIG. 1) from the results of the first and second determinations 10 and 11 by the registration mechanism 3. For example, the determination may be performed using vectors that represent the relation of the medical device 1 to the object 6 according to the different methods.

(12) If the degree of conformance established between the results is not the prespecified degree of conformance (e.g., fails to achieve the prespecified degree) the low degree of conformance is signaled 14, followed by a repeated performance of the method. This provides that the spatial relation R between the medical device 1 and the object 6 is determined with particular accuracy and high reliability.

(13) The elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present invention. Thus, whereas the dependent claims appended below depend from only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent. Such new combinations are to be understood as forming a part of the present specification.

(14) While the present invention has been described above by reference to various embodiments, it may be understood that many changes and modifications may be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it he understood that all equivalents and/or combinations of embodiments are intended to he included in this description.