DE102013213496A1 - Apparatus and method for detecting head movement of a patient - Google Patents

Abstract

The invention relates to a device for detecting a head movement of a patient, wherein the device (1) at least one anchor element (2) and at least one sensor holder (6), wherein the anchor element (2) on at least one tooth (Z) of the patient mechanically rigid is attachable and has at least one connecting means, wherein the sensor holder (6) at least one sensor element (12) of a position detection device and at least one corresponding connecting means, wherein the connecting means and the corresponding connecting means are formed such that in a connected state, a predetermined position and orientation the sensor holder (6) is repeatedly adjustable relative to the anchor element (2), and a method for detecting a head movement of a patient.

Description

The invention relates to a method and a device for detecting a head movement of a patient. More particularly, the invention relates to an apparatus and method for detecting head movement of a patient during an ultrasound scan to position an ultrasound sensor, such as an ultrasound head, relative to the patient's head in a desired location and orientation.

In ultrasound-based examinations of the head or brain of a patient, the problem arises that only small sound windows exist, through which ultrasound can penetrate into the brain. Thus, the patient's skull presents an obstacle to ultrasound-based examinations that may require an ultrasound-based imaging of e.g. Brain regions prevented. Typically, an ultrasound sensor is therefore positioned in the region of a temple or in the region of an eye in order to generate ultrasound-based images of desired brain regions.

However, in order to detect different areas of the brain, it is necessary to pivot the ultrasound sensor in the area of the temple or the eye, that is to change its orientation. In particular, it is necessary to keep a position of the ultrasonic sensor approximately constant while changing an orientation of the ultrasonic sensor in order to image desired regions. Such an approach is unusual for a treating physician and causes alignment difficulties. Especially in multiple examinations, it is difficult to reproduce results, i. to reproduce the same target region again.

Should e.g. If it is necessary to quantify whether a hematoma has decreased or increased in the area of the brain, it is necessary to reorient the ultrasound sensor positioned on the temple or the eye so as to detect the area of the brain in which the hematoma is located.

At the same time, for some medical applications, it is desirable to associate ultrasound-based data with three-dimensional data from computed tomography (CT) and / or magnetic resonance imaging (MRI) examinations. For example, it may be desirable to display both CT and / or MRT data as well as ultrasound data in the correct position and orientation.

It is therefore necessary to determine coordinates of the images generated by ultrasound in a coordinate system of the CT and / or MRT data or in a common reference coordinate system. For this purpose, it may be necessary to detect a position and orientation of the ultrasound sensor during the generation of ultrasound images in order to be able to determine the position of the structures imaged by the images in the common reference coordinate system.

The US 5,143,086 describes a device for determining a lower jaw movement, wherein three light-emitting diodes are temporarily attached to teeth of a subject. Here, the light-emitting diodes are attached to a holder and arranged in a triangular shape. The holder is attached to a rod which can be inserted into a tubular member, which in turn is attached to a plate which is releasably secured to teeth.

The technical problem arises of providing a method and a device for detecting a head movement of a patient, which make it possible to determine the head movement of the patient repeatedly in a fixed predetermined reference coordinate system, in particular after re-attachment of the device to the head of the patient.

It is a basic idea of the invention that a part of the device is arranged stationary relative to the head, in particular the skull, of the patient, while a detachable or detachable further part of the device is formed such that the fixedly fixed part and the further part to each other can be mechanically fastened, that a desired position and / or orientation of the parts to each other is ensured by the mechanical connection.

Proposed is a device for detecting a head movement of a patient, in particular a movement of the skull of the patient.

The device has at least one anchor element and at least one sensor holder.

The anchoring element can be fastened mechanically rigidly to at least one tooth of the patient, in particular to at least one tooth of an upper jaw of the patient. This means that the anchor element is stationary relative to the skull or the upper jaw of the patient can be arranged. A position and orientation of the anchor element relative to the skull thus does not change in the fastened state of the anchor element.

The anchor element has at least one connecting means for the mechanical connection of the Anchor element with the sensor holder. Here, the anchor element can form this connection means.

The sensor holder has at least one sensor element of a position detection device and at least one corresponding connection means.

In this case, the sensor element designates an element of a position detection device, wherein the position detection device can detect a position and orientation of the sensor element. The sensor element can in this case be connected wirelessly and / or wired to other parts of the position detection device.

The term sensor element includes in this case that the sensor element is a passive element or an active element. In a passive element, no consumption of external electrical energy, for example from a battery, is required in order to detect the position and orientation of the sensor element and / or to transmit corresponding output signals to an evaluation device. For example, the sensor element as a receiving element, in particular as a receiving coil, be formed, which is connected via a cable to an evaluation device.

In the case of an active sensor element, external electrical energy is necessary to detect the position and orientation and / or transmission of corresponding signals of the sensor element.

The position detection device in one of the described embodiments is also included in the scope of the invention. In particular, the position detection device can have an evaluation device which evaluates information about the position and / or orientation of the sensor element and thus of the device and in this way detects the position and / or orientation. Another part of the position detecting means is, for example, an array of transmitters for transmitting electromagnetic fields received by the receiving element.

The sensor element has the at least one corresponding connection means, which is designed as a mechanical connection means. In this case, the sensor holder can form the corresponding connection means.

According to the invention, the connecting means of the anchoring element and the corresponding connecting means of the sensor holder are designed such that the anchoring element and the sensor holder can be fastened to one another repeatedly in a predetermined relative position and orientation, in particular stably fastened. Stable in this context means that a predetermined actuation force is necessary for changing the set position and orientation, in particular for releasing the anchor element and the sensor holder. As a result, an unintentional change in the position and orientation is prevented.

In other words, a predetermined position and orientation of the sensor holder is set relative to the anchor element, which is then in the attached state for fastening, so for producing a fixed state.

It is also conceivable that the connecting means are designed such that the sensor holder can be fixed to the latter exclusively in the predetermined position and / or orientation relative to the anchor element. In a fixed state, a predetermined actuating force is necessary to release the sensor holder from the anchor element or to change the relative position and orientation.

However, there may also exist a plurality of predetermined positions and orientation of the sensor holder relative to the anchor element, in which the sensor holder and the anchor element are mutually mechanically stably fastened to each other.

It is characteristic that the connection means and the corresponding connection means are designed such that a predetermined position and orientation of the sensor holder relative to the anchor element can be set repeatably by the nature of the mechanical connection.

The connecting means and the corresponding connecting means thus enable a releasable mechanical connection of the anchor element and the sensor holder.

For example, the connecting means and the corresponding connecting means may be elements of a latching connection, a plug connection, a snap connection, a screw connection or another releasable mechanical connection. In particular, the connecting means and the corresponding connecting means allow a positive connection between the anchor element and the sensor element.

Of course, it is also possible that the connecting means and the corresponding connecting means are formed such that in a stable connected state only one or one of several predetermined position (s) and orientation (s) of the sensor holder is set relative to the anchor member.

In particular, the connection means can be designed such that the sensor holder can be fastened to the latter in a form-fitting manner exclusively in one or in a plurality of predetermined position (s) and orientation (s) relative to the anchor element.

Also, the connection means and the corresponding connection means may be formed such that only one or more predetermined positions (and no orientation (s)) of the sensor holder relative to the anchor member are set in a stably connected state. In this case, for example, a plurality of devices according to the invention may be present, whose anchor elements are arranged stationary relative to the skull. If these anchor elements each sensor holder fixed to a predetermined position relative to the corresponding anchor elements stable, so an orientation of the head of the patient can be determined depending on the positions of the various sensor elements. In this case, for example, at least three anchor elements and three sensor holders may be provided, each with a sensor element.

This advantageously makes it possible for a sensor element of a position detection device to be repeatedly fastened to it with the same position and orientation relative to the head of the patient, in particular relative to the skull of the patient. Thus, the position and orientation of the sensor element can always be detected in the same coordinate system, which is stationary relative to the head of the patient.

If this coordinate system forms a reference coordinate system for e.g. Ultrasound images generated by an ultrasonic sensor can be simplified, in particular without re-registration, ultrasound images from the same region e.g. of the brain. For this purpose, for example, a position and orientation of the ultrasonic sensor can be detected and determined with respect to the reference coordinate system. This allows e.g. in a first examination, positioning an ultrasound sensor with a desired location and orientation on a patient's temple such that an ultrasound image is generated from a desired region of the brain. During the examination, the position and orientation of the sensor element can be detected, wherein the position and orientation of the ultrasound sensor relative to the position and orientation of the sensor element is determined and stored. After the examination, the sensor holder can be released from the anchor element.

For re-examination, the sensor holder can again be attached to the anchor element with the same position and orientation that was also set during the first examination. After that, the ultrasonic sensor can in turn be positioned in such a way that the same relative position and orientation is set between the ultrasonic sensor and the sensor element. In this case, exactly the same target region is imaged in the brain. Thus, the repeated ultrasound imaging is greatly simplified.

The proposed device also simplifies the superposition of, for example, CT and / or MRT data, which were recorded, for example, before an ultrasound examination, with ultrasound images currently generated. Typically, CT and / or MRI data is spatially referenced to a coordinate system relative to the head. Since a position and orientation of the sensor element is also fixed relative to the head, a head movement can be determined as a function of the position changes and orientation changes of the sensor element. The determination of the head movement then allows e.g. a correct position and orientation representation of CT data / MRI data, e.g. in a reference coordinate system which is not stationary relative to the head. CT and / or MRI data may e.g. are shown relative to the reference coordinate system. For this purpose, a single registration of the CT and / or MRT data on this reference coordinate system may be necessary. The reference coordinate system may be, for example, a coordinate system of the previously described position detection device.

If the position and orientation of the ultrasound sensor in this reference coordinate system are also determined, a simple superposition of ultrasound images with CT and / or MRT data is made possible.

In a preferred embodiment, the sensor element is designed as an electromagnetic sensor. The electromagnetic sensor in this case forms a component or an element of a particular electromagnetic position detection device, which can also be referred to as an electromagnetic tracking system.

This advantageously allows a simple, accurate and reliable detection of the position and orientation of the sensor element and thus also the position and orientation of the patient's head. In particular, there is no concealment problem as with an optical position detection device.

In a further embodiment, the anchor element is sleeve-shaped. For example, the anchor element at least partially be hollow cylindrical or have a hollow cylindrical portion. The anchoring element may, for example, be arranged at least partially in a potting or adhesive material, wherein the potting or adhesive material is arranged around at least a part of at least one tooth, in particular a tooth of an upper jaw. In this case, the sleeve-like portion may protrude from the potting or adhesive material.

A free end of the sensor holder is in this case designed plug-shaped, wherein the free end can be arranged in an inner volume of the sleeve-like section. The free end may additionally comprise elements for a positive mechanical connection with the sleeve-like section. For example, the free end can have latching noses, which can engage in corresponding latching recesses, wherein the latching recesses are arranged in the inner volume of the sleeve-like section. Due to the latching connection, an unambiguous position and orientation of the sensor holder relative to the anchoring element is advantageously ensured if these are locked together. Of course, other types of connections are conceivable.

The proposed embodiment advantageously enables a simple mechanical connection of anchor element and sensor holder.

In an alternative embodiment, at least a part of the anchor element is plug-shaped. Also in this case, the anchor element may be at least partially disposed in a potting or adhesive material which is arranged around at least a part of at least one tooth, in particular a tooth of an upper jaw. The plug-shaped part can protrude from the potting or adhesive material.

A free end of the sensor holder has a sleeve-like section. The free end of the sensor holder can be plugged onto the plug-shaped part of the anchor element. In accordance with the explanations given above, in this case the plug-shaped part and the sleeve-shaped part can have elements of a latching, snap-action or other connection. For example, the plug-shaped part can have or form latching lugs which can engage in latching recesses which are arranged in the region of an inner volume of the sleeve-like section.

This embodiment also advantageously enables the simplest possible mechanical connection of sensor holder and anchor element. Advantageously, however, that no dirt or saliva can accumulate in the inner volume of the sleeve-like portion, since the anchor member arranged in the mouth region is plug-shaped and not sleeve-like.

In a further embodiment, at least one sterile cover is attached to the sensor holder. The sterile cover may be formed, for example, as a sterile film. In this case, the sterile cover can be attached to the sensor holder such that the sensor element can be covered by the sterile cover with respect to an external volume.

If the sensor element is e.g. connected via a cable to other parts (in particular an evaluation device) of a position detection device, the sterile cover can be arranged such that the cable or at least a portion of the cable can be covered by the sterile cover.

In a further embodiment, the sterile cover is attached in rolled-up form to the sensor holder such that it can be unrolled away from the free end of the sensor holder. This results in an advantageous manner that a sensor element can be arranged on a sensor holder, wherein thereafter the cover mounted in rolled-up form on the sensor holder via the sensor element and optionally a cable attached to the sensor element can be unrolled. Thereafter, the sensor holder can be connected by means of the corresponding connecting means with the anchor element. This results in an advantageous manner that germs can not get from the sensor element into a mouth of the patient. At the same time allows the attachment of the cover to the sensor holder as simple as possible integration of a sterile cover in the device according to the invention.

In a further embodiment, the sensor holder has a connection element and a sensor element. The connecting element has the at least one corresponding connecting means or forms this. Furthermore, the connecting element and the sensor element are detachably connectable to one another in such a way that the connecting element and the sensor element can be fastened to one another repeatedly in a predetermined relative position and orientation, in particular are stably fastened. The connecting element and / or the sensor element may have correspondingly formed connecting means for this purpose. For example, the sensor element can be fixed to the latter exclusively in the predetermined position and / or orientation relative to the connecting element. In a fixed state, a predetermined operating force is necessary to move the sensor element from To solve connecting element or to change the relative position and orientation.

As a result, it is advantageously ensured that the sensor element can be repeatedly fastened to the connecting element in a desired position and orientation.

In particular, this makes it possible for the detection of the head movement first the sensor element is arranged with a predetermined position and orientation on the connecting element. After this, for example, a sterile cover arranged on the connecting element can be arranged above the sensor element, for example unrolled over the sensor element. Thereafter, the connecting member may be stably fixed to the anchor member, wherein, as previously explained, in the attached state, the predetermined position and orientation of the sensor holder is adjusted relative to the anchor member.

Further proposed is a method for detecting a position and orientation of a head of a patient. In this case, an anchor element of a device according to one of the embodiments explained above is fixed mechanically rigidly to at least one tooth, in particular a tooth of an upper jaw, of the patient. In this case, therefore, the anchor element is fixed in place relative to the skull or upper jaw of the patient.

Further, a sensor holder with a predetermined position and orientation relative to the anchor elements attached to this, in particular stably fixed. Furthermore, a position and orientation of a sensor element, which is arranged on the sensor holder, detected. Depending on the position and orientation of the sensor element, a position and orientation of the head of the patient is determined. In particular, changes in position and orientation changes of the head can be determined.

The proposed method advantageously allows the transformation of image data, which is taken with an image capture device from the patient's head, into a coordinate system fixed relative to the head. For this purpose, a position and orientation of the image capture device relative to the position and orientation of the sensor element and thus also relative to the position and orientation of the head can be determined. In particular, the image capture device may be an ultrasonic sensor that generates ultrasound images of regions within the head, especially the brain.

If the image capture device is repeatedly aligned in such a way that the same relative position and orientation of the image acquisition device for the position and orientation of the sensor element is given, images of identical regions of the head, in particular of the brain, can be generated repeatedly.

Thus, a method for transforming images produced by an image capture device into a relatively fixed coordinate coordinate system will also be described. Here, the position and orientation of the sensor element in the coordinate system of a position detection device is determined, wherein a spatial relationship between the coordinate system of the position detection device and the fixed relative to the head coordinate system in dependence of the position and orientation of the sensor element is determined. Furthermore, a position and orientation of the image capture device in the coordinate system of the position detection device is determined. Depending on the previously described spatial relationship, the transformation of the images into the coordinate system fixed relative to the head can then take place.

In the method, the sensor element can be attached to a connecting element, wherein the connecting element and the sensor element form the sensor holder. In particular, the sensor element can be fastened to the connecting element with a predetermined, reproducible position and orientation. Hereinafter, the connecting element, e.g. via a corresponding connecting means, mechanically connected to the anchoring element, which is arranged stationary relative to the skull of the patient, with a predetermined reproducible position and orientation.

This advantageously allows a simple composition of the device to perform the proposed method.

In a further embodiment, a rolled-up sterile covering device arranged on the sensor holder, in particular on the previously explained connecting element, is unrolled away from a free end of the sensor holder. In this case, the covering device can be unrolled in such a way that the sensor element is covered by the covering device. In particular, a cable may also be used to connect the sensor element e.g. connects to the position detection device, are covered by the sterile cover device.

As a result, it is achieved in an advantageous manner that no or only a few germs can pass from the sensor element or the cable into a mouth of the patient.

In a further embodiment, a position and orientation of a further instrument determined relative to the position and orientation of the head. Thus, the position and orientation of the further instrument can be determined with respect to a relative to the head stationary coordinate system. As previously explained, for this purpose a position and orientation of the further instrument can be determined for example in a coordinate system of the position detection device or converted into this coordinate system. For example, the position and orientation of the further instrument can be determined by means of the position detection device.

In particular, the further instrument may be the previously described image capture device, for example an ultrasound sensor. Of course, however, it is also possible that the further instrument is a medical instrument, for example an invasive medical instrument, for example a biopsy needle.

This advantageously allows the further instrument to be aligned with the head even during or after movements of the head in the correct position and orientation.

The invention will be explained in more detail with reference to an embodiment. The individual figures show:

1 a schematic illustration of a device according to the invention,

2 a section through the plug-shaped part and

3 a cross section through the anchor element.

Hereinafter, like reference numerals designate elements having the same or similar technical features.

In 1 is a schematic device of the invention 1 shown. Around a tooth Z of a patient around a potting compound VM, for example made of cement, arranged. In the potting compound VM is an anchor element 2 brought in. Here it is shown that the anchor element 2 sleeve-shaped and an internal volume 3 includes. Part of the anchor element 2 is disposed within the potting compound VM, while another part of the anchor element 2 protrudes from the potting compound VM. However, it is also possible, the anchor element 2 completely within the potting VM, but with at least one opening 4 the anchor element from outside the potting compound VM must be accessible. In 1 is shown that the anchor element 2 is formed such that the inner volume locking recesses 5 formed. The detent recesses 5 are here at one end of the anchor element 2 arranged, which is arranged opposite an end of the anchor element, on which the opening 4 of the internal volume 3 is arranged.

Also shown is a sensor holder 6 , This has a plug-shaped free end 8th on. At a free end 8th of the plug-shaped part 7 forms the plug-shaped part 7 locking lugs 9 made in such a way that they are in the locking recesses 5 of the internal volume 3 can intervene.

Next includes the sensor holder 6 a sensor element 12 , which with a predetermined position and orientation relative to the sensor holder 6 attachable to this. Also shown is a sterile cover sheet 13 , which in a rolled up condition on the sensor holder 6 is attached. Dashed lines illustrate the sterile cover foil 13 in an unrolled state. This covers the sterile cover film 13 the sensor element 12 and a cable 14 which is the sensor element 12 For example, connects to a position detection device, not shown, from.

In 2 is a section through the plug-shaped part 7 shown. It can be seen that the locking lugs 9 on cut-free locking tongues 10 are arranged, wherein the locking tongues 10 a gap 11 include. This allows the locking tongues 10 during the insertion of the male part 7 in the interior volume 3 of the anchor element are moved towards each other, whereby the movement through the internal volume 3 is possible. Reach the locking lugs 9den the area of the locking recesses 5 , so are the locking lugs 9 by a spring force of the locking tongues 10 , due to this deformation on the spring tongues 10 acts in the locking recesses 5 intervention.

In 3 is a cross section through the anchor element 2 shown. Here it is shown that the locking recesses 5 are arranged at predetermined positions along a circumference of the sleeve-like portion. Thus, the locking lugs 9 only in the locking recesses 5 engage when a predetermined position and orientation of the sensor holder is adjusted relative to the anchor element.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5143086 [0007]

Claims (10)

Device for detecting a head movement of a patient, the device ( 1 ) at least one anchor element ( 2 ) and at least one sensor holder ( 6 ), wherein the anchor element ( 2 ) is mechanically rigidly fastened to at least one tooth (Z) of the patient and has at least one connecting means, wherein the sensor holder ( 6 ) at least one sensor element ( 12 ) of a position detection device and at least one corresponding connection means, characterized in that the connection means of the anchor element ( 2 ) and the corresponding connecting means of the sensor holder ( 6 ) are formed such that the anchor element ( 2 ) and the sensor holder ( 6 ) are repeatably fastened together in a predetermined relative position and orientation. Device according to claim 1, characterized in that the sensor element ( 12 ) is designed as an electromagnetic sensor. Device according to one of claims 1 or 2, characterized in that the anchor element ( 2 ) has a sleeve-like portion, wherein a free end of the sensor holder ( 6 ) is plug-shaped, wherein the free end in an internal volume ( 3 ) of the sleeve-like portion can be arranged. Device according to one of claims 1 or 2, characterized in that at least a part of the anchor element ( 2 ) is plug-shaped, wherein a free end of the sensor holder ( 6 ) has a sleeve-like portion, wherein the free end on the male part of the anchor element ( 2 ) can be plugged. Device according to one of claims 1 to 4, characterized in that on the sensor holder ( 6 ) at least one sterile cover ( 13 ) is attached. Device according to claim 5, characterized in that the sterile cover ( 13 ) in a rolled-up form on the sensor holder ( 6 ) is attached, that this is unrolled away from the free end. Device according to one of claims 1 to 6, characterized in that the sensor holder ( 6 ) a connecting element and the sensor element ( 12 ), wherein the connecting element comprises or forms the at least one corresponding connecting means, wherein the connecting element and the sensor element ( 12 ) are detachably connectable with each other such that the connecting element and the sensor element ( 12 ) are repeatably fastened together in a predetermined relative position and orientation. Method for detecting a position and orientation of a head of a patient, wherein an anchor element ( 2 ) a device ( 1 ) according to one of claims 1 to 7 mechanically rigidly attached to at least one tooth (Z) of the patient, wherein a sensor holder ( 6 ) with a predetermined position and orientation relative to the anchor element ( 2 ) is attached thereto, wherein a position and orientation of a sensor element ( 12 ) of a position detection device is detected, wherein, depending on the position and orientation of the sensor element ( 12 ) a position and orientation of the head is determined. Method according to claim 8, characterized in that one on the sensor holder ( 6 rolled-up sterile covering device ( 13 ) away from a free end of the sensor holder ( 6 ) is unrolled. Method according to one of claims 8 or 9, characterized in that a position and orientation of a further instrument relative to the position and orientation of the head is determined.

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