DE102021116536A1 - Method for measuring and manufacturing a prosthetic socket - Google Patents

Abstract

The invention relates to a method for measuring a prosthesis socket, which has a closed distal end, an open proximal end for inserting an amputation stump, an inner surface and a fastening element for fastening at least one prosthesis component, the method having the following steps: providing a reference object, positioning the prosthesis socket in such a way that a position of the fastening element relative to the reference object is known and/or can be calculated, detecting the inner surface and at least part of the reference object in a joint 3D scan, so that the position of the inner surface relative to the reference object is known and/or can be calculated is, determining the position of the inner surface relative to the fastener.

Description

The invention relates to a method for measuring a prosthesis socket, which has a closed distal end, an open proximal end for inserting an amputation stump, an inner surface and a fastening element for fastening at least one prosthesis component. The invention also relates to a method for producing a definitive prosthesis socket.

A prosthetic socket of a modern prosthesis can be thought of as the link between the patient's amputation stump and the prosthesis replacing a missing body part. It has a closed distal end and an open proximal end into which the amputation stump is inserted. The shape and form of the amputation stump depends on a variety of factors and is individual to each patient. In addition, not only the contour and shape of the amputation stump, but also the distribution of different types of tissue, for example soft tissue or scar tissue, and the positioning and expansion of bony structures within the amputation stump varies from patient to patient. In particular, prosthesis sockets with which a leg prosthesis is arranged on a lower leg stump or a thigh stump are exposed to immense loads over a long period of time. The patient will load such a prosthesis socket with his full body weight when walking and will want to carry out as many movements as possible that can also be carried out with a healthy leg. It is therefore particularly, but not exclusively, important in the case of such prosthesis sockets to adapt the prosthesis socket individually to the needs and situation of the respective patient.

In addition to this individual design and fit, the prosthesis socket must be made of a material that is light on the one hand and on the other hand can withstand the high mechanical loads over as long a period of time as possible. Therefore, prosthetic sockets are usually made of carbon fiber composite material.

It is known from the prior art to first request the amputation stump, for example by creating a plaster mold or by generating scan data. The main purpose of this step is to get a base for and make a test socket. The test socket is then tested on the patient and requested to the needs. The prosthesis socket to be produced must not only fit the patient when it is not loaded, but especially when it is loaded, and it must also be able to be worn pain-free over a long period of time. The data on which the test stem is based are therefore not perfect. For example, it is not possible with a plaster mold to simulate loaded and unloaded states, since only one state can be molded. However, this is often still done manually by an orthopedic technician, who, based on his experience, recognizes and feels areas that are particularly sensitive to pain or areas that are due for pain, as well as, for example, bony protrusions, and allows this information to flow into the plaster molding by skillfully shaping the plaster material. The advantage of an electronic scan, for example by an optical scanner, is that different scanning processes and the data determined from them can be combined here, so that different situations and in particular different load conditions can be simulated and summarized. However, there is usually no physical contact between the patient and the orthopedic technician.

Regardless of the method used, it is almost impossible to produce a trial socket that meets all of the patient's requirements. Rather, it is customary and also advantageous to produce the test socket from a material that can still be deformed and adapted to individual needs. This is done comprehensively in order to give the patient the best possible wearing comfort and sufficient stability and security.

The fit and stability of the prosthesis socket is determined in particular by the inner contour and the inner surface of the prosthesis socket. By changing the wall thickness at certain points, for example, points that are subjected to particularly high mechanical loads can be reinforced. Space can be left for cushions and upholstery, for example, by deliberately providing a distance between the inner wall of the prosthesis socket and the amputation stump. In addition, the socket is usually reduced in the area of the soft tissues, since these can absorb the load, while areas with bony structures are to be relieved. However, it is also important for wearing comfort and a gait pattern that is as natural as possible that further prosthetic elements, for example an artificial knee, a lower leg or a prosthetic foot, can be arranged in the best possible position and orientation, not only relative to one another but also relative to the amputation stump. For this purpose, such a prosthesis socket has at least one fastening element to which such a further prosthesis component can be fastened. The position and orientation of such fasteners is of crucial importance.

The problem is that at the moment when a prosthesis socket is deformed and adapted to the patient, the optimal position and orientation of the fastening element may also change and the fastening element itself must be displaced or moved.

If the test socket has been adapted to the patient's individual requirements to such an extent that a final socket, which is also referred to as a "definitive socket", can be manufactured, this is done on the basis of the adapted test socket. The problem here is that the individually adapted inner surface of the test socket, which has been modified and deformed with respect to the test socket originally produced and is so important for a good fit, and the position and orientation of the fastening element relative to one another must be known.

A similar problem also arises if the patient already has a well-fitting definitive socket, but this needs to be replaced. Digital production data is often not available and plaster models and test sockets are rarely kept, as this takes up space and is therefore expensive.

The invention is based on the object of proposing a method with which a prosthesis socket can be measured easily, quickly and reliably in such a way that the inner surface of the amputation stump relative to the fastening element is known.

• - Bereitstellen eines Referenzobjektes,
• - Positionieren des Prothesenschaftes derart, dass eine Position des Befestigungselementes relativ zu dem Referenzobjekt bekannt und/oder berechenbar ist,
• - Erfassen der Innenfläche und zumindest eines Teils des Referenzobjektes in einem gemeinsamen 3d-Scan, sodass die Position der Innenfläche relativ zu dem Referenzobjektes bekannt und/oder berechenbar ist,
• - Bestimmen der Position der Innenfläche relativ zu dem Befestigungselement.

The invention solves the problem by such a method that has the following steps:

• - Provision of a reference object,
• - Positioning the prosthesis socket in such a way that a position of the fastening element relative to the reference object is known and/or can be calculated,
• - detecting the inner surface and at least part of the reference object in a joint 3D scan, so that the position of the inner surface relative to the reference object is known and/or can be calculated,
• - determining the position of the inner surface relative to the fastener.

The measurement of the prosthesis socket is divided into two parts by the method according to the invention. In one part, the position of the fastening element relative to a reference object is determined or the prosthesis socket is at least positioned in such a way that this orientation and/or position can be determined. For this it is sufficient and for some requirements also advantageous if at least part of the fastening element, preferably the entire fastening element and at least part of the reference object, preferably the entire reference object, can be detected and is detected in a common 3D scan. In the second part of the method, the position of the inner surface of the prosthesis socket and at least part of the reference object is recorded in a joint 3D scan. From this information, ie the position of the fastening element relative to the reference object and the position of the inner surface relative to the reference object, it is possible to determine the position of the inner surface relative to the fastening element.

In one embodiment of the invention, the position of the fastening element relative to the reference object is recorded by a further joint 3D scan. This means that there are two 3D scans, each containing the reference object. It is thus possible to combine both scans into a single scan by aligning and matching the position and orientation of the reference object in both scans. Then the two scans are superimposed. A known method for this is, for example, the so-called best-fit method.

With the method according to the invention it is consequently possible to represent the position of the inner surface of the prosthesis socket and the position of the fastening element in a single common coordinate system and thus to determine the relative position to one another and preferably to store it so that it can be processed by electronic data processing equipment.

In a preferred embodiment, the prosthesis socket is positioned in such a way that the orientation of the fastening element relative to the reference object is also known and/or can be calculated, that the inner surface and the part of the reference object are recorded in such a way that the orientation of the inner surface relative to the reference object is also known and/or is calculable, and that the orientation of the inner surface relative to the fastening element is also determined.

Regardless of whether only the position or also the orientation of the various elements to one another is recorded, determined or calculated, the sequence of the steps is of secondary importance. It is irrelevant whether the position and/or orientation of the fastening element relative to the reference object or the position and/or orientation of the inner surface relative to the reference object is determined or calculated first. It is important that the required information is available when the position and/or the orientation of the inner surface relative to the fastener is to be determined or calculated.

The prosthesis socket is preferably positioned on a holding device on which the reference object is preferably located. In a particularly preferred embodiment, the prosthesis socket is attached to the holding device with the attachment element. This is possible in a particularly simple manner if the holding device is set up and designed in such a way that the fastening element itself can be positioned and arranged on the holding device. By positioning the prosthesis socket on a known holding device, it is not necessary to record and/or calculate the position and/or the orientation of the fastening element relative to the reference object using a common 3D scan. Rather, this relative position and/or relative orientation is known independently of the design of the prosthesis socket, provided that the fastening element itself is fastened to the holding device.

In a preferred embodiment, a scanner, preferably a hand-held scanner, which emits and/or detects electromagnetic radiation, preferably visible light, particularly preferably laser light, is used to detect the inner surface and at least part of the reference object, but advantageously the entire reference object. The inner surface can thus be detected, for example, by means of photogrammetry. As an alternative or in addition to this, the object to be measured can also be irradiated with light in the form of strips, ie alternating strips of light and darkness, the width and spacing of which is known. For this purpose, a camera records the illuminated object and conclusions can be drawn from the image data about the geometry and the proportions of the object to be measured, in this case the inner surface of the prosthesis socket.

The electromagnetic radiation is preferably deflected by at least one mirror before it strikes the inner surface, the at least one mirror preferably being part of the scanner or being arranged on it. This means that undercuts or indentations on the inner surface of the prosthesis socket can also be measured without any problems, without it being necessary to cut open or destroy the prosthesis socket.

The scanner preferably has a required minimum distance from the object to be scanned and the at least one mirror has a distance from the scanner that is smaller than this minimum distance. The distance of the game from the actual scanner is particularly preferably adjustable. The mirror itself can be rigidly connected to the scanner so that the mirror cannot move relative to the scanner. Alternatively, the at least one mirror can also be attached to the scanner so that it can move, for example tilt and/or rotate. By moving the mirror, at least part of the object to be detected can be scanned.

An outer surface of the prosthesis socket is preferably also recorded and an overall representation of the prosthesis socket is particularly preferably created from the data recorded in this way on the outer surface, the inner surface and the fastening element. This is preferably done in an electrical controller, preferably an electronic data processing device that can access the recorded data.

• - Bereitstellen eines Schaftes mit einem geschlossenen distalen Ende, einem offenen proximalen Ende zum Einführen eines Amputationsstumpfes und einer Innenfläche,
• - Vermessen des Schaftes mittels eines Verfahrens gemäß einem der vorstehenden Ansprüche,
• - Fertigen des Definitiv-Prothesenschaftes gemäß den Ergebnissen des Vermessens.

The invention also solves the problem set by a method for producing a definitive prosthesis socket, which has the following steps:

• - providing a shaft with a closed distal end, an open proximal end for insertion of an amputation stump and an inner surface,
• - Measurement of the shaft by means of a method according to one of the preceding claims,
• - Manufacture of the definitive prosthesis socket according to the results of the measurement.

The socket provided can be a test socket or a prosthesis socket that is no longer used or can no longer be used, on the basis of which the definitive socket is to be manufactured.

The inner surface of the shaft is preferably deformed and/or a fastening element for fastening at least one prosthesis component is positioned before the shaft is measured.

In a preferred embodiment, the definitive socket is produced in a 3D printing process. This does not mean that the complete definitive socket is manufactured in such a process. An essential part, for example a base body of the upper, is manufactured in this process.

• 1 bis 8 - unterschiedliche Verfahrensschritte.

An exemplary embodiment of the present invention is explained in more detail below with the aid of the attached drawings. Show it

• 1 until 8th - different process steps.

1 1 schematically shows a sectional view of a prosthesis socket 2 which has a closed distal end 4 , an open proximal end 6 , an inner surface 8 and a fastening element 10 .

2 shows the sectional view of the prosthesis socket 2 from 1 , A reference object 12 being arranged on the prosthesis socket 2 by means of a holding device 14 . It is important that the position and/or the orientation of the reference object 12 is clearly and unchangeably defined by the holding device 14 . 3 shows another embodiment of the holding device 14, via which the reference object 12 is positioned and oriented relative to the prosthesis shaft 2. The holding device 14 in 3 has a base 16 that simplifies handling.

4 shows another process step. For the sake of simplicity, the further method steps are carried out using the holding device 14 2 described. However, you can also use other holding devices, for example the holding device 14 3 , be performed. The reference object 12 is attached to the prosthesis socket 2 via the holding device 14 . The inner surface 8 of the prosthesis socket 2 is scanned by means of a hand-held scanner 18, the reference object 12 also being recorded during the scan. The hand-held scanner 18 emits electromagnetic radiation which hits a mirror 20 before it is redirected to the inner surface 8 of the prosthetic socket 2 . In this way, undercuts and cavities can also be scanned that are actually too small, since a minimum distance between the object to be scanned and the scanner could not be maintained if the hand-held scanner 18 were arranged in such a cavity, for example.

5 shows the situation in which an outer side 22 of the prosthesis socket 2 is scanned by means of a further scanner 24, which can also be designed as a hand-held scanner. It is advantageous if the mirror 20 can be arranged on the hand-held scanner so that it can be removed, so that the same scanner can be used for the inside and outside. Although there are advantages in grasping the outside 22, it is not necessary. It is important that the position of the fastening element 10 and the position and orientation of the reference object 12 are recorded in the scan.

6 shows schematically a monitor 26, which shows that the corresponding method steps are carried out in a computer. Two scans are displayed on the monitor. The left part of the monitor 26 shows the first scan, in which the position of the reference object 12 relative to the inner surface 8 of the prosthesis socket 2 is shown. The second scan is shown on the right part, which also shows the reference object 12 and the outside 22 of the prosthesis socket 2 and the fastening element 10 .

In 7 the two scans are off 6 brought together and are displayed together on the monitor 26. The reference object 12, the inside 8, the outside 22 and the fastening element 10 of the prosthesis socket 2 can be seen. This means that all information relating to the geometric properties of the different elements of the prosthesis socket 2 and the position and/or orientation of the different elements to one another is known. so that a corresponding prosthetic socket can be produced.

this is in 8th shown, in which a 3-D printer 28 is shown schematically, which is used to produce the prosthesis socket 2, which is again shown schematically in the sectional view.

Reference List

2

prosthetic socket

4

distal end

6

proximal end

8th

Inner surface

10

fastener

12

reference object

14

holding device

16

stand

18

hand scanner

20

mirror

22

outside

24

scanner

26

monitor

28

3D printer

Claims (11)

Method for measuring a prosthesis socket, which has a closed distal end, an open proximal end for inserting an amputation stump, an inner surface and a fastening element for fastening at least one prosthesis component, the method having the following steps: - providing a reference object, - positioning the prosthesis socket in such a way that a position of the fastening element relative to the reference object is known and/or can be calculated - detecting the inner surface and at least part of the reference object in a joint 3D scan, so that the position of the inner surface relative to the reference object is known and/or can be calculated, - determining the position of the inner surface relative to the fastening element. procedure after claim 1 , characterized in that - the prosthesis socket is positioned in such a way that the orientation of the fastening element relative to the reference object is also known and/or can be calculated, - the inner surface and the part of the reference object are recorded in such a way that the orientation of the inner surface relative to the reference object is known and/or can be calculated, and the orientation of the inner surface is also determined relative to the fastening element. procedure after claim 1 or 2 , characterized in that the prosthesis socket is positioned on a holding device on which the reference object is preferably located. procedure after claim 3 , characterized in that the prosthesis socket is fastened to the holding device with the fastening element. Method according to one of the preceding claims, characterized in that a scanner, preferably a hand-held scanner, which emits and/or detects electromagnetic radiation, preferably visible light, particularly preferably laser light, is used to detect the inner surface and part of the reference object. procedure after claim 5 , characterized in that the electromagnetic radiation is deflected by at least one mirror before it hits the inner surface, wherein the at least one mirror is preferably part of the scanner or arranged on it, preferably releasably arranged. procedure after claim 6 , characterized in that the scanner has a required minimum distance from the object to be scanned and a distance of the mirror from the scanner is smaller than the minimum distance, the distance preferably being adjustable. Method according to one of the preceding claims, characterized in that an outer surface of the prosthesis socket is also recorded and an overall representation of the prosthesis socket is preferably created from the recorded data. Method of manufacturing a definitive prosthetic socket, comprising the following steps: - providing a shaft with a closed distal end, an open proximal end for insertion of an amputation stump and an inner surface, - Measurement of the shaft by means of a method according to one of the preceding claims, - Manufacture of the definitive prosthesis socket according to the results of the measurement. procedure after claim 9 , characterized in that the inner surface of the shaft is deformed and/or a fastening element for fastening at least one prosthesis component is positioned before the shaft is measured. procedure after claim 9 or 10 , characterized in that the definitive prosthetic socket is produced in a 3D printing process.

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