The invention relates to a prosthetic device for a lower extremity, comprising a prosthetic foot and a lower-leg part fastened to the prosthetic foot, and a device for manually adjusting an orientation of the lower-leg part relative to the prosthetic foot. The invention likewise relates to an adjustment device for manually adjusting an orientation of a lower-leg part relative to a prosthetic foot, of a prosthetic device, of a lower extremity, and a method for manually adjusting an orientation of a lower-leg part, of a prosthetic device, of a lower extremity relative to a prosthetic foot fastened to the lower-leg part, wherein an adjustment device with an inertial angle sensor is arranged on the prosthetic device, the inertial angle sensor detecting the orientation of the lower-leg part in space and being coupled to an output device.
Prostheses replace missing or lost limbs, the intention generally being that the prosthesis replaces not only the shape but also at least some of the functions of the limb. Prosthetic devices of the lower extremity comprise a foot part, the prosthetic foot, which is secured to the patient. Provided the lower leg or part of the lower leg is still intact, the prosthetic foot can be secured to the respective stump via a lower-leg socket. The lower-leg socket can be secured to the stump in various ways, for example using a prosthetic liner and suction socket technology. If the natural knee joint has been lost, the prosthetic device is generally secured to a thigh stump via a thigh socket. Then, a prosthetic knee joint is secured to the thigh socket, the prosthetic knee joint having a lower-leg tube or a lower-leg part for coupling the prosthetic foot to the prosthetic knee joint. Damping devices, adjusting devices and sensors and control devices, for example for controlling the damping device for the purposes of influencing the prosthetic knee joint, may be arranged on or in the lower-leg part.
The prosthetic foot can be mounted on the lower-leg part in articulated and motor-driven fashion in order to assist the patient with the respectively envisaged movement. Coordinating the movements in the knee joint and the ankle joint is very complicated in such an embodiment, and moreover the respective drive requires much space and is comparatively heavy. In the simplest embodiment of a prosthetic foot, the latter is embodied as a prosthetic foot without joints and—once it has been aligned—it is permanently secured to the lower-leg part. In this case, it is difficult to adapt the alignment of the prosthetic foot to different heel heights when the patient changes footwear. Furthermore, prosthetic feet that are mounted to be pivotable about an ankle joint and have a passive damping device to influence dorsiflexion or plantar flexion are known. Furthermore, there are prosthetic feet with a foot part and a proximal connection means, which is pivotably connected to the football. By way of an adjusting device, the foot part is adjustable relative to the connection means. The adjusting device can be assigned at least one position sensor which is coupled to a signal generation element, the latter outputting a signal regarding the attainment of the position of the foot part on the basis of the signal of the position sensor. The position sensor ascertains the relative position of the foot part with respect to the connection means or the lower-leg part fastened thereto. Alternatively, the position sensor ascertains the relative spatial position of the foot part during an adjustment procedure. Such a prosthetic foot is known from DE 10 2014 010 938 A1. As a result, it is possible to retrieve heel height settings.
A disadvantage of the device proposed in the prior art is that the correct position must be set individually for each shoe since it is only the relative angle between prosthetic foot and lower leg that is ascertained. For a new heel height it is therefore necessary to initially ascertain the correct setting and store the latter as a reference. Moreover, the user must identify the signal fitting to the respective heel height from a multiplicity of reference signals, possibly leading to incorrect settings.
It is therefore an object of the present invention to provide a prosthetic device, an adjustment device and a method for adjusting an orientation of a lower-leg part of a prosthetic device, which is simple to apply and which provides the user with reliable feedback about the correct prosthesis set up.
According to the invention, this object is achieved by a prosthetic device having the features of the main claim, and by an adjustment device and a method having the features of the alternative independent claims. Advantageous embodiments and developments of the invention are disclosed in the dependent claims, the description and the figures.
The prosthetic device for a lower extremity, comprising a prosthetic foot and a lower-leg part fastened to the prosthetic foot, and a device for manually adjusting an orientation of the lower-leg part relative to the prosthetic foot provides for an inertial angle sensor to be arranged on the prosthetic device, to serve to detect the orientation of the lower-leg part in space and to be coupled to an output device which outputs, in a manner identifiable by a user by way of an output signal, the orientation of the lower-leg part in space or the attainment of an orientation defined in advance. The output device preferably outputs, in a manner identifiable by a user, for example in optical, acoustic or tactile fashion, the defined orientation of the lower-leg part in space and thus provides feedback about the orientation of the lower-leg part in space. The output can be qualitative and/or quantitative, or else specify by way of a signal that an orientation of the lower-leg part in space, having been stored once, has been attained. Instead of measuring the orientation of the prosthetic foot in space and comparing whether this orientation corresponds to the desired orientation, it is the relative spatial position of the lower-leg part that is detected and not the relative position of the lower-leg part in relation to the prosthetic foot. Using such a prosthetic device it is possible, following the assembly of an adjustable prosthetic foot on the lower-leg part, to optimally adjust the prosthetic device by an orthopedic technician, that is to say ensure an optimal prosthesis setup. The prosthesis setup is the positioning and orientation of the respective prosthesis components in relation to one another. The prosthesis setup is set individually for each patient and contributes significantly to the functionality of the prosthetic device and its acceptance by the patient. Once the prosthesis setup has been correctly set, the patient can easily retrieve the optimal prosthesis setup using the prosthetic device according to the invention when a different shoe model with a deviating heel height and a deviating sole rigidity is used. By adjusting the prosthetic foot relative to the lower part until the stored standard angle or reference angle of the lower part in space is attained, the optimal setting set by the orthopedic technician is easily retrieved, and the prosthetic foot can be fixed to the lower-leg part in this position following a change of footwear or the like. The combination of determination of the lower-leg angle by means of an inertial sensor or inertial sensors and an output device allows the heel height to be adjusted for any prosthetic foot which comprises a device for manually adjusting an orientation of the lower-leg part. Adjusting an orientation of the lower-leg part in this case is implemented in fully manual fashion, from unlocking the joint via adjusting the angle to renewed locking. Accordingly, no complicated mechatronic ankle joint is required. Rather, a simple and reliable option for each adjustable ankle joint is offered to the patient in relation to retrieving the correct adjustment for different heel heights. The orientation in space is in particular the orientation of the lower-leg part relative to the direction of gravity. By way of example, if the lower leg is within the sagittal plane, the orientation of the lower-leg part is defined by the forward inclination or backward inclination in the opposite direction, proceeding from the perpendicular. If the user of the prosthetic device unlocks the prosthetic foot, in particular unlocks the latter manually, the prosthetic foot can be moved relative to the lower leg part. This is advantageously implemented when the prosthetic foot is put on and the lower leg part is pivoted within the sagittal plane, for example about a pivot axis in the region of the ankle joint. A signal perceivable by the user is output when the correct position of the lower-leg part is attained.
A development of the invention provides for the inertial angle sensor and the output device to be combined as a module and installed in the prosthetic device or detachably fastened thereto. As a result, it is possible to subsequently attach the adjustment device to a prosthetic device or to undertake retrofitting and equip prosthetic devices not originally designed to this end with the module. In principle, provision is made for the inertial angle sensor to be seated at any position on the lower-leg part, for example quite distally, in order to detect the relative spatial position without falsification where possible. Preferably, the inertial sensor is proximal of the prosthetic foot and proximal of the ankle joint such that valuable installation space in the prosthetic foot can be saved. The output device can be arranged at an easily accessible or more easily perceivable position, for example on a lower-leg socket, a thigh socket or at a separate location that is independent of the prosthetic device. In the case of a configuration as a separate element, the output device can be designed as tag on a set of keys, in a pocket, as an armband or as an app on a cellular telephone such that the user can receive the feedback as conveniently as possible. Then, the inertial angle sensor is preferably coupled to the output device in wireless fashion, by radio or a similar data transfer process. In the case of a configuration as a module, in particular as a retrofittable module, the inertial angle sensor and the output device are permanently interconnected, in particular by means of a cable. In the case of a separate arrangement, the output device may be coupled to the inertial angle sensor only when required. Then, the inertial angle sensor is coupled to a transmission device, which may also be designed as part of a control device for the remaining prosthetic device, the transmission device being used to supply the output device with the corresponding signal about the position of the lower-leg part in space. Both the inertial angle sensor and the output device are preferably coupled to a control device in which the sensor data are evaluated. By way of example, a computer and a memory device are available in the control device in order to evaluate the sensor data, perform a comparison with a reference angle in space, and output a signal.
The inertial angle sensor can preferably be arranged on the lower-leg part. As an alternative thereto, provision is made for the inertial angle sensor to be fastened to an element of the prosthetic device arranged proximally thereto, for example to an upper part of a prosthetic knee joint or to a thigh socket. From the information about the relative spatial position of the proximal element in conjunction with an angle sensor which measures the position of the lower-leg part with respect to the thigh socket, it is possible to calculate the relative spatial position of the lower-leg part. Alternatively or in addition, the ascertainment of the lower-leg angle can be implemented with a previously defined relative angle between thigh and lower leg such that no angle sensor is required. To this end, provision could be made for the user to always carry out or have to carry out the adjustment with the knee fully extended, for example.
A development of the invention provides for a load sensor to be arranged on the prosthetic device and be coupled to the output device in such a way that the output signal is output if a load is detected. The orientation of the lower-leg part may change in the case of different loads, in particular in the case of different axial loads. Different lower-leg orientations and hence a different prosthesis setup in each case may arise when a shoe is changed on account of different sole rigidities and sole geometries. By way of the load sensor it is possible to ensure that the adjustment is always implemented under the same load, e.g., axial load, as a result of which an unchanging prosthesis setup is ensured. The load sensor may be designed as an axial force sensor, pressure sensor or torque sensor and may be arranged, for example, in the lower-leg part, in a connecting device between the prosthetic foot and the lower-leg part, on a joint or on the prosthetic foot.
The output device is preferably designed to output an optical, acoustic and/or tactile output signal and can indicate the current relative spatial position of the lower-leg part, in particular in the sagittal plane, the deviation in a certain direction to the entered and stored orientation, and/or the attainment of the specified orientation. The output device may also be connected to, or integrated in, the device for manually adjusting an orientation of the lower-leg part. In this case, the user unlocks the adjusting device and moves the prosthetic foot manually until the reference position has been attained. A signal is output when the reference position is attained, as a result of which the user receives feedback that the correct setting was found.
Preferably, the prosthetic foot is mounted so as to be pivotable in the sagittal plane in order to compensate changes in the heel height. Provided a relative spatial position is also registered in the frontal plane, it is possible for example to output a warning signal should the deviation from a previously set value be too large.
A development of the invention provides for a deactivation device to deactivate the inertial angle sensor and/or the output unit or the connection between the inertial angle sensor and the output unit after the orientation defined in advance has been attained so that energy can be saved. The output unit preferably only operates when adjusting and fitting to a new shoe is intended. To this end, the prosthetic device can be put into an adjustment mode, for example by way of an input field in the output device or by way of another switch or command. Once adjustment and setting has been completed, this may either be detected automatically or be confirmed manually. The adjustment mode is then terminated, and the output device is deactivated. The inertial angle sensor can continue to be operated, for example in order to provide sensor data for a control device of any other prosthesis component, for example for controlling a prosthetic knee joint. Preferably, the inertial angle sensor is designed as part of a control device of the prosthetic device such that the relative spatial position data of the inertial angle sensor are not only used for identification and adjustment purposes when changing the heel height or changing footwear, but also serve when walking as a basis for, e.g., a change in a damping resistance in the ankle joint and/or the knee joint.
The adjustment device for manually adjusting an orientation of a lower-leg part relative to a prosthetic foot, of a prosthetic device, of a lower extremity provides for the adjustment device to comprise an inertial angle sensor which detects the orientation of the lower-leg part in space and which is coupled to an output device which outputs, in a manner identifiable by a user by way of an output signal, the orientation of the lower-leg part in space or the attainment of an orientation defined in advance. In particular, the output is implemented as an optical, acoustic and/or tactile output signal, wherein the output device in one variant of the invention is coupled to the inertial angle sensor and a computing device to form a module, for the purposes of evaluating the inertial angle sensor data and transmitting these to the output device.
A fastening device for securing to a prosthetic device can be arranged or formed on the adjustment device; by way of example, interlocking elements, such as clips, hook-and-loop fastener parts, screws, snap-fit elements and/or hooks, or frictionally connected elements such as magnets may be arranged or formed on the respective component in order to ensure a permanent or detachable and replaceable attachment. The attachment is preferably implemented on the lower-leg part or any other prosthesis component in a defined orientation, for example along an abutment edge or any other guide, for example on a rail or in a groove.
The method for manually adjusting an orientation of a lower-leg part of a prosthetic device to a lower extremity relative to a prosthetic foot fastened to the lower-leg part, wherein an adjustment device with an inertial angle sensor is arranged on the prosthetic device, the inertial angle sensor detecting the orientation of the lower-leg part in space and being coupled to an output device, provides for a reference orientation of the lower-leg part in space to be set for a user and the attainment of the reference orientation set in advance to be output in a manner identifiable by a user by way of an output signal. The reference orientation of the lower-leg part is preferably set by an orthopedic technician or another expert schooled to this end. The reference orientation is preferably input in the applied state of the prosthetic device, in the case of a reference setup for the prosthetic device in the case of a usual load. By way of example, a usual load is given by standing with a uniform weight load on the supported and unsupported side. In the case of such a method, it is possible to use the orientation of the lower-leg part in space as a relevant variable so that there is no need to store reference positions for different positions for each prosthetic foot. The user receives only a single signal, specifically once the reference orientation has been attained, optionally with notifications about the magnitude and the direction of the adjustment required in order to reach the reference orientation. The adjustment is implemented manually, in particular by pivoting about an ankle joint axis that extends perpendicular to the longitudinal extent of the lower-leg part in the frontal plane. This ensures that the lower-leg part is only pivoted in the sagittal plane. Alternatively, there can be pivoting on the fastening device of the foot part on the lower-leg part, for example at the so-called pyramid adapter, with pivoting in the frontal plane also being possible there as a matter of principle.
The orientation of the lower-leg part is preferably adjusted in the case of an applied, in particular loaded prosthetic device in order to be able to ensure for the user a prosthesis setup that remains unchanged during use, even in the case of different shoes.
The adjustment can be initiated and carried out automatically for each prosthetic foot change, for each heel height change or following a separate activation signal. By way of example, if a relative spatial position deviating from the reference orientation is detected following the application of the prosthetic device, a notification can be output to the user in respect of a reorientation or a check, and an adjustment or checking mode can be activated. Following the adjustment, the adjustment device preferably deactivates automatically; in particular, the output device is deactivated in order to minimize the power consumption. By way of example, if a shoe is changed, the output device provides an output signal or feedback that the lower-leg orientation currently present deviates from the reference orientation. Subsequently, the relative angle between the lower leg and prosthetic foot is adjusted manually until the output device provides the output signal or feedback that the lower-leg orientation corresponds to, or is sufficiently close to, the reference orientation. Once the correct position has been attained, the prosthetic foot is secured in this position, in particular by hand, such that the proximal connection means of the prosthetic foot, e.g., a pyramid adapter, no longer moves relative to the lower-leg part. The prosthetic foot itself may have a joint or move relative to the lower-leg part in regions. The end of the adjustment procedure may be indicated or output by way of the output device, for example after there was automatic recognition that the correct adjustment is present, or once a corresponding confirmation signal has been entered.
Exemplary embodiments of the invention are explained in more detail below on the basis of the attached figures, in which:
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Number | Date | Country | Kind |
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10 2019 118 118.6 | Jul 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/068367 | 6/30/2020 | WO |
Number | Date | Country | |
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20220354670 A1 | Nov 2022 | US |