Prosthetic Ankle Orientation Adjustment Using Inertial Sensor Feedback
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Solution Overview
Problem
Existing prosthesis systems for lower extremities require individual setting for each shoe height, leading to potential misalignments and complexity in adjusting the prosthesis foot relative to the lower leg.
Innovation Solution
A prosthesis facility equipped with an inertial angle sensor that detects the orientation of the lower leg part in space and is linked to an output device, providing clear feedback to the user for achieving the correct orientation, thus simplifying the adjustment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the prosthetic foot is permanently fixed to the lower leg section after alignment, then the structural stability is improved, but the adaptability to different shoe heights deteriorates
Solution Approach 1:
The prosthetic foot is designed with a pivotable ankle joint that allows dynamic adjustment of the foot orientation relative to the lower leg section. This enables the system to adapt to different shoe heights while maintaining structural integrity through controlled movement rather than permanent fixed connections.
Solution Approach 2:
The adjustment mechanism allows the prosthetic foot to be pre-adjusted to the correct orientation for different shoe heights before the patient wears the prosthesis. This preliminary positioning ensures optimal alignment is achieved in advance, eliminating the need for complex real-time adjustments.
2Measurement precision
If multiple sensors and adjustment mechanisms are integrated into the lower leg section, then the measurement precision and control capability are improved, but the device complexity increases
Solution Approach 1:
The inertial angle sensor serves multiple functions: it detects the orientation of the lower leg section, provides feedback for adjustment, and can potentially control the damping mechanism. This multi-functionality reduces the need for separate specialized components, thereby managing device complexity while maintaining measurement precision.
Solution Approach 2:
The inertial angle sensor provides real-time feedback on the orientation of the lower leg section, enabling precise control and adjustment of the prosthetic foot position. This feedback mechanism allows the system to achieve high measurement precision without requiring overly complex mechanical adjustment mechanisms.
3Adaptability or versatility
If the prosthetic foot incorporates passive damping devices and adjustment mechanisms, then the functionality and comfort are improved, but the weight of the prosthesis increases
Solution Approach 1:
The damping function is extracted from active motorized systems and implemented through passive damping devices integrated into the prosthetic foot structure. This extraction eliminates the need for heavy motors and power sources while maintaining the essential damping functionality, thereby reducing overall prosthesis weight.
4Measurement precision
If the adjustment mechanism uses position sensors to determine relative position, then the measurement accuracy is improved, but the difficulty of detecting and measuring spatial orientation increases
Solution Approach 1:
The mechanical position sensing system is replaced with an inertial angle sensor that uses inertial measurement units (accelerometers and gyroscopes) to directly measure spatial orientation. This substitution simplifies the detection process by eliminating complex mechanical linkages and relative position measurements, while providing direct absolute orientation data in space.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for easy and secure adjustment of the prosthesis structure, ensuring optimal positioning and orientation of the prosthesis components, even with different shoe models, thereby enhancing the functionality and acceptance of the prosthesis system.
Implementation Method 1
an inertial angle sensor which detects the orientation of the lower leg section in space
Data Source
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AI summary
The invention relates to a prosthetic device for a lower extremity comprising a prosthetic food (10) and a lower leg part (20) secured to the prosthetic foot (10), as well as a device for manually adjusting an orientation of the lower leg part (20) relative to the prosthetic foot (10), wherein an inertial angle sensor (30) is arranged on the prosthetic device, which detects the orientation of the lower leg part (20) in the space and which is coupled to an output device (40) which in turn outputs the orientation of the lower leg part (20) in the space or the reaching of a previously determined orientation with an output signal in a manner that can be perceived by a user.