Bone Stiffness Measurement via Oscillatory Force Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for assessing bone stiffness in vivo are limited, as they cannot differentiate between skin and bone compression and require bone fracture for measurement, making them inaccurate and invasive.
Innovation Solution
A parametric model-based method and system that applies superposition of static and oscillatory forces to a skin-bone complex, measuring oscillatory forces and accelerations to determine bone stiffness using a data analyzer and processor, fitting a parametric mathematical model to estimate bone stiffness without the need for bone fracture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current methods are used to assess bone stiffness in vivo, then measurement can be performed, but the methods cannot differentiate between skin and bone compression leading to inaccurate results
Solution Approach 1:
The patent segments the mechanical response into distinct components by applying oscillatory forces at multiple frequencies and analyzing the frequency-specific acceleration responses. This allows separation of skin soft tissue compliance from bone stiffness through spectral analysis of the mechanical response at different frequency ranges.
Solution Approach 2:
The patent applies oscillatory mechanical vibrations at multiple frequencies to the skin-bone complex. By analyzing the frequency-dependent acceleration responses, the system can differentiate between the compliant skin layer and the stiffer bone structure, as each component responds differently to varying vibration frequencies.
2Measurement precision
If current methods are used to measure bone stiffness, then a measurement can be obtained, but bone fracture is required making the method invasive
Solution Approach 1:
The patent replaces destructive mechanical testing (fracture-based measurement) with non-invasive oscillatory mechanical analysis. By measuring the frequency response and acceleration of the skin-bone complex under controlled oscillatory loading, the system derives bone stiffness without causing structural damage or fracture to the bone.
Solution Approach 2:
The patent employs periodic oscillatory forces at multiple frequencies instead of static or progressive loading that would lead to fracture. The periodic nature of the applied forces allows measurement of elastic properties and stiffness through frequency response analysis, eliminating the need for bone failure.
3Reliability
If current methods are used, then bone stiffness assessment can be performed, but the methods are inaccurate due to inability to separate skin and bone responses
Solution Approach 1:
The patent uses mechanical vibration at multiple frequencies to excite the skin-bone complex. The frequency-dependent response allows differentiation between skin and bone contributions, as the stiffer bone component dominates at higher frequencies while skin compliance is more apparent at lower frequencies.
Solution Approach 2:
The patent transitions from static or quasi-static measurement to dynamic oscillatory measurement. By analyzing the time-varying acceleration responses to oscillatory forcing, the system can separate the mechanical properties of different tissue layers based on their dynamic response characteristics.
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
Enables non-invasive, accurate measurement of bone stiffness by differentiating skin and bone responses, providing a reliable assessment of bone mechanical properties in vivo without causing damage to the bone.
Implementation Method 1
applying a superposition of static and oscillatory forces (F) over a range of frequencies (f) to a region of a skin-bone complex thereby exciting oscillatory accelerations (a) over the range of frequencies (f) of the skin-bone complex
Data Source
AI summary
Parametric model based computer implemented methods for determining the stiffness of a bone, systems for estimating the stiffness of a bone in vivo, and methods for determining the stiffness of a bone. The computer implemented methods include determining a complex compliance frequency response function Y(f) and an associated complex stiffness frequency response function H(f) and fitting a parametric mathematical model to Y(f) and to H(f). The systems include a device for measuring the stiffness of the bone in vivo and a data analyzer to determine a complex compliance frequency response function Y(f) and an associated complex stiffness frequency response function H(f). The methods for determining the stiffness include fitting a parametric model to stiffness of the skin-bone complex as a function of frequency H(f) and the compliance of the skin-bone complex as a function of frequency Y(f).