Wireless Bone Lengthening Nail With External Drive Coupling
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Solution Overview
Problem
Existing intramedullary bone lengthening nails are cumbersome, prone to infection, and lack structural strength, compromising their reliability and weight-bearing capacity, while existing solutions with electronics inside the nail compromise structural integrity and are difficult to implant due to space constraints.
Innovation Solution
A wirelessly operable implant system with an extramedullary component that provides controlled bone lengthening using an intramedullary nail integrated with a motion translation unit, operated by an extracorporeal wireless controller through electromagnetic or magnetic coupling, allowing for compact, sturdy, and reliable bone lengthening without fragile components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If electronics and drive system are placed inside the intramedullary nail, then bone lengthening control is achieved, but structural strength is compromised
Solution Approach 1:
The patent extracts the electronics and drive system from the intramedullary nail and places them in an external handheld controller. The intramedullary nail retains only the motion translation unit and bone anchoring components, while the motor, battery, and control circuitry are located externally. This separation preserves the structural integrity and weight-bearing capacity of the nail while achieving automated bone lengthening control through wireless operation.
Solution Approach 2:
The patent introduces a motion translation unit as an intermediary mechanism between the external rotational input and the linear distraction/compression action on the bone. This unit converts rotational motion from the external actuator into precise linear movement of the bone segments, enabling controlled lengthening without requiring electronics inside the nail itself.
2Adaptability or versatility
If distraction mechanisms and electronics are accommodated in the intramedullary nail, then bone lengthening function is provided, but device complexity increases and reliability decreases
Solution Approach 1:
The patent segments the bone lengthening system into distinct functional modules: (1) the intramedullary nail with motion translation unit and bone anchoring components, (2) the external actuator with motor and power supply, and (3) the control system. This modular segmentation distributes complexity across separate components rather than concentrating all functions within the constrained intramedullary space, improving both manageability and reliability.
Solution Approach 2:
The patent moves the drive system from the one-dimensional intramedullary space to the external three-dimensional space, where the actuator and electronics can be accommodated without spatial constraints. This dimensional transition allows for larger, more reliable components while maintaining compact intramedullary implant design.
3Ease of manufacture
If intramedullary nail is made compact to fit intramedullary cavity, then ease of implantation is improved, but weight-bearing capacity is reduced
Solution Approach 1:
The patent extracts the heavy drive system components (motor, battery, electronics) from the intramedullary nail, allowing the nail to be designed as a compact, lightweight structure optimized for intramedullary implantation. The weight-bearing function is maintained through the nail's structural design and material selection, while the extracted drive system provides the necessary actuation forces externally.
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
The system offers improved reliability, safety, and ease of implantation by separating electronic components from the body, enabling controlled bone lengthening with enhanced structural integrity and weight-bearing capacity, reducing the need for external support during the lengthening phase.
Implementation Method 1
a receiver (121) configured to receive at least one of energy and one or more control signals wirelessly
Implementation Method 2
an acoustic transmitter configured to transmit one or more acoustic signals wirelessly
Data Source
AI summary
The present invention discloses a wirelessly operable implant system for providing controlled lengthening of a bone. The wirelessly operable implant system (100) comprises a bone lengthening intramedullary nail (110), an extracorporeal wireless controller (130), and an implantable drive unit (120). The bone lengthening intramedullary nail (110) fixes in intramedullary cavity (16) and its extending elements (111) and (112) fix with different bone segments (14) and (15). The bone lengthening intramedullary nail (110) distracts the bone segments (14) and (15) when provided with input rotational motion to the unit (113) fitted within. This input rotational motion is given with physical connection by extramedullary implant (120) which is intracorporal and extramedullary. The extramedullary implant (120) is operated by an extracorporeal wireless controller (130).