Robotic Ligament Balancer for Precise Knee Gap Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surgical instruments for ligament balancing in total knee arthroplasty lack cost-effective, reusable tools that provide digital measurements for patient-specific balancing, often leading to user error and imbalanced ligaments due to the absence of digital components or high costs of single-use sensors.
Innovation Solution
A mechanical ligament balancing device coupled to a robotic device, which is rotatable and pivotable, allowing for maximum bone contact and force measurement without sensors, integrated with a robotic surgery system to assess ligament forces and gap measurements, facilitating proper joint balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual apparatuses are used for ligament balancing, then the device complexity is low, but measurement precision is poor and user error is common
Solution Approach 1:
The patent replaces manual mechanical measurement apparatuses with a robotically-controlled mechanical device. The robotic system provides precise positioning and force application while the mechanical device structure (shaft, head portion, paddles) maintains simplicity. This substitution enables digital measurement capabilities without requiring complex sensor systems within the device itself, as the robotic control system provides the precision.
2Measurement precision
If single-use sensors are used for ligament balancing, then measurement precision is improved, but the cost increases prohibitively
Solution Approach 1:
The patent inverts the disposable concept by creating a reusable mechanical device. Instead of using expensive single-use sensors, the invention employs a durable mechanical apparatus that can be sterilized and reused. The device lacks expensive electronic sensors, making it cost-effective while maintaining measurement capability through robotic control and mechanical force application.
Solution Approach 2:
The mechanical device is designed to be self-sufficient without requiring expensive external sensors or electronics. The robotic system provides the measurement capability through controlled force application and position tracking, while the mechanical device itself serves as a simple, reusable tool that does not require complex manufacturing or disposal protocols.
3Reliability
If robotic device is used for ligament balancing, then measurement precision and control are improved, but device complexity increases
Solution Approach 1:
The patent segments the system into two distinct parts: a simple, reusable mechanical device (shaft, head portion, paddles) and a robotic control system. This segmentation allows the mechanical device to remain simple and sterilizable, while the robotic system handles the complex control and measurement functions. The coupling mechanism connects these segments, enabling the mechanical device to be used with different robotic systems.
Solution Approach 2:
The mechanical device is designed with universal coupling capabilities that allow it to interface with various robotic systems. The coupling mechanism (mount with coupling portion) provides a standardized interface, making the mechanical device adaptable to different robotic platforms. This universality reduces overall system complexity by allowing the same mechanical device to work with multiple robotic systems rather than requiring integrated custom solutions.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A device for ligament balancing includes a mount at a first end of the device and a head portion at a second end of the device, the head portion having a substantially planar surface, a first paddle, and a second paddle, wherein the first and second paddle are rotatable about a first longitudinal axis and a second longitudinal axis, respectively, relative to the substantially planar surface. The device further includes a stem extending from the head portion and a shaft extending between the stem and the mount. The mount includes a coupling portion configured to couple the device to a robotic device such that movement of the device is controlled by the robotic device.