Parallel Linkage Physiotherapy Apparatus for Precision Neck Manipulation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing dynamic physiotherapy apparatus for treating the head, neck, and shoulders suffer from reduced accuracy, complexity, and high cost due to serial linkage structures, which lead to errors in position and orientation, and can be intimidating for patients, reducing treatment effectiveness.

Innovation Solution

A physiotherapy apparatus utilizing a parallel linkage device, such as a Stewart platform with magnetic ball joints and tendon joints, providing improved accuracy, reduced mass, and increased range of motion, along with a signal-emitting and detecting system for precise positioning and orientation, and a controller for smooth and controlled movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If serial linkage structure is used for manoeuvring the body part, then the apparatus can achieve movement and manipulation capability, but the accuracy of position and orientation deteriorates due to accumulation of errors from one motor to the next

Engineering Contradiction:
Improveaccuracy of position and orientationVSAvoidserial linkage structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional serial linkage architecture to a parallel linkage structure (Stewart platform). Instead of connecting motors in series where errors accumulate, the invention connects six actuators in parallel to simultaneously control the position and orientation of the cradle, eliminating error propagation and achieving sub-millimeter accuracy.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the mechanical serial linkage system with a parallel mechanical system (Stewart platform). This substitution fundamentally changes the error propagation characteristics from multiplicative (serial) to independent (parallel), where each actuator contributes independently to the final position and orientation accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If serial linkage structure with multiple motors is used, then the apparatus can provide controlled movement, but the mass of the apparatus increases

Engineering Contradiction:
Improvecontrolled positioning capabilityVSAvoidmass of apparatus
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The patent inverts the conventional serial linkage architecture to a parallel linkage structure (Stewart platform). Instead of connecting motors in series where errors accumulate, the invention connects six actuators in parallel to simultaneously control the position and orientation of the cradle, eliminating error propagation and achieving sub-millimeter accuracy.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The Stewart platform manipulator serves multiple functions simultaneously: it provides six-degree-of-freedom positioning, supports the weight of the cradle and patient, enables complex therapeutic trajectories, and maintains high accuracy. This multi-functionality is achieved through the parallel architecture where all six actuators work together to accomplish both positioning and load-bearing tasks.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If complex serial linkage apparatus is used for dynamic therapy, then the apparatus can manoeuvre the body part along predetermined trajectory, but the apparatus becomes intimidating to patients, preventing their relaxation

Engineering Contradiction:
Improvetherapeutic manoeuvring capabilityVSAvoidpatient anxiety and lack of relaxation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a simplified, patient-friendly version of the therapeutic apparatus by replacing the intimidating serial linkage structure with a compact parallel Stewart platform. The cradle is designed to be comfortable and non-threatening while internally incorporating the sophisticated six-actuator system that enables complex therapeutic maneuvers, thus copying the therapeutic functionality while eliminating the intimidating appearance.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent nests the six actuators and their drive mechanisms within a compact Stewart platform structure. The complex mechanical systems are contained within the platform's legs and base, leaving the patient-facing cradle clean and simple. This nesting allows the apparatus to provide full therapeutic capability while presenting a calm, non-intimidating appearance to patients.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Use of energy by moving object

If parallel linkage device with reduced mass is used, then the power consumption is reduced, but the structural stiffness must be maintained

Engineering Contradiction:
Improvepower consumptionVSAvoidstructural stiffness
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The patent optimizes the structural parameters of the Stewart platform legs and actuator mounting points to achieve the minimum mass required for adequate stiffness. By carefully selecting material properties, cross-sectional dimensions, and leg lengths, the design reduces mass to lower power consumption while maintaining the structural rigidity needed for precise positioning and patient safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials or optimized material selections for the Stewart platform structure to achieve high stiffness-to-mass ratio. By using materials with superior mechanical properties, the apparatus attains the required structural stiffness with reduced mass, thereby minimizing power consumption while maintaining positioning accuracy and patient safety.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3199135B1Physiotherapy apparatus
Publication Date: 2018.09.05 ENRAF NONIUS
  • EP3199135B1 patent drawingFigure 1
  • EP3199135B1 patent drawingFigure 2A~4C
  • EP3199135B1 patent drawingFigure 5~6

AI summary

An apparatus (1) for treating a body part (5) of a patient (3) is provided. The apparatus comprises a support (7) for at least partially supporting and holding the body part, a manipulator (11) connected to the support for supporting and manoeuvring the support and a controller. The apparatus is configured to determine the spatial position and orientation of the first and second portions relative to each other, to determine, based on that, a first manoeuvring sequence of the body part, and to control the apparatus (1) to operate the manipulator (11) to manoeuvre the support (7) in such a way that the body part, when appropriately positioned on, and possibly held by, the support, is manoeuvred according to at least the first manoeuvring sequence. Further, a method and a storage medium are provided.