Single Chamber Mixing Device for Bone Cement

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Solution Overview

Problem

Existing single-chamber devices for mixing and dispensing components in medical applications, such as bone cement, face challenges in simplifying the process while maintaining hygiene and safety, particularly when dealing with sterile products that require blending of components in liquid, paste, or powder form.

Innovation Solution

A single-chamber device with a syringe housing, piston, mixing assembly, and plunger unit that allows for the sequential drawing in and mixing of components, featuring a mixing rod with a snap recess and handle for easy operation, enabling the mixing and dispensing of the mixture through a standardized Luer-Lok system outlet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a separate pusher driven by the mixing rod is inserted for dispensing the mixture, then the mixing function is achieved, but the device complexity increases

Engineering Contradiction:

Improvemixing functionVSAvoiddevice structure

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the dispensing function with the existing piston and mixing rod assembly. The piston serves dual purposes: it pushes the mixture through the needle during dispensing and transmits rotational motion to the mixing rod during mixing, eliminating the need for a separate pusher mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The piston is designed to perform multiple functions: it acts as a dispensing plunger, a rotational drive mechanism for the mixing rod, and a sealing element. This multi-functionality reduces the overall number of components needed in the device.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If components are manually metered, combined, and mixed in the open, then the operation simplicity is improved, but the hygiene and safety are compromised

Engineering Contradiction:

Improveoperation simplicityVSAvoidhygiene and safety

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The device divides the preparation process into distinct sealed stages: component storage in separate syringes, controlled injection into the mixing chamber, closed mixing, and sealed dispensing. This segmentation maintains hygiene while simplifying the overall操作流程.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The mixing chamber acts as an intermediary sealed environment where components are combined and mixed without direct manual handling. The piston and mixing rod serve as intermediaries that transfer motion and force while maintaining the closed system.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If multiple steps are involved in closed systems, then the hygiene and safety are improved, but the handling complexity increases

Engineering Contradiction:

Improvehygiene and safetyVSAvoidhandling simplicity

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

Multiple functions (dispensing, mixing, and rotational drive) are merged into a single integrated mechanism. The piston's linear motion simultaneously achieves dispensing and, through the articulation, generates rotational motion for mixing, reducing the number of separate handling steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The components are pre-loaded into sealed syringes with the piston already in position. The mixing rod is pre-attached to the piston via articulation. This preliminary preparation allows the user to simply push the plunger to initiate the entire process without complex assembly during use.

Inventive Principle:

Principle #10Preliminary action

4Adaptability or versatility

If a standardized Luer-Lok system outlet is used, then the adaptability is improved, but the device complexity increases

Engineering Contradiction:

Improveoutlet compatibilityVSAvoiddevice structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The Luer-Lok outlet provides universal compatibility with standard medical equipment while the internal mechanism remains simple. The standardized interface allows the device to work with various needles and administration systems without adding complexity to the core mixing and dispensing mechanism.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 device simplifies the mixing and dispensing process by allowing components to be combined and mixed within a single chamber, enhancing safety and hygiene by reducing manual handling steps and ensuring efficient dispensing of the resulting mixture.

Implementation Method 1

The mixing rod (10) has a snap recess (14) at its end on the piston side

Methodology Applied

Scientific EffectMechanical engagement: Mechanical Fastener

Data Source

PatentUS8167835B2Single chamber device for drawing in and dispensing components

Publication Date: 2012.05.01 MEDMIX SWITZERLAND AG

AI summary

A single chamber device for drawing in and dispensing components comprising a syringe housing, a piston that is actuatable by a plunger unit, and a mixing assembly whose rod is guided through the piston and operatively connected to the plunger unit. The plunger unit comprises a plunger rod that is articulated at the mixing rod and provided with means that are engageable with the mixing rod. In this manner, a mixture of different components, particularly also bone cement, can be both created and dispensed in a simple and inexpensive single chamber device.