Bone Marrow Cannula with Movable Internal Sampling Lumen
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Solution Overview
Problem
Current bone marrow harvesting techniques face challenges in efficiently collecting stem cells from multiple sites without causing discomfort to the patient, as they struggle to maintain high suction pressure through multiple holes distributed along the cannulas, and lack precise alignment of internal and external cannula holes for optimal sampling.
Innovation Solution
A device featuring an external guide cannula with axially and circumferentially distributed holes, and an internal collecting cannula with corresponding hole distributions, allowing axial and angular displacement for precise alignment and high suction at multiple sampling sites, using spacer elements or elastic snap mechanisms for relative positioning, ensuring high depression and efficient stem cell collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple holes are distributed along the cannulas to enable sampling at multiple sites, then the ability to collect biological material from multiple sites is improved, but maintaining high suction pressure through multiple holes becomes difficult
Solution Approach 1:
The system divides the sampling function into multiple independent hole groups distributed along the cannulas. Each hole or group of holes can be selectively activated by positioning the internal cannula at specific locations, allowing the suction pressure to be concentrated at one sampling site at a time rather than distributed across multiple sites, thus maintaining high suction pressure while enabling multi-site collection capability
Solution Approach 2:
The internal cannula is made movable relative to the external cannula through axial and angular displacement. This dynamic positioning allows the operator to align specific holes of the internal cannula with corresponding holes of the external cannula at different locations, enabling selective activation of different sampling sites while maintaining optimal suction pressure at the active site
2Manufacturing precision
If the internal cannula can be displaced axially and angularly to align holes at different positions, then the precision of hole alignment for optimal sampling is improved, but the complexity of the device increases
Solution Approach 1:
The internal collecting cannula is nested within the external guide cannula, with the internal cannula having a smaller diameter and fitting coaxially inside the external cannula. This nested configuration allows the internal cannula to be freely displaced axially and angularly within the external cannula to achieve precise hole alignment at different sampling locations, while the outer cannula provides structural support and guidance, effectively managing the complexity through hierarchical nesting
Solution Approach 2:
The internal cannula acts as an intermediary element between the external cannula and the biological material. By positioning the internal cannula at different locations through axial and angular displacement, it selectively aligns holes with the external cannula to access different sampling sites, thereby achieving precise alignment without requiring complex external positioning mechanisms
3Object-affected harmful factors
If the external cannula remains fixed in the bone to avoid patient discomfort, then patient comfort is improved, but the ability to sample from multiple locations requires moving the internal cannula, increasing operational complexity
Solution Approach 1:
The sampling function is segmented between the fixed external cannula (embedded in bone) and the movable internal cannula. The external cannula remains stationary to avoid repeated bone penetration and patient discomfort, while the internal cannula is divided into sections with distributed holes that can be selectively positioned to access different sampling sites along the external cannula's length
Solution Approach 2:
The system introduces dynamic movement of the internal cannula relative to the fixed external cannula. The internal cannula can be displaced axially and angularly to align its holes with different locations of the external cannula, enabling multi-site sampling from a single fixed insertion point, thus maintaining patient comfort while providing operational flexibility
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 easier, faster, and more efficient collection of bone marrow and stem cells with minimized pain and distress, allowing selective movement of the internal cannula to align holes for optimal suction at different sites without repositioning the external cannula, ensuring high depression values across various sampling sites.
Implementation Method 1
the internal cannula is capable of being coaxially tucked inside the external cannula so that the two cannulas are sliding respect to each other according to an axial translation and/or an angular displacement
Implementation Method 2
the internal cannula is capable of being coaxially tucked inside the external cannula so that the two cannulas are sliding respect to each other according to an axial translation and/or an angular displacement
Implementation Method 3
an aspiration vacuum is applied to the proximal, external end of the sampling cannula
Implementation Method 4
it is necessary to make at the holes a high suction action, i.e., to make a higher depression
Data Source
AI summary
A device for collecting biological material, in particular bone marrow and especially stem cells, includes an external cannula for guiding an internal sampling cannula. The external cannula has a mantle wall defining an internal lumen and a distal terminal, and a plurality of openings distributed axially and circumferentially in different longitudinal and/or angular positions. The internal sampling cannula has a mantle wall that defines an internal lumen and that can be coaxially inserted inside the external cannula so that the two cannulas are mobile with respect to each other by axial and/or an angular displacement, and further has a plurality of openings that are distributed axially and circumferentially along the lateral wall in different longitudinal and/or angular positions. The holes in the external and internal cannula are distributed to enable a selective sampling in different angular and/or axial positions along the axial extension of the external cannula.