Microneedle with Flat Blade and Microchannel for Capillary Blood Sampling
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Solution Overview
Problem
Current blood sampling methods, such as finger pricking and intravenous extraction, are invasive, painful, and inefficient, leading to significant dead volumes and discomfort for patients, while lacking a fully integrated device for dry blood spot capillary sampling.
Innovation Solution
A microneedle device with a flat blade and microchannel configuration that incises the skin and aspirates blood via capillary action, allowing for painless and minimally invasive blood sample collection, which is then stored in a retaining material for analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If finger pricking or intravenous extraction is used for blood sampling, then blood can be obtained for analysis, but the procedure becomes invasive and painful for the patient
Solution Approach 1:
The microneedle is divided into functionally distinct segments: a blade portion for incising the skin and a microchannel portion for blood aspiration. This segmentation allows the cutting function and sampling function to be performed by separate structural elements within a single integrated needle, reducing the invasiveness while maintaining effectiveness.
Solution Approach 2:
The microchannel acts as an intermediary structure that passively transports blood from the incision site to the collection reservoir using capillary action. This eliminates the need for active pumping mechanisms and reduces the mechanical trauma associated with traditional needle insertions, thereby reducing pain while still enabling blood collection.
2Productivity
If separate blood-aspirating components are used with microneedles, then blood can be collected, but dead volumes increase and sampling efficiency decreases
Solution Approach 1:
The microneedle integrates the blade, microchannel, and blood collection reservoir into a single unified structure. This merging eliminates the interfaces and connection volumes between separate components, thereby minimizing dead volume and maximizing sampling efficiency. The entire aspiration path is contained within the needle itself, reducing waste and improving productivity.
3Ease of operation
If traditional blood sampling devices are used, then blood can be extracted, but the device complexity increases due to multiple components
Solution Approach 1:
The device combines the incising blade, blood transport microchannel, and collection reservoir into a single integrated microneedle assembly. This reduces the number of separate components that need to be assembled and handled, thereby simplifying the device structure and improving ease of operation while maintaining all necessary functions.
Solution Approach 2:
The microneedle structure serves multiple functions simultaneously: the blade portion performs the incising function, the microchannel performs the blood transport function, and the reservoir performs the collection function. This multi-functionality within a single structure reduces overall device complexity while maintaining operational simplicity.
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 enables efficient, minimally invasive blood sampling with reduced pain and risk of long-term skin damage, facilitating high-quality diagnostics and allowing for the collection of small blood volumes for quantitative analysis, such as with LC-MS/MS, while being safer for transportation and storage.
Implementation Method 1
The passage is configured to transport the blood sample away from the opening via capillary action
Implementation Method 2
The retaining material is fluidically connected to the channel and configured to absorb and store the blood sample
Data Source
AI summary
A microneedle (100) for extracting a blood sample from the skin (10) of a mammal subject is disclosed. The microneedle comprises at least one substantially flat blade (110) comprising at least one cutting edge (120a, 120b) configured to incise the skin of the mammal subject, and at least one microchannel (130) comprising an opening (132) and a passage (134). The at least one microchannel is arranged adjacent to the at least one blade and configured to be inserted into the skin of the mammal subject together with the at least one blade. The passage is configured to transport the blood sample away from the opening via capillary action. A device (200) for extracting a blood sample from a mammal subject comprising a microneedle is also disclosed.