Capillary Blood Collection Cannula With Reciprocating Spin Motion
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Solution Overview
Problem
Current devices for collecting blood from capillaries are painful and inefficient, causing deformation of skin tissues and obstructing blood flow due to the use of thin needles, which results in prolonged bleeding and discomfort for patients.
Innovation Solution
A device employing a cannula with reciprocating or intermittent spin motion and a built-in or external pressure source for blood collection, which reduces tissue deformation and facilitates blood flow, allowing for painless and efficient blood collection by minimizing the need for large skin cuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a very thin needle (around 200 microns in diameter) is used for blood collection, then the pain is reduced, but the needle still deforms skin and hypodermic tissues and obstructs blood flow, causing prolonged bleeding
Solution Approach 1:
The patent applies reciprocating or intermittent spin motion to the cannula during insertion. This dynamic motion allows the cannula to progressively penetrate the skin and hypodermic tissues without causing deformation or obstruction, while maintaining minimal injury to the tissue structure. The motion transforms a static piercing action into a progressive, controlled entry that preserves blood flow pathways.
Solution Approach 2:
The cannula performs periodic reciprocating or intermittent spin movements during the insertion process. This periodic action distributes the mechanical stress over time, allowing tissue to accommodate the cannula's presence without significant deformation. The periodic motion prevents continuous obstruction of blood capillaries, enabling painless insertion with maintained blood flow.
2Productivity
If a lancet is used to make a nick or cut on the finger to cause spontaneous bleeding, then blood collection is enabled, but the patient experiences pain and prolonged bleeding requiring care
Solution Approach 1:
The patent replaces the mechanical cutting action of a lancet with a cannula-based insertion system that uses reciprocating or intermittent spin motion. Instead of creating a sharp nick that causes spontaneous bleeding and pain, the cannula progressively enters the tissue through controlled motion, enabling blood collection without the harmful effects of cutting. The system substitutes a gentle mechanical insertion for a harsh cutting mechanism.
3Object-affected harmful factors
If a thin needle is used to minimize pain, then patient comfort is improved, but the needle deforms skin tissues and bars blood flow
Solution Approach 1:
The patent employs dynamic reciprocating or intermittent spin motion of the cannula during insertion. This motion allows the thin cannula to penetrate tissue without causing deformation or obstruction, as the progressive entry distributes mechanical stress. The dynamic action prevents the cannula from acting as a static obstruction that would block blood flow, while maintaining the pain-reducing benefit of thin gauge insertion.
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 effectively reduces pain and enhances the efficiency of blood collection by promoting cannula intrusion into skin tissues without obstructing blood flow, allowing for easy and controlled collection of small blood volumes.
Implementation Method 1
The cannula with reciprocating or intermittent spin motion intrudes into skin tissues without causing considerable deformation
Implementation Method 2
a built-in or external pressure source for blood collection, which reduces tissue deformation and facilitates blood flow
Data Source
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AI summary
A device is used in combination with a fluid pressure source and a replaceable sampling tube having a pointed cannula section and a hollow for capillary blood collection. The device is provided with: a body defining a bore extending along an axis; a first flow path in fluid communication with the fluid pressure source; a rotor fitting in the bore and being capable of spinning in both directions about the axis; a boss section extending along the axis and so dimensioned as to rotatably support the sampling tube coaxially with the axis and expose the cannula section out of the boss section; and a detachable fastening binding the sampling tube to the rotor so as to set the sampling tube into rotation concentric with the axis and establish fluid communication between the first flow path and the hollow of the sampling tube.