Filtering Needle Cap Seal Minimizes Dead Volume

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Solution Overview

Problem

Existing filtered needle systems face challenges in providing an inexpensive and reliable method for filtering liquid payloads before administration, particularly due to the complexity and potential for debris generation in one-step processes and the need for costly disposable devices in two-step processes.

Innovation Solution

A filtered needle system comprising a hollow needle with a hub and a filtering needle cap that includes a filter element and a sealing sleeve to remove debris, allowing for efficient filtration and minimizing dead volume, with the seal positioned closer to the distal end to prevent air ingress and ensure effective liquid transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-stage filtering process is used, then filtration reliability is improved, but device complexity and cost increase due to requiring separate filter and needle components

Engineering Contradiction:

Improvefiltration reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the filter element and needle into a single integrated filtering needle assembly. The filter element is positioned within the needle structure, allowing both filtration and injection functions to be performed by one component rather than requiring separate filter and needle components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The filtering needle serves multiple functions simultaneously: it acts as both the filtration medium and the injection needle. The single component performs both the filtering function and the parenteral administration function, eliminating the need for separate devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If a frangible needle with filter is used for one-step process, then productivity is improved, but manufacturing difficulty increases and potential for debris generation occurs

Engineering Contradiction:

ImproveproductivityVSAvoidmanufacturing difficulty

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The filtering needle is designed as a two-part assembly that can be separated: a reusable needle portion and a disposable filter portion. The filter element is positioned to be broken off after use, taking the filter and any trapped debris with it, while leaving the needle intact for potential reuse or proper disposal.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The filter element is designed to be discarded after a single use, while the needle portion can be recovered and reused. The frangible connection allows the filter to be easily separated and disposed of, taking contaminated materials with it, while the clean needle can be sterilized and reused.

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If seal is positioned closer to distal end, then reliability of liquid transfer is improved by preventing air ingress, but dead volume increases

Engineering Contradiction:

Improveliquid transfer reliabilityVSAvoiddead volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The seal is positioned at a specific location within the filtering needle assembly, closer to the distal end but not at the extreme tip. This localized positioning creates an optimal balance: it is close enough to prevent air ingress during liquid transfer, maintaining reliability, while not extending so far as to create excessive dead volume that would waste medication.

Inventive Principle:

Principle #3Local quality

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 system provides a cost-effective and reliable method for filtering liquid payloads by minimizing dead volume and reducing the risk of bacterial contamination, with fewer steps and less chance of debris exposure compared to traditional two-step processes.

Implementation Method 1

a seal to seal around an outside diameter of the hollow needle so that liquid payload is drawn into the lumen in the hollow needle as liquid payload is drawn into the fluid fitting

Methodology Applied

Scientific EffectSealing:

Implementation Method 2

a filter element adapted for removing debris from the liquid payload as the liquid payload is drawn through the filtering needle cap into the lumen within the hollow needle

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Data Source

PatentUS10512728B2Filtering needle cap with a seal around a needle

Publication Date: 2019.12.24 CARRTECH CORP

AI summary

A filtered needle for use in administering a liquid payload, including a needle and connector portion and a filtering needle cap. The filtering needle cap including a distal open end in fluid communication via an internal channel with a proximal open end of the filtering needle cap. The filtering needle cap proximal end sized to receive the distal end of the hub within the proximal end of the filtering needle cap to reversibly engage the hub when needle distal end is inserted into the internal channel. The filtering needle cap including a filter element and a seal to seal around an outside diameter of the hollow needle so that liquid payload is drawn into the lumen in the hollow needle as liquid payload is filtered and drawn into the fluid fitting. The filtering needle cap is designed to limit a dead volume of liquid payload drawn into the filtering needle cap but not entering into the distal end of the hollow needle.