Retained Surgical Item Counting With Resonant Beacon Tags

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Solution Overview

Problem

Existing technologies for detecting and inventorying surgical items in medical settings face challenges due to physical obstructions and rapid degradation in the presence of dielectric or conductive materials, leading to inefficiencies in presence detection and identification.

Innovation Solution

An inventory system utilizing an antenna inserted into a surgical site to detect surgical items, employing beacon tags that transmit resonant frequencies and ring-down decay rates, along with RFID tags for identification and inventory management, to ensure accurate detection and counting of retained surgical items.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If beacon tags with resonant frequency detection are used, then detection precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system divides surgical items into two categories: those requiring precise resonant frequency detection (beacon tags) and those requiring only identification (RFID tags). This segmentation allows high-precision detection only where necessary, reducing overall system complexity while maintaining detection precision for critical items.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies full resonant frequency detection capability only to beacon tags when needed, rather than equipping all surgical items with complex detection mechanisms. This partial application of excessive action maintains precision for critical detection while avoiding unnecessary complexity for routine items.

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If RFID tags are used for identification, then inventory management is improved, but detection reliability degrades in presence of dielectric or conductive materials

Engineering Contradiction:
Improveinventory managementVSAvoiddetection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system introduces resonant frequency detection as an intermediary mechanism that operates independently of dielectric and conductive materials. When RFID detection reliability degrades due to material interference, the resonant frequency-based beacon tag detection serves as a reliable alternative, ensuring continuous inventory management capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the detection parameter from RFID electromagnetic field interaction (sensitive to dielectric/conductive materials) to resonant frequency measurement (immune to such materials). This parameter change maintains inventory management productivity while eliminating reliability degradation in challenging material environments.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If components are made physically smaller, then ease of operation is improved, but detection precision may be compromised

Engineering Contradiction:
Improveease of operationVSAvoiddetection precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system replaces mechanical/proximity-based detection methods with resonant frequency-based detection. This substitution allows for smaller, less obtrusive tag components while maintaining or improving detection precision, as resonant frequency detection is not limited by physical size constraints of traditional detection mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 precise detection and counting of retained surgical items by utilizing unique resonant frequencies and decay rates, ensuring reliable inventory management and reducing the risk of unintended medical consequences.

Implementation Method 1

the electrical characteristic may be a resonant frequency of the beacon tag

Methodology Applied
Scientific EffectResonant frequency: Resonance

Implementation Method 2

the electrical characteristic may be a ring-down decay rate of the beacon tag

Methodology Applied
Scientific EffectRing-down decay: Damping

Data Source

PatentEP4141740B1Inventory systems and methods for detecting and counting potentially retained surgical items
Publication Date: 2025.07.30 COVIDIEN LP
  • EP4141740B1 patent drawingFigure 1
  • EP4141740B1 patent drawingFigure 2
  • EP4141740B1 patent drawingFigure 3

AI summary

An inventory system configured for detecting and counting potentially retained surgical items within a body of a patient includes a tag configured to transmit a return signal including an electrical characteristic when energized, a signal generator configured to generate an energizing signal for the tag, an antenna operably coupled to the signal generator and configured to receive at least the return signal transmitted by the tag, a processor, and a memory. The memory includes instructions stored thereon, which, when executed by the processor, cause the inventory system to energize the tag by the energizing signal, receive the return signal from the tag by the antenna, and determine a presence of the beacon tag based on the electrical characteristic.