Sterile Barrier Coupling for Precise Robotic End Effector Exchange

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Solution Overview

Problem

Existing surgical drapes for robotic arms and end effectors suffer from perforations that require replacement during surgery, leading to time loss and positioning inaccuracies due to compressibility and deflection, compromising sterile field integrity.

Innovation Solution

A sterile barrier assembly with kinematic couplers and a protective covering that kinematically couples surgical components, providing a deterministic and repeatable connection while maintaining a continuous barrier against contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If surgical drapes have perforations for connections, then mechanical and electrical connections can be made between robotic arm and end effector, but the perforations become uncovered when end effector is replaced or changed, requiring replacement of the surgical drape which takes up valuable time

Engineering Contradiction:
ImproveConnection capability between robotic arm and end effectorVSAvoidTime for drape replacement during surgery
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

A sterile adapter assembly acts as an intermediary component between the robotic arm and end effector. The adapter includes a non-sterile adapter portion that interfaces with the robotic arm and a sterile adapter portion that interfaces with the end effector, with a sterile barrier between them. This intermediary structure allows multiple end effectors to be connected without replacing the sterile barrier, as the adapter remains in place and only the end effector is exchanged.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If surgical drape is compressed between robotic arm and end effector, then connections can be made, but unintended rips or tears may occur and positioning of the end effector is imprecise due to compressibility

Engineering Contradiction:
ImproveConnection capabilityVSAvoidPositioning accuracy of end effector
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The sterile adapter assembly serves as a rigid intermediary structure that eliminates the need to compress the sterile drape for connection purposes. The adapter portions provide structured interfaces that maintain precise positioning while allowing connections to be made without deforming the sterile barrier, thereby maintaining both connection capability and positioning accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sterile barrier is implemented as a thin film that remains intact and uncompressed. Instead of relying on compression of the drape to achieve connections, the design uses the thin film as a continuous barrier within the adapter assembly, allowing connections to be made through structured interfaces without deforming the film, thus maintaining positioning precision.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If thick drape is used to prevent rips and tears, then integrity is maintained, but the drape deflects under normal end effector loads causing errors in positioning accuracy of the tool center point

Engineering Contradiction:
ImproveIntegrity of surgical drapeVSAvoidPositioning accuracy of tool center point
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sterile adapter assembly acts as a rigid intermediary structure that bears the mechanical loads between the robotic arm and end effector. The sterile barrier within the adapter does not need to support structural loads, eliminating deflection issues. The adapter structure itself provides the necessary rigidity to maintain positioning accuracy while the barrier maintains integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If surgical drape is replaced when end effector needs to be changed, then sterility is maintained, but valuable surgical time is lost during drape removal and installation

Engineering Contradiction:
ImproveSterile field integrityVSAvoidSurgical procedure efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The sterile adapter assembly serves as a reusable intermediary that remains in place during end effector changes. The sterile barrier is part of the adapter assembly that stays on the robotic arm, while only the end effector portion is exchanged. This allows multiple end effectors to be used with a single sterile adapter, maintaining sterility without requiring drape replacement, thus improving surgical efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sterile adapter assembly is pre-assembled with the sterile barrier integrated into the adapter structure before surgery begins. This preliminary configuration allows for rapid exchange of end effectors without needing to reconfigure or replace the sterile barrier, as the adapter is already prepared to receive different end effectors while maintaining sterility.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4552599B1Sterile barrier assembly for coupling surgical components therethrough
Publication Date: 2026.04.22 STRYKER CORP
  • EP4552599B1 patent drawingFigure 1
  • EP4552599B1 patent drawingFigure 2~3
  • EP4552599B1 patent drawingFigure 4~5

AI summary

A sterile barrier assembly (22, 222, 422) configured to establish a barrier between a first mounting portion (24, 224, 424) associated with a robotic arm (R) and a second mounting portion (26, 226, 426) associated with an end effector (EE) for the robotic arm (R) is described. The first mounting portion (24, 224, 424) and the second mounting portion (26, 226, 426) each includes a plurality of receptacles (30, 32, 34, 230, 232, 234, 432; 36, 38, 40, 236, 238, 240, 438) and each receptacle includes a contact surface (50, 52, 54, 250, 252, 254, 452; 56, 256, 456). The sterile barrier assembly (22, 222, 422) comprises an interface (60, 260, 460) having a plurality of kinematic couplers (28, 228, 428) configured to engage the contact surfaces (50, 52, 54, 250, 252, 254, 452; 56, 256, 456) of the receptacles (30, 32, 34, 230, 232, 234, 432; 36, 38, 40, 236, 238, 240, 438) of the first mounting portion (24, 224, 424) and the second mounting portion (26, 226, 426) and to provide a kinematic coupling between the first and second mounting portions (24, 224, 424; 26, 226, 426) to constrain six degrees of freedom between the robotic arm (R) and the end effector (EE). The sterile barrier assembly (28, 228, 428) further comprises a drape (62, 262, 462) comprising a ring (468) that defines an opening configured to receive and engage the interface (60, 260, 460), and a flaccid portion attached to the ring (468).