Ball-and-Socket Trajectory Guide for Chronic Burr Hole Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing trajectory guides for interventional procedures, such as those in the brain, often protrude above the burr hole, making them unsuitable for chronic placement and risking instrument accuracy during removal or repositioning.
Innovation Solution
A ball-and-socket trajectory guide that can be secured within the burr hole, allowing the instrument to be delivered accurately without needing later release, with a guide stem that can be peeled apart and a sealing cap for fluid delivery, and fiducial markers for image-guided alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a raised ball-and-socket trajectory guide is used to deliver the instrument to the desired target, then the instrument can be accurately positioned, but the trajectory guide protrudes substantially above the burr hole requiring later removal which risks perturbing the accuracy of the carefully-placed instrument
Solution Approach 1:
The trajectory guide is divided into two functional segments: a low-profile secured portion that remains in the burr hole for chronic placement, and a removable guide stem that provides alignment during instrument delivery. This segmentation allows the guide to be removed in sections without disturbing the secured portion and the already-positioned instrument.
Solution Approach 2:
The trajectory guide is designed with pre-configured alignment features and a low-profile secured portion that is ready for immediate chronic placement. The guide stem with its bore is pre-aligned to the ball passage, eliminating the need for complex post-delivery adjustments or repositioning operations.
2Measurement precision
If a raised trajectory guide is used for instrument delivery, then accurate target delivery is achieved, but the protrusion creates risk of injury to the subject in a chronic ambulatory setting
Solution Approach 1:
The harmful protruding elements (guide stem and locking mechanisms) are extracted from the chronic placement configuration. The guide stem is designed to be removed after instrument delivery, leaving only the low-profile secured portion that sits substantially within the burr hole, eliminating the injury risk while preserving delivery accuracy.
Solution Approach 2:
The trajectory guide transitions from a high-profile configuration during instrument delivery to a low-profile configuration for chronic placement. The guide stem can be removed or repositioned, allowing the system to dynamically adapt its profile height based on the procedural stage, ensuring both accuracy during delivery and safety during chronic use.
3Duration of action of stationary object
If the guide stem is removed after instrument delivery, then chronic placement is enabled, but the instrument position may be perturbed during removal or repositioning
Solution Approach 1:
The guide system is segmented into a permanent low-profile secured portion and a temporary guide stem. The secured portion with the ball passage remains fixed in the burr hole throughout chronic placement, while the guide stem is removed only after the instrument has been delivered and secured, ensuring the instrument position is not disturbed during removal.
Solution Approach 2:
The ball passage acts as an intermediary element that maintains the instrument's trajectory alignment even after the guide stem is removed. The ball passage remains secured in the burr hole, providing a stable reference path that prevents instrument position perturbation during the guide stem removal process.
Data Source
AI summary
A trajectory guide for introducing an instrument into a human or animal subject is described. A guide stem can be removed in sections without disturbing the aligned instrument. An access port portion of the trajectory guide can be left in place, without disturbing trajectory alignment, and can allow overlying skin to be sutured closed. The access port can provide infusate delivery, such as using an injection port, catheter or the like. A fiducial marker arrangement can provide easy and accurate trajectory alignment, for use with the present trajectory guide, another trajectory guide, or without any trajectory guide.