Abstract
State-of-the-art neurosurgery intervention relies heavily on information from tissue imaging taken at a pre-operative stage. However, the data retrieved prior to performing an opening in the patient’s skull may present inconsistencies with respect to the tissue position observed by the surgeon during intervention, due to both the pulsing vasculature and possible displacements of the brain. The consequent uncertainty of the actual tissue position during the insertion of surgical tools has resulted in great interest in real-time guidance techniques. Ultrasound guidance during neurosurgery is a promising method for imaging the tissue while inserting surgical tools, as it may provide high resolution images. Microfabrication techniques have enabled the miniaturisation of ultrasound arrays to fit needle gauges below 2 mm inner diameter. However, the integration of array transducers in surgical needles requires the development of advanced interconnection techniques that can provide an interface between the microscale array elements and the macroscale connectors to the driving electronics. This paper presents progress towards a novel packaging scheme that uses a thin flexible printed circuit board (PCB) wound inside a surgical needle. The flexible PCB is connected to a probe at the tip of the needle by means of magnetically aligned anisotropic conductive paste. This bonding technology offers higher compactness compared to conventional wire bonding, as the individual electrical connections are isolated from one another within the volume of the paste line, and applies a reduced thermal load compared to thermo-compression or eutectic packaging techniques. The reduction in the volume required for the interconnection allows for denser wiring of ultrasound probes within interventional tools. This allows the integration of arrays with higher element counts in confined packages, potentially enabling multi-modality imaging with Raman, OCT, and impediography. Promising experimental results and a prototype needle assembly are presented to demonstrate the viability of the proposed packaging scheme. The progress reported in this work are steps towards the production of fully-functional imaging-enabled needles that can be used as surgical guidance tools.
Highlights
State-of-the-art neurosurgery navigation relies on brain images generated prior to clinical intervention
Ultrasound transducer arrays have been designed and fabricated for an operating centre frequency of 15 MHz, which provides a lateral resolution of about 200 μm (Lockwood et al 1996), and an overall die size that can fit within a 1.9 mm inner diameter needle
This article addressed the challenge of packaging ultrasound transducer dies at the tip of small gauge surgical tools such as needles
Summary
State-of-the-art neurosurgery navigation relies on brain images generated prior to clinical intervention. Most of the work reported in the literature on the integration of ultrasound transducer arrays in needle probes achieved separate element interconnections on sets of discrete pads that are distributed on dedicated interconnection structures extending well outside the transducer area (Ritter et al 2002; Michau et al 2004; Lukacs et al 2006; Brown et al 2007; Bernassau et al 2012; Bezanson et al 2012) This type of packaging can be implemented by using standard techniques such as wire bonding for the electrical interconnections. Ultrasound transducer arrays have been designed and fabricated for an operating centre frequency of 15 MHz, which provides a lateral resolution of about 200 μm (Lockwood et al 1996), and an overall die size that can fit within a 1.9 mm inner diameter needle For this application, the confined volume of the inner needle cavity prevents the use of conventional wire bonding techniques for the interconnections. A bonding technology is demonstrated that uses anisotropic conductive paste (ACP) to electrically connect separate array electrodes within a compact bond line
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
