Real-Time 3D Laparoscopic Ultrasonography

Abstract

We have previously described 2D array ultrasound transducers operating up to 10 MHz for applications including real time 3D transthoracic imaging, real time volumetric intracardiac echocardiography (ICE), real time 3D intravascular ultrasound (IVUS) imaging. We have recently built a pair of 2D array transducers for real time 3D laparoscopic ultrasonography (3D LUS), and real time 3D transesophageal echocardiography (TEE). These transducers are intended to be placed down a trocar during minimally invasive surgery. The first is a forward viewing 5 MHz, 11 x 19 array with 198 operating elements. It was built on an 8 layer multi-layer flex circuit. The interelement spacing is 0.20 mm yielding an aperture that is 2.2 mm x 3.8 mm. The O.D. of the completed transducer is 10.2 mm , and includes a 2 mm tool port. The average measured center frequency is 4.5 MHz, and the -6 dB bandwidth ranges from 15% to 30%. The 50 Ohm insertion loss, including Gore MicroFlat cabling, is -81.2 dB. The second transducer is a 7 MHz, 36 x 36 array with 504 operating elements. It was built upon a 10 layer multi-layer flex circuit. This transducer is in the forward viewing configuration, and the interelement spacing is 0.18 mm. The total aperture size is 6.48 mm x 6.48 mm. The O.D. of the completed transducer is 11.4 mm. The average measured center frequency is 7.2 MHz, and the -6 dB bandwidth ranges from 18% to 33%. The 50 Ohm insertion loss is -79.5 dB, including Gore MicroFlat cable. Real time in vivo 3D images of canine hearts have been made including an apical 4 chamber view from a substernal access with the first transducer to monitor cardiac function. In addition we produced real time 3D rendered images of the right pulmonary veins from a right parasternal access with the second transducer which would be valuable in the guidance of cardiac ablation catheters for treatment of atrial fibrillation.

Video‐Assisted Thoracoscopic Implantation of the Left Ventricular Pacing Lead for Cardiac Resynchronization Therapy

“…In 100% of cases we placed the screw‐in lead in a preselected area successfully in support of work done by Mair et al 7 This success is reflected in the finding that all patients who underwent VAT epicardial lead placement responded well clinically with a reduction in NYHA score. This advantage of direct intraoperative access to the LV lateral wall is even more important with emerging technology such as modern intraoperative electrophysiological mapping and 3D TEE 16 . This technology will allow the surgeon to determine the most delayed site of LV contraction and place the lead in the area identified.…”

Navigated ultrasound in laparoscopic surgery

“…One method would be to make use of 3D LUS probes, which are not yet available commercially. But papers about development of such probes have been published (Light et al, 2005). 3D LUS can also be obtained by freehand scanning over the area of interest and tracking the LUS image as mentioned previously.…”

Integrated Interventional Devices For Real Time 3D Ultrasound Imaging and Therapy

“…5A) and 3D rendered views (Fig. 5B) [15]. We have also begun modifying the 3D scanner and such endoscopic and laparoscopic probes to incorporate a steerable ultrasound hyperthermia beam for possible application in enhanced drug delivery for thermally activated pharmaceutical agents.…”