5E-6 Analysis of a Vibrating Interventional Device for 3D ColorMark Tracking

Ultrasound guidance of interventional devices during minimally invasive surgical procedures has been investigated by many researchers. Previously, we extended the methods used by the ColorMark tracking system to several interventional devices using a real-time 3D ultrasound system [Fronheiser, MP, et al., 2004; Smith, SW, et al., 2002]. These results showed that we needed to improve the efficiency and reliability of the tracking. Here, we describe an analytical model to predict the transverse vibrations along the length of an atrial septal puncture needle to enable design improvements of the tracking system. The initial results show an ability to predict the natural nodes and anti-nodes along the needle. Simulations show that applying a forcing function to the device at a natural anti-node yields an order of magnitude larger vibration than when driving the device at a node. 3D pulsed wave spectral Doppler data was acquired along the distal portion of the needle in a water tank using 3D transesophageal echocardiography (TEE) transducer probe. This data was compared to simulations of forced vibrations from the model. These initial results suggest that the model is a good first approximation of the vibrating device in a water tank. It is our belief that knowing the location of the natural nodes and anti-nodes will improve our ability to drive the device, which should improve our ability to track the device in vivo