Ultrasound stylet

Abstract

A stylet includes a handle assembly with an indicator display and a stiff wire assembly extending distally from the handle assembly having a non-imaging ultrasonic device on a distal end. The stylet includes a circuit assembly having one or more of a pulser, a transmit/receive chip, a bandpass filter, a differential amplifier, an ADC, and an MCU, operable to control the operation of the ultrasonic device and to receive and analyze data from the ultrasonic device to facilitate implantation of a device such as a catheter.

1 - 24 . (canceled) 
     
     
         25 . A system for implanting a catheter comprising:
 a stylet;   an ultrasonic device configured to be operated in one-dimensional amplitude mode fixedly attached to a distal end of the stylet;   an indicator configured to selectively activate an alignment status prompt;   a circuit assembly comprising a microprocessor, a pulser, a transmit/receive chip, a bandpass filter, and an analog-to-digital converter, wherein the circuit assembly is configured to (i) control the timing and frequency of ultrasonic waves generated by the ultrasonic device; (ii) receive and analyze data from the ultrasonic waves characterizing ultrasonic waves detected by the ultrasonic device; and (iii) generate and transmit a control signal to the indicator to control the alignment status prompt.   
     
     
         26 . The system of  claim 25 , wherein the indicator is fixedly attached to a proximal end of the stylet; 
     
     
         27 . The system of  claim 25 , wherein the ultrasonic device comprises a single ultrasonic transducer that is selectively operable to generate ultrasonic waves and to detect ultrasonic waves. 
     
     
         28 . The system of  claim 25 , wherein the ultrasonic device comprises a plurality of ultrasonic transducers comprising fewer than ten transducers. 
     
     
         29 . The system of  claim 28 , wherein the plurality of ultrasonic transducers are disposed in an array wherein, a distal face of all of the transducers are coplanar. 
     
     
         30 . The system of  claim 28 , wherein the plurality of ultrasonic transducers are formed from a single crystal. 
     
     
         31 . The system of  claim 28 , wherein the alignment status prompt includes a controllable display marking to indicate a direction to pivot the stylet. 
     
     
         32 . The system of  claim 25 , further comprising a handle that encloses the indicator and the circuit assembly. 
     
     
         33 . The system of  claim 32 , further comprising a cable that extends from the ultrasonic device through the stylet and to the circuit assembly to operably connect the ultrasonic device with the circuit assembly. 
     
     
         34 . The system of  claim 25 , further comprising an elongate catheter configured to slidably receive the stylet and the ultrasonic device. 
     
     
         35 . The system of  claim 34 , wherein the catheter further has a distal end that is either open or is closed with an acoustic lens. 
     
     
         36 . The system of  claim 25 , wherein the indicator is disposed directly over a proximal end of the stylet and is oriented perpendicular to the stylet. 
     
     
         37 . The system of  claim 25 , wherein the system is configured to be disposable. 
     
     
         38 . The system of  claim 25 , wherein the stylet is configured to be disposable and the circuit assembly is configured to be reusable. 
     
     
         39 . A method for guiding a stylet through tissue towards a target internal fluid-tissue boundary comprising:
 positioning a stylet with a non-imaging ultrasonic device on an outer surface of the tissue, wherein the ultrasonic device includes an indicator that is configured to selectively generate a first prompt;   activating the non-imaging ultrasonic device;   receiving signal data from the non-imaging ultrasonic device representing scattered ultrasonic signals;   analyzing the received signal data to determine if the stylet is oriented toward the target internal fluid-tissue boundary;   displaying the first prompt with the indicator if the stylet is oriented toward the target internal fluid-tissue boundary;   pivoting the stylet until the indicator provides the first prompt;   urging the stylet through the tissue while maintaining the stylet in an orientation, such that the indicator provides the first status prompt.   
     
     
         40 . The method of  claim 39 , wherein the indicator comprises a visual display. 
     
     
         41 . The method of  claim 39 , wherein the step of analyzing the received signal data comprises demodulating the received signal data. 
     
     
         42 . The method of  claim 39 , wherein the step of analyzing the received signal data comprises analyzing the timing and amplitude of the received signal data. 
     
     
         43 . The method of  claim 39 , wherein the step of analyzing the received signal data comprises analyzing a pulsatility characteristic of the received signal data. 
     
     
         44 . The method of  claim 39 , wherein the step of analyzing the received signal data comprises analyzing a color Doppler characteristic of the received signal data. 
     
     
         45 . The method of  claim 39 , wherein the step of analyzing the received signal data comprises determining if one or more of an amplitude characteristic, a timing characteristic, a depth characteristic, a color Doppler characteristic, and a pulsatility characteristic exceeds a predetermined threshold.