Three-dimensional digital ultrasound tracking system

• US 5,515,853 A
• Filed: 03/28/1995
• Issued: 05/14/1996
• Est. Priority Date: 03/28/1995
• Status: Expired due to Term

• Current Assignee: Sonometrics Corporation
• Original Assignee: Sonometrics Corporation
• Inventors: Gubbels, Andrew W., Vesely, Ivan, Smith, Wayne L.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US08/411,959
• Time in Patent Office: 413 Days
• Field of Search: 128/660.06, 128/660.07, 128/660.08, 128/660.09, 128/661.01, 128/916, 73/624, 73/625, 73/626, 73/602
• US Class Current: 600/437
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2063 Acoustic tracking systems, e.g. using ultrasound
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 2090/3908 Soft tissue, e.g. breast tissue
• CPC Class Codes: A61B 2090/3929 Active markers
• CPC Class Codes: A61B 2090/3958 emitting a signal
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4245 involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 90/10 : for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/11 : with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61B 90/17 : for soft tissue, e.g. breast-holding devices
• CPC Class Codes: A61B 90/36 : Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/39 : Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61M 2025/0166 : Sensors, electrodes or the like for guiding the catheter to a target zone, e.g. image guided or magnetically guided
• CPC Class Codes: A61M 25/0105 : Steering means as part of the catheter or advancing means; Markers for positioning systems for detection of markers A61B
• CPC Class Codes: G01H 3/00 : Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01H 5/00 : Measuring propagation velocity of ultrasonic, sonic or infrasonic waves , e.g. of pressure waves
• CPC Class Codes: G01S 11/14 : using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 15/101 : Particularities of the measurement of distance G01S15/12, G01S15/14, and G01S15/18 take precedence
• CPC Class Codes: G01S 15/66 : Sonar tracking systems
• CPC Class Codes: G01S 15/86 : Combinations of sonar systems with lidar systems; Combinations of sonar systems with systems not using wave reflection
• CPC Class Codes: G01S 15/87 : Combinations of sonar systems
• CPC Class Codes: G01S 15/876 : Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S15/872 takes precedence
• CPC Class Codes: G01S 15/88 : Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00
• CPC Class Codes: G01S 15/899 : Combination of imaging systems with ancillary equipment
• CPC Class Codes: G01S 15/8993 : Three dimensional imaging systems
• CPC Class Codes: G01S 5/18 : using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 7/52003 : Techniques for enhancing spatial resolution of targets G01S7/52046 takes precedence
• CPC Class Codes: G01S 7/5206 : Two-dimensional coordinated display of distance and direction; B-scan display
• CPC Class Codes: G01S 7/52074 : Composite displays, e.g. split-screen displays; Combination of multiple images or of images and alphanumeric tabular information
• CPC Class Codes: G01S 7/52079 : Constructional features constructional features of transducers B06B; mounting transducers G10K11/00; constructional features of ultrasonic medical diagnostic devices A61B8/44
• CPC Class Codes: G01S 7/6245 : Stereoscopic displays; Three-dimensional displays; Pseudo-three dimensional displays
• CPC Class Codes: Y10S 128/916 : Ultrasound 3-D imaging

Abstract

A method and apparatus for simultaneous measurement of multiple distances by means of networked piezoelectric transducers. Through the use of high frequency digital counters, the propagation delay between the activation of an ultrasonic transducer and the reception by similar transducers is quickly and accurately defined. By alternating the duty cycle between transmit and receive modes, the system can track and triangulate the three-dimensional positions for each transducer.

Claims

1. A digital ultrasound tracking system, comprising:

a) a plurality of spaced apart ultrasound transceivers;

b) a controller module connected to said plurality of spaced apart ultrasound transceivers for selectively enabling individual ones of said transceivers to operate as one of either a transmitter or a receiver, and for energizing each respective transmitter such that each said transmitter generates an output oscillation signal which is detected by at least one associated receiver; and

c) a counter module connected to said plurality of spaced apart ultrasound transceivers and said controller module, said counter module including a high speed counter associated with each said associated receiver for generating a digital count value corresponding to an elapsed time between said energizing of the transmitter and detection of said output oscillation signal by said at least one associated receiver.

2. The digital ultrasound tracking system of claim 1, wherein said controller module further includes circuitry for adjusting repetition rate of said energizing of each transmitter.

3. The digital ultrasound tracking system of claim 1, wherein said controller module further includes circuitry for adjusting duration of said energizing of each transmitter.

4. The digital ultrasound tracking system of claim 1, wherein said controller module further includes circuitry for inhibiting each said high speed counter for a variable period after energizing of each said transmitter, thereby avoiding count errors due to electromagnetic interference resulting from energizing of each said transmitter.

5. The digital ultrasound tracking system of claim 1, wherein each of said transceivers further comprises:

d) a transmitter input for receiving a digital input signal from said controller module;

e) a step-up isolation transformer for translating said digital input signal into a crystal energizing signal;

f) a piezoelectric crystal for receiving said energizing signal in transmit mode and in response generating said output oscillation signal, and for detecting said output oscillation signal in receiver mode and in response generating and applying an input oscillation signal to said step-up transformer;

g) circuitry connected to said step-up transformer for amplifying and converting said input oscillation signal to a digital output signal; and

h) a receiver output for transmitting said digital output signal to said counter module for halting the high speed counter associated therewith at said digital count value.

6. A three dimensional ultrasound tracking system for attachment to an object whose position is to be monitored, comprising:

a) three ultrasound transceivers mounted to said object so as to form a first two-dimensional plane;

b) a fourth ultrasound transceiver mounted to said object on one side of said two-dimensional plane;

c) a plurality of ultrasound transmitters arranged in three-dimensional space around said ultrasound transceivers; and

d) circuitry for (i) sequentially enabling respective ones of said transmitters to generate ultrasound signals for reception by said ultrasound transceivers, (ii) sequentially measuring elapsed time between generation of said ultrasound signals and reception thereof by respective ones of said transducers, and (iii) calculating via triangulation from said elapsed time position and orientation of said object relative to said plurality of ultrasound transmitters.

7. A catheter guidance system, comprising:

a) at least two piezoelectric crystals mounted adjacent a tip of a catheter for insertion into a patient, whereby said at least two piezoelectric crystals form an internal reference frame;

b) a plurality of additional piezoelectric crystals located externally of the patient so as to form an external reference frame;

c) circuitry for (i) sequentially enabling respective ones of said piezoelectric crystals to generate ultrasound signals for reception respective other ones of said piezoelectric crystals, (ii) sequentially measuring elapsed time between generation of said ultrasound signals and reception thereof by said respective other ones of said piezoelectric crystals, and (iii) calculating via triangulation from said elapsed time, position and orientation of said catheter relative to said plurality of additional piezoelectric crystals.

8. The catheter guidance system of claim 7, wherein each of said two piezoelectric crystals are fabricated from a high dielectric material having low Curie temperature.

9. The catheter guidance system of claim 8, wherein said material is lead zirconate titanate.

10. The catheter guidance system of claim 7, wherein each of said piezoelectric crystals is coated with a layer of radio-opaque material for contrast with said catheter during x-ray imaging of said patient.

11. The catheter guidance system of claim 10, wherein each of said piezoelectric crystals coated with a layer of radio-opaque material is further encapsulated in biocompatible material having an acoustic impedance which does not interfere with propagation of said ultrasound signals.

12. The catheter guidance system of claim 7, wherein each of said two piezoelectric crystals are cylindrical for generating omnidirectional ultrasound radiation patterns.

13. The catheter guidance system of claim 7, wherein each of said additional piezoelectric crystals are disk-shaped and of larger size than said two piezoelectric crystals.

14. The catheter guidance system of claim 7, further comprising a coated stainless steel wire connecting said two piezoelectric crystals to said circuitry, said wire being disposed in an internal sheath within said catheter which also houses steering guide wires of said catheter.

15. The catheter guidance system of claim 7, wherein said two piezoelectric crystals are positioned concentrically along an axis of said catheter and spaced sufficiently apart to prevent signal interference therebetween but sufficiently close to indicate directionality of said tip of said catheter.

16. The catheter guidance system of claim 7, wherein said additional piezoelectric crystals are mounted to a harness adapted to be worn by said patient.