Invasive system employing a radiofrequency tracking system

• US 5,443,066 A
• Filed: 09/02/1994
• Issued: 08/22/1995
• Est. Priority Date: 11/18/1991
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Dumoulin, Charles L., Darrow, Robert D.
• Primary Examiner(s): Pfaffle, Krista M.
• Application Number:
  US08/299,976
• Time in Patent Office: 354 Days
• Field of Search: 128/653.1, 128/653.2, 128/897, 128/898, 128/899, 128/903, 607/154, 607/156, 250/216, 250/221, 340/825.36, 340/825.49
• US Class Current: 600/424
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/07 Endoradiosondes
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

An invasive imaging system employs a self-contained RF transmitter attached to an invasive device which allows tracking of the invasive device within a subject without physical connections to a tracking/display system and without the use of ionizing rays. An imaging system obtains a medical diagnostic image of the subject. The self-contained RF transmitter is comprised of a power generator means, a power conversion means such as an oscillator which converts the generated power to a radiofrequency (RF) signal, and a broadcasting means such as a tuned transmit coil for radiating the RF signal. The radiated RF signal is received by receive coils of a tracing/display means which calculates the location of the RF transmitter. The tracking/display means displays the medical diagnostic image on a monitor and superimposes a symbol on the image at a position corresponding to the calculated location of the RF transmitter. Prior to operation, the power generator may be energized inductively, photo-voltaically, or by direct contact with an external power supply. The power generator means may also be a charged battery sealed inside the RF transmitter. The RF transmitter may be implanted to track the motion of internal tissues.

Claims

1. An invasive imaging system to provide interactive images during an invasive procedure of a subject, comprising:

a) a imaging means adapted for providing an image of said subject;

b) an invasive device adapted to be inserted into said subject;

c) a radiofrequency (RF) transmitter attached to an end of the invasive device, the RF transmitter including;

i. power conversion means for converting electrical power into an RF signal at a selected frequency,

ii. power generation means for providing electrical power to the power conversion means;

said power generation means comprised of;

1. a photo-voltaic device which converts light energy into an electrical power; and

2. an energy storage means coupling the photo-voltaic device to the power conversion means, for storing the converted electrical power and providing the power to the power conversion means

iii. broadcasting means for broadcasting the RF signal so as to create a dipole magnetic field, and

iv. hermetically sealed case constructed from non-bioreactive materials encasing the power conversion means, power generation means and broadcasting means having a size and shape allowing it to move freely within said patient;

d) a plurality of receive coils placed at a plurality of known locations for receiving the broadcasted RF signal; and

e) external RF tracking/display means employing a phase-locked loop for synchronizing the external RF tracking/display means with the RF transmitter, the external RF tracking/display means coupled to the receive coils and responsive to the RF signal for determining a location and orientation of the RF transmitter based upon strength and phase of the broadcasted RF signal received at the receive coils, and adapted for displaying the image of the subject and a symbol on the image at a position corresponding to the location of the RF transmitter in the subject.

2. The invasive imaging system of claim 1 wherein the invasive device comprises one of the group consisting of a guide wire, a catheter, an endoscope, a laparoscope, a biopsy need, a surgical tool and a therapeutic device.

3. The invasive imaging system of claim 1 wherein the energy storage device comprises a battery.

4. The invasive imaging system of claim 1 wherein the energy storage device comprises a capacitor.

5. The invasive imaging system of claim 1 further comprising a switch in series with the energy storage means and the power conversion means to control the passage of power to the power conversion means.

6. The invasive imaging system of claim 1 wherein the hermetically sealed case has a size and shape allowing it to be surgically implanted and tracked as it passes through said body by the external RF tracking/display means.

7. The invasive imaging system of claim 1 wherein the imaging means comprises one of the group consisting of positron emission tomography (PET) imaging means, gamma ray camera, computed axial tomography (CAT) imaging means.