Motion monitor system for use with imaging systems

Abstract

A bellows-based patient breath-hold monitoring and feedback system for use in intermittent mode CT fluoroscopy-guided biopsies of the lung or upper abdomen where respiratory motion is a problem. Breath-hold monitoring and feedback with the bellows system allows a patient to perform consistent breath-holds at a preselected level, which in turn, optimizes intermittent mode CT fluoroscopy-guided biopsies of the lung or upper abdomen by allowing target lesions to be reliably visualized.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of the components comprising the bellows movement system in accordance with an embodiment of the invention;

FIG. 2 is a pictorial view of the bellows, the belt, and the pressure tube of the bellows movement system of FIG. 1;

FIG. 3 is a pictorial view of the control unit and a display which form part of the system of FIG. 1;

FIG. 4 is a graph of respiration motion monitored by the system of FIG. 1;

FIG. 5 is a flow chart of the process by which the bellows movement system of FIG. 1 monitors patient respiration; and

FIG. 6 is a graphic representation of diode curve stored in the control unit of FIG. 3.

Claims

1. A motion detection system for monitoring the motion of a subject during a medical procedure, the combination comprising: a) a motion detector positioned to measure subject motion and produce an input signal;b) a control unit connected to receive the input signal from the motion detector and being operable in response thereto to produce displacement data indicative of subject motion from a reference position;c) a display having multiple indicators, each of which represents a unit of displacement from the reference position; ande) a wireless communication link between the control unit and the display for conveying the displacement data from the control unit to the display such that the display indicators provide feedback to the subject.

2. The motion detection system of claim 1, wherein the motion detector includes: a deformable gas-filled bellows;a tubing filled with the same gas as the bellows, a first end of the tubing connected to an interior of the bellows;a reference valve connected to the tubing and being operable when operated to couple the interior of the tubing to the surrounding ambient air and to thereby equalize the pressure therein with the ambient air pressure; anda transducer connected to a second end of the tubing and being operable to produce the input signal in response to the pressure on the interior of the tubing.

3. The motion detection system as recited in claim 2 in which the control unit includes a switch for manually energizing the reference valve.

4. The motion detection system as recited in claim 1 which includes an additional display that receives displacement data from the control unit using the wireless communications link.

5. A motion detection system for monitoring the respiratory motion of a subject during a medical procedure, the combination comprising: a motion detector for sensing the respiratory motion of the subject and producing an input signal, the sensitivity of the motion detector being set such that the dynamic range of the motion detector input signal is substantially less than the dynamic range of subject motion during a complete respiratory cycle;a control unit connected to receive the input signal from the motion detector and being operable in response thereto to produce displacement data indicative of subject motion from a reference position;a display coupled to the control unit for indicating the displacement of the subject from the reference position; anda reference switch which is coupled to the motion detector and is manually operable to establish a reference position in the subject's respiratory cycle from which displacement is measured.

6. The motion detection system as recited in claim 5 in which the motion detector includes a bellows which deforms in shape in response to respiratory motion of the subject to change air pressure therein, and a transducer which produces the input signal in response to the air pressure in the bellows.

7. The motion detector system as recited in claim 6 in which the reference switch operates a solenoid valve to equilibrate pressure in the bellows with surrounding ambient pressure.

8. The motion detector system as recited in claim 5 in which the control unit stores a curve that relates the input signal to subject motion and the operation of the reference switch shifts the operating range of the stored curve.

9. The motion detector system as recited in claim 8 in which the motion detector includes a bellows which deforms in shape in response to respiratory motion of the subject to change air pressure therein, and a transducer which produces the input signal in response to the air pressure in the bellows.

10. The motion detector system as recited in claim 9 in which the zero switch operates a solenoid valve to equilibrate pressure in the bellows with surrounding ambient pressure.