Ultrasound scanning system

Abstract

A three dimensional ultrasound scanning system includes devices to capture an acquisition state for a scan including quantitative data about the conditions under which the scan was obtained. The conditions may include pose and contact force of an ultrasound probe in relation to a target. This data may be used to obtain a three dimensional reconstructed volume of a target.

What is claimed is: 
     
         1 . A system for ultrasound scanning comprising:
 a handheld ultrasound probe comprising at least one transducer to capture a plurality of ultrasound image of a target through a skin surface in a scan;   a fiducial marker with predetermined dimensions applied to the skin surface;   a camera mechanically coupled to the handheld ultrasound probe, the camera positioned to record a digital image of the skin surface during the scan when the handheld ultrasound probe is placed for use against the skin surface; and   a processor in communication with the handheld ultrasound probe and the camera, the processor configured to perform the steps of:
 identifying the fiducial marker in two or more digital images from the camera; 
 establishing a world coordinate system using the predetermined dimensions of the fiducial marker and the two or more digital images; 
 estimating a three dimensional pose of the handheld ultrasound probe with respect to the two or more images; and 
 aligning the plurality of ultrasound images in the world coordinate system to obtain a reconstructed volume of the target. 
   
     
     
         2 . The system of  claim 1  further comprising a lighting source mechanically coupled to the handheld ultrasound probe and positioned to illuminate the skin surface when the handheld ultrasound probe is placed for use against the skin surface. 
     
     
         3 . The system of  claim 1  further comprising a display to display one of the plurality of ultrasound images. 
     
     
         4 . The system of  claim 1  further comprising a display to display one of the two or more digital images. 
     
     
         5 . The system of  claim 1  further comprising a memory to store data from the handheld ultrasound probe and the camera. 
     
     
         6 . The system of  claim 5  wherein the memory is a remote memory storage device. 
     
     
         7 . The system of  claim 6  further comprising a wireless interface for coupling the handheld ultrasound probe in a communicating relationship with the remote storage device. 
     
     
         8 . A method for obtaining a three dimensional reconstructed volume of a target using a handheld ultrasound probe comprising:
 mechanically coupling a camera to the handheld ultrasound probe, the camera positioned to capture a digital image of a skin surface of a target when the handheld ultrasound probe is place for use against the skin surface;   applying a fiducial marker with predetermined dimensions to the skin surface;   concurrently obtaining an ultrasound image from the handheld ultrasound probe and a digital image from the camera in a scan of the target, wherein the digital image includes the fiducial marker;   establishing a world coordinate system using the predetermined dimensions of the fiducial marker;   estimating a three-dimensional pose of the handheld ultrasound probe with respect to the skin surface for the digital image; and   aligning the ultrasound images in the world coordinate system.   
     
     
         9 . The method of  claim 8  further comprising aligning a plurality of ultrasound images to the world coordinate system and reconstructing a volume of the target from the plurality of ultrasound images. 
     
     
         10 . The method of  claim 8  further comprising mechanically coupling a lighting source to the ultrasound probe, the lighting source positioned to illuminate the skin surface when the handheld ultrasound probe is placed for use against the skin surface. 
     
     
         11 . The method of  claim 8  wherein the step of estimating a three dimensional pose of the handheld ultrasound probe includes computing an image-to-world homography matrix. 
     
     
         12 . The method of  claim 8  wherein the fiducial marker is a square. 
     
     
         13 . The method of  claim 12  wherein establishing the world coordinate system comprises selecting the four corners of the square. 
     
     
         14 . The method of  claim 8  further comprising wirelessly transmitting ultrasound data from the handheld ultrasound probe to a remote storage facility. 
     
     
         15 . The method of  claim 8  further comprising displaying at least one ultrasound image obtained from the handheld ultrasound probe. 
     
     
         16 . The method of  claim 8  further comprising displaying at least one digital image recorded by the camera. 
     
     
         17 . A system comprising:
 a handheld ultrasound probe including one or more ultrasound transducers to capture an ultrasound image of a target through a skin surface;   a sensor system configured to obtain a pose of the handheld ultrasound probe;   a force sensor configured to obtain a pressure applied by the handheld ultrasound probe to the skin surface; and   a memory that stores an acquisition state for an ultrasound image, the acquisition state including the pose and the pressure.   
     
     
         18 . The system of  claim 17 , further comprising a fiducial marker adhered to the skin surface and having one or more predetermined features, wherein the sensor system includes a camera and a processor programmed to identify the one or more predetermined features and calculate the pose of the handheld ultrasound probe using the one or more predetermined features and an image from the camera that includes the fiducial marker. 
     
     
         19 . The system of  claim 17  wherein the sensor system includes at least one inertial sensor. 
     
     
         20 . The system of  claim 17  wherein the sensor system includes an external electromechanical system coupled to the handheld ultrasonic probe for tracking a pose of the handheld ultrasonic probe through direct measurements. 
     
     
         21 . The system of  claim 17  wherein the sensor system includes an external optical system. 
     
     
         22 . The system of  claim 17  wherein the force sensor includes a pressure transducer coupled to the handheld ultrasound probe and configured to sense an instantaneous contact force between the handheld ultrasound probe and the skin. 
     
     
         23 . The system of  claim 17  further comprising a lighting source mechanically coupled to the handheld ultrasound probe and positioned to illuminate the skin surface when the handheld ultrasound probe is place for use against the skin surface. 
     
     
         24 . The system of  claim 17 , further comprising:
 a linear drive system mechanically coupled to the handheld ultrasound transducer and including a control input, the linear drive system responsive to a control signal received at the control input to translate the ultrasound transducer along an actuation axis; and   a controller electronically coupled to the force sensor and the control input of the linear drive system, the controller including processing circuitry configured to generate the control signal to the control input in a manner that maintains a substantially constant predetermined contact force between the ultrasound transducer and the target.   
     
     
         25 . A method comprising:
 capturing an ultrasound image with a handheld ultrasound probe;   capturing a pose of the handheld ultrasound probe substantially concurrently with the ultrasound image;   capturing a contact force of the handheld ultrasonic probe substantially concurrently with the ultrasound image; and   storing the ultrasound image and an acquisition state for the ultrasound image, the acquisition state including the pose and the contact force.   
     
     
         26 . The method of  claim 25  further comprising capturing a plurality of ultrasound images. 
     
     
         27 . The method of  claim 26  further comprising normalizing the ultrasound images to a common contact force.