Method and apparatus for three dimensional reconstruction of a joint using ultrasound

Inventors

Mahfouz, Mohamed R.

Assignees

JointVue LLC

Abstract

A method of generating a 3-D patient-specific bone model, the method comprising: (a) acquiring a plurality of raw radiofrequency (“RF”) signals from an A-mode ultrasound scan of a patient's bone at a plurality of locations using an ultrasound probe that comprises a transducer array; (b) tracking the acquiring of the plurality of raw RF signals in 3-D space and generating corresponding tracking data; (c) transforming each of the plurality of raw RF signals into an envelope comprising a plurality of peaks by applying an envelope detection algorithm to each of the plurality of raw RF signals, each peak corresponding with a tissue interface echo; (d) identifying a bone echo from the tissue interface echoes of each of the plurality of raw RF signals to comprise a plurality of bone echoes by selecting the last peak having a normalized envelope amplitude above a preset threshold, wherein the envelope amplitude is normalized with respect to a maximum peak existing in the envelope; (e) determining a 2-D bone contour from the plurality of bone echoes corresponding to each location of the ultrasound probe to comprise 2-D bone contours; (f) transforming the 2-D bone contours into an integrated 3-D point cloud using the tracking data; and, (g) deforming a non-patient specific 3-D bone model corresponding to the patient's bone in correspondence with the integrated 3-D point cloud to generate a 3-D patient-specific bone model.

Core Innovation

The invention generates a virtual three dimensional subject-specific musculoskeletal model from ultrasound scan data. For a plurality of raw signals obtained from an ultrasound scan of at least a portion of a subject, the method generates an envelope for each raw signal, where each envelope includes one or more peaks. The method then generates contour lines based on the peaks of the envelopes.

The invention transforms the contour lines into a three dimensional point cloud using tracking information obtained by tracking a position of an ultrasound transducer during the ultrasound scan. Multiple aligned point clouds are integrated into a composite 3-D point cloud representation.

The described approach optimizes a template tissue model with respect to the point cloud to generate a virtual three dimensional subject-specific musculoskeletal model. The extension includes generating a cartilage 3-D model reconstruction by probabilistic modeling of cartilage using a classifier trained from MRI-ultrasound registered datasets and a cartilage statistical atlas.

Claims Coverage

The provided independent claim set includes two independent claims, covering four main inventive features: envelope generation from ultrasound raw signals, contour-line generation from envelope peaks, transformation of contour lines into a 3-D point cloud using transducer tracking, and optimization of a template tissue model with respect to the point cloud.

Across the independent claims, the core coverage is the same sequence of envelope and peaks extraction from ultrasound raw signals, contour-line derivation from those peaks, conversion of contours into a 3-D point cloud using ultrasound transducer tracking, and optimization of a template tissue model against the point cloud to produce a virtual 3-D subject-specific musculoskeletal model.

Stated Advantages

Documented Applications

No documented applications found