Search

EP-4734821-A1 - FRACTURE HEALING ASSESSMENT OF MUSCULO-SKELETAL TISSUE STRUCTURES

EP4734821A1EP 4734821 A1EP4734821 A1EP 4734821A1EP-4734821-A1

Abstract

A system for assessing fracture healing in real time using low intensity pulsed ultrasound (LIPUS) excitation includes a transducer that transmits a longitudinal fracture healing assessment diagnostic signal at an angle of 0º(> (normal) to the transducer or at an oblique angle up to a first critical angle of 20 degrees, or receives one or more FHA echo signatures, and a processor. The processor is configured to sum the received echo signatures, convert the received echo signatures to an analytic echo signal, normalize the analytic signal against healthy bone signatures, sum the set of normalized analytic signatures and create a data vector; generate a. real-time diagnostic fracture healing assessment metric by processing the data vector using one or more metrics; and identify a stage of bone fracture healing by using the real-time diagnostic fracture healing assessment metrics.

Inventors

  • WINDER, ALAN
  • MURATORE, ROBERT
  • WINDER, Jason

Assignees

  • Sonogen Medical, Inc.
  • Winder, Alan
  • Muratore, Robert
  • Winder, Jason

Dates

Publication Date
20260506
Application Date
20230804

Claims (15)

  1. 1. A system for assessing the real-time healing of a bone fracture in real time using low intensity pulsed ultrasound (LIPUS) excitation, comprising:. a transducer that transmits into a bone fracture a longitudinal fracture healing assessment (FHA) diagnostic signal at an angle of 0° (normal) to the transducer or at an oblique angle tip to a first critical angle of about 20 degrees, or receives one or more FHA echo signatures; and a processor, wherein the processor is configured to: (a) sum the received echo signatures, convert the recei ved echo signatures to an analytic echo signal, normalize the analytic signal against a bone standard and generate a set of normalized analytic signatures, sum the set of normalized analytic signatures, and create a data vector; (b) generate a real-time diagnostic .fracture healing assessment metric by processing the data vector using one or more metrics, wherein the one or more metrics include bone mineral density, speed-of-sound, ultrasound attenuation, or elastic modulus; and (c) identify a stage of bone fracture healing by using one or more of the real-time diagnostic fracture healing assessment metrics.
  2. 2 The system of Claim I , wherein the FHA diagnostic signal includes a Gaussian structural waveform and is transmitted at a resonant carrier frequency between 0.5 MHz to 5.0 MHz, a pulse width of about 4 microseconds, a pulse repetition frequency (PRE) of about 1.0 kHz, and a spatial average-temporal average intensity (ISPTA) of about 30 mW/cnr.
  3. 3. The system of Claim 2, wherein the FHA diagnostic signal is transmitted at a resonant carrier frequency between 2.0 MHz and about 3.0 MHz, and wherein the resonant carrier frequency is modulated by linear frequency modulation so that spatial resolution, dynamic range, signal-to-noise ratio (SNR) are increased, and clutter interference is reduced.
  4. 4. The system of Claim I, wherein the FHA signal is transmitted by one or two acoustic transducers in a frequency range of 2.0 to about 3.0 MHz, that provide the longitudinal FHA transmission at 0 degrees along the M.RA or at an oblique angle up to the first critical angle.
  5. 5. The system of Claim 4, wherein the one or two acoustic transducers focus the FHA signal at an ISATA intensity level of about 30 mW/cm 2 into the bone fracture.
  6. 6. The system of Claim 4, wherein two acoustic transducers are positioned on each side of the bone fracture, and wherein a propagation velocity of the FHA signal across the bone fracture is another metric that establishes the stage of bone fracture healing by comparing the received echo of the bone fracture to that of an in tact bone.
  7. 7. The system of Claim 4, wherein multiplied outputs of two transducers are sent to a low-pass filter that .removes high-frequency outputs by doubling a directivity of the multiplicative array and a system dynamic range (in dB).
  8. 8. The system of Claim 4, wherein the one or two transducers are positioned within or alongside a larger AMC-embedded transducer resonant at 1.0 MHz.
  9. 9. The system of Claim 1 , wherein the transducer is a multi-elenient transducer and uses a beamformer that electronically sweeps the FHA diagnostic signal through a series of angular direction steps from a first angle to a second angle via adjustments to a phase of a signal that drives each transducer array element of the multi-element transducer, selects a signal with a maximum amplitude or signal-to-noise ratio from a set of signals received at each angle, and transmits the selected signal into the bone fracture.
  10. 10. The system of Claim 1 , wherein the transducer is a multi-element transducer and uses a beamformer that electronically sweeps the FHA diagnostic signal through a series of angular direction steps from a first angle to a second angle via adjustments to a phase of a signal that drives each transducer array element of the multi-element transducer, processes signals received at each of the angles, and transmits a desired signal from the processed signals into the bone fracture.
  11. 1 1 . The system of Claim I , wherein the FHA signal is transmitted by one or more circular ring transducers in a range of 0.5 to 5.0 MHz and that form a concaved or focused dedicated annular array, wherein an AMC-embedded transducer is positioned at the center of the annular array, wherein each circular ring of the annular array has a thickness of about 1 .5 to 2 mm, and wherein each circular ring of the annular array is separated from an adjacent ring by about 100 microns.
  12. 12. The system of Claim 1, wherein the transducer is a time modulated array (TMA) implemented as a multi-element planar array that transmits multiple acoustic beams, wherein the acoustic beams are transmited either sequentially or simultaneously by controlling the harmonic number.
  13. 13. The system of Claim I , wherein the processor estimates state variables of the transducer by suboptimal filtering, wherein the state variables include radiated pressure, acceleration, input, cun-ent to the transducer, or efficiency.
  14. 14. The system of Claim I , wherein the processor converts the data vector from analog to digital format, stores the digital data vector in persistent memory, and transmits the digital data vector to another system for data analysis purposes.
  15. 15. The system of Claim 1 , further comprising a therapeutic bone growth stimulation (BGS) device.

Description

FRACTURE HEALING ASSESSMENT OF MUSCULOSKELETAL TISSUE STRUCTURES BACKGROUND Technical Field: Embodiments of the disclosure are directed to a method and system that produces longitudinal acoustic waves for real-time monitoring the quality of bone fracture healing achieved with primarily shear waves. Discussion of the Related Art: Bone fractures are one of the most common traumas that humans experience and are the main outcome of osteoporosis, a common chronic disease associated with aging. Skeletal tissue repair is currently assessed at several levels: at the tissue and whole organ level, via X-Ray, computed tomography (CT), micro-CT, and magnetic resonance imaging (MRI); at the cellular level, via micro-CT and histological analysis; and at. the molecular level, via immune-histological analysis, as well as analysis of messenger RNA (mRNA) and protein expression. These modalities all have significant limitations, notably including size, cost, complexity and the use of ionizing radiation, that a home use approach employing ultrasound excitation would overcome. Conversely, low intensity pulsed ultrasound (LIPUS) is a highly promising imaging modality that has been shown to be non-ionizing and capable of measuring the change in osseous tissue properties, based on the core principle that sonic propagation velocity' is directly correlated to a material's elastic modulus and Poisson’s ratio, and that spectrum and correlation technology allow estimation of bone mechanical strength and anisotropy [1-4], SUMMARY Embodiments of this disclosure provide a method that obtains and analyzes data in real- time. Embodiments disclose computing four metrics to increase accuracy of healing assessment: bone mineral density, speed-of-sound, ultrasound attenuation, and elastic modulus. Embodiments further disclose transmitting a longitudinal signal at an angle either normal to the long bone axis, or at the first critical angle of about 15 to 20 degrees relative to the long bone axis, thereby' producing a longitudinal signal that travels along the surface of the long bone axis (i.e.,, the periosteum). In an embodiment herein, “real-time” refers to each treatment session, wherein the data collected for assessment is made in one minute of a standalone FHA diagnostic device operation, or the first minute of an integrated FHA and bone growth stimulation (BGS) diagnostic/ treatment cycle of 21 minutes. Real-time monitoring during the first two stages of bone fracture healing will substantially encourage patient compliance and may detect delayed or non-union fractures at an earlier point in time, which could possibly lead to earlier surgical intervention where necessary. According to an embodiment of the disclosure, there is provided a system for assessing the real-time healing of a bone fracture in real time using low intensity pulsed ultrasound (L1.PUS) excitation. The system includes a transducer that transmits into a bone fracture a longitudinal fracture healing assessment (FHA) diagnostic signal, at an angle of 0° (normal) to the transducer or at an oblique angle up to a first critical angle of about 20 degrees, or receives one or more FHA echo signatures, and a processor. The processor is configured to: (a) sum the received echo signatures, convert the received echo signatures to an analytic echo signal, normalize the analytic signal against a bone standard and generate a set of normalized analytic signatures, sum the set of normalized analytic signatures, and create a data vector; (b) generate a real-time diagnostic fracture healing assessment metric by processing the data vector using one or more metrics, wherein the one or more metrics include bone mineral density, speed-of-sound, ultrasound atenuation, or elastic modulus; and (c) identify a stage of bone fracture healing by using one or more of the real- time diagnostic fracture healing assessment metrics. According to a further embodiment of the disclosure, the FHA diagnostic signal includes a Gaussian structural waveform and is transmitted at a resonant carrier frequency between 0,5 MHz to 5,0 MHz, with a duty cycle of 0.4-20%, a period of 1 ms, a pulse width of 4-200 microseconds, a pulse repetition frequency (PRF) of about 1.0 kHz, and a spatial average-temporal average intensity (ISPTA) of about 30 mW/cni2. According to a further embodiment of the disclosure, the FHA diagnostic signal is transmitted at a resonant carrier frequency between 2.0 MHz and 3.0 MHz, and wherein the resonant carrier frequency is modulated by linear frequency modulation so that spatial resolution, dynamic range, signal-to-noise ratio (SNR) are increased, and clutter interference is reduced. According to a further embodiment of the disclosure, the FHA signal is transmitted by one or two acoustic transducers in a range of 0.5 to 5.0 MHz, that provide the longitudinal FHA transmission at 0 degrees along the MKA or at an oblique angle up to the first critical angle, According to a further embodiment