# US 2014/0155748 A1 · Ultrasound apparatus for assessing the quality of a patient's bone tissue

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0155748 A1
- Document ID: US20140155748A1
- Status: Published application
- Kind: A1
- Application number: 14/081,826
- Filed: 2013-11-15
- Published: 2014-06-05
- Earliest claimed: 2011-05-16
- Assignees: ECHOLIGHT S.p.A.
- Applicants: Echolight S.R.L.
- Inventors: Matteo PERNISA; Sergio CASCIARO; Francesco CONVERSANO; Ernesto CASCIARO
- Web page: https://patentgrep.com/patent/US20140155748A1

## CPC

- A61B 5/4509: {Bone density determination}
- A61B 8/0875: {for diagnosis of bone}
- A61B 8/14: Echotomography
- A61B 8/5207: {involving processing of raw data to produce diagnostic data, e.g. for generating an image}
- A61B 8/5223: {for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012)}
- G01S 15/8952: {using discrete, multiple frequencies}
- G06T 7/0012: {Biomedical image inspection}
- G16H 50/30: for calculating health indices; for individual health risk assessment
- A61B 8/485: {involving measuring strain or elastic properties}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA

## Abstract

An apparatus (100) for assessing the condition of the bone tissue in a patient's bone region (21), comprising an ultrasound device (11) that has a means for transmitting/receiving ultrasounds along a plurality of ultrasound propagation lines (151) arranged for achieving the bone region (21), and for receiving in response from the bone region (21) a plurality of raw reflected ultrasound signals (36,38); a means for generating an ultrasound signal, a sonographic image formation means for forming a sonographic image (29) of the bone region (21), starting from the raw reflected ultrasound signals (36,38); a means for extracting at least one frequency spectrum (43i,44i,47,48) starting from at least one part of said plurality of raw reflected ultrasound signals (36,38) coming from corresponding points (34) of the bone region (21), each having a plurality of harmonic components whereinto each frequency (v) of the frequency range an intensity is associated (A) of a portion of one of the raw reflected ultrasound signals.

## Claims

### Claim at position 1

1-19. (canceled)

### Claim 20

An apparatus (100) for assessing the condition of the bone tissue in a patient's bone region (21), said apparatus (100) comprising:
an ultrasound device (11) provided with an ultrasound transceiving means that is configured to emit ultrasound pulses along a plurality of ultrasound propagation lines (15i) that can reach said bone region (21), and to receive raw ultrasound signals (36, 38) from said bone region (21), in response to said emitted ultrasound pulses;
said ultrasound transceiving means comprising an ultrasound signal generation means, which is arranged in said ultrasound transceiving means and configured to generate an ultrasound signal that has frequencies of a frequency range comprising a nominal frequency, said ultrasound transceiving means being configured to emit said generated ultrasound signals during a prefixed emission time (25), said ultrasound transceiving means being arranged to transmit said ultrasound pulses and to receive said raw ultrasound signals from a same side of said bone region, such that said received raw ultrasound signals are return raw ultrasound signals reflected by said bone region;
a sonographic image formation means for forming a sonographic image (29) of said bone region (21), starting from said received raw ultrasound signals (36, 38), said sonographic image formation means displaying said image, to allow an operator to identify a zone of said region to be investigated and to direct said ultrasound device towards said zone,
characterised
in that said sonographic image formation means are adapted to determine the reflected signals (36) coming from the cortical part (40′) of said bone region (21) received by said ultrasound device (11) after a delay time set between a first time threshold (t1) and a second time threshold (t2), and the reflected signals coming from the trabecular part (41′) of said bone region (21) received by said ultrasound device (11) after a delay time longer than said second time threshold (t2), and
in that said apparatus (100) further comprises
spectrum extraction means, configured for extracting a plurality of frequency spectra (43i, 44i, 47, 48) starting from said return raw ultrasound signals (36, 38) reflected from corresponding points (34) of said bone region (21), said frequency spectra (43i, 44i, 47, 48) having a plurality of harmonic components in which, to each frequency (v) of said frequency range, an intensity is associated (A) of a portion of one of said raw reflected ultrasound signals that have said frequency, said spectrum extraction means being adapted to determine spectra (43i, 44i, 47, 48) associated with the cortical part (40′) of said bone region (21), corresponding to the raw ultrasound signals (36, 38) received by said ultrasound device (11) within time interval from said first threshold (t1) and said second threshold (t2), and spectra associated with the trabecular part (41′) of said bone region (21), corresponding to the raw reflected ultrasound signals received by said ultrasound device (11) after said second time threshold (t2),
a memory means configured for memorizing at least one reference spectrum (52) associated with at least one healthy and/or pathological subject, and
frequency spectra comparison and diagnostic parameter calculation means (24), for comparing said frequency spectra (43i, 44i, 47, 48) associated with the cortical (40′) and/or trabecular (41′) parts of said bone region (21), which are extracted by said extraction means, with said at least one reference spectrum (52) recorded in said memory means, and for calculating a diagnostic parameter according to said comparison.

### Claim 21 (depends on 20)

An apparatus (100) according to claim 20, wherein said frequency spectra comparison means is configured to calculate a correlation coefficient between each frequency spectrum of a plurality of frequency spectra (43i, 44i, 47, 48) and a reference spectrum (52) of a healthy subject and/or of a pathological subject, i.e. of a healthy model and/or of a pathological model, and to calculate said diagnostic parameter according to said correlation coefficient.

### Claim 22 (depends on 20)

An apparatus (100) according to claim 20, wherein said calculation means for comparing said frequency spectrum (43i,44i) with at least one reference spectrum (52) is configured to:
calculate respective correlation coefficients with said at least one reference spectrum (52) of a plurality of frequency spectra (43i,44i) that are associated with respective segments of ultrasound propagation lines (15i) included in said bone region (21),
select a set of valid frequency spectra, wherein at least one of said correlation coefficients exceeds a predetermined threshold value;
calculate a percentage of healthy valid spectra or of pathological valid spectra or of intermediate valid spectra, wherein one of said valid spectra (43i,44i) is a healthy spectrum or a pathological spectrum or an intermediate spectrum if said correlation coefficient with said healthy model (52) or with said pathological model (52) or with said intermediate model (52), respectively, is substantially higher than the correlation coefficient with the other models (52);
define a diagnostic parameter selected from the group consisting of:
said percentage of healthy or pathological or intermediate valid spectra, respectively;
a parameter according to the average value of said correlation coefficient of said valid frequency spectra;
a statistic parameter or a combination of statistic parameters that describe a distribution of values of said correlation coefficients of said valid spectra;
a diagnostic parameter associated to a reference spectrum (52) selected among a plurality of reference spectra that represent specific pathology seriousness levels.

### Claim 23 (depends on 22)

An apparatus (100) according to claim 22, wherein said correlation coefficient is a Pearson's correlation coefficient, and said threshold value is selected between 0.7 and 0.8, more in particular, said threshold value is about 0.75.

### Claim 24 (depends on 20)

An apparatus (100) according to claim 20, wherein said frequency spectrum extraction means is configured to perform a transformation (46) in the frequency domain of raw reflected ultrasound signals coming from points (34) of a segment of an ultrasound propagation line (15i) included in said bone region (21), such that a frequency spectrum (43i,44i) is obtained that is associated with said segment of an ultrasound propagation line (15i).

### Claim 25 (depends on 24)

An apparatus (100) according to claim 24, wherein said segment of an ultrasound propagation line (15i) is selected from the group consisting of:
a segment of an ultrasound propagation line (15i) included in a cortical part (40) of said bone region (21);
a segment of an ultrasound propagation line (15i) included in a trabecular part (41) of said bone region (21);
a segment of an ultrasound propagation line (15i) included in a cortical part and in a trabecular part (40, 41) of said bone region (21).

### Claim 26 (depends on 24)

An apparatus (100) according to claim 24, wherein said frequency spectrum extraction means is configured to extract a frequency spectrum (47,48) associated with a region of interest (37), starting from a plurality of spectra (43i, 44i) associated with segments of ultrasound propagation lines (15i) included in said bone region (21).

### Claim 27 (depends on 26)

An apparatus (100) according to claim 26, wherein said frequency spectrum extraction means is configured to extract a frequency spectrum by calculating an average (49) of spectra (43i,44i) that are associated with respective segments of ultrasound propagation lines (15i).

### Claim 28 (depends on 26)

An apparatus (100) according to claim 26, wherein said frequency spectrum extraction means is configured to calculate, for each frequency, an arithmetic mean value of intensity values (A) of each of said reflected ultrasound signals.

### Claim 29 (depends on 20)

An apparatus (100) according to claim 20, wherein said frequency spectra comparison means is configured to calculate said diagnostic parameter as a shape parameter of said at least one frequency spectrum (43i,44i,47,48), or as a combination of a plurality of shape parameters of said at least one frequency spectrum (43i,44i,47,48).

### Claim 30 (depends on 29)

An apparatus (100) according to claim 29, wherein said shape parameter or said shape parameters is/are selected from the group consisting of:
an area (53) defined by the frequency spectrum (42) in a predetermined range of frequencies (54) and/or in a predetermined range of amplitudes (55);
a width (54) of said frequency spectrum (42) at a predetermined amplitude level (56), in particular at a level defined by an amplitude value (56) lower than a maximum value (57) of said frequency spectrum (42) by a predetermined amount, in particular by 3 dB or by 1 db;
a frequency (58) corresponding to a maximum value (57) of said frequency spectrum (42);
a slope (59) of a line (60) that interpolates a plurality of points (61) of said frequency spectrum (42) in a predetermined range of frequencies (62);
the coefficient of a polynomial that interpolates points (66) of said frequency spectrum (42) in a frequency range (54) that contains a frequency (58) corresponding to a maximum value (57) of said frequency spectrum (42);
a ratio of physical quantities that can be deducted from the frequency spectrum (42);
any parameter that is adapted to describe the shape of said frequency spectrum.

### Claim 31 (depends on 20)

An apparatus (100) according to claim 20, wherein said frequency spectra comparison means (24) for comparing said at least one frequency spectrum (43i,44i,47,48) with a reference spectrum is configured to calculate a parameter selected from the group consisting of:
T score;
Z score,
as a further diagnostic parameter

### Claim 32 (depends on 20)

An apparatus (100) according to claim 20, comprising a surface recognizing and/or defining means for recognizing and/or defining a limiting surface (27) of said bone region (21), such that a non-significant bone portion or other tissue portion can be left out of said bone region (21) to be assessed in quality.

### Claim 33 (depends on 20)

An apparatus (100) according to claim 20, comprising a space selection means configured to define a region of interest (37) of said bone region (21) on said sonographic image (29).

### Claim 34 (depends on 33)

An apparatus (100) according to claim 33, wherein said space selection means for defining a region of interest (37) is configured to define and to recognize at least one anatomical reference point in said bone region (21), and to identify in a measurement session a region of interest that coincides with a previously defined region of interest, said previously defined region of interest defined in a previous sonographic session, on the basis of said at least one anatomical reference point.

### Claim 35 (depends on 20)

An apparatus (100) according to claim 20, wherein said apparatus comprises a ultrasound probe (11) that is equipped with a plurality of piezoelectric crystals arranged to transceive respective ultrasound signals that travel along respective said ultrasound propagation lines (15i) of a same sonographic plane (17) or of a 3D volume, and said sonographic image (29) is an image of a plane cross section of said bone region (21) taken along said sonographic plane (17) or in a 3D sonographic volume.

### Claim 36 (depends on 20)

An apparatus (100) according to claim 20, wherein said memory means configured for memorizing at least one reference spectrum comprises a computation means for computing said reference spectra, which is configured to:
select a sonographic frame containing a bone region to be used as a model;
obtain an overall trabecular spectrum of said region and a trabecular spectrum of sub-regions of said region;
for each sub-region, identify an interface of the bone region to be investigated;
generating a bundle of ultrasound propagation lines that meet said interface;
on each radiofrequency signal that corresponds to an ultrasound propagation line of said bundle, select a portion corresponding to the reflection coming from a trabecular region of said bone region;
calculate a spectrum, for example by FFT, for each portion of said signal;
calculate an average spectrum of all the single spectra defined by the portions of said signal;
use this average spectrum as a reference spectrum.

### Claim 37 (depends on 36)

An apparatus (100) according to claim 36, wherein said computation means for computing said reference spectra is also configured to:
for each spectrum defined by a respective signal portion, calculate a correlation coefficient, for example the Pearson's correlation coefficient, between this spectrum of a respective signal portion and the mean spectrum;
among all the spectra defined by the portions of said signal, select the spectra for which the correlation coefficient with the average spectrum is larger than a minimum reference value, in particular the spectra for which the Pearson's correlation coefficient is higher than 0.900;
calculate a further average spectrum of the spectra that have a correlation coefficient higher than said minimum value;
for each spectrum defined by a respective signal portion, calculate a further correlation coefficient, for example the Pearson's coefficient, between this spectrum defined by a respective signal portion and the average spectrum of the spectra that have correlation coefficients higher than a minimum value;
among all the spectra defined by respective portions of signal, select the spectra that have in turn a correlation coefficient with the average spectrum of the spectra that have a correlation coefficient higher than the minimum that is in turn higher than this minimum value, in particular select the spectra that have the Pearson's coefficient r>0.900;
calculate a further average spectrum of the selected further average spectra;
repeat computing said new correlation coefficient, selecting said further spectra and computing the further correlation coefficient until a final average spectrum is obtained such that:
each residual spectrum that is included in the final average spectrum has a correlation coefficient with the final average spectrum larger than the minimum value, in particular it has a Pearson's correlation coefficient r>0.900;
each other spectra that is not included in the final average spectrum has the correlation coefficient with the final average spectrum lower than or the same value as the minimum value≦0.900.

### Claim 38 (depends on 36)

An apparatus (100) according to claim 36, wherein said computation means for computing said reference spectra is configured to generate a reference model for a vertebra, in particular a lumbar vertebra, and is also configured to:
carry out said calculation steps for said vertebra and for other three vertebrae, in particular three lumbar vertebrae, finally obtaining four final spectra, one for each of such vertebrae;
calculate a final vertebral average spectrum of the four final spectra.

### Claim 39 (depends on 20)

An apparatus (100) according to claim 20, characterised in that said nominal frequency of the emitted ultrasound pulses is set between 2 and 9 MHz, in particular it is selected among 3.5, 5 and 7.5 MHz.