# US 11,076,776 B2 · Apparatus and method for real-time tracking of bony structures

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- Number: US 11,076,776 B2
- Document ID: US11076776B2
- Status: Granted
- Kind: B2
- Application number: 16/274,039
- Filed: 2019-02-12
- Published: 2019-08-15
- Granted: 2021-08-03
- Earliest claimed: 2012-10-26
- Assignees: Varian Medical Systems Particle Therapy GmbH; Varian Medical Systems, Inc.
- Applicants: Varian Medical Systems; Varian Medical Systems Particle Therapy GmbH
- Inventors: John R. Adler, Jr.; Ralf Bruder; Floris Ernst; Achim Schweikard
- Web page: https://patentgrep.com/patent/US11076776B2

## CPC

- A61B 5/1079: {using optical or photographic means}
- A61B 5/0035: {adapted for acquisition of images from more than one imaging mode, e.g. combining MRI and optical tomography}
- A61B 5/0036: {including treatment, e.g., using an implantable medical device, ablating, ventilating}
- A61B 5/0064: {Body surface scanning}
- A61B 5/0075: {by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy (A61B5/0071 takes precedence)}
- A61B 5/1075: {for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer (A61B8/0858 takes precedence)}
- A61B 5/441: {Skin evaluation, e.g. for skin disorder diagnosis}
- A61B 5/4504: {Bones (A61B5/4547 takes precedence)}
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61B 5/4887: {Locating particular structures in or on the body}
- A61B 6/5247: {combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound}
- A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam}
- G16H 30/40: for processing medical images, e.g. editing
- G16H 40/63: for local operation
- G16H 50/50: for simulation or modelling of medical disorders
- A61B 5/442: {Evaluating skin mechanical properties, e.g. elasticity, hardness, texture, wrinkle assessment}
- A61B 5/72: {Signal processing specially adapted for physiological signals or for diagnostic purposes}
- A61B 6/032: {Transmission computed tomography [CT]}
- A61B 6/501: {for diagnosis of the head, e.g. neuroimaging or craniography}
- A61B 6/505: {for diagnosis of bone}
- A61B 2090/061: {for measuring dimensions, e.g. length}
- A61N 2005/1059: {using cameras imaging the patient}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)
- G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA

## Abstract

A method for measuring skin thickness. The method includes at a first 3D point on an outer surface of a patient, exposing the first point to near infrared (NIR) energy from an NIR source. The method includes measuring reflected energy emanating near the first 3D point, or beam incident point. The method includes determining a pattern of the reflected energy based on a distance from a center of the reflected energy, wherein the center is approximated by the first 3D point. The method includes determining a skin thickness measurement based on the pattern.

## Claims

### Claim 1

A system, comprising:
a processor; and
memory coupled to the processor, the memory having instructions stored therein that, when executed, cause the system to perform a method comprising:
receiving and measuring reflected energy from a patient at a detector device, the reflected energy from reflection of a beam of near infrared (NIR) energy by the patient's skin at a first point of the patient's skin;
generating a pattern of the reflected energy based on a distance from the first point;
determining a thickness measurement of the patient's skin at the first point based on the pattern;
repeating said receiving, said measuring, said generating, and said determining for a plurality of additional points on the outer surface of the patient's skin other than the first point, to determine a plurality of thickness measurements that includes the thickness measurement at the first point;
determining points of a bone surface of the patient using at least a subset of the thickness measurements;
determining a position of a target in the patient with respect to the bone surface; and
determining an alignment for a beam of radiation that aligns the beam of radiation with the target.

### Claim 2 (depends on 1)

The system of claim 1, wherein the NIR energy has a fixed wavelength.

### Claim 3 (depends on 1)

The system of claim 1, wherein the beam of NIR energy comprises multiple collinear laser beams comprising a combination of various wavelengths and various polarizations.

### Claim 4 (depends on 1)

The system of claim 1, wherein said generating a pattern comprises, for each point on the outer surface of the patient's skin including the first point:
defining a respective plurality of concentric rings around said each point;
determining a respective reflected photon accumulated count for each said respective plurality of concentric rings; and
plotting the respective photon accumulated count for each said respective plurality of concentric rings to generate the pattern for the each point.

### Claim 5 (depends on 4)

The system of claim 4, wherein said determining a thickness measurement comprises, for said each point:
comparing the pattern for said each point against a plurality of predefined patterns reflecting thicknesses of skin;
matching the pattern for said each point to a predefined pattern of the plurality of predefined patterns; and
assigning a thickness measurement associated with the predefined pattern to said each point.

### Claim 6 (depends on 1)

The system of claim 1, wherein said using at least a subset of the thickness measurements comprises:
generating a three-dimensional (3D) point cloud of the skin surface based on said repeating;
generating a 3D point cloud of the patient's skeletal anatomy using the points of the bone structure and the subset of the thickness measurements; and
registering the 3D point cloud of the patient's skeletal anatomy with a 3D positioning of the skeletal anatomy obtained from a base scan of the patient.

### Claim 7

A system, comprising:
a processor; and
memory coupled to the processor, the memory comprising program modules that are executable by the processor, the program modules configured to:
measure reflected energy received at a detector device, the reflected energy from reflection of a beam of near infrared (NIR) energy by points on a surface of a patient during a first scan of the patient with the beam of NIR energy;
for each of the points on the surface of the patient, determine a corresponding skin thickness based on a pattern of the reflected energy;
for said each of the points on the surface of the patient, compensate for the corresponding skin thickness to determine a skeletal position associated with and underlying said each of the points;
determine a position of skeletal anatomy of the patient derived from the skeletal positioning for said each of the points;
determine a position of a target in the patient with respect to the position of the skeletal anatomy; and
determine an alignment for a beam of radiation that aligns the beam of radiation with the target.

### Claim 8 (depends on 7)

The system of claim 7, wherein the program modules are further configured to, for said each of the points on the surface of the patient, subtract the corresponding skin thickness to determine the skeletal position corresponding to the point.

### Claim 9 (depends on 7)

The system of claim 7, wherein the program modules are further configured to obtain a relative position of the skeletal anatomy and a relative position of a target within the skeletal anatomy from a base scan performed prior to the first scan.

### Claim 10 (depends on 9)

The system of claim 9, wherein the program modules are further configured to register the position of the skeletal anatomy derived from the first scan and the position of the skeletal anatomy derived from the base scan to determine the relative position of the target within the skeletal anatomy.

### Claim 11 (depends on 10)

The system of claim 10, wherein the program modules are further configured to:
determine a first identifiable feature on the surface of the patient in the base scan, wherein the identifiable feature comprises an associated location on the skeletal anatomy derived from the base scan;
determine a second identifiable feature on the surface of the patient derived from the first scan, wherein the second identifiable feature comprises an associated location on the skeletal anatomy derived from the first scan;
match the first and second identifiable features based on common characteristics; and
register the position of the skeletal anatomy derived from the first scan and the position of the skeletal anatomy derived from the base scan using the alignment between the first and second identifiable features.

### Claim 12 (depends on 11)

The system of claim 11, wherein the program modules are further configured to determine the second identifiable feature based on related skin thicknesses or related patterns of reflected signals from points associated with the second identifiable feature.

### Claim 13 (depends on 11)

The system of claim 11, wherein the program modules are further configured to determine rotational alignment between the position of the skeletal anatomy derived from the first scan and the position of the skeletal anatomy derived from the base scan.

### Claim 14 (depends on 7)

The system of claim 7, wherein the program modules are further configured to, for said each of the points:
define a plurality of concentric rings around the point;
determine a reflected photon accumulated count for each of the concentric rings;
plot photon accumulated counts for each of the concentric rings to generate the pattern;
compare the pattern of against a plurality of predefined patterns reflecting thicknesses of skin;
match the pattern to a predefined pattern of the plurality of predefined patterns; and
assign a thickness measurement associated with the pattern to the point.

### Claim 15

A system, comprising:
a detector operable for receiving and measuring reflected energies, the reflected energies from reflection of a beam of near infrared (NIR) energy, from an NIR source, by a patient's skin at each point of a plurality of points on the patient's skin exposed to the beam by an optical scanner; and
a computer system coupled to the detector and operable for performing operations comprising:
determining patterns comprising a pattern of each reflected energy of the reflected energies based on a distance from a respective point of the points;
determining thickness measurements comprising a thickness measurement of the patient's skin at said each point of the points based on the pattern around said each point;
determining points of a bone surface of the patient using at least a subset of the thickness measurements; and
determining a position of a target in the patient with respect to the bone surface.

### Claim 16 (depends on 15)

The system of claim 15, wherein the detector is aligned with the beam's paths to capture the reflected energies around beam incident points, wherein the points on the outer surface of the patient's skin comprise the beam incident points.

### Claim 17 (depends on 15)

The system of claim 15, wherein the NIR energy has a fixed wavelength.

### Claim 18 (depends on 15)

The system of claim 15, wherein the operations further comprise:
defining a respective plurality of concentric rings around said each point;
determining a respective reflected photon accumulated count for each the respective plurality of concentric rings; and
plotting the respective photon accumulated count for each the respective plurality of concentric rings to generate the patterns.

### Claim 19 (depends on 18)

The system of claim 18, wherein the operations further comprise:
comparing the patterns against a plurality of predefined patterns reflecting thicknesses of skin;
matching each pattern of the patterns to a respective predefined pattern of the plurality of predefined patterns; and
assigning a thickness measurement associated with the respective predefined pattern to a respective point of the points.