U.S. patent application number 16/882801 was filed with the patent office on 2020-10-01 for minimally invasive collection probe and methods for the use thereof.
The applicant listed for this patent is Board of Regents, The University of Texas System. Invention is credited to Livia Schiavinato Eberlin, Noah Giese, Nitesh Katta, Thomas Milner, Jialing Zhang.
Application Number | 20200305723 16/882801 |
Document ID | / |
Family ID | 1000004943831 |
Filed Date | 2020-10-01 |
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United States Patent
Application |
20200305723 |
Kind Code |
A1 |
Eberlin; Livia Schiavinato ;
et al. |
October 1, 2020 |
MINIMALLY INVASIVE COLLECTION PROBE AND METHODS FOR THE USE
THEREOF
Abstract
Method and devices are provided for assessing tissue samples
from a plurality of tissue sites in a subject using molecular
analysis. In certain aspects, devices of the embodiments allow for
minimally invasive collection of liquid tissue samples and delivery
of the samples for mass spectrometry analysis.
Inventors: |
Eberlin; Livia Schiavinato;
(Austin, TX) ; Milner; Thomas; (Austin, TX)
; Zhang; Jialing; (Austin, TX) ; Giese; Noah;
(Austin, TX) ; Katta; Nitesh; (Austin,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Board of Regents, The University of Texas System |
Austin |
TX |
US |
|
|
Family ID: |
1000004943831 |
Appl. No.: |
16/882801 |
Filed: |
May 26, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2018/062625 |
Nov 27, 2018 |
|
|
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16882801 |
|
|
|
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62591179 |
Nov 27, 2017 |
|
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62640385 |
Mar 8, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 33/4833 20130101;
A61B 2090/395 20160201; A61B 5/0075 20130101; H01J 49/0431
20130101; A61B 10/06 20130101; A61B 1/3132 20130101; A61B 34/30
20160201; A61M 25/0026 20130101; A61B 2090/3983 20160201; A61B
17/34 20130101; H01J 49/165 20130101; A61B 10/02 20130101 |
International
Class: |
A61B 5/00 20060101
A61B005/00; G01N 33/483 20060101 G01N033/483; H01J 49/04 20060101
H01J049/04; H01J 49/16 20060101 H01J049/16; A61B 1/313 20060101
A61B001/313; A61B 17/34 20060101 A61B017/34; A61B 10/02 20060101
A61B010/02; A61M 25/00 20060101 A61M025/00; A61B 34/30 20060101
A61B034/30 |
Goverment Interests
[0002] This invention was made with government support under Grant
No. R00 CA190783 awarded by the National Institutes of Health. The
government has certain rights in the invention.
Claims
1. An apparatus comprising: a chamber comprising a solvent; a mass
spectrometer; a probe comprising a reservoir, a first conduit, a
second conduit and a third conduit, wherein: the probe is, or is
comprised in, the cannula of a surgical instrument; the first
conduit is in fluid communication with the chamber; the second
conduit is in fluid communication with gas supply; and the third
conduit is in fluid communication with the mass spectrometer.
2. The apparatus of claim 1, wherein the surgical instrument is a
laparoscope.
3. The apparatus of claim 1, wherein the surgical instrument is a
trocar needle.
4. The apparatus of claim 1, wherein the surgical instrument is a
biopsy guide.
5. The apparatus of claim 1, wherein the surgical instrument is a
multiple-lumen catheter.
6. The apparatus of claim 1, wherein the surgical instrument is
robotic.
7. The apparatus of claim 1, wherein the reservoir is a space
formed in said first, second or third conduits.
8. The apparatus of claim 7, wherein the reservoir is a space
formed in said first conduit.
9. The apparatus of claim 1, wherein the reservoir comprises from
0.01 to 1.0 ml of fluid.
10. The apparatus of claim 1, wherein the surgical instrument
comprises a fin that can be gripped.
11. The apparatus of claim 1, further comprising a fourth conduit,
wherein: the first conduit, the second conduit and the third
conduit are each in fluid communication with the fourth
conduit.
12. The apparatus of claim 11, further comprising: a first valve
configured to control flow between the first conduit and the fourth
conduit; and a second valve configured to control flow between the
second conduit and the fourth conduit.
13. The apparatus of claim 12, further comprising a third first
valve configured to control flow between the third conduit and the
fourth conduit.
14. The apparatus of claim 1, wherein the gas supply provides air
from an atmosphere of the probe, nitrogen or carbon dioxide to the
probe.
15. The apparatus of claim 1, wherein the probe comprises a
tracking device or dye to track a location of the probe.
16. The apparatus of claim 1, further comprising a control system
configured to control: a solvent flow from the chamber through the
first conduit; and a sample flow through the third conduit to the
mass spectrometer.
17. The apparatus of claim 1, wherein the mass spectrometer is in
electronic communication with a computer that can provide sample
analysis, and the computer provides a visual or auditory read-out
of the sample analysis.
18. The apparatus of claim 1, further comprising a waste container
in fluid communication with the third conduit.
19. The apparatus of claim 1, further comprising a pump in fluid
communication with the third conduit.
20. The apparatus of claim 19, wherein the pump is configured to
increase the velocity of the contents within the third conduit.
21. The apparatus of claim 1, further comprising a heating element
coupled to the third conduit.
22. The apparatus of claim 21, wherein the heating element is a
heating wire.
23. The apparatus of claim 1, further comprising an ionization
device in fluid communication with the third conduit.
24. The apparatus of claim 23, wherein the ionization device is an
electrospray ionization (ESI) device.
25. The apparatus of claim 23, wherein the ionization device is an
atmospheric pressure chemical ionization (APCI) device.
26. The apparatus of claim 23, wherein the ionization device is to
form a spray proximal to an inlet for mass spectrometer.
27. The apparatus of claim 1, wherein the third conduit is not
directly coupled to the mass spectrometer.
28. The apparatus of claim 1, further comprising a venturi device
in fluid communication with the third conduit.
29. The apparatus of claim 1, wherein the apparatus does not
include device for application of ultrasonic or vibrational
energy.
30. A method for assessing tissue samples from a subject
comprising: (a) applying a fixed or discrete volume of a solvent to
a tissue site in the subject through the cannula of a surgical
instrument; (b) collecting the applied solvent to obtain a liquid
sample; and (c) subjecting the sample to mass spectrometry
analysis.
Description
[0001] This application is a continuation of International
Application No. PCT/US2018/062625 filed Nov. 27, 2018, which claims
the benefit of U.S. Provisional Patent Application No. 62/591,179,
filed Nov. 27, 2017 and 62/640,385, filed Mar. 8, 2018, each of
which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0003] The present invention relates generally to the field of
medicine, molecular biology and biochemistry. More particularly, it
concerns methods and devices for assessment of tissue samples using
mass spectrometry.
2. Description of Related Art
[0004] Clinical diagnosis is commonly performed through the
evaluation of tissue samples pre-operatively, intra-operative, and
post-operatively, at several other stages of the patient's
treatment process. Tissue evaluation is very critical in the
diagnosis and management of cancer patients. Intra-operative
pathologic assessment of excised tissues, for example, is routinely
performed for diagnosis and surgical margin evaluation in a variety
of cancer surgeries. The resected tissue specimens are sent to a
nearby room, often called the "frozen room", for tissue
preparation, staining, and evaluation. The tissue specimen is
frozen, sectioned, stained, and interrogated using light microscopy
by an expert pathologist who carefully evaluates if the surgical
margins contain cancer cells (positive margin) or not (negative
margin). While intraoperative frozen section analysis has been
performed in clinical practice for decades, it presents many
challenges. Freezing artifacts occur during tissue processing and
interfere with tissue structure and cell morphology, thus
complicating pathologic interpretation, causing the analysis to be
unreliable and subjective. Moreover, certain tumor cells are very
difficult to recognize due to their atypical pattern of growth and
shape. Molecular approaches could provide highly accurate and
potentially real-time assessments of tissue samples. Coupling the
molecular approaches with minimally invasive surgical techniques,
or non-invasive techniques could provide a highly accurate, yet low
trauma, way to assess and diagnose tissue and surgical samples.
However, to date, adequate devices or methodologies have not been
developed that provide effective molecular assessment of tissue
samples.
SUMMARY OF THE INVENTION
[0005] In a first embodiment there is provided a method for
obtaining a mass spectrometry profile comprising using a probe to
apply a fixed or discrete volume of a solvent to an assay site
(e.g., a tissue site); using the probe to collect the applied
solvent to obtain a liquid sample; and subjecting the liquid sample
to mass spectrometry analysis. In further embodiment a method is
provided for assessing tissue samples comprising obtaining a
plurality of liquid samples from a plurality of tissue sites in a
subject and subjecting the plurality of liquid samples to mass
spectrometry.
[0006] Still a further embodiment provides an apparatus for
obtaining or producing samples (e.g., from tissues) for mass
spectrometry analysis, the apparatus comprising: a chamber
comprising a solvent; a gas supply (e.g., a pressurized gas
supply); a mass spectrometer; a probe comprising a reservoir, a
first conduit, a second conduit and a third conduit, wherein: the
reservoir is in fluid communication with the first conduit, the
second conduit and the third conduit; the first (solvent) conduit
is in fluid communication with the chamber; the second (gas)
conduit is in fluid communication with a gas supply; and the third
(collection) conduit is in fluid communication with the mass
spectrometer. In some aspects, the gas supply can be a pressurized
gas supply. In some aspects, the probe is, or is comprised in, the
cannula of a surgical instrument. In further aspects, the surgical
instrument may be a laparoscope, trocar needle, biopsy guide, or
multiple-lumen catheter. In certain aspects, the surgical
instrument manually operated. In other aspects, the surgical
instrument is robotic.
[0007] In yet still further aspects, the probe comprises a distal
probe end and the distal probe end comprises a shutter that can be
closed to prevent fluid communication outside of the probe. In some
aspects, the shutter is a balloon that can be inflated to prevent
fluid communication outside of the probe. In certain aspects, the
balloon can be inflated with a gas or a liquid. In specific
aspects, the shutter is a door that can be closed to prevent fluid
communication outside of the probe. In other aspects, the shutter
is configured such that is can be opened and closed multiple times.
The shutter may be controlled manually or robotically. In several
aspects, the first, second or third conduit is more than 1 meter in
length. In additional aspects, the first conduit is in fluid
communication with the third conduit; and the second conduit is in
fluid communication with the third conduit. In further specific
aspects, the first conduit is disposed within the third conduit. In
other aspects, the second conduit is disposed within the third
conduit.
[0008] In certain specific aspects, the first conduit and the
second conduit are disposed within the third conduit. In further
aspects, the first conduit comprises a first distal end; the second
conduit comprises a second distal end; the third conduit comprises
a third distal end; and the first distal end and the second distal
end are located within the third conduit. In some aspects, the
third distal end is located within the probe. In another aspect,
the first distal end is located a first distance from the distal
probe end; the second distal end is located a second distance from
the distal probe end; the third distal end is located a third
distance from the distal probe end; the first distance is greater
than the third distance; and the second distance is greater than
the third distance. In an additional aspect, the first distal end
and the second distal end terminate proximal to a sample collection
region of the third conduit. In certain aspects, the sample
collection region is located between the first and second distal
ends and the third distal end. In further specific aspects, the
sample collection region is in fluid communication with the mass
spectrometer via the third conduit. In some additional aspects, the
apparatus further comprises a control system configured to control;
a solvent flow from the chamber through the first conduit to the
first distal end; a gas flow from the gas supply through the second
conduit to the second distal end; and a sample flow through the
third conduit to the mass spectrometer.
[0009] In yet still further aspects, the apparatus may additionally
comprise a fourth conduit, wherein the first conduit, the second
conduit and the third conduit are each in fluid communication with
the fourth conduit. In some aspects, the apparatus may further
comprise a first valve configured to control flow between the first
conduit and the fourth conduit; and a second valve configured to
control flow between the second conduit and the fourth conduit. In
an additional aspect, the apparatus may further comprise a third
first valve configured to control flow between the third conduit
and the fourth conduit. In still additional aspects, the gas supply
provides air, nitrogen or carbon dioxide to the probe. In certain
aspects, the gas supply is a pressurized gas supply that provides a
gas to the probe at a pressure between 0.1 psig and 5.0 psig. In
other aspects, the pressurized gas supply provides a gas to the
probe at a pressure between 0.5 psig and 2.5 psig. In specific
aspects, the pressurized gas supply provides a gas to the probe at
a pressure less than 100 psig. In some aspects, the gas for use in
an apparatus of the embodiments may be provided by a pressurized
gas supply. In further aspects, the gas can be pumped into an
apparatus. Likewise, in some aspects, the gas can be pulled through
an apparatus by use of a vacuum. In some aspects, the vacuum is
provided by the mass spectrometer inlet. In further aspects, an
additional vacuum system is employed. In certain aspects wherein
the apparatus is used for a laparoscopic procedure, the gas supply
is preferably a pressurized gas supply.
[0010] In some aspects, the solvent comprises water. In more
specific aspects, the solvent comprises sterile water. In several
aspects, the solvent comprises ethanol. In certain specific
aspects, the solvent comprises an aqueous mixture including from 1
to 25% ethanol.
[0011] In still further aspects, the probe comprises a tracking
device or dye to track a location of the probe. In additional
aspects, the apparatus may further comprise a control system
configured to control: a solvent flow from the chamber through the
first conduit; a gas flow from the gas supply through the second
conduit; and a sample flow through the third conduit to the mass
spectrometer. In some aspects, the control system is configured to:
control the solvent flow at a flow rate between 200 and 5000
microliters per minute for a period of time between 1 and 3
seconds; control the gas flow at a flow rate between 0.1 and 15
psig for a period of time between 5 and 50 seconds; and/or control
the sample flow for a period of time between 5 and 50 seconds. In
certain aspects, the control system comprises programming that
initiates solvent flow.
[0012] In additional aspects, the mass spectrometer is in
electronic communication with a computer that can provide sample
analysis. In some aspects, the computer provides a visual or
auditory read-out of the sample analysis. In further aspects, the
apparatus may additionally comprise a waste container in fluid
communication with the third conduit. In certain aspects, the
apparatus may further comprise a valve configured to diverge a
fluid from the third conduit to the waste container. In other
aspects, the apparatus may further comprise a pump configured to
remove contents of the waste container. In still further aspects,
the apparatus may comprise a pump in fluid communication with the
third conduit. In some aspects, the pump is configured to increase
the velocity of the contents within the third conduit. In several
aspects, the apparatus may further comprise a heating element
coupled to the third conduit. In a specific aspect, the heating
element is a heating wire.
[0013] In yet still further aspects, the apparatus may comprise an
ionization device in fluid communication with the third conduit. In
certain aspects, the ionization device is an electrospray
ionization (ESI) device. In other aspects, the ionization device is
an atmospheric pressure chemical ionization (APCI) device. In some
aspects, the ionization device is to form a spray proximal to an
inlet for mass spectrometer. In several aspects, the third conduit
is not directly coupled to the mass spectrometer. In specific
aspects, the apparatus may further comprise a venturi device in
fluid communication with the third conduit. In certain aspects, the
apparatus does not include device for application of ultrasonic or
vibrational energy.
[0014] In a further embodiment there is provided a method for
assessing tissue samples from a subject comprising (a) applying a
fixed or discrete volume of a solvent to a tissue site in the
subject through the cannula of a surgical instrument; (b)
collecting the applied solvent to obtain a liquid sample; and (c)
subjecting the sample to mass spectrometry analysis. In some
aspects, the fixed or discrete volume of a solvent is not applied
as a spray. In other aspects, the fixed or discrete volume of a
solvent is applied as a droplet. In certain aspects, the surgical
instrument is a laparoscope, trocar needle, or biopsy guide. The
surgical instrument may be manually operated or robotic.
[0015] In further aspects, the cannulas comprised in a probe having
a distal probe end and the distal probe end comprises a shutter
that can be closed to prevent fluid from passing out of the cannula
of the probe. In some aspects, the shutter is a balloon that can be
inflated to prevent fluid communication outside of the probe. In
specific aspects, the balloon can be inflated with a gas. In
certain aspects, the shutter is a door than can be closed to
prevent fluid communication outside of the probe. For example, the
shutter can be an iris diaphragm, a mechanical closure, gate, or
tapenade. In some aspects, the shutter can be manually controlled
or may be automated. For example, in some aspects, the shutter may
be on a timer that activates the shutter after solvent has been in
contact with the tissue site for a predetermined time period (e.g.,
at least about 1, 2, or 3 seconds). In still further aspects, the
fixed or discrete volume of a solvent is applied at using a
pressure of less than 100 psig. In other aspects, the fixed or
discrete volume of a solvent is applied at using a pressure of less
than 10 psig. In some aspects, the fixed or discrete volume of a
solvent is applied using a mechanical pump to move the solvent
through a solvent conduit. In certain aspects, collecting the
applied solvent comprises applying a negative pressure to pull the
sample into a collection conduit and/or applying a gas pressure to
push the sample into a collection conduit. In other aspects,
collecting the applied solvent comprises applying a negative
pressure to pull the sample into a collection conduit and applying
a positive pressure to push the sample into a collection conduit.
In certain specific aspects, the solvent is applied through a
solvent conduit that is separate from the collection conduit. In
further aspects, the gas pressure is applied through a gas conduit
that is separate from the solvent conduit and the collection
conduit. In still other aspects, applying a gas pressure to push
the sample into a collection conduit comprises applying a pressure
of less than 100 psig.
[0016] In yet still further aspects, the method produces no
detectable physical damage to the tissue. In some aspects, the
method does not involve application of ultrasonic or vibrational
energy to the tissue. In certain aspects, the solvent may be
sterile. In specific aspects, the solvent may be a pharmaceutically
acceptable formulation, and further an aqueous solution, and still
further sterile water. In further specific aspects, the solvent
consists essentially of water. In other aspects, the solvent
comprises from about 1 to 20% of an alcohol. In some aspects, the
alcohol comprises ethanol. In still additional aspects, the
discrete volume of solvent is between about 0.1 and 100 .mu.L. In
certain aspects, the discrete volume of solvent is between about 1
and 50 .mu.L. In further aspects, collecting the applied solvent is
between 0.1 and 30 seconds after the applying step. In another
aspect, collecting the applied solvent is between 1 and 10 seconds
after the applying step. In some aspects, the tissue site in an
internal tissue site that is being surgically assessed.
[0017] In still further aspects, the method additionally comprises
collecting a plurality liquid samples from a plurality of tissue
sites. In certain aspects, the liquid samples are collected with a
probe. In specific aspects, the probe is washed between collection
of the different samples. In some aspects, the probe is disposable
and is changed between collection of the different samples. In
another aspect, the probe comprises a collection tip and further
comprising ejecting the collection tip from the probe after the
liquid samples are collected. In further aspects, the plurality of
tissue sites comprises 2, 3, 4, 5, 6, 7, 8, 9 or 10 tissues sites.
In an additional aspect, the plurality of tissue sites surrounds a
section of tissue that has been surgically resected. In some
aspects, the resected tissue is a tumor. In other aspects, the
method is further defined as an intraoperative or post operative
method. In certain aspects, the mass spectrometry comprises ambient
ionization MS. In certain specific aspects, subjecting the sample
to mass spectrometry analysis comprises determining a profile
corresponding to the tissue site. In a further aspect, the method
comprises comparing the profile to a reference profile to identify
tissue sites that include diseased tissue. Still a further aspect
comprises resecting tissue sites that are identified to include
diseased tissue. In another aspect, the method is performed using
an apparatus in accordance with the embodiments and aspects
described above.
[0018] In further aspects, the mass spectrometer is in
communication with a computer that provides a sample analysis. In
certain aspects, the results of each sample analysis are provided
by a visual or auditory output from the computer. For example, the
results of each sample analysis by the computer can be indicated by
a differently colored light that is illuminated or by a different
frequency of sound produced. In some aspects, the mass spectrometer
is a mobile the mass spectrometer. In further aspects, the mass
spectrometer can comprise an uninterruptable power supply (e.g., a
battery power supply). In still further aspects, the mass
spectrometer comprises an inlet that may be closed to keep
instrument vacuum. In yet further aspects, the mass spectrometer is
separated from the probe by a mesh filter (e.g., to block
contamination).
[0019] In some aspects, the reservoir is configured to form a
droplet of the solvent. In certain aspects, the pressurized gas
supply provides a gas to the probe at a pressure between 0.1 psig
and 5.0 psig. In further aspects, the pressurized gas supply
provides a gas to the probe at a pressure between 0.5 psig and 2.5
psig. In several aspects, the pressurized gas supply provides air
to the probe. In other aspects, the pressurized gas supply provides
an inert gas such as nitrogen or carbon dioxide to the probe. In
some aspects, a gas supply for use according to the embodiments is
at atmospheric pressure. For example, the conduit for delivery of
gas may be supplied by the atmosphere around the apparatus.
[0020] In additional aspects, the apparatus further comprises a
pump configured to transfer the solvent from the chamber to the
first conduit. In further aspects, the apparatus may comprise a
first valve configured to control a flow from the third conduit to
the mass spectrometer. In some aspects, the third conduit is under
a vacuum when the first valve is in the open position. In other
aspects, the apparatus may comprise a second valve configured to
control a flow of gas (e.g., pressurized gas) through the second
conduit.
[0021] In certain aspects, the solvent may comprise water and/or
ethanol. In several aspects, the probe is formed from
polydimethylsiloxane (PDMS) and/or polytetrafluoroethylene (PTFE).
In some aspects, the probe is disposable. In particular aspects,
the probe may include a collection tip that is ejectable (e.g.
capable of being ejected from the probe). In further aspects, the
probe comprises a tracking device configured to track a location of
the probe. In some aspects, the reservoir has a volume between 1
microliter and 500 microliters, between about 1 microliter and 100
microliters or between about 2 microliters and 50 microliters. In
additional aspects, the reservoir has a volume between 5.0
microliters and 20 microliters.
[0022] In still further aspects, the apparatus may additionally
comprise a control system configured to control: a solvent flow
(e.g., flow of a fixed or discrete volume of solvent) from the
chamber through the first conduit to the reservoir; a gas flow from
the gas supply through the second conduit to the reservoir; and a
sample flow from the reservoir through the third conduit to the
mass spectrometer. In some aspects, the control system is
configured to: control the solvent flow at a flow rate between 100
and 5000 microliters per minute (e.g., between 200 and 400
microliters per minute) for a period of time between 1 and 3
seconds; control the gas flow at a flow rate between 1 and 10 psig
for a period of time between 10 and 15 seconds; and control the
sample flow for a period of time between 10 and 15 seconds. For
example, in some aspects, the control system comprises a trigger or
button to initiate solvent flow. In further aspects, the control
system comprises a pedal (i.e., that can be operated by foot
action) to initiate solvent flow. A skilled artisan will recognize
that the lengths of the first and/or second conduit may be adjusted
to fit the particular use of the system. In yet further aspects,
the control system is configured to control: a solvent flow (e.g.,
flow rate for a fixed period of time) from the chamber through the
first conduit to the reservoir. In further aspects, an apparatus of
the embodiments does not include a device for producing ultrasonic
or vibrational energy (e.g., in sufficient amounts to disrupt
tissues).
[0023] A further embodiment provided a method for assessing tissue
samples from a subject comprising applying a solvent to a tissue
site on the subject, collecting the applied solvent to obtain a
liquid sample, and subjecting the sample to mass spectrometry
analysis. In certain aspects, the solvent may be sterile. In some
aspects, the solvent is pharmaceutically acceptable formulation. In
specific aspects, the solvent is an aqueous solution. For example,
the solvent may be sterile water or consist essentially of water.
In other aspects, the solvent may comprise from about 1% to 5%,
10%, 15%, 20%, 25% or 30% of an alcohol. In some aspects, the
solvent comprises 0.1% to 20% of an alcohol, 1% to 10% of an
alcohol or 1% to 5% 1% to 10% of an alcohol (e.g., ethanol). In
some cases, the alcohol may be ethanol.
[0024] In some aspects, applying the solvent to the tissue
comprises applying a discrete volume of solvent to the tissue site.
In some aspect, the solvent is applied in a single droplet. In a
further aspect, the solvent is applied in a discrete number of
droplets from 1 to 10. In some embodiments, the solvent is applied
to the sample from the reservoir via a channel independent of the
gas. In further embodiments, the solvent is applied to the sample
under low pressure. For example, in some aspects, the solvent is
applied by a mechanical pump such that solvent is applied to the
tissue site (e.g., moved into a reservoir where it is in contact
with the tissue site) with minimal force thereby exerting minimal
pressure (and producing minimal damage) at a tissue site. The low
pressure may be less than 100 psig, less than 90 psig, less than 80
psig, less than 70 psig, less than 60 psig, less than 50 psig, or
less than 25 psig. In some embodiments, the low pressure is from
about 0.1 psig to about 100 psig, from about 0.5 psig to about 50
psig, from about 0.5 psig to about 25 psig, or from about 0.1 psig
to about 10 psig. In particular aspects, the discrete volume of
solvent is between about 0.1 and 100 or between about 1 and 50
.mu.L. In further aspects, collecting the applied solvent is
between 0.1 and 30 seconds after the applying step. In a specific
aspect, collecting the applied solvent is between 1 and 10 seconds
after the applying step (e.g., at least 1, 2, 4, 5, 6, 7, 8 or 9
seconds). In further aspects, a method of the embodiments does not
involve application of ultrasonic or vibrational energy to a sample
or tissue. In some aspects, the tissue site in an internal tissue
site that is being surgically assessed.
[0025] In a further aspect, a method of the embodiments comprises
applying a fixed or discrete volume of a solvent (e.g., using
mechanical pump) to a tissue site through a solvent conduit. In
some aspects, the fixed or discrete volume of a solvent is moved
through a solvent conduit into a reservoir where it is in direct
contact with a tissue site (e.g., for 0.5-5.0 seconds). In further
aspects, collecting the applied solvent comprises applying a
negative pressure to pull the sample into a collection conduit
and/or applying a gas pressure to push the sample into a collection
conduit. In some aspects, the solvent is applied through a solvent
conduit that is separate from the collection conduit. In further
aspects, wherein a gas pressure is applied to push the sample into
the collection conduit the gas pressure is applied through a gas
conduit that is separate from the solvent conduit and the
collection conduit. In certain aspects, wherein a gas pressure is
applied to push the sample into the collection conduit, the applied
gas pressure of less than 100 psig. For example, the gas pressure
is preferably less than 10 psig, such as 0.1 to 5 psig. In still
further aspects, a method of the embodiments is defined as
producing no detectable physical damage to the tissue being
assessed.
[0026] In still further aspects, the method may additionally
comprise collecting a plurality liquid samples from a plurality of
tissue sites. In some cases, the device (e.g., the probe) used to
collect the samples is washed between each sample collection. In
other aspects, a device used to collect the samples includes a
disposable collection tip (probe) that can be changed between each
sample collection. In particular aspects, the collection tip may be
ejectable (e.g. capable of being ejected from the device). In
certain aspects, the plurality of tissue sites comprise 2, 3, 4, 5,
6, 7, 8, 9, 10 or more tissues sites in vivo. In another aspect,
the plurality of tissue sites surround a section of tissue that has
been surgically resected (e.g., ex vivo). In a specific aspect, the
resected tissue is a tumor. In some aspects, the method may be
defined as an intraoperative method.
[0027] A further embodiment provides a method of identifying a
sampled tissue site and a method to communicate location of the
site to the device (probe) operator. Identification of a sampled
tissue site allows the operator to access the molecular information
recorded at sampled tissue site at a time after sampling molecules
collected from the tissue. At least three types of identification
approaches are recognized. In the first approach, an exogenous
material is attached to the sampled tissue site that identifies the
sampled molecular information. In a second approach, the device
(probe) is equipped with a tracking sensor/emitter that allows
recording the location of the probe (device) and communication to
an imaging device when the molecular information is sampled. In a
third approach, the tissue region is modified so that the site may
be easily identified after harvesting tissue molecules. In the
first approach, materials that may be attached to the sampled
tissue site include, for example, a suture, a surgical clip, a
biocompatible polymer that adheres to the tissue, or an RFID chip
that is attached to a magnetic bead that allows easy reading and
removal. In the second approach type, the probe may contain an RF
emitter that is part of a RF surgical tracking system, an
ultrasound emitter or reflector that is part of an intra-operative
US imaging system. In this second approach, when the operator
initiates collection of tissue molecules, the tracking system
records location of the probe in the associated imaging system
(e.g., RF, US, CT, MRI) that may be in communication with the
device. The operator may then identify any of the sampled tissue
sites at a later time by referring to the recorded image(s) that
can indicate the location of sampled sites to the operator. In the
third approach, the tissue is modified. In this third approach, a
laser source in communication with the probe may be used to ablate
or coagulate a pattern into the tissue that identifies the sampled
site. Any of these three approaches may be combined. For example,
approach 1, 2 and 3 could be combined wherein an exogenous material
is attached to the tissue site after harvesting tissue molecules
and a laser patterns the exogenous tissue while an RF sensor
records location of the harvest location and communicates to the
imaging device.
[0028] In yet still further aspects, the mass spectrometry
comprises ambient ionization MS. As disclosed herein a probe in
contact with a tissue site can be in fluid communication with the
MS via a conduit. In some aspects, conduit between the probe and
tissue site is less than about 10 m, 8 m, 6 m or 4 m from MS. In
further aspects, the conduit is between about 0.5, 1.0, 1.5, 2.0,
2.5, 3.0 and 4.0 m in length. In several aspects, subjecting the
sample to mass spectrometry analysis may comprise determining a
profile corresponding to the tissue site. In another aspect, the
method may additionally comprise comparing the profile to a
reference profile to identify tissue sites that include diseased
tissue. In other aspects, the method also comprises resecting
tissue sites that are identified to include diseased tissue. In
some aspects, the method is performed using an apparatus in
accordance with any of the embodiments and aspects described
above.
[0029] In a further embodiment, the invention provides an ex vivo
method for assessing tissue samples comprising obtaining a
plurality of liquid samples from a plurality of tissue sites in a
subject, subjecting the plurality of liquid samples to mass
spectrometry to obtain a plurality of profiles corresponding to the
tissue sites, and comparing the plurality of profiles to reference
profiles to identify tissue sites that include diseased tissue. In
certain aspects, the liquid samples are comprised in a solvent. In
further aspects, the diseased tissues comprise cancer cells.
[0030] In some aspects of the embodiments, the diseased tissue
sites for assessment by methods and devices of the embodiments
comprise (or are suspected of comprising) cancer cells. Cancer
cells that may be assessed according to the embodiments include but
are not limited to cells or tumor tissues from a thyroid,
parathyroid, lymph node, bladder, blood, bone, bone marrow, brain,
breast, colon, esophagus, gastrointestine, gum, head, kidney,
liver, lung, nasopharynx, neck, ovary, pancreas, prostate, skin,
stomach, testis, tongue, or uterus (or tissues surrounding such
tumors). In some aspects, the cancer may be a neoplasm, malignant;
carcinoma; carcinoma, undifferentiated; giant and spindle cell
carcinoma; small cell carcinoma; papillary carcinoma; squamous cell
carcinoma; lymphoepithelial carcinoma; basal cell carcinoma;
pilomatrix carcinoma; transitional cell carcinoma; papillary
transitional cell carcinoma; adenocarcinoma; gastrinoma, malignant;
cholangiocarcinoma; hepatocellular carcinoma; combined
hepatocellular carcinoma and cholangiocarcinoma; trabecular
adenocarcinoma; adenoid cystic carcinoma; adenocarcinoma in
adenomatous polyp; adenocarcinoma, familial polyposis coli; solid
carcinoma; carcinoid tumor, malignant; branchiolo-alveolar
adenocarcinoma; papillary adenocarcinoma; chromophobe carcinoma;
acidophil carcinoma; oxyphilic adenocarcinoma; basophil carcinoma;
clear cell adenocarcinoma; granular cell carcinoma; follicular
adenocarcinoma; papillary and follicular adenocarcinoma;
nonencapsulating sclerosing carcinoma; adrenal cortical carcinoma;
endometroid carcinoma; skin appendage carcinoma; apocrine
adenocarcinoma; sebaceous adenocarcinoma; ceruminous
adenocarcinoma; mucoepidermoid carcinoma; cystadenocarcinoma;
papillary cystadenocarcinoma; papillary serous cystadenocarcinoma;
mucinous cystadenocarcinoma; mucinous adenocarcinoma; signet ring
cell carcinoma; infiltrating duct carcinoma; medullary carcinoma;
lobular carcinoma; inflammatory carcinoma; paget's disease,
mammary; acinar cell carcinoma; adenosquamous carcinoma;
adenocarcinoma w/squamous metaplasia; thymoma, malignant; ovarian
stromal tumor, malignant; thecoma, malignant; granulosa cell tumor,
malignant; androblastoma, malignant; sertoli cell carcinoma; leydig
cell tumor, malignant; lipid cell tumor, malignant; paraganglioma,
malignant; extra-mammary paraganglioma, malignant;
pheochromocytoma; glomangiosarcoma; malignant melanoma; amelanotic
melanoma; superficial spreading melanoma; malig melanoma in giant
pigmented nevus; epithelioid cell melanoma; blue nevus, malignant;
sarcoma; fibrosarcoma; fibrous histiocytoma, malignant;
myxosarcoma; liposarcoma; leiomyosarcoma; rhabdomyosarcoma;
embryonal rhabdomyosarcoma; alveolar rhabdomyosarcoma; stromal
sarcoma; mixed tumor, malignant; mullerian mixed tumor;
nephroblastoma; hepatoblastoma; carcinosarcoma; mesenchymoma,
malignant; brenner tumor, malignant; phyllodes tumor, malignant;
synovial sarcoma; mesothelioma, malignant; dysgerminoma; embryonal
carcinoma; teratoma, malignant; struma ovarii, malignant;
choriocarcinoma; mesonephroma, malignant; hemangiosarcoma;
hemangioendothelioma, malignant; kaposi's sarcoma;
hemangiopericytoma, malignant; lymphangiosarcoma; osteosarcoma;
juxtacortical osteosarcoma; chondrosarcoma; chondroblastoma,
malignant; mesenchymal chondrosarcoma; giant cell tumor of bone;
ewing's sarcoma; odontogenic tumor, malignant; ameloblastic
odontosarcoma; ameloblastoma, malignant; ameloblastic fibrosarcoma;
pinealoma, malignant; chordoma; glioma, malignant; ependymoma;
astrocytoma; protoplasmic astrocytoma; fibrillary astrocytoma;
astroblastoma; glioblastoma; oligodendroglioma;
oligodendroblastoma; primitive neuroectodermal; cerebellar sarcoma;
ganglioneuroblastoma; neuroblastoma; retinoblastoma; olfactory
neurogenic tumor; meningioma, malignant; neurofibrosarcoma;
neurilemmoma, malignant; granular cell tumor, malignant; malignant
lymphoma; hodgkin's disease; hodgkin's; or paragranuloma. In
further aspects the cancer is a thyroid cancer, brain cancer (e.g.,
a glioma), a prostate cancer, a breast cancer (e.g., a triple
negative breast cancer), a pancreatic cancer (e.g., a pancreatic
ductal adenocarcinoma), acute myeloid leukemia (AML), melanoma,
renal cell cancer or a cancer that has metastasized to a lymph
node.
[0031] In still a further embodiment there is provided a method for
characterizing a material comprising (a) applying a fixed or
discrete volume of a solvent to the material; (b) collecting the
applied solvent to obtain a liquid sample; and (c) subjecting the
sample to mass spectrometry analysis to provide a mass spectrometry
profile that characterizes the material. In some aspects, the
material is commodity product and characterizing the material
comprises identifying the material. For example, the commodity
product can be food, such as a meat, fish, fungus, vegetable or
fruit. Thus, in some aspects, characterizing the material comprises
identifying the type of meat or fish the material is composed of.
In the case where the material is a meat the method can comprise
identifying the meat as, for example, lamb, deer, moose, chicken,
turkey, sheep, dog, cat, horse, pork, beef, buffalo or goat. In
further aspects, the method can be used to identify a meat as meat
from a grass fed or grain fed animal. In the case where the
material is a fish the method can comprise identifying the fish as,
for example, tuna, salmon, cod, trout, halibut or sea bass. In
further aspects, the method can be used to identify a fish as from
a farm-raised or wild caught fish. In still further aspects, the
fish can be a shell fish. In still further aspects, methods of the
embodiments may be used to identify the region of origin for the
food product such a fish or meat. In certain aspects, a method of
characterizing a material is carried-out using an apparatus as
described herein. For example the apparatus can comprise apparatus
comprising: a chamber comprising a solvent; a gas supply (e.g. a
pressurized gas supply); a mass spectrometer; and a probe
comprising a reservoir, a first conduit, a second conduit and a
third conduit, wherein: the first conduit is in fluid communication
with the chamber; the second conduit is in fluid communication with
gas supply; and the third conduit is in fluid communication with
the mass spectrometer.
[0032] In a further embodiment there is provided a method for
characterizing a material comprising (a) applying a fixed or
discrete volume of a solvent to the material; (b) collecting the
applied solvent to obtain a liquid sample; and (c) subjecting the
sample to mass spectrometry analysis to provide a mass spectrometry
profile that characterizes the material. In some aspects,
characterizing the material comprises detecting and/or quantifying
the amount of a compound in the material. For example, the compound
may be small molecule, such as pharmaceutical, a drug (e.g., a pain
killer), a pesticide (e.g., an insecticide), a herbicide, an
antibiotic or a toxin. For example, in some aspects, the a drug can
be adderall, cocaine, codeine, morphine, marijuana, amphetamine,
methamphetamine, MDMA, heroin, ketamine, lysergic acid diethylamide
or oxycodone. In further aspects, the compound can be a pesticide
or herbicide such as dicamba, glyphosate, azoxystrobin or atrazine.
In certain aspects, a method of characterizing a material is
carried-out using an apparatus as described herein. For example the
apparatus can comprise apparatus comprising: a chamber comprising a
solvent; a gas supply (e.g. a pressurized gas supply); a mass
spectrometer; and a probe comprising a reservoir, a first conduit,
a second conduit and a third conduit, wherein: the first conduit is
in fluid communication with the chamber; the second conduit is in
fluid communication with gas supply; and the third conduit is in
fluid communication with the mass spectrometer.
[0033] As used herein, "sample" or "liquid samples" can refer to
extracts from tissues or other biological specimens (e.g., extracts
comprising proteins and metabolites) obtained by contacting tissue
or biological specimen with a solvent according to the embodiments.
In some aspects, a sample can be an extract from a non-biological
specimen, such as the surface on an object (e.g., a forensic
sample).
[0034] As used herein, "essentially free," in terms of a specified
component, is used herein to mean that none of the specified
components has been purposefully formulated into a composition
and/or is present only as a contaminant or in trace amounts. The
total amount of the specified component resulting from any
unintended contamination of a composition is therefore well below
0.01%. Most preferred is a composition in which no amount of the
specified component can be detected with standard analytical
methods.
[0035] As used herein in the specification and claims, "a" or "an"
may mean one or more. As used herein in the specification and
claims, when used in conjunction with the word "comprising", the
words "a" or "an" may mean one or more than one. As used herein, in
the specification and claim, "another" or "a further" may mean at
least a second or more.
[0036] As used herein in the specification and claims, the terms
"conduit" and "tube" are used interchangeably and refer to a
structure that can be used to direct flow of a gas or liquid.
[0037] As used herein in the specification and claims, the term
"about" is used to indicate that a value includes the inherent
variation of error for the device, the method being employed to
determine the value, or the variation that exists among the study
subjects.
[0038] Other objects, features and advantages of the present
invention will become apparent from the following detailed
description. It should be understood, however, that the detailed
description and the specific examples, while indicating certain
embodiments of the invention, are given by way of illustration
only, since various changes and modifications within the spirit and
scope of the invention will become apparent to those skilled in the
art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The following drawings form part of the present
specification and are included to further demonstrate certain
aspects of the present invention. The invention may be better
understood by reference to one or more of these drawings in
combination with the detailed description of specific embodiments
presented herein.
[0040] FIG. 1: Representative schematic of a mass spectroscopy
probe for minimally invasive surgery.
[0041] FIG. 2: Multilumen tubing for use with the mass spectroscopy
probe for minimally invasive surgery.
[0042] FIG. 3: A cannula and trocar needle for housing and
inserting the mass spectrometry probe for minimally invasive
surgery.
[0043] FIG. 4: Representative schematic of a mass spectrometry
probe for minimally invasive surgery. This embodiment includes a
shutter for occluding the probe.
[0044] FIG. 5: Mass spectra of mouse brains tissue section from the
minimally invasive mass spectrometry probe using Q Exactive
Orbitrap Mass Spectrometer. PTFE tubing of 1.5 meters was used with
an inner diameter of 2 mm and outer diameter of 4 mm.
[0045] FIG. 6: Mass spectra of mouse brains tissue section from the
minimally invasive mass spectrometry probe using Q Exactive
Orbitrap Mass Spectrometer. PTFE tubing of 3.5 meters was used with
an inner diameter of 2 mm and outer diameter of 4 mm.
[0046] FIG. 7: Mass spectra of mouse brains tissue section from the
minimally invasive mass spectrometry probe using Q Exactive
Orbitrap Mass Spectrometer. PTFE tubing of 4.5 meters was used with
an inner diameter of 2 mm and outer diameter of 4 mm.
[0047] FIG. 8: Mass spectra of mouse brain tissue section from the
minimally invasive mass spectrometry probe using Q Exactive
Orbitrap Mass Spectrometer.
[0048] FIG. 9: Representative schematice of a mass spectrometry
probe for minimally invasive surgery. Depicted on the lower left is
the multichannel probe tip.
[0049] FIG. 10: Simulated laparoscopic surgery shown from a
laparoscopic optical camera on a simulated uterus. Shown on the
right are forceps holding the minimally invasive mass spectrometry
probe.
[0050] FIG. 11: Mass spectra generated from a 16 .mu.m mouse brain
section using 4.5 meter long tubing compared to the water
background.
[0051] FIG. 12: Mass spectra generated with the minimally invasive
mass spectrometry probe using Q Exactive Orbitrap Mass Spectrometer
and conduits of 1.5-4.0 mm diameter.
[0052] FIG. 13: Depiction of the mechanics of a balloon shutter for
use with the minimally invasive mass spectrometry probe.
[0053] FIG.14: Mass spectra of human lung tissue section from the
minimally invasive mass spectrometry probe using Q Exactive
Orbitrap Mass Spectrometer.
[0054] FIG. 15: Diagram of washing chamber for minimally invasive
mass spectrometry probe.
[0055] FIGS. 16A-16D: Schematic representation of the laparoscopic
MasSpec Pen system being used in a (a) manual laparoscopic MIS
procedure and (b) robotic assisted MIS. (c) The pen tip was
designed with a grasping fin to allow manipulation and application
of the MasSpec Pen using forceps or other graspers. (d) The tip
contacts tissue for analysis and when the system is triggered (t=0
sec) by use of the foot pedal, the syringe pump delivers a
controlled volume of water to the reservoir. The discrete water
droplet interacts with the tissue to extract molecules. After 3
seconds, the vacuum and the gas conduits are concomitantly opened
to transport the droplet from the MasSpec Pen to the mass
spectrometer through the tubing system for molecular analysis.
[0056] FIGS. 17A-17C: Comparison between designs and performance of
the handheld and laparoscopic MasSpec Pen. (a) The handheld MasSpec
Pen contains a PDMS tip and three PTFE conduits, which provide
incoming water (1) and gas (2) to the tip, and an outgoing conduit
(3) for the water droplet to the mass spectrometer. The pen tip
holds a water droplet within the reservoir, which contacts tissue
for analysis. (b) The laparoscopic MasSpec Pen PDMS tip is grafted
with two micro-PTFE tubes, one for the incoming water (1), and
another for incoming gas (2). The proximal end of the pen tip was
then connected to a larger PTFE conduit, which functions as the
outgoing water conduit (3). Using this design, the hollow space in
the distal end of pen tip functions as the water droplet reservoir
(c) Representative mass spectra obtained with the handheld and
laparoscopic MasSpec Pen of a mouse brain tissue section, both
operated at 2.7 mm reservoir diameter and a 1.5 meter tubing
length.
[0057] FIGS. 18A-18C: Different tubing lengths between the
laparoscopic MasSpec Pen (2.7 mm reservoir diameter) and the mass
spectrometer were evaluated using mouse brain tissue sections.
Similar molecular profiles were obtained at different transfer
times using (a) 1.5 m (3.8 seconds, n=10), (b) 3.0 m (5.8 seconds,
n=10), and (c) 4.5 m (7.5 seconds, n=10).
[0058] FIGS. 19A-19B: An automated system was developed for
automatic mass spectrometry data acquisition, statistical analysis,
and communication of results. (a) A foot pedal is used to trigger
the analysis workflow through communication with an Arduino
microcontroller, which then activates water droplet deposition by
triggering the syringe pump. In the GUI, the user selects which
type of tissue is being evaluated prior to usage, so that the
software selects the proper statistical classifier, providing a
predictive diagnosis with the associated cancer probability. (b)
The laparoscopic MasSpec Pen platform was tested using a mannequin
through an 8 mm cannula. Laparoscopic forceps were used to
manipulate the MasSpec Pen, while a video camera was employed to
transmit an image and/or video of the organs inside the abdomen and
guide the operator during the procedure.
[0059] FIGS. 20A-20C: (a-c) Representative mass spectra obtained
from mouse brain tissue sections with laparoscopic MasSpec Pen at
reservoir diameters of 1.5, 2.7, and 4.0 mm and a 4.5 meter tubing
length.
[0060] FIG. 21: Representative mass spectra obtained with the
laparoscopic MasSpec Pen (2.7 mm reservoir diameter and a 4.5 meter
tubing length) of a human normal and a cancerous ovarian
tissues.
[0061] FIG. 22: Representative mass spectra obtained with the
MasSpec Pen from samples of beef, lamb, chicken and pork using
CAN:DMF 1:1 as the solvent. Results show that the spectra obtained
using the MasSpec Pen were able to assess the source of the meat
with a high level of accuracy.
[0062] FIG. 23: Representative mass spectra obtained with the
MasSpec Pen from samples of grass-fed versus grain-fed beef (using
CAN:DMF 1:1 as the solvent). Results show that the spectra obtained
using the MasSpec Pen were able determine whether the meat was
sourced from a grass-fed or grain-fed animal with a high level of
accuracy.
[0063] FIG. 24: Representative mass spectra obtained with the
MasSpec Pen from samples of beef, lamb, chicken and pork using
water as the solvent. Results show that the spectra obtained using
the MasSpec Pen were able to assess the source of the meat with a
high level of accuracy even when using water as the only
solvent.
[0064] FIG. 25: Representative mass spectra obtained with the
MasSpec Pen from samples of fish, including Atlantic salmon,
sockeye salmon, steelhead trout, cod loin or halibut (using ACN:DMF
(1:1) as a solvent). Results show that the spectra obtained using
the MasSpec Pen were able to assess the source of the fish with a
high level of accuracy.
[0065] FIG. 26: Representative mass spectra obtained with the
MasSpec Pen from samples including amounts of illicit drugs,
cocaine and amphetamine. Results show that the spectra obtained
using the MasSpec Pen were able to detect the drugs with a high
degree of sensitivity and quantify the amount of drug in the
sample.
[0066] FIG. 27: Representative mass spectra obtained with the
MasSpec Pen from samples including amounts of oxycodone. Results
show that the spectra obtained using the MasSpec Pen were able to
detect and quantify the amount of oxycodone in the sample.
[0067] FIG. 28: Representative mass spectra (and a comparative
chromatograph) obtained with the MasSpec Pen from samples including
the pesticide azoxystrobin. Results show that the MasSpec Pen
analysis was able to detect and quantify the amount of pesticide in
the sample.
[0068] FIG. 29: Representative mass spectra (and a comparative
chromatograph) obtained with the MasSpec Pen from samples including
the pesticide atrazine. Results show that the MasSpec Pen analysis
was able to detect and quantify the amount of pesticide in the
sample.
[0069] FIG. 30: Representative mass spectra obtained with the
MasSpec Pen from grapes. Results show that the MasSpec Pen analysis
was able to produce a spectrum that could be used to characterize
the sample.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
I. THE PRESENT EMBODIMENTS
[0070] In certain aspects, the instant application provides methods
and devices for minimally invasive molecular assessment of samples,
such as tissue samples. In particular, aspects the methods can be
used to assess multiple tissue sites during an operation (or
biopsy) of the tissue. This feature allows for accurate
identification of diseased tissues (e.g., tissue sites retaining
cancer cells) in "real-time" allowing surgeons to more accurately
address only the diseased tissue relative to surrounding normal
tissues. In particular aspects, the methods disclosed here can
involve delivery of a fixed or discrete volume of solvent to a
tissue site, followed by collection of a liquid sample from the
site and analysis of the liquid sample by mass spectrometry.
Importantly, rather than being applied in a high-pressure spray,
solvent is applied as discrete droplets and at low pressure. These
methods allow for accurate collection of samples from a distinct
tissue site while avoiding damage to the tissue being assessed. The
resulting mass spectrometry profile from collected samples allows
for differentiation of diseased versus normal tissue sites. The
method can be repeated at multiple sites of interest to very
accurately map molecular changes (e.g., in a tissue). Importantly,
the profiles of samples could be differentiated even without the
use of an ionization source. Thus, while methods of the embodiments
could be used in conjunction with an ionization source, the use of
such a source is not required. These methodologies can allow
assessment of plurality of tissue sites over a short range of time,
thereby allowing for very accurate assessment of the boundaries of
diseased versus normal tissues.
[0071] In some aspects, the methods detailed herein can be used to
collect and analyze samples from a wide range of sources. For
example, the methods can be used to assess surgical, forensic,
agriculture, pharmaceutical, and/or oil/petroleum samples.
[0072] In some aspects, the materials (PDMS and PTFE) and solvent
(e.g., water only solvents) used in the devices of the embodiments
are biologically compatible, such that they can be used in surgery
in for real-time analysis. Furthermore, because the devices can be
very compact, it can be hand-held and used in used in minimally
invasive surgical procedures, or non-surgical procedures.
[0073] In some aspects, the present invention provides devices of
extended length and increased compactness for delivery of fixed or
discrete volumes of solvents to tissues for use in minimally
invasive surgeries. In some aspects, these methods can be
encapsulated in a variety of form factors such as a conduit,
ranging from 0.5 mm to 10.0 mm inner diameter (e.g., with an inner
diameter of between about 1.0 and 5.0; 1.0 and 10.0; 2.0 and 8.0;
or 5.0 and 10.0 mm). In some aspects, the site of delivery of a
fixed or discrete volume of solvent, followed by collection of a
liquid sample may be inside the body, such as a surgical site. In
some aspects, two smaller conduits may be inserted into a third,
larger, conduit to create a multi-lumen catheter. For example, the
multi-lumen catheter can have 2, 3, 4, 5, 6 or more luminal spaces
with each having an internal diameter of, e.g., 0.05 to 5.0 mm; 0.1
to 5.0 mm; 0.25 to 3.0 mm; or 0.5 mm to 10.0 mm. The multi-lumen
catheter may be attached to a mass spectrometry device for analysis
of sample tissues inside the body during surgery, while avoiding
unnecessary damage to surrounding tissues.
[0074] In some aspects, the device may be used through cannulas or
catheters in minimally invasive surgical or endoscopy procedures,
or may be used in non-surgical procedures through needle guides or
biopsy guides. In some aspects, the present invention can be
integrated into a robotic surgical system allowing several regions
of the human body cavity to be quickly sampled and analyzed. In
some aspects, the device be used to analyze tissues using a
database of molecular signatures and machine learning algorithms,
allowing diagnosis in real time for each sampled region. The
present invention may be used in a wide variety of oncological and
other surgical interventions, such as endometriosis, for which real
time characterization and diagnosis of tissues are needed.
[0075] In some aspects, the present disclosure provides an
attachment to the probe, for fine manipulation of the probe during
minimally or non-invasive procedures. For example, the attachment
to the probe may be a fin. In some aspects, such a fin may be
composed of the same material as the probe. In some cases, the fin
is made of PDMS. A fin can, in some aspects, be formed by an
injection molding process or it may be 3D printed. In some aspects,
the present invention may further comprise a device for grasping
the probe, external to the probe, in order to manipulate the probe
during laparoscopic procedures. The grasping device may be used to
hold, rotate, or move the probe, or may grasp the fin attached to
the probe, in order to move or rotate the probe.
[0076] In some aspects, the present invention maintains a reservoir
using a multi-lumen catheter with recessed ports for depositing
water and nitrogen gas during laparoscopic surgical procedures. A
multi-lumen catheter may be formed, for example, using a
multi-lumen extrusion as is well known in the art. These catheters
may be utilized in any cannula. The most commonly used cannulas are
of 5 mm and 10 mm diameters, and are typically used for
laparoscopic surgeries.
[0077] In some aspects, the present disclosure provides tools,
devices and methods for manipulation of the probe during endoscopy.
For example, multi-lumen tubing may be used with an external vacuum
source in order to attach the probe to the tissue surface while
analyzing.
[0078] In some aspects, the present invention provides a shutter
system that occludes the orifice of the minimally invasive surgical
device. In some aspects, this shutter system may be a catheter
balloon that is integrated within the device or added separately to
the device. The shutter, or balloon, may close the probe tip,
preventing unwanted biological material from entering the device,
including the lumens and tubing, upon insertion of the catheter
into the patient. The shutter or balloon may disallow endogenous
biological fluids from entering the mass spectrometer after
analysis has been initiated, thus preventing contamination of the
results. Finally, closing of the shutter or balloon may prevent
excess nitrogen gas and water from entering the body. Inclusion of
lengthened probes for minimally invasive surgeries and occlusion
technologies for the tips of the probes may mitigate the
unpredictable and often tumultuous nature of internal organ
movement and organ systems during surgery which could affect signal
acquisition. Balloons technologies could also be used in other
region of the device instead or in addition to the pinch valves to
control solvent and gas motions through the tubes.
[0079] In some aspects, the present invention may be used with
robotic manipulation. In some aspects, the technologies of the
present invention may integrate in modern surgical theaters through
an accessory port, or via a robotic arm. These devices may be
integrated into robotic systems such as the Intuitive Surgical da
Vinci robotic surgical system. A device of the present invention
may have its own dedicated arm in a robotic system, or be handled
by robotic graspers by incorporating a "fin" onto the probe.
Smaller and larger diameters can also be used to be coupled to any
existing catheters, cannulas and also needle/biopsy guides.
[0080] In some aspects, a tracking probe can be integrated with
this device in order to display and record where the tissue sample
has been analyzed to better assist the surgeon in localizing the
sampling points both intraoperatively or otherwise. For example,
during intraoperative ultrasound, an ultrasound emitter on the
device may be utilized to display the probe when sampling. The
probe may be integrated with a tracking device based on radio
frequency technology, such as the Biosense Webster Carto system. In
that case, the probe may display the device/sampling location on
any of a variety of imaging modalities, such as intraoperative
UltraSound (US)/Computed Tomogrpahy (CT)/Magnetic Resonance Imaging
(MRI)/Optical Coherence Tomography (OCT). Additionally, fluorescent
imaging and molecular dyes may be used to track the analyzed areas
and charted to provide 2-dimensional or 3-dimensional spatial
imaging. More simply, the probe tip may be coated with a surgical
dye which is then stamped on the tissue to track the region
analyzed. Yet another tracking approach is to integrate an RF
emitter into the probe so that the spatial location may be
tracked.
[0081] In some aspects, the probe of the present invention may be
used to assist surgeons and medical professionals during minimally
invasive surgical interventions by providing comprehensive and
definitive diagnostic molecular information in vivo and in real
time, without necessarily causing damage or alteration to the
patient's native living tissues. The handheld MasSpec Pen has
demonstrated a capacity to do this during
non-laparoscopic/endoscopic surgical procedures (U.S. patent
application Ser. No. 15/692,167 incorporated herein by reference,
in its entirety). Similarly to the handheld MasSpec Pen, the
present invention is suitable for ex vivo analysis of tissues
(fresh, frozen, sections, biopsies) or other clinical specimens
that might be examined by a pathologist, and may be used for
chemical analysis of any given sample for which direct analysis is
desired in confined and spatially limited domains (animals, plants,
explosives, drugs, etc). A variety of tissue types may be analyzed
as well, including but not limited to, breast, kidney, lymph node,
thyroid, ovary, pancreatic and brain tissues.
[0082] In some aspects, the probe of the present invention may be
used in conjunction with surgical instruments for the treatment of
a disease. A variety of surgical instruments may be used to excise
or ablate cells or tissues, including, but not limited to, laser
ablation tools, tools for cauterization or electrocauterization, or
tools for the manual dissection of tissue such as a scalpel.
[0083] Thus, many regions of the human body cavity can be quickly
sampled during surgery, and analyzed (e.g., by using a database of
molecular signatures and machine learning algorithms). Therefore,
the diagnostic results may be provided in real time for each
sampled region. Exemplary devices for use in these methods are
detailed below.
II. EXEMPLARY FEATURES OF A DEVICE OF THE EMBODIMENTS
[0084] A. Shutter Systems
[0085] In some aspects a device of the embodiments further
comprises a shutter system that can occlude the orifice, and
creates a separation between the reservoir and the tissue. For
example, the shutter system can activate after the droplet rests
for 3 seconds and before the droplet is transported to the mass
spectrometer. One reason for this is to ensure no biological
material reach the mass spectrometer and cause damage to the
instrument. The shutter can be an iris diaphragm, a mechanical
closure, gate, or tapenade. An additional design for the shutter is
a balloon mechanism, which seals the exterior of the device from
the tissue. The balloon can be positions on the distal end of the
conduit, e.g., perpendicular to the pen or probe. When activated,
the balloon expands and fills up the reservoir towards the
direction of the tissue. This accomplishes at least 3 things: first
it gently lifts the pen tip off of the tissue using the inflated
balloon, insuring that there is no damage to the tissue. This is to
ensure that the probe remains nondestructive and biocompatible in
case the analyzed tissue is determined to be `normal`. Secondly, it
seals the solvent droplet that is inside the reservoir and prevents
leakage or absorbance of lipids after the sampling window. Thirdly,
it creates a seal at the end of the conduit, which will allow for
more effective transfer of the droplet to the mass
spectrometer.
[0086] B. Catheter Systems
[0087] In some cases, where a probe is incorporated into a
laparoscopic/endoscopic device a reservoir includes using a
multi-lumen catheter, e.g., with recessed ports for depositing
water and nitrogen gas. The reservoir also retains the water during
the extraction period. A multi-lumen catheter can be formed for
example using a multi-lumen extrusion as is well known in the art.
It has been demonstrated that these catheters can be utilized in
any cannula, most commonly 5 mm and 10 mm diameters, for
laparoscopic surgeries. This technology is compatible with robotic
manipulation such as the Intuitive Surgical da Vinci robotic
surgical system. The Laparoscopic/Endoscopic probes will easily
integrate in current surgical theaters through an accessory port or
via a robotic arm. Smaller and larger diameters can also be used to
be coupled to any existing catheters, cannulas and also
needle/biopsy guides.
[0088] C. Valve Systems
[0089] In further aspects, a probe system of the embodiments can
incorporate additional valves. For example, micro-solenoid valves
can be located at each conduit, e.g., at the distal end of the
sampling probe. These will be individually controlled by an
arduino, microcontroller, or signal. In some cases the value
operation is automated. In other cases it can be manually
controlled. In some aspects, valves are positioned in the inner
wall of the solvent conduit sealing the conduits. Thus, by using
such values, only two or even one conduit can be used in the
sampling operation. For example, a delivering solvent conduit and a
return conduit to transfer the droplet to the mass spectrometer.
Additional micro-solenoids could be implanted to have more control.
For example, three or four micro-solenoids can be into the probes
of the embodiments.
[0090] D. Further Surgical System Features
[0091] In some aspects, medical devices require passage to areas of
the body that are difficult to maintain manual control. One
solution is to use endoscopic catheters, but these are often less
precise when compared to handheld devices. Further control can be
attained using robotic tools that can function nearly to the same
extent, and sometimes better than physicians equipped with a
traditional scalpel. A further feature of the
Laparoscopic/Endoscopic probes of the embodiments is a `fin` that
can be grasped by forceps, robotic tools, or laparoscopic graspers.
This will allow the probe to be used in a variety of modalities
without sacrificing resolution or sensitivity. In some aspects, the
fin itself is a gradual sloped protrusion from the exterior of the
conduit running parallel to said conduit. It is textured to provide
extra traction for the grasping mechanism.
[0092] In further aspects, a tracking probe can be integrated with
this device in order to display and record where the tissue sample
has been analyzed to better assist the surgeon in localizing the
sampling points both intraoperatively or otherwise. For
intraoperative ultrasound, an ultrasound emitter on the device may
be utilized to display the probe when sampling. Alternatively, the
probe can be integrated with a tracking device based on radio
frequency technology, such as the e.g., Biosense Webster Carto
system. With this approach, the probe displays the device/sampling
location on any various imaging modalities like intraoperative
UltraSound (US)/Computed Tomography (CT)/Magnetic Resonance Imaging
(MRI)/Optical Coherence Tomography (OCT).
[0093] In some further aspects, tissue sites that are assessed by a
probe of the embodiments can be marked. For example, a dye that is
up-taken by cancerous cells and normal cells, which will mark where
the probe has been placed. In some aspects, a chemical dye can be
delivered using an additional conduit in the catheter or by using a
multilumen catheter. An alternative delivery of a tracking dye is
to dissolve it in the solvent that we use to analyze the tissue.
For instance, one advantage of using a dye within the solvent is
that it will directly correlate with where the tissue sample was
taken, instead of the peripheral region. Of course in this aspects,
the chemical dye would be present in the mass spectra and would
have to be distinguished from biomolecules in a sample. In some
aspects, it may useful to make the dye visible (e.g., in white
operating room light). In other aspects, the dye may be a
fluorescent dye. In yet a further aspect, the pen tip can be coated
with a surgical dye, which is then stamped on the tissue to track
the region analyzed. Likewise, as discussed above, a tracking
approach can be used to virtually map the tissues sites analyzed.
For instance, a RF emitter can be integrated into a probe so that
the spatial location may be tracked. Thus, in some aspects, dyes
(or probe tracking) can be used to track analyzed areas of tissues.
In some aspects, tissues analyzed can be charted to provide 2
dimensional and 3 dimensional spatial imaging.
[0094] In further aspects, a probe system can include a filter. For
example a filter can prevent biological tissue from going into the
conduits. For example, a filter mesh system can be incorporated
within the device to prevent smaller bodies of tissue, protein
aggregates, or coagulated cell clusters from entering. This mesh
could be placed at the opening and have contact with the tissue, or
be positioned higher up within the probe, such that no tissue
contact occurs. In some aspects such a filter mesh comprises
average apature sizes of less than about 1.0, 0.5, 0.25 or 0.1 mm.
Since solid matter can damage a mass spectrometer, such a filter
system can increase instrument lifespan with out negatively
effecting signal detected.
[0095] In still further aspects, an endoscopic/laparoscopic probe
of the embodiments is integrated with a microcontroller, user
interface, and/or associated hardware that will operate with
appropriate software.
[0096] In some further cases, a light, such as a LED will be
incorporated to provide visual feed back to the user, for example,
to indicate that the probe is ready for sampling, in the process of
doing so, or needs to be replaced/repaired. Acoustic feedback can
also be used, for instance, to let the user know what step of the
process the device is in (e.g., since physical cues may be
unavailable laparoscopically). A user interface system can also be
integrated with the device, such as in a foot pedal and buttons on
the housing of the probe.
III. ASSAY METHODOLOGIES
[0097] In some aspects, the present disclosure provides methods of
determining the presence of diseased tissue (e.g., tumor tissue) or
detecting a molecular signature of a biological specimen by
identifying specific patterns of a mass spectrometry profile.
Biological specimens for analysis can be from animals, plants or
any material (living or non-living) that has been in contact with
biological molecules or organisms. A biological specimen can be
samples in vivo (e.g. during surgery) or ex vivo.
[0098] A profile obtained by the methods of the embodiments can
correspond to, for example, proteins, metabolites, or lipids from
analyzed biological specimens or tissue sites. These patterns may
be determined by measuring the presence of specific ions using mass
spectrometry. Some non-limiting examples of ionizations methods
that can be coupled to this device include chemical ionization,
laser ionization, atmospheric-pressure chemical ionization,
electron ionization, fast atom bombardment, electrospray
ionization, thermal ionization. Additional ionization methods
include inductively coupled plasma sources, photoionization, glow
discharge, field desorption, thermospray, desorption/ionization on
silicon, direct analysis in real time, secondary ion mass
spectroscopy, spark ionization, and thermal ionization.
[0099] In particular, the present methods may be applied or coupled
to an ambient ionization source or method for obtaining the mass
spectral data such as extraction ambient ionization source.
Extraction ambient ionization sources are methods with, in this
case, liquid extraction processes dynamically followed by
ionization. Some non-limiting examples of extraction ambient
ionization sources include air flow-assisted desorption
electrospray ionization (AFADESI), direct analysis in real time
(DART), desorption electrospray ionization (DESI), desorption
ionization by charge exchange (DICE), electrode-assisted desorption
electrospray ionization (EADESI), electrospray laser desorption
ionization (ELDI), electrostatic spray ionization (ESTASI), Jet
desorption electrospray ionization (JeDI), laser assisted
desorption electrospray ionization (LADESI), laser desorption
electrospray ionization (LDESI), matrix-assisted laser desorption
electrospray ionization (MALDESI), nanospray desorption
electrospray ionization (nano-DESI), or transmission mode
desorption electrospray ionization (TM-DESI).
[0100] As with many mass spectrometry methods, ionization
efficiency can be optimized by modifying the collection or solvent
conditions such as the solvent components, the pH, the gas flow
rates, the applied voltage, and other aspects which affect
ionization of the sample solution. In particular, the present
methods contemplate the use of a solvent or solution which is
compatible with human issue. Some non-limiting examples of solvent
which may be used as the ionization solvent include water, ethanol,
methanol, acetonitrile, dimethylformamide, an acid, or a mixture
thereof. In some embodiments, the method contemplates a mixture of
acetonitrile and dimethylformamide. The amounts of acetonitrile and
dimethylformamide may be varied to enhance the extraction of the
analytes from the sample as well as increase the ionization and
volatility of the sample. In some embodiments, the composition
contains from about 5:1 (v/v) dimethylformamide:acetonitrile to
about 1:5 (v/v) dimethylformamide:acetonitrile such as 1:1 (v/v)
dimethylformamide:acetonitrile. However, in preferred embodiment
the solvent for use according to the embodiments is a
pharmaceutically acceptable solvent, such as sterile water or a
buffered aqueous solution.
IV. EXAMPLES
[0101] The following examples are included to demonstrate preferred
embodiments of the invention. It should be appreciated by those of
skill in the art that the techniques disclosed in the examples
which follow represent techniques discovered by the inventor to
function well in the practice of the invention, and thus can be
considered to constitute preferred modes for its practice. However,
those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the
specific embodiments which are disclosed and still obtain a like or
similar result without departing from the spirit and scope of the
invention.
Example 1
Minimally Invasive Probe for Mass Spectrometry Design
[0102] The system developed consists of three main parts: 1) a
syringe pump that is programmed to deliver a discrete solvent
volume using a controlled flow rate; 2) tubing systems integrated
to two-way pinch valves for controlled solvent and gas transport;
3) a probe tip which is used for direct sampling of biological
tissues. The tubing systems and probe tip are also integrated into
a minimally invasive surgical device such as a cannula or catheter
for use in laparoscopic or endoscopic surgeries. Several iterations
of the system were explored and optimized with the ultimate goal of
minimizing tissue damage, maximizing tissue-analyte extraction, and
maximizing solvent transmission to the mass spectrometer. FIG. 1
shows a schematic figure of one example of a minimally invasive
apparatus for analyzing biological tissue. The syringe pump feeds
solvent and gas into the minimally invasive probe via micro-PTFE
tubing. The probe maintains contact with the sample, retains
solvent during interaction with the tissue. The tip was
manufactured using 3D-printing and is made of biologically
compatible polydimethylsiloxane (PDMS). The probe has three main
ports: one for the incoming tubing system, a central port for gas
delivery, and a third for the outgoing tubing system. All ports
come in junction at a small reservoir where the droplet is retained
and exposed to the tissue sample for a controlled amount of time,
allowing for efficient extraction of molecules. The size of the
reservoir determines the spatial resolution of the device. A
solvent volume of 10 .mu.L is exposed to the tissue sample. FIG. 2
shows the three conduit tubes. The three conduit tubes used are
made of polytetrafluoroethylene (PTFE), which is also biologically
compatible. The tube from the syringe pump is used to deliver
solvent from syringe pump to the probe tip, while the other
micro-PTFE tube is used to deliver an inert gas (N.sub.2 or
CO.sub.2) to the probe tip. The gas serves three main purposes: 1)
tissue drying prior to analysis; 2) prevent solvent gap due to the
mass spectrometer's vacuum when the reservoir is closed by
contacting the tissue specimen; 2) assist solvent transport from
tissue to the mass spectrometer through the wider PTFE tubing. The
larger PTFE tubing is directly connected to the inlet of the mass
spectrometer so that the positive pressure of the mass spectrometer
vacuum system is used to drive the droplet from the reservoir to
the mass spectrometer inlet for ionization. FIG. 9 shows a
schematic of the minimally invasive probe which includes a diagram
of the tip of the probe, including the tree conduit tubes and the
reservoir at the base (labelled 4). FIG. 3 shows two of the
possible devices to house the minimally invasive probe. The cannula
shown has the gas and solvent tubing entering the top, as well as
the tubing to the mass spectrometer. The probe is shown emerging
from the bottom of the cannula. The probe may also be introduced
into the body cavity using a trocar needle. FIG. 10 depicts a
simulated laparoscopic uterine surgery, and shows that the
minimally invasive probe may be controlled by forceps. A shutter
system that occludes the orifice of the minimally invasive probe
may be employed as shown in FIG. 4. One option for the shutter is
to use a catheter balloon which may close the probe tip, a diagram
of which is shown in FIG. 13, preventing unwanted biological
material from entering the device, including the lumens and tubing,
upon insertion of the catheter into the patient. The shutter may
disallow endogenous biological fluids from entering the mass
spectrometer after analysis has been initiated, thus preventing
contamination of the results. Closing of the shutter can also
prevent excess nitrogen gas and water from entering the body. The
use of a shutter in the lengthened probes necessary for minimally
invasive surgery may help mitigate the unpredictable and often
tumultuous nature of internal organ movement and organ systems
during surgery which could affect signal acquisition. The minimally
invasive mass spectrometry probe may also include a vacuum tube
separate from the sample vacuum above. The purpose of this second
vacuum tube is to gently secure, or latch, the tip of the probe
onto the tissue during analysis.
[0103] The time events involved in the device operation are
automated and precisely controlled by software that communicates
with an Arduino system and two two-way pinch valves. All pinch
valves are closed until the process is initiated when, under 300
.mu.L/min, a pulse is sent to the pump to infuse the solvent for
two seconds and stop, generating a 10 .mu.L droplet filling in the
minimally invasive probe reservoir. The gas and mass spectrometer
tubes are closed at pinch valves, allowing the solvent in the
reservoir to interact with the tissue for three seconds to extract
the molecules. The pinch valves controlling the gas and mass
spectrometer tubes are opened simultaneously, allowing the droplet
to transfer to the mass spectrometer for ionization and molecular
analysis. A pulse is sent to the pump to infuse the solvent for
another 12 seconds and stop, to completely drive all the extracted
molecules into the mass spectrometer. The gas and mass spectrometer
tubes are left open for another 20 seconds to allow all the solvent
in the mass spectrometer tube to go into the mass spectrometer. The
total analyzing time is 37 seconds.
[0104] The probe may be washed between analyses in a variety of
methods. Generally, the tip of the probe is wiped with sterile
water. An additional design that can facilitate the washing step is
a retractable design that will wash the exterior of the probe
without having to remove the device from the patient (FIG. 15). The
design consists of a chamber with valves located at the openings to
maintain a water and gas seal. A longer tube that contains the
probe tip, water, and gas conduits will transect only the top valve
when the tip is located in the washing chamber, but will pass
through both valves when the tip is deployed into the patient
environment. After the probe tip, tubing, or both have become
contaminated during the surgery process, the probe will withdraw
into the washing chamber. Water tubes can be located inside the
washing chamber and point upwards providing a strong jet of
cleaning solvent. Two positions of vacuum tubing will be located
above the first and second valve to remove dirtied solvent. The
vacuum tube placed above the first valve is an emergency tube in
case any water breaks the first valve barrier. The entire system
will fit smoothly inside of a trocar, and the deployable probe will
be located inside of this system. The vacuums located inside the
probe will also operate during this cleaning process, which will
flush the tubing until clean.
Example 2
Molecular Profiles and Analysis
[0105] The system described herein operates by directly connecting
the transfer tube to the mass spectrometer inlet for transporting
the analyte-containing solvents to the mass spectrometer for
molecular analysis. This set up greatly simplifies operational
details and precludes the use of ionization sources. After the
probe interacts with the tissue, the solvent is then transported to
the mass spectrometer and directly infused without the need of an
additional ionization source. Since the system is fully automated
so that each 10 .mu.L solvent droplet is delivered separately to
the inlet, the mass spectrometer operates without any impact on its
performance. Rich molecular information is obtained in this manner,
similar to what is observed from other solvent-extraction ambient
ionization techniques such as desorption electrospray ionization.
The ionization mechanism may be similar to inlet ionization. For
inlet ionization methods, the ionization occurs in the inlet
pressure drop region between atmosphere and vacuum. Because of the
nature of minimally invasive surgical techniques, the diameter of
tubing, and length of tubing is of critical importance. A variety
of tube lengths were tested for the delivery of solvent to the mass
spectrometer, as seen in FIGS. 5-8).
[0106] FIGS. 5-8 show the total ion chromatograms obtained from
mouse brain sections during the total analysis period while using
tubing lengths of 1.5 meters up to 4.5 meters. Rich molecular
profiles were observed in all cases. At a tube length of 4.5 meters
the molecular profile is easily established over the background
signal of the water (FIG. 11). FIG. 12 shows total ion
chromatograms obtained using conduit sizes from 1.5 mm to 4.0 mm.
Again, rich molecular profiles were observed with each conduit
size. To further demonstrate the utility of the minimally invasive
probe for mass spectrometry, human lung tissue was analyzed (FIG.
14), and generated a robust molecular profile.
[0107] The molecular profiles generated by the minimally invasive
mass spectrometry probe can also be used for tissue typing. A
series of tissue samples were evaluated with the minimally invasive
mass spectrometry probe and were able to be identified with an
overall accuracy of 98.55% (Table 1).
TABLE-US-00001 TABLE 1 Tissue typing results. TRUE Thyroid Lymph
Parathyroid Breast Lung Ovarian Pancreas Thyroid 42 0 1 0 0 0 0
Lymph 0 26 0 0 0 0 0 Parathyroid 0 1 62 0 0 0 0 Breast 0 0 0 29 0 0
0 Lung 0 0 0 0 47 0 0 Ovarian 0 1 0 1 0 41 0 Pancreas 0 0 0 0 0 0
24
[0108] The system was able to identify lymph, breast, and lung
tissues with 100% accuracy, thyroid and parathyroid with between
97% and 99% accuracy, ovarian with 95.35% accuracy, and pancreas
tissue with 83.33% accuracy. These tissue typing results were
generated from selected features of the mass spectrometry profiles
shown in Table 2.
TABLE-US-00002 TABLE 2 Selected features for tissue typing. Thyroid
Lymph Parathyroid Breast Lung Ovarian Pancreas m/z -0.25915
-1.37199 0.833471 -0.44036 -0.34999 2.269018 -0.68101 125.01 0 0 0
0 0 0.097137 0 130.06 0 0 0.008242 0 0 0 0 146.05 0 0 -0.00177 0 0
0 0 147.69 0 0 0.28651 0 0 0 0 148.95 0 0 0 0 0 0.025703 0 183.96 0
0 0 0 0 0.014118 0 191.02 0 0 0 0 0 -0.01003 0 194.99 0 0 0 0
0.00062 0 0 200.17 0 -0.00053 0 0 0 0 0 205.46 0 0 0 0 0 0 0.260268
218.1 0 0 -0.01171 0 0 0 0 239.17 0 -0.02264 0 0 0 0 0 241.92 0 0 0
0 0 0.00716 0 243.97 0 0 -0.01202 0 0 0 0 244.92 0 0 0.004177 0 0 0
0 250.96 0.064681 0 0 0 0 0 0 251.96 0 0 0 0 0 0.030521 0 252.85 0
0.00771 0 0 0 0 0 255.9 0 0 0 0 0 0.032836 0 256.23 0 0 0 0
0.009842 0 0 271 0 0 -0.0484 0 0 0 0 271.19 0 -0.00793 0 0 0 0 0
272.01 0 0 0.042591 0 0 0 0 273.08 0 0 0.015766 0 0 0 0 276.8
0.014438 0 0 0 0 0 0 279.24 0 0 0 0 0.011053 0 0 279.92 0 0 0 0
-0.03074 0 0 287.01 0 0 0 0 0 0.026693 0 287.98 0 0 0.131242 0 0 0
0 291.01 0 0.081933 0 0 0 0 0 294.82 0 0 -0.01746 0 0 0 0 296.09 0
0 -0.01414 0 0 0 0 296.94 0 0 0 0 0 0 0.105634 306.07 0 0 0 0
0.016765 0 0 318.85 0 0 0 0 0 0.004345 0 323.91 0 0 0 0 0 0.025689
0 326.06 0 0 0.031889 0 0 0 0 332.27 0 0 0 0 0 0.064138 0 341.27 0
0 0 0.01519 0 0 0 344.97 0 0 0 0 0 0.066306 0 354.16 0 0 0 0 0
-0.04315 0 357.84 0 0 0 0 0 0.011447 0 362.24 0 0 -0.07847 0 0
0.000379 0 407.23 0 0 0 0 0 -0.00779 0 428.03 0 0.089313 0 0 0 0 0
428.19 0 0 0 0 0 -0.00888 0 436.28 0 0 0 0 0 0 0.006734 437.29 0 0
0 0 0 0 0.077554 444.08 0.151553 0 0 0 0 0 0 453.28 0 0 0 0 0
-0.00176 0 455.8 0 0 0 0 0 0.01032 0 460.23 0 0 0 0 0 -0.04105 0
462.3 0 0 0 0 0 0 0.08139 463.98 0 0 0.024299 0 0 0 0 465.3 0 0 0 0
0 -0.03072 0 465.32 0 0 0 0 0 0 0.012348 476.21 0 0 -0.02093 0 0 0
0 485.2 0 0 0 0 0 0.032981 0 519.32 0 0 0 0.181706 0 0 0 524.3 0 0
0 0 0 0 0.0418 530.26 0 0 0.011799 0 0 0 0 535.13 0 0 0 0 0
0.041376 0 565.05 0 0 0.076194 0 0 0 0 578.27 0 0.067343 0 0 0 0 0
616.17 0 0 0 0 0 -0.03131 0 637.33 0.100992 0 0 0 0 0 0 655.51 0 0
0 0 0 0 0.088267 688.51 0 0 0 0.064253 0 0 0 690.51 0 0 0 0
0.044558 0 0 701.53 0 0 0 0 0 -0.00473 0 714.51 0 0 0 0 0 -0.02904
0 715.54 0 0 0 0.286059 0 0 0 717.53 0 0 0.032346 0 0 0 0 718.54 0
0 0 0 0.107471 0 0 719.49 0 0 0 0 0.166554 0 0 721.5 0 0 0 0
0.019482 0 0 724.99 0 0 0.012692 0 0 0 0 725.49 0 0 0.061029 0 0 0
0 726.5 0 0 0.022406 0 0 0 0 729.37 0 0.077857 0 0 0 0 0 741.53 0 0
0.04295 0 0 0 0 743.57 0 0 0 0.023627 0 0 0 747.52 0 0 0 0 0
-0.0096 0 748.52 0 0 0 0 0.140912 0 0 752.56 0 0 0 0 0.022913 0 0
758.4 0.0479 0 0 0 0 0 0 761.4 0.025123 0 0 0 0 0 0 764.52 0 0
0.003296 0 0 0 0 768.55 0 0 0.002224 0 0 0 0 769.5 0 0 0 0 0
-0.00431 0 769.51 0 0 0 0 0.004727 0 0 770.53 0 0 0 0 0.08501 0 0
771.52 0 0 0 0 0 -0.03674 0 775.55 0 0 0 0 0 -0.02396 0 776.55 0 0
0 0 0.121705 0 0 793.56 0 0.012003 0 0 0 0 0 795.52 0 0 0 0
0.039051 0 0 796.52 0 0 0 0 0.024792 0 0 809.52 0 0 0.063972 0 0 0
0 811.53 0 0.047294 0 0 0 0 0 812.55 0 0.087882 0 0 0 0 0 813.55 0
0.031647 0 0 0 0 0 822.47 0.062048 0 0 0 0 0 0 823.48 0.215822 0 0
0 0 0 0 833.52 0 -0.0026 0 0 0 0 0 835.54 0 -0.00055 0 0 0 0 0
836.55 0 0.311816 0 0 0 0 0 838.56 0 0.020823 0 0 0 0 0 860.54 0 0
0.004644 0 0 0 0 861.55 0 0 0 0 0 -0.02476 0 991.29 0 0.001467 0 0
0 0 0 991.69 0 0.069562 0 0 0 0 0 1305.95 0 0 0 0 0 0.058809 0
1448.97 0 0 0.002613 0 0 0 0
[0109] Similarly to the differentiation of tissue types, the
minimally invasive mass spectrometry probe can be used to
differentiate between normal and cancerous tissues. The system
predicted normal tissues with greater than 89% accuracy, and cancer
tissues with greater than 91% accuracy as seen in Table 3.
TABLE-US-00003 TABLE 3 Cancer tissue prediction results. Predicted
Normal Cancer True Normal 247 28 Cancer 12 129
[0110] These tissues were predicted based on the selected features
shown in Table 4.
TABLE-US-00004 TABLE 4 Selected features used for the prediction of
cancer tissues. Cancer MaxIntensityNorm MinIntensityNorm
MaxIntensity MinIntensity m/z -0.1200838 0.00000000 0 0.0 0 124.01
-40.9603959 0.07309089 0 1910468.9 0 146.05 -25.4909642 0.08721183
0 4249182.8 0 154.06 -1.7548952 0.27268945 0 1028115.5 0 165.02
42.8950874 0.02168110 0 189918.4 0 174.04 114.2977347 0.01893967 0
703388.7 0 175.02 -27.1843207 0.21139870 0 6752479.6 0 175.03
-24.4596324 0.12211639 0 2175467.9 0 187.04 -60.8607370 0.22046140
0 5731647.5 0 201.04 118.9618023 0.08163593 0 1262331.3 0 214.05
-128.8755917 0.03867785 0 773249.9 0 215.03 -31.7356346 0.09055005
0 3274645.3 0 221.01 138.9164198 0.01083151 0 568690.6 0 241.04
-74.5285436 0.01626196 0 3302753.8 0 246.95 -2.9550154 0.05776215 0
1111366.1 0 267.07 4.3468095 0.03979236 0 4039159.9 0 268.8
-51.7317355 0.04524576 0 1488145.8 0 271 -3.2679671 0.06004618 0
492594.7 0 283.27 -55.5183712 0.14933261 0 2355024.1 0 296.94
7.5951233 0.22379688 0 2429905.2 0 313.16 -3.7134875 0.17606736 0
7786035.2 0 328.06 71.2579706 0.04428292 0 957525.7 0 332.9
23.4374773 0.03396153 0 1214185.0 0 341.27 -1.6023939 0.28304768 0
6590254.4 0 345.16 -50.1650411 0.04368856 0 1696500.0 0 346.05
83.1031168 0.01781918 0 628038.1 0 353.16 23.4132756 0.06995437 0
2172310.7 0 377.09 -9.9688497 0.10964367 0 1100627.9 0 559.47
-2.7064435 0.05334380 0 49840406.6 0 572.48 83.3837979 0.01727858 0
1439590.6 0 585.49 -20.0678254 0.09010271 0 86114572.9 0 615.17
-115.9821356 0.03578691 0 2801168.1 0 722.51 66.9597188 0.04599428
0 13448313.9 0 742.54 89.8907769 0.04732031 0 8284542.5 0 744.55
64.7272067 0.02038387 0 905261.7 0 748.52 -39.0756981 0.04027318 0
1870669.2 0 766.54 -23.4133796 0.05266494 0 4504433.6 0 773.53
-60.0910994 0.09127090 0 3784388.4 0 788.54 44.1054014 0.04591038 0
1660366.4 0 788.55 -1.4204710 0.03125159 0 4032842.0 0 822.47
-19.2490565 0.05601076 0 738427.0 0 823.48 -66.6013083 0.02864992 0
320932.5 0 861.55 -135.4621348 0.05829841 0 9614626.2 0 885.55
25.0244403 0.12046562 0 9712708.6 0 888.57 90.5815624 0.02339633 0
1145858.3 0
[0111] To evaluate the system performance, consecutive analysis was
conducted on the same tissue section, and on different tissue
sections to demonstrate that the system is highly reproducible
within samples and across different samples.
[0112] Materials and Methods.
[0113] Mass Spectrometer. Q Exactive Hybrid Quadrupole-Orbitrap
mass spectrometer (Thermo Scientific, San Jose, Calif.) was used.
Full-scan was carried out at the range of m/z 500-1800, and the
other mass spectrometric parameters were listed as follows:
resolving power 140,000, micro scan 2, maximum injection time 300
ms, capillary temperature 350.degree. C. and S-lens RF level
100.
[0114] Biological Tissues. Wild-type mouse brains were purchased
from Bioreclamation IVT. 62 frozen human tissue specimens including
breast, thyroid, lymph node, ovarian, and kidney were obtained from
Cooperative Human Tissue Network and Baylor College Tissue Bank.
Samples were stored in a -80.degree. C. freezer. Tissue slides were
sectioned at 16 .mu.m using a CryoStar NX50 cryostat. Frozen tissue
specimen were thawed under room temperature before use.
[0115] Statistical Analysis. IBM SPSS Statistics 22.0 (IBM
Corporation, Armonk, N.Y., USA) was used to perform principal
component analysis (PCA) to reveal patterns in the data. The
analysis was performed directly using the raw data. The 10 peaks of
the top relative intensities in the m/z range of 700-900 were used
for PCA. Typically, the first three components, which all
encompassed more than 85% of the total variance, are used in the
present results.
Example 3
System Automation for Handheld and Laparoscopic Use
[0116] Because all the materials (PDMS and PTFE) and solvent (only
water) used in the minimally invasive probe design are biologically
compatible, the system has a high potential to be used in
laparoscopic and endoscopic surgeries for real-time analysis. More
than that, due to the small dimension of the device, it can be
integrated to a robotic surgical system, such as the Da Vinci
surgical system, through an accessory port or one of its robotic
arms. Several regions of the human body cavity can be quickly
sampled during surgery with or without wash/flush steps in between
each analysis, and analyzed by using a database of molecular
signatures and machine learning algorithms. Therefore, the
diagnosing results may be provided in real time for each sampled
region. This system can be broadly used in a wide variety of
oncological and other surgical interventions (such as
endometriosis) for which real-time characterization and diagnosis
of tissues are needed.
[0117] Thus, a laparoscopic MasSpec Pen platform was developed,
which may be used in manual or robotically controlled MIS
procedures (FIGS. 16A and 16B). The laparoscopic MasSpec Pen
platform was developed with emphasis on three main design features:
1) adherence to dimensions and material specifications necessary
for use in the laparoscopic environment; 2) similar performance
specification to the handheld MasSpec Pen to ensure compatibility
with the previously generated statistical models; and 3)
integration to an automated software and graphical user interface
for real time data analysis and statistical classification.
[0118] The laparoscopic MasSpec Pen was engineered with the
specifications needed to function in MIS. Design modifications
allowed introduction of the MasSpec Pen through the cannula of a
laparoscopic trocar, or through the open ports of robotic systems
(commonly of 5 mm, 8 mm, or 12 mm in diameter), while maintaining
similar operation to the handheld MasSpec Pen. The handheld MasSpec
Pen has a diameter of 10 mm, which was dictated by the diameter of
the 3D printed polydimethylsiloxane (PDMS) pen tip. The tip of the
handheld MasSpec Pen was designed with three conduits (incoming
water, incoming gas, and outgoing water), which are in fluid
communication with an open reservoir that positions the water
droplet for contact with tissue surface (FIG. 17A). In the
laparoscopic MasSpec Pen, two micro-polytetrafluoroethylene (PTFE)
tubes (OD 0.794 mm, ID 0.339 mm), one for the incoming water, and
another for incoming gas, were grafted into a 3D printed PDMS tip
(FIG. 17B). The proximal end of pen tip was connected to a larger
PTFE conduit (OD 1.59 mm, ID 0.794 mm) to serve as the outgoing
water conduit. In this design, the hollow space in the distal end
of pen tip functions as the water droplet reservoir and can be
customized to varied diameters depending on the intended use.
[0119] In this study, the reservoir was designed with three
diameters of 1.5 mm, 2.7 mm, and 4.0 mm to display a range of
capabilities. Although reservoir diameters below 1.5 mm could be
manufactured via micromolding, these were not tested due to
limitations in manufacturing capabilities. Further, current
recommended cancer-free margins for solid cancer excision are often
larger than 1.5 mm--such as 3 mm for basal cell carcinoma, 2 mm for
breast cancer, and 5 cm for gastric cancer.
[0120] To manipulate the MasSpec Pen for contact with the organ of
interest in vivo, a grasping fin was incorporated on the pen tip to
provide an anchor point for a laparoscopic tool, such as forceps or
a robotic arm (FIG. 16C). As in any laparoscopic procedure, organ
access is dictated by trocar placement. One benefit of the
laparoscopic MasSpec Pen is flexibility and light weight of the
polymer-based tubing system. These features allow the device to be
easily manipulated through a trocar in the x, y, and z directions
given the cannula's placement in reference to an organ of interest.
A 3 mm in length fin was incorporated into the 3D printed molds
unilaterally at the proximal end of the pen tip to avoid increasing
the diameter of the device. The total diameter of the laparoscopic
MasSpec Pen including the fin was 7.5 mm for the 1.5 and 2.7 mm
reservoir diameter tips, and 9.5 mm for the 4.0 mm reservoir
diameter tip; all compatible for use through common sized
trocars.
[0121] Different tube lengths between the laparoscopic MasSpec Pen
and the mass spectrometer were investigated for use within the
operating room environment (FIG. 18). Longer tubing lengths than
those used in the handheld MasSpec Pen (1.5 m) were tested
considering the additional length needed to insert the MasSpec Pen
through the laparoscopic trocars (5-12 mm length), constraints of
the operating room (OR) workspace, and the need for instrument
placement outside of the surgical sterile field. As with the
handheld MasSpec Pen, 3 seconds of contact time between the water
droplet within the pen tip and the probed brain tissue section was
used for molecular extraction (FIG. 16D).
[0122] After the sampling period, a 4-second water flush was used
to facilitate droplet transport from the pen tip, through the PTFE
tube, to the mass spectrometer. The PTFE tube was directly
connected to an extended, heated mass spectrometer transfer tube
(350.degree. C.) via flexible silicon tubing, therefore eliminating
the use of an external ionization source. Analyses were performed
in the negative ion mode. FIGS. 18A-C show the mass spectra
obtained from serial sections of mouse brain tissue analyzed with
the 2.7 mm laparoscopic MasSpec Pen at 1.5 m, 3.0 m and 4.5 m
tubing lengths. Similar patterns were observed in the recorded mass
spectra, displaying high relative abundances of a variety of
negatively charged ions, identified as lipid species typically
observed from mouse brain tissue sections using MasSpec Pen and
other ambient ionization techniques. For example, m/z 834.529
(identified as [PS(40:6)-H].sup.-), m/z 885.550 (identified as
[PI(38:4)-H].sup.-), and m/z 790.539 (identified as
[PE(40:6)-H].sup.-) were observed at high relative abundances in
the mass spectra obtained from the grey matter of mouse brain.
[0123] An average cosine similarity of 0.93 (n=12) was achieved for
the mass spectra obtained with various tube lengths, which
demonstrates that the molecular information obtained is
reproducible and independent of tube length (Table 5).
Additionally, transfer time was measured for each length tested,
yielding 3.8 s.+-.0.5 s (n=10), 5.8 s.+-.0.7 s (n=10), and 7.5
s.+-.0.4 s (n=10), for tube lengths of 1.5 m, 3.0 m, and 4.5
meters, respectively (Table 6). Interestingly, tripling the tube
length from 1.5 m to 4.5 m resulted in doubling of the transfer
time, which indicates a non-linear velocity of droplet transport in
the tubing system. At a tube length of 4.5 meters, different
laparoscopic MasSpec Pen reservoir diameters (1.5, 2.7, and 4.0 mm)
were tested, yielding comparable performance with expected changes
in the mass spectral profile due to sampling of different brain
tissue regions (FIG. 20).
[0124] To compare the performance of the laparoscopic MasSpec Pen
with that of the handheld system, serial tissue sections of mouse
brain were analyzed using the same dimensions previously described
for the handheld MasSpec Pen (2.7 mm pen tip diameter and 1.5 m
tubing length). Similar profiles were observed from mouse brain
tissue sections analyzed with both designs across the full m/z
range (m/z 120-1800, cosine similarly=0.88, n=8) and restricted m/z
range (m/z 600-1800, cosine similarly=0.92, n=8) (FIG. 17C). These
results suggested that the laparoscopic MasSpec Pen produced
comparable results to those obtained with the handheld MasSpec Pen,
despite changes in reservoir design and tube length. A 2.7 mm
reservoir diameter and 4.5 m tubing length were chosen for the
remaining experiments performed with the laparoscopic MasSpec Pen.
Using these parameters, an overall measurement time of .about.20
seconds/spot was achieved, which includes the time employed for
tissue sampling (3 seconds), droplet transport (7 seconds), and
droplet ionization and analysis (.about.10 seconds).
[0125] To facilitate clinical use of the laparoscopic MasSpec Pen,
a software with a graphical user interface (GUI) was developed for
real time mass spectrometry data acquisition, statistical analysis,
and display of results. As previously reported for the handheld
MasSpec Pen, a foot pedal is used to trigger the analysis workflow.
Here, the system was further refined so that the foot pedal also
triggers the lab-built software (FIG. 19A). Using this approach,
the user selects which type of tissue is being evaluated in the GUI
prior to tissue analysis, so that the software properly selects the
corresponding statistical model for data analysis. Then, upon
activation by the pedal, a syringe pump is triggered so that a
discrete water droplet is formed in the pen tip, where it interacts
with the tissue for 3 seconds. Following the tissue contact, the
droplet enriched with extracted bio-molecular species is
transported to the Orbitrap mass spectrometer through a PTFE tube
for ionization and mass analysis, as previously explained. The mass
spectra data is continuously recorded and read by the software
program. The three mass spectra with the highest intensity for
selected ions are averaged and pre-processed for statistical
analysis. Prediction is then performed using the statistical models
previously built by the Lasso method using data acquired from
histologically validated tissues and the probability of the tissue
being cancer is reported in the GUI.
[0126] To test performance of the integrated system for tissue
diagnosis, 12 human ovarian tissue samples including 7 normal
tissues and 5 high grade serous carcinoma (HGSC) were analyzed
following the workflow described above. A statistical classifier
previously built for ovarian cancer diagnosis was incorporated in
the software and analysis was triggered using foot pedal
activation. For larger-sized tissue specimens, several regions
within the same tissue sample were analyzed, yielding a total of 24
analyses. The mass spectra obtained presented characteristic lipid
profiles similar to those we have previously described for normal
and cancer ovarian tissues (FIG. 21). Using the software and
statistical classifier, a cancer probability and associated
predictive diagnosis were reported for each region analyzed.
[0127] Based on the cut-off values generated through the
statistical classifier, samples with a predictive probability
greater than 0.51 were as "cancer", while samples with predictive
probabilities lower than 0.51 were called "normal". As shown in
Table 7, 100% sensitivity for cancer diagnosis was achieved, as all
of the regions of the five cancer samples analyzed were classified
as cancer. One of the seven normal tissue samples (ON_164b) was
misclassified as cancer in both regions analyzed, while one of the
four regions analyzed of sample ON_135a was classified as cancer,
yielding 80% selectivity. Overall, an 87.5% agreement between the
predictive and pathologic diagnoses was achieved.
[0128] Lastly, the laparoscopic MasSpec Pen was tested using a
laparoscopic simulation mannequin. The laparoscopic MasSpec Pen was
inserted into the mannequin through an 8 mm cannula. Inside the
mannequin, laparoscopic forceps were used to manipulate the MasSpec
Pen, while a video camera was employed to transmit an image and/or
video of the organs inside the abdomen and guide placement of the
laparoscopic MasSpec pen during the procedure (FIG. 19B). Normal
and cancer human ovarian samples were placed on top of a mimic
organ and accessed through the laparoscopic incisions inside the
mannequin, and then analyzed using the laparoscopic equipment.
Forceps were used to grasp the engineered fin and correctly guide
the pen to the tissue surface for analysis. Using the foot pedal,
the analysis was automatically activated, as previously described.
A predictive diagnosis of "normal" was achieved for the normal
ovarian tissue (probability of cancer=0.37), while a predictive
diagnosis of "cancer" was achieved for the ovarian cancer tissue
(probability of cancer=0.68), which agrees with the histopathologic
diagnosis of the samples. Overall, the laparoscopic MasSpec Pen
showed robust performance in the simulated mannequin suggesting its
compatibility for use in MIS procedures.
TABLE-US-00005 TABLE 5 Cosine similarity results between the mass
spectra obtained using the laparoscopic MasSpec Pen (2.7 mm
reservoir diameter) and different tubing lengths. Tubing Length 1.5
meters (n = 4) 3.0 meters (n = 4) 3.0 meters (n = 4) 0.91 -- 4.5
meters (n = 4) 0.92 0.97
TABLE-US-00006 TABLE 6 Droplet transport time from pen tip to mass
spectrometer through various tubing lengths. Droplet Transport Time
Average (n = 10) Relative Standard Deviation (RSD) 1.5 meters 3.8
12.4% 3.0 meters 5.8 11.5% 4.5 meters 7.5 5.2%
TABLE-US-00007 TABLE 7 Pathologic diagnosis, software predictive
diagnosis and cancer probabilities for the human ovarian tissue
samples analyzed using the laparoscopic MasSpec Pen (2.7 mm
reservoir diameter and 4.5 m tubing length). Software Pathologic
Predictive Cancer Diagnosis Tissue ID Diagnosis Probability Normal
Ovary ON_135a Spot 1 Cancer 0.59 Spot 2 Normal 0.40 Spot 3 Normal
0.32 Spot 4 Normal 0.01 ON_263c Spot 1 Normal 0.39 Spot 2 Normal
0.42 ON_294a Spot 1 Normal 0.04 ON_220a Spot 1 Normal 0.11 Spot 2
Normal 0.38 ON_164b Spot 1 Cancer 0.76 Spot 2 Cancer 0.62 ON_335c
Spot 1 Normal 0.00 Spot 2 Normal 0.00 ON_161a Spot 1 Normal 0.38
Spot 2 Normal 0.36 High Grade OT_403a Spot 1 Cancer 0.88 Serous
Ovarian Spot 2 Cancer 0.98 Cancer OT_054a Spot 1 Cancer 0.98 Spot 2
Cancer 0.72 OT_337a Spot 1 Cancer 0.89 Spot 2 Cancer 1.00 OT_405a
Spot 1 Cancer 0.99 Spot 2 Cancer 0.99 OT_058a Spot 1 Cancer
0.93
[0129] In conclusion, the laparoscopic MasSpec Pen is an automated
device that provides near real time diagnostic information for MIS.
The unique design and features of laparoscopic MasSpec Pen
described meet many of the requirements needed for manual and
robotic MIS. When compared to the handheld version, similar
molecular patterns were obtained from mouse brain tissue sections.
Different pen tip diameters and tube lengths were also tested for
various clinical needs. Finally, a customized lab-built software
was developed, providing a fully automated workflow for tissue
analysis and diagnostic feedback. This technology may be a
complementary tool for MIS, which could expedite clinical workflow
and improve surgical outcomes.
Example 4
Materials and Methods
[0130] Laparoscopic MasSpec Pen Design. Three different
laparoscopic/robotic MasSpec Pen tips were created from PDMS with
diameters of 1.5 mm, 2.7 mm, and 4.0 mm. Grasping fins were
built-in unilaterally in order to minimize overall cross section.
Two micro-PTFE tubings (OD 0.794 mm, ID 0.339 mm) were grafted to
the interior of the PDMS tip near the distal end. The micro-PTFE
tubing was terminated 2 millimeters above the reservoir in order to
avoid tissue interaction. The PDMS mixing solution from Dow Corning
(Midland, Mich.) was molded into negative prints created by a
Stratasys uPrint SE Plus 3D Printer (Eden Prairie, Minn., USA).
PTFE tubing was purchased from Sigma-Aldrich (St. Louis, Mich.,
USA), and silicone tubing was purchased from Saint Gobain (Tygon
#3550, Malvern, Pa., USA). This design allows the formation of a
water droplet at the distal end of the PDMS tip that interacts with
tissue to extract cellular lipids and small metabolites via phase
diffusion. This entire system was inserted into a laparoscopic
simulation mannequin through a 10 mm HiCap 30107 H5 trocar by Karl
Storz, (Tuttlingen, Germany). Images were taken with a wireless
endoscope IP67 snake camera in the simulation mannequin.
[0131] Tissue Samples. Human tissues were obtained from the
Cooperative Human Tissue Network (CHTN) (Charlottesville, Va.)
under approved Institutional Review Board protocol. Mouse brains
were obtained from BioIVT (Westbury, N.Y., USA). Tissue samples
were thawed to room temperature before analysis.
[0132] Mass Spectrometry Analysis. Experiments were performed on a
Q Exactive.TM. Hybrid Quadrupole-Orbitrap.TM. mass spectrometer
(Thermo Fisher Scientific, San Jose, Calif., USA). HPLC grade water
was used for analysis. Full scan mode was carried out at the range
of m/z 120 to 1800, at a resolving power of 140,000, capillary
temperature was set to 350.degree. C., and an S-lens radio
frequency level was set to 100.
[0133] Statistical Analysis and Software Tools. The statistical
analysis procedure for generating the statistical model using Lasso
was explained in a previous work. The lab-built desktop software
designed to predict and display a diagnosis in real time. Following
activation by the pedal through the Arduino microcontroller, data
from the mass spectrometer is continuously read using MSFileReader
(Thermo Fisher Scientific) and the MSFileReader-Python-bindings
package open-sourced on GitHub. The three consecutive mass spectra
of highest intensity for selected ions are averaged and
pre-processed for statistical prediction. Then, using the
previously fitted Lasso model, a prediction is generated and
displayed back to the user via the GUI.
Example 5
Characterizing Materials Using the MasSpec Pen
[0134] The MasSpec pen was also used to obtain samples from various
materials to further evaluate the use of the pen is characterizing
materials in the environment such a foods and forensic samples.
Results demonstrated a wide range of further application for the
mass spectroscopy analyses of the embodiments. For example, studies
presented in FIGS. 22-25 and 30 demonstrated effect spectra could
be produced from a wide range of food products including meats,
fish and fruits. These spectra could be used to accurately
characterize the source material for the samples, such the type of
meat or fish that was being assessed. For these studies, meat and
fish (salmon, trout, atlantic cod, and pollack) samples were
obtained from a local supermarket (Central Market, Austin, Tex.
Samples were stored in a fridge (4.degree. C.) until analysis at
room temperature. Analysis was performed using LTQ Orbitrap XL mass
spectrometer (Thermo Scientific) coupled to the MasSpec Pen.
Analyzed regions of the samples were marked to prevent duplicated
analysis. Molecular profiles of each sample were collected and used
to create a classification model with the least absolute shrinkage
and selection operator (Lasso). Lasso was used to identify
predictive markers of meat type and build a classification models
for identification of unknown samples.
[0135] The MasSpec Pen was used to analyze meat samples as well as
5 samples of each type of fish. Initial experiments were performed
to optimize parameters of the MasSpec Pen for the highest lipid
extraction and transmission. In the negative ion mode, detection of
various glycerophospholipid species (GP), such as
glycerophosphoinositols, glycerophosphoserines, and
glycerophosphoethanolamines was achieved. In addition to GP, small
metabolites, sphingolipids (SP), such as ceramides, and free fatty
acids (FA), such as arachidonic acid and oleic acid were also
observed. Despite the mass spectra complexity, the profiles
obtained demonstrated trends in ion abundances characteristic of
each meat sample. Statistical analysis was then applied to identify
predictive markers of each meat type, as well as to build and
evaluate the performance of classification models for prediction of
meat type. These analysis demonstrated a high degree of accuracy in
correctly identifying source meat samples. In fact, the methods
were sensitive enough to even discern between grass-and
grain-raised meat products (FIG. 24). Accordingly, methods of the
embodiments could be used to authenticate consumer products such as
meats and fish, which would otherwise be difficult to accurately
and quickly authenticate.
[0136] The methods likewise can be used to detect and quantify the
amounts of compounds present in materials. For example, in the case
of forensic samples, the amount of illicit drugs could be
accurately determined using a sampling taken by the MasSpec Pen
(see, FIGS. 26 and 27). Likewise, the methods have been shown to be
effective in detecting the presence of pesticides in source
materials (see, FIGS. 28-29). Thus, methods of the embodiments can
be effectively applied to characterize a wide range of materials
and the determine and quantify the presence of compounds of
interest in the materials.
[0137] All of the methods disclosed and claimed herein can be made
and executed without undue experimentation in light of the present
disclosure. While the compositions and methods of this invention
have been described in terms of preferred embodiments, it will be
apparent to those of skill in the art that variations may be
applied to the methods and in the steps or in the sequence of steps
of the method described herein without departing from the concept,
spirit and scope of the invention. More specifically, it will be
apparent that certain agents which are both chemically and
physiologically related may be substituted for the agents described
herein while the same or similar results would be achieved. All
such similar substitutes and modifications apparent to those
skilled in the art are deemed to be within the spirit, scope and
concept of the invention as defined by the appended claims.
* * * * *