Exploration and Application of Intelligent Difficult Airway Assessment Scheme
Conditions: Difficult Airway
Sponsor: Min Su

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Exploration and Application of Intelligent Difficult Airway
Assessment Scheme
Protocol
(Version :1.0
Date: June 18, 2024)
Project Name: Exploration and Application of Intelligent Difficult Airway
Assessment Scheme
Sponsor: Min Su
Principal Investigators: Min Su, Cheng Wenjie

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Protocol Summary
Trial Name
Exploration
and Application
of
Intelligent
Difficult Airway
Assessment Scheme
Applicant
Min Su
Principal
Investigators
Min Su, Cheng Wenjie
Objective of
the Trial
To investigate the correlation between the intelligent airway
assessment system with Articulation
and tongue position
adjustment
and
the
improved
Mallampati
grading
and
Cormack-Lehane grading, and to establish a model and plan for
predicting difficult airways.
Trial Design
A prospective, self-controlled design is adopted.
Sample Size
A total of 430 subjects are planned to be enrolled.
Case Selection
Inclusion Criteria:
1.Age ≥18 years, gender unrestricted;
2.Subjects planned to undergo general anesthesia and require
endotracheal intubation;
3.Subjects classified as ASA-PS (American Society of
Anesthesiologists Physical Status) Class I, II, and III;
4.Volunteers who participate in this clinical trial and sign the
informed consent form.
Exclusion Criteria:
1.Subjects with known airway deformities, tumors, or other
structural abnormalities that may affect airway assessment;
2.Subjects with mental abnormalities who cannot cooperate;
Pregnant or lactating women;
3.Subjects who have participated in other interventional clinical
trials within 1 month before the start of this trial;
4.Subjects deemed unsuitable for this clinical trial by the
investigators.
Validity
Indicators
Primary
Evaluation
Indicator:
The
correlation
between
the
intelligent airway assessment system with Articulation
and
tongue position adjustment and the improved Mallampati grading
and Cormack-Lehane grading.
Secondary Evaluation Indicators:
1.The consistency between different methods of the intelligent
airway assessment system with Articulation
and tongue position

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adjustment;
2.The accuracy of the intelligent airway assessment system
with Articulation
and tongue position adjustment in predicting
difficult airways;
3.The duration of endotracheal intubation, the need for
assistance, and the number of intubation attempts.
Safety
Indicators
Complications related to endotracheal intubation.
Statistical
Analysis
Analysis will be conducted using R 4.3.2 software.
Presentation
of Research
Findings
Publication of 1-2 research papers.

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Clinical Trial Schedule
Item
Screenin
g Period
(Day 3 to
-1)
Trial Period
Follow-up Period
(Day 3 to
-1)
Day 1
Day 2
10 minutes
Post-Extubatio
n
1 Day
Post-Extubatio
n
Pre-op
Visit
Intubati
on
Baseline Data
Informed Consent
√
Medical History
√
Inclusion/Exclusio
n Criteria
√
Demographic Data
√
Vital Signs
√
Physical
Examination
√
Laboratory Tests
Complete Blood
Count (WBC, Gra)
√
Coagulation
Function (APTT, PT,
TT, D-dimer)
√
Electrocardiogram
√
Research Methods
M Grade
√
N Grade
√
A Grade
√
C-L Grade
√
Research Evaluation Indicators
Endotracheal
Intubation Time
√
Number of
Endotracheal
Intubation
Attempts
√
Need for Assistance
√
Safety Indicators

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Complications of
Endotracheal
Intubation
√
√
Note: WBC: White Blood Cell count; Gra: Neutrophil percentage; APTT: Activated Partial
Thromboplastin Time; PT: Prothrombin Time; TT: Thrombin Time. M Grade: Modified
Mallampati Grade; A Grade: Articulation and Tongue Position Adjustment Software Assessment;
N Grade: Articulation
and Tongue Position Adjustment Physician Assessment; C-L Grade:
Cormack-Lehane Grade.
Abbreviation
AE
Adverse Event
BMI
Body Mass Index
ASA
American Society of Anesthesiologists
SAE
Serious Adverse Event
CRF
Case Report Form
ICF
Informed Consent Form
CRO
Contract Research Organization
FAS
Full Analysis Set
PPS
Per-Protocol Set
SS
Safety Set
GCP
Good Clinical Practice
CRA
Clinical Research Associate

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I. Research Background
1. Definition and Classification of Difficult Airway
The American Society of Anesthesiologists (ASA) defines a difficult airway as a
situation where "an anesthesiologist with routine training experiences difficulty with
mask ventilation of the upper airway, difficulty with tracheal intubation, or both." It
encompasses clinical situations that anesthesiologists may anticipate or not anticipate,
including but not limited to the following one or more scenarios: mask ventilation,
laryngoscopy, use of supraglottic airway devices, tracheal intubation, extubation, or
invasive airway management[1].A large-scale retrospective study including 50,000
general subjects undergoing general anesthesia showed that the incidence of difficult
mask
ventilation
and
impossible
mask
ventilation
were
2.2%
and
0.15%,
respectively[2].Another study analyzing 861,533 general anesthesia events found the
incidence of difficult or failed intubation to be between 0.43% and 0.52% [3].
China, being the most populous country in the world, leads to a significant
demand for healthcare resources, especially in the fields of surgery and anesthesia.
The large number of general anesthesia procedures provides a wealth of clinical data
but also poses a challenge to the healthcare system in terms of providing efficient and
high-quality services. Additionally,
the diverse regional, ethnic, and genetic
backgrounds of the Chinese population may affect airway structure differences,
thereby influencing airway management strategies and increasing the challenge of
difficult airways for anesthesiologists.
2. Preoperative Airway Assessment
Airway management is a core area in anesthesiology and emergency medicine,
crucial for ensuring the safety of surgical patients. Predicting difficult airways and
taking appropriate management measures can significantly reduce anesthesia-related
complications [4].The modified Mallampati grade and the Cormack-Lehane grade are
two commonly used clinical methods for predicting difficult airway assessment. The
Mallampati grade assesses airway difficulty by observing the visibility of oral
structures. It was first proposed by Dr. Seshagiri Mallampati in 1985, classifying

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patients' airways into three levels based on the visibility of the soft palate, uvula,
tonsils, and posterior pharyngeal wall, playing a significant role in guiding airway
management decisions and helping anesthesiologists predict potential intubation
difficulties. However, over time, its application has shown limitations and variability.
Factors such as patient positioning and tongue size can affect the Mallampati grade,
leading to inconsistent predictions of intubation difficulties. To address these
limitations, Samsoon and Young introduced the modified Mallampati grade in 1987,
which added a fourth level for when only the hard palate is visible, which is now the
most commonly used modified Mallampati four-grade assessment system.
The Cormack-Lehane grading system is another key tool used in anesthesia and
airway management to assess the visibility of laryngeal structures during direct
laryngoscopy. It was first proposed by Drs. Robert J. Cormack and William C.
Lehane in 1984, classifying laryngeal views into four grades based on the
visualization of the glottic structures. These methods are widely used in clinical
practice, and literature has pointed out their correlation[5].The modified Mallampati
grade does not require subjects to articulate, and literature has proven that articulation
exposes more than non-articulation[6].
Previous methods relied on clinicians' intuitive observations of subjects' oral
anatomical structures to judge the ease of intubation. However, these methods suffer
from strong subjectivity, poor repeatability, and limited accuracy, especially in
non-standardized
assessment
environments,
where
their
predictive
power
is
challenged. With the advancement of medical technology, especially the rapid
development of Artificial Intelligence (AI) and telemedicine, new opportunities have
emerged to improve the assessment methods for difficult airways. Using intelligent
devices and algorithms, more precise measurements and analyses of subjects' airway
anatomical structures can be made, thereby improving the accuracy and reliability of
assessments. This new method not only reduces the interference of subjectivity but
also enhances repeatability through standardized image capture and analysis processes.
Additionally, the application of intelligent airway assessment methods also supports
telemedicine and intelligent healthcare. In areas with limited resources or remote

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locations, doctors can use intelligent devices to assess subjects' airways through
remote connections, achieving high-quality medical services. At the same time, the
development of this method aligns with the current trend of digital transformation in
the healthcare industry, helping to improve overall medical efficiency and subject
safety.
In our extensive clinical practice, we have found that introducing slight
articulation of "ha" and adjusting tongue position during the modified Mallampati
grade may affect the position of the base of the tongue and the view of the oropharynx,
potentially improving the accuracy and reliability of the grading. However, there is
currently little research on this assessment method, and its correlation with the
Cormack-Lehane grade and its actual application value in predicting difficult airways
have not been fully verified. Accordingly, we propose to use a combination of
changing patients' articulation and adjusting tongue position with an intelligent airway
assessment system, and to explore and compare the correlation of this new method
with the modified Mallampati grade for the Cormack-Lehane grade, with the aim of
establishing a prediction model and corresponding plan for difficult airways.
3. Introduction to the Intelligent Airway Assessment Software
Our intelligent airway assessment software (the "zhyayolo" mobile app) is
developed based on the modified Mallampati grading system. It includes a reading
module and a deep learning module for the airway grading system. The airway
grading system is a cloud-based image data listening program deployed on the server
side. After taking a photo, the uploaded images are stored in the cloud via Alibaba
Cloud OSS. The airway grading system predicts the images uploaded in real-time to
the cloud and writes the prediction data into the database. The airway grading system
retrieves data from the cloud, predicts data that has not been predicted on the cloud,
and returns it to the cloud. The prediction is carried out using a deep learning
four-class model for airway grading, trained with a large dataset of airway grading
samples. The YOLO object recognition network, trained under the Darknet
architecture, is used as a pre-trained network for determining the presence of specific
targets and the exact levels, as well as for bounding them. The test units include a

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photo-taking interface unit, an image uploading unit, and an intelligent shooting
prompt unit. By clicking on the mouth opening test unit, one enters the main interface,
which features operational instructions, a start test button, and an image upload button.
Clicking the start test button leads to the photo-taking interface unit. The top left
corner of this interface has a template image that can be clicked to enlarge for viewing.
The hollowed-out area in the middle of the interface is the core sampling area, where
one should aim the center of the target for shooting.
4. Significance of the Study
The results of this study will help clinical doctors more accurately assess the risk
of difficult airways, optimize airway management strategies, reduce complications
during anesthesia and surgery, thereby enhancing the safety and satisfaction of
subjects. Additionally, the research outcomes may also provide new theoretical
foundations and practical guidelines for the field of airway assessment, promoting the
development and innovation of related technologies and methods. By thoroughly
exploring the effectiveness and feasibility of changing articulation and tongue
position assessment methods, this study not only fills the gaps in existing research but
may also propel
the field of airway management towards more precision,
personalization, and applicability to intelligent assessment.
II. Research Objectives
To explore and compare the correlation between the intelligent airway assessment
system combined with altered patient articulation and tongue position adjustment, the
modified Mallampati grading, and the Cormack-Lehane grading. The aim is to
establish a prediction model and corresponding grading measures for difficult airways,
promote innovative iterative development of the airway management field towards
remote intelligent assessment, and enhance the quality of anesthetic management.
III. Trial Design

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1.Overall Design
A prospective, self-controlled clinical trial design will be employed.
2.Research Methods
Subjects undergoing elective tracheal intubation under general anesthesia in the
operating room of the trial unit (aged ≥18 years, both genders) will be selected and
divided into three groups based on a self-controlled design:
Group 1:
Method A: The anesthesiologist uses the modified Mallampati grading method to
observe the subject's oropharyngeal anatomical structure and assigns a grade.
Group 2:
Method B: The subject opens their mouth wide, relaxes the base of the tongue,
extends the tongue outward as much as possible, and lightly articulates the "ha"
sound. The anesthesiologist observes and then assigns a grade.
Group 3:
Method C: The subject opens their mouth wide, relaxes the base of the tongue,
extends the tongue outward as much as possible, and lightly articulates the "ha"
sound. After the anesthesiologist takes a photo of the subject, the software assigns
a grade.
Preoperatively, the subject's thyromental distance, mouth opening, and degree of neck
mobility will be measured. After anesthesia induction, the oropharyngeal anatomical
structure will be exposed using a video laryngoscope, and the anesthesiologist will
assign a Cormack-Lehane laryngoscope exposure grade and record the endotracheal
intubation time, the number of intubation attempts, and whether intubation assistance
was needed.
Assessment criteria: The modified Mallampati airway grade refers to the literature [7],
defined as: Grade I allows visibility of the hard palate, soft palate, palatoglossus arch,
and uvula; Grade II allows visibility of the hard palate, soft palate, and uvula; Grade
III allows visibility of the hard palate and soft palate; Grade IV allows visibility of
only the hard palate. The Cormack-Lehane laryngoscope exposure grade refers to the
literature [8], defined as: Grade I allows full visibility of the glottis, Grade II allows

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partial visibility of the glottis and the posterior commissure, Grade III allows visibility
of only the epiglottis, and Grade IV allows no visibility of the epiglottis or glottis.
Endotracheal intubation time is defined as the period from the video laryngoscope
blade reaching the lips until the endotracheal tube is confirmed to be in place (three
consecutive normal end-tidal carbon dioxide waveforms appear on the monitor).
Intubation assistance is defined as including, but not limited to, the need for pressure
on the cricoid cartilage or assistance from other physicians.
3.Sample Size Estimation
It is anticipated that 430 subjects will be enrolled.
4.Inclusion/Exclusion Criteria
4.1 Inclusion Criteria
1.Age ≥18 years, gender unrestricted;
2.Subjects planned to undergo general anesthesia and require endotracheal
intubation;
3.Subjects classified as ASA-PS (American Society of Anesthesiologists Physical
Status) Class I, II, and III;
4.Volunteers who participate in this clinical trial and sign the informed consent
form.
4.2 Exclusion Criteria
1.Subjects
with
known
airway
deformities,
tumors,
or
other
structural
abnormalities that may affect airway assessment;
2.Subjects with mental abnormalities who cannot cooperate;
Pregnant or lactating women;
3.Subjects who have participated in other interventional clinical trials within 1
month before the start of this trial;
4.Subjects deemed unsuitable for this clinical trial by the investigators.
5. Subject Withdrawal Criteria and Procedures
5.1 Dropout Criteria
Any subject who has signed the informed consent form and qualified for the trial,
regardless of when or for what reason they withdraw from the trial, will be considered

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a dropout case. This includes: the subject themselves requesting to withdraw from the
clinical trial; the investigator considering it medically necessary for the subject to
discontinue the trial.
5.2 Criteria and Procedures for Terminating the Trial/Trial Treatment
(1) If significant errors are found in the clinical trial protocol or significant
deviations occur during the trial, making it difficult to evaluate the safety and
effectiveness of the trial product;
(2) The sponsor (for reasons such as funding, management, etc.) requests the
termination of the trial;
(3) The administrative authority revokes the trial.
6. Medical Ethical Requirements
(1) The principal investigator is responsible for the trial and must submit the
clinical research protocol and written informed consent form to the Ethics Committee
of The First Affiliated Hospital of Chongqing Medical University for approval before
the trial can commence.
(2) Before participating in the trial, the subject must provide written informed
consent. The investigator must explain the nature, purpose, and risks of the clinical
trial to the subject, and ensure that the subject is convinced that they have the right to
withdraw from the trial at any time after giving their consent. After due consideration,
the subject voluntarily participates in the clinical trial, and both the subject and the
investigator sign the informed consent form, noting the date.
IV. Evaluation Methods
1. Effectiveness Evaluation
1.1 Primary Evaluation Indicator:The correlation between the intelligent airway
assessment
with Articulation
and
tongue
position
adjustment,
the
modified
Mallampati grading, and the Cormack-Lehane grading.
1.2 Secondary Evaluation Indicators:
(1) The consistency between different methods of the intelligent airway

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assessment system with Articulation
and tongue position adjustment;
(2) The accuracy of the intelligent airway assessment with Articulation
and
tongue position adjustment in predicting difficult airways;
(3) Endotracheal intubation time, the need for assistance, and the number of
intubation attempts.
1.3 Methods and Timing for Evaluating, Recording, and Analyzing Effectiveness
Parameters
1.3.1 Primary Evaluation Indicator:The correlation between the intelligent airway
assessment with Articulation
and tongue position adjustment, and the modified
Mallampati grading and Cormack-Lehane grading.
Evaluation Criteria:The correlation coefficient will be calculated using the
Spearman rank correlation coefficient based on the different assessment results of the
same anesthesiologist and their video laryngoscopic Cormack-Lehane grading
assessment results. The correlation coefficients will be transformed using Fisher's z
transformation and subjected to a z-test.
1.3.2 Secondary Evaluation Indicators
(1) Construct a confusion matrix for the different assessment methods of the new
method and calculate the Kappa coefficient: The Kappa coefficient will be calculated
based on the data from the confusion matrix. The closer the Kappa coefficient is to 1,
the more consistent the observations are. Calculate the positive agreement rate and the
negative agreement rate: The positive and negative agreement rates will be calculated
based on the confusion matrix to understand the degree of consistency for positive
and negative cases.
Table 1
Confusion Matrix
Confusion Matrix
N
Grade
I
Grade
Ⅱ
Grade
Ⅲ
Grade
Ⅳ
Total
A
Grade
I

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Grade
Ⅱ
Grade
Ⅲ
Grade
Ⅳ
Total
*A: Articulation and Tongue Position Adjustment Software Assessment; N: Physician Assessment
of Articulation and Tongue Position Adjustment.
Calculation Formula:
Kappa=(1−Pe)/(Po−Pe)​
Where, Po is the observed agreement, i.e., the probability that two observers agree
on the classification; Pe is the expected agreement, i.e., the probability of agreement
by chance.
Recorded Time Point: During the trial period.
(2) Accuracy in Predicting Difficult Airways: Sensitivity, specificity, positive
predictive value, and negative predictive value under each method.
Table 2
Different Method Assessment Results
Cormack-Lehane Assessment*
Total
Positive
(+)
Negative
(−)
Different Method
Assessment**
Positive
(+)
a
b
a+b
Negative
(−)
c
d
c+d
Total
a+c
b+d
N
*Cormack-Lehane assessment > Grade 2 is recorded as an anticipated difficult airway;
**Different method assessment includes M, N, and A > Grade 2 is recorded as a questionable
difficult airway.

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Calculation Formulas:
Positive agreement rate = True positive cases / (True positive cases + False negative
cases) * 100%
That is, Positive agreement rate = a / (a+c) * 100%
Negative agreement rate = True negative cases / (True negative cases + False positive
cases) * 100%
That is, Negative agreement rate = d / (b+d) * 100%
(3) Endotracheal intubation time, need for assistance, number of intubation
attempts: Calculate the mean, standard deviation, median, and maximum and
minimum values under each method.
Recorded time point: During the trial period.
2.Safety Evaluation
Complications of endotracheal intubation.
V. Trial Process
1. Research Process

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Note：Method M (Standard Modified Mallampati Grading Assessment): The patient sat upright,
looked straight ahead, and opened their mouth as wide as possible. The researcher observed the
anatomical structures of the patient's pharynx and larynx using the modified Mallampati grading
method and assigned a grade.Method N (New Method with Pronunciation and Tongue Extension):
The patient sat upright with a slight head extension (10-20°), opened their mouth as wide as
possible, relaxed the base of the tongue, extended the tongue outward as much as possible,
exhaled, and gently pronounced "ha". The researcher observed the anatomical structures of the
patient's pharynx and larynx and assigned a grade.Method A (New Method Combined with
Artificial Intelligence Software Assessment): The same as Method N, but the intelligent
assessment software graded based on images captured by a camera. The camera was positioned
approximately 15 cm from the patient's face and perpendicular to the oral axis.

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2. Implementation of the Trial (Methods, Content, Steps, etc.)
Before any trial-related procedures, an informed consent form must be signed,
and a unique identification number must be assigned to each subject, which remains
unchanged throughout the trial.
2.1 Screening Period (Days -3 to -1)
(1) Sign the informed consent form;
(2) Medical history;
(3) Inclusion/exclusion criteria;
(4) Demographic data (gender, age, height, weight);
(5) Vital signs: temperature, pulse, respiration, blood pressure;
(6) Physical examination.
After obtaining the data from the screening period, the investigator must review it
to ensure that the subject is eligible to continue participating in the trial. If the subject
does not meet the inclusion criteria or meets the exclusion criteria, the subject is
screened out.
2.2 Trial Period
2.2.1 Day 1
(1) The physician assesses the grade based on the modified Mallampati;
(2) The software assesses the grade based on voice modulation and tongue
position adjustment;
(3) The physician assesses the grade based on the voice modulation and tongue
position adjustment method.
2.2.2 Day 2
(1) Cormack-Lehane grading;
(2) Intubation time, number of attempts, and need for assistance.
2.3 Follow-up Period
(1) Complications related to endotracheal intubation.
VI. Bias Control Measures

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Before the start of the clinical trial, the monitor, in conjunction with the principal
investigator, should provide training to other researchers on the trial protocol and
product use to ensure that researchers understand and master the trial software,
protocol, and procedures.
VII. Enrollment Time
The time when the subject signs the informed consent form and meets all
inclusion criteria and does not meet any exclusion criteria is the enrollment time.
The expected overall duration of the clinical trial and the reasons for its
determination
This trial is an observational study, expected to be completed within 15 months.
The expected duration of each subject's participation
Based on the assessment and follow-up time, combined with the signing of the
informed consent form, the maximum expected duration of participation in this
clinical study for each subject is 5 days.
The number of subjects required for the clinical trial
This trial is expected to enroll 430 subjects for the trial.
VIII. Statistical Considerations
(I) Sample Size Estimation
The primary outcome measure for sample size estimation is the difference in
correlation between the intelligent airway assessment technology with voice
modulation and tongue position adjustment and the modified Mallampati grading with
the Cormack-Lehane grading. Existing literature has shown that the correlation
between the modified Mallampati grading and the Cormack-Lehane grading ranges
from 0.5 to 0.9 [6,9]. For this trial, it is assumed that the correlation between the
modified Mallampati grading and the Cormack-Lehane grading is 0.70, the

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correlation between the software assessment of the intelligent airway assessment
technology
with voice
modulation
and
tongue
position
adjustment
and the
Cormack-Lehane grading is 0.80, and the correlation between the physician
assessment of the intelligent airway assessment technology with voice modulation and
tongue position adjustment and the Cormack-Lehane grading is 0.90. Using Fisher's z
transformation to calculate z-scores, with a predetermined significance level α of
0.05, a power of 1−β of 0.80, and Bonferroni correction for multiple comparisons,
the minimum sample size required for the software assessment method of the
intelligent airway assessment technology with voice modulation and tongue position
adjustment and the modified Mallampati grading to achieve the target difference is
approximately 390 cases, for the physician assessment method approximately 50
cases, and for the comparison between the software and physician assessment
methods
approximately
150
cases.
Considering
the
research
objectives
and
significance of this trial, the sample size is determined based on the target difference
between the modified Mallampati grading and the software assessment method of the
intelligent airway assessment technology with voice modulation and tongue position
adjustment. With an expected 10% dropout rate, 430 subjects are planned to be
included.
(II) Analysis Data Sets
Full Analysis Set (FAS): Refers to the ideal subject set that is as close as possible
to the intention-to-treat principle. This data set is derived from all subjects with the
least and most reasonable method of subject exclusion.
Per Protocol Set (PPS): Also known as the valid case, valid sample, or evaluable
case sample. It is a data set produced by a subset of cases that fully comply with the
trial protocol and is a subset of the FAS. Compliance includes considerations such as
the treatment received, the feasibility of primary outcome measurements, and no
major violations of the trial protocol.
Safety Analysis Set (SS): The set of subjects used for summarizing safety and
tolerability assessments is called the safety analysis set.

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(III) Subject Exclusion Criteria
1. Subjects who violate the inclusion or exclusion criteria and affect statistics
after data review;
2. Subjects whose images cannot be recognized by the software after enrollment
or whose tracheal intubation was not performed using a video laryngoscope.
(IV) Statistical Methods
1. Statistical Design
This trial uses a prospective, self-controlled clinical trial design.
2. General Principles
This trial mainly uses descriptive methods, and the main outcome measures
calculate confidence intervals.
Quantitative indicators will calculate the mean, standard deviation, median,
minimum, and maximum values.
Categorical indicators will describe the number and percentage of each category.
3. Data Analysis Methods
3.1 Subject Characteristics
Baseline demographic analysis: Mainly uses descriptive analysis methods, using
quantitative and qualitative data description methods according to the type of data.
3.2 Effectiveness Evaluation Indicators
Primary Effectiveness Indicator:The correlation between the intelligent airway
assessment system with voice modulation and tongue position adjustment and the
modified Mallampati grading with the Cormack-Lehane grading is calculated
according to the evaluation criteria, and the 95% confidence interval of the correlation
is calculated.
Secondary Effectiveness Indicators:Accuracy in predicting difficult airways: The
positive agreement rate under each method. Tracheal intubation time, need for
assistance, number of intubation attempts: Calculate the mean, standard deviation,
median, maximum, and minimum values under each method to show the distribution

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of these indicators. Complication incidence rate: Calculate the complication incidence
rate corresponding to each method and statistically describe it using the number of
cases and percentage.
4. Acceptance Criteria for Clinical Trial Results
Not applicable for this trial.
(V) Handling of Missing and Outlier Values
The clinical trial process should be strictly controlled, and there should be no
missing values in principle. If a subject is normally included in the clinical trial, the
effectiveness evaluation indicators should not be missing. Cases with missing
effectiveness evaluation indicators due to subject dropout are not included in the PPS.
If missing values occur during the clinical trial process, the missing values are not
carried forward and are handled according to missing data procedures.
IX. Risk-Benefit Analysis
(I) Potential Benefits
Participants in this study will receive treatment and care from clinically
experienced medical staff and will have individualized subject files established.
Through personalized preoperative airway assessment, anesthesiologists can more
accurately predict and identify difficult airways, providing subjects with safer and
more appropriate anesthetic management strategies. With more accurate airway
assessment, anesthesiologists can take appropriate preventive measures and response
strategies
in
advance,
reducing
complications
caused
by
improper
airway
management, such as hypoxemia, endotracheal intubation failure, etc. This will
directly improve surgical safety, reduce the subject's postoperative recovery time, and
medical costs. By participating in this study, subjects will receive medical services
that pay more attention to individual differences. Anesthesiologists will be more
meticulous and cautious when managing
the airway, reducing
the subject's
preoperative anxiety and intraoperative discomfort, thereby improving overall

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satisfaction and surgical experience. The results of this study will help promote the
development of medical services towards a more personalized and precise direction.
The participation of subjects will not only bring direct benefits to themselves but also
provide optimized and safer airway management strategies for future subjects.
(II) Risk Analysis
This study aims to explore and compare the correlation between the intelligent
airway assessment system combined with altered patient articulation and tongue
position adjustment, the modified Mallampati grading, and the Cormack-Lehane
grading, in order to provide more accurate airway management strategies for clinical
use. This study will not affect the actual treatment measures of the subjects, only
assessing and recording the airway structure of the participants, without involving any
invasive
interventions.
Airway
assessment
will
be
conducted
by
qualified
anesthesiologists in this hospital, ensuring the professionalism and safety of the
assessment process. The assessment methods selected in this study (modified
Mallampati grading and Cormack-Lehane grading) are commonly used airway
assessment tools in clinical practice. For software photo shooting, we will strictly
implement subject privacy protection measures, including:
①Strictly limit the
shooting range: To minimize the risk of privacy leakage, the shooting is limited to the
necessary oral and surrounding areas, ensuring that the upper boundary does not
exceed the lower edge of the orbit, and the lower boundary does not exceed the chin;
②Photo processing and storage: All photos used for assessment will be automatically
deleted from the computer after being uploaded to the dedicated computer for
intelligent
analysis,
without
retaining
any
copies;
③Data
encryption
and
anonymization processing: Advanced data encryption technology is used to protect
the security of transmission throughout the upload and assessment process, and the
photos are anonymized to ensure that they cannot be directly associated with specific
individuals. Moreover, the operation process does not require the use of additional
drugs or invasive operations, so it will not increase the subject's drug costs and
medical risks. In addition, this study does not involve additional medical equipment,

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and all assessment work is completed in a routine clinical environment, ensuring the
simplicity and feasibility of the operation.
In summary, the risks and discomforts of this study are very low. We will take all
necessary measures to ensure the safety and comfort of the subjects, and strictly
follow ethical principles and standards to protect the privacy and rights of the subjects.
Through this study, we hope to provide more accurate airway assessment methods for
clinical use, thereby improving surgical safety and subject satisfaction. If any
discomfort occurs during the study, we will intervene in time, and our hospital has
corresponding operating procedures and measures to ensure the safety of the subjects
throughout the process.
X. Quality Control of Clinical Trials
(I) Training of Investigators
Before the start of the clinical trial, the trial unit institution or sponsor should
provide necessary training to investigators according to the investigator's manual,
product instructions, and clinical protocol.
(II) Measures to Improve Subject Compliance
Investigators should earnestly implement informed consent to ensure that subjects
fully understand the trial requirements and cooperate with the trial.
XI. Ethical Issues and Informed Consent of Clinical Trials
(I) Ethical Considerations
Clinical trials must be conducted in accordance with the Declaration of Helsinki
and relevant clinical trial research regulations and laws in our country. Before the start
of the trial, the trial protocol must be approved by the ethics committee of the
responsible unit for the clinical trial before the clinical trial can be implemented.

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Before each subject is included in this trial, the research physician has the
responsibility to fully and comprehensively introduce the purpose, procedures, and
possible risks of this trial in written form to them or their designated representative.
Subjects should be informed that they have the right to withdraw from this trial at any
time. A written informed consent form must be given to each subject before selection,
and the research physician is responsible for ensuring that each subject obtains
informed consent before entering the trial, and the informed consent form should be
retained as part of the clinical trial documentation.
(II) Informed Consent Process
Before a subject participates in a clinical trial, the researcher should fully explain
the details of the clinical trial to the subject or their guardian/legally authorized
representative, including known and foreseeable risks and possible adverse events.
After a full and detailed explanation, the subject or their legally authorized
representative signs the name and date on the Informed Consent Form, and the
researcher who performs the informed consent should also sign the name and date on
the Informed Consent Form.
The Informed Consent Form should indicate the date it was established or the
date of the revised version. If the Informed Consent Form is revised during the trial,
the revised version must be reviewed and approved by the ethics committee before it
is implemented. After the revised Informed Consent Form is approved and filed with
the clinical trial institution, all subjects who have not completed the trial process must
sign the newly revised Informed Consent Form.
XII. Provisions for Adverse Events
(I) Definition and Reporting Regulations of Adverse Events
1. Definition of Adverse Events
An adverse event refers to any unfavorable medical occurrence during the clinical
trial process, regardless of whether it is related to the trial or not. In this trial, adverse
events are recorded starting from the airway assessment.
2. Assessment of the Severity of Adverse Events

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Observe the process, degree, treatment, and outcome of adverse events in detail, and
fill them out in the adverse event report form. According to the following standards,
the severity of adverse events can be divided into five levels:
- Level 1: Mild; asymptomatic or minor; only seen clinically or diagnostically; no
treatment needed.
- Level 2: Moderate; requires minor, local, or non-invasive treatment; limitations
in instrumentally activities of daily living appropriate for age.
- Level 3: Severe or medically significant but not immediately life-threatening;
hospitalization or prolongation of hospital stay; disability; limitations in self-care
activities of daily living.
- Level 4: Life-threatening; requires urgent intervention.
- Level 5: Death related to the adverse event.
3. Evaluation of Adverse Events
Adverse events are evaluated according to four levels of association with the
assessment: definitely related, possibly related, possibly unrelated, and definitely
unrelated.
- Related to the assessment: (1) There is a reasonable temporal relationship
between the two; (2) The known risks of the assessment method or can be explained
by the mechanism of the assessment method; (3) The injury is reduced or disappears
after stopping the assessment; (4) The injury reappears after reassessing; (5) It cannot
be explained by other influencing factors. If all five are met, it is judged as "definitely
related"; if two are met, it is judged as "possibly related".
- Unrelated to the assessment: (1) There is no reasonable temporal relationship
between the two; (2) The adverse event is a type of event that the assessment could
not possibly cause; (3) The adverse event can be explained by concomitant
medication/devices, progression of the subject's condition, or other treatments. If all
three are met, it is judged as "definitely unrelated"; if one is met, it is judged as
"possibly unrelated".
4. Expected Adverse Events and Handling Measures
This trial will not have adverse events directly caused by the assessment. The
assessment results generated in this trial need to be confirmed as valid by a physician
and are for reference only.
(II) Definition of Serious Adverse Events
1. Definition of Serious Adverse Events
Serious adverse events refer to events that occur during the study process, leading
to death or a significant deterioration in health status, including fatal diseases or
injuries, permanent defects in body structure or function, hospitalization or
prolongation of hospital stay, medical measures needed to avoid permanent defects in
body structure or function; events leading to fetal distress, fetal death, or congenital
abnormalities, birth defects, etc.
2. Management and Recording of Serious Adverse Events
- Management and recording

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1. Any serious adverse event should be handled immediately according to
routine.
2. Any serious adverse event must be followed up until it is completely resolved
or the treatment is finished.
3. Any serious adverse event should be recorded, including the time of
occurrence, diagnosis, diagnosis time, treatment, duration, and sequelae.
4. If a serious adverse event occurs, in addition to the active treatment and
recording mentioned above, it should be reported in writing to the principal
investigator and the ethics committee within 24 hours.
5. If the death of a subject is related to the study medication, the clinical trial
should be immediately stopped, and the incident should be reported to the ethics
committee as soon as possible, with detailed records and careful preservation of
relevant documents. The ethics committee will decide when the study can resume.
XIII. Provisions for Deviations from and Amendments to the Clinical Trial
Protocol
Deviations from the protocol are generally reported regularly to the ethics
committee, with the sponsor and/or investigator explaining the cause, impact, and
handling measures of the event. After each deviation from the protocol, there should
be handling or improvement measures to remedy the mistake or prevent similar
deviations from occurring repeatedly.
After this protocol is approved by the ethics committee, any modifications must
be documented in a "Protocol Amendment Explanation," signed by the principal
investigator, and approved again by the ethics committee before implementation.
XIV. Direct Access to Source Data and Documents
Investigators should allow inspection by the clinical trial institution management
department, ethics committee, drug regulatory authority, health administration
department, or monitors, auditors, and provide direct access to source data/documents.
XV. Confidentiality Principle
This trial protocol is confidential and is intended for medical experts, researchers,
and other trial-related staff involved in this trial, as well as medical institutions, ethics
committees, and contract research organizations entrusted with this trial. Except for
explaining the situation to the subjects, no content of this trial protocol shall be
disclosed or leaked to a third party without the prior written consent of the sponsor. In
addition, any part or all of the results of this clinical trial shall not be published
externally to societies, magazines, etc., without the written consent of the sponsor.

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