| Objective: Adenoid hypertrophy is the pathological hyperplasia of adenoids due to a variety of reasons,which obstructs the posterior nostril and the back of the nasal cavity and thus affects the normal ventilation function,resulting in nasal congestion,snoring,open mouth breathing and other clinical manifestations in children.The aim of this study was to prepare a novel graphene/urethane nanoscale flexible strain sensor and use it to compare and detect the nasal respiratory airflow size of children with and without adenoid hypertrophy,and to quantify the subjective feelings of children with adenoid hypertrophy using OSAHS-specific Quality of Life survey(OSA-18).To explore the feasibility of a novel graphene/urethane nano flexible strain sensor for nasal respiratory airflow detection,and to study the significance of nasal respiratory airflow size in diagnosing adenoid hypertrophy and evaluating the impact of adenoid hypertrophy on sleep quality of life in children.Methods: This study is divided into two parts: sensor preparation and clinical study.As for the laboratory research part,the influence of graphene content on the conductivity of polyurethane urea elastomer was first explored.By preparing nano-composites with different graphene content,the conductive percolation threshold of the system was determined.From non-conductive to conductive saturation,the system was divided into 5 groups(4wt%-6wt%)on average,and the micro-morphology and mechanical properties were carried out.As well as functional tests,such as transduction,bending,cyclic tensile and response time tests,to identify the best graphene components and verify their suitability for respiratory detection for further clinical studies.A total of 55 children with adenoid hypertrophy admitted to the otolaryngology Department of Shengjing Hospital of China Medical University were enrolled as the diseased group,and 25 children without adenoid hypertrophy were enrolled as the healthy group.Parents of children in the affected group were asked to fill in OSA-18 scale to investigate the influence of adenoid hyperplasia on sleep and life quality of children,and the difference of nasal respiratory airflow between the two groups was detected and analyzed by graphene/urethane nano flexible strain sensor.Results: 1)Performance test of flexible strain sensor based on graphene/urethane nanocomposites:(1)The average thickness of graphene nanosheets characterized by atomic force microscopy(AFM)is 1.183±0.045 nm,about 3-4 layers.The cross-section morphology of urethane nanocomposites with graphene content of 5 wt% was characterized by scanning electron microscopy(SEM).It was observed that graphene was uniformly dispersed in urethane matrix,which promoted the establishment of continuous and effective conductive network in the system,and made the nanocomposites have good conductive properties.(2)When the content of graphene is 5 wt%,the polyurethane urea nanocomposites composed of graphene have the best electrical conductivity,mechanical properties and sensing properties.(3)Graphene/urethane flexible strain sensor has good reactivity to deformation,and the larger the deformation,the more obvious the change of resistance;During 1000 cycles,the resistance change rate is always between-0.1% and 0.2%,and the difference of resistance change rate before and after 20 cycles is not large,which has good stability and durability.The response time of initial strain,maximum strain and vanishing strain is 0.02 s,0.01 s and 0.01 s,respectively.It has the ability to detect breathing and distinguish different breathing states.2)(1)Eighty children admitted to the otorhinolaryngology ward of Shengjing Hospital of China Medical University were collected.According to the diagnostic criteria of adenoid hypertrophy,they were divided into the diseased group(55 cases,68.75%)and the control group(25 cases,31.25%).The resistance change rate of the diseased group was 0.0208(0.0164,0.0275),and that of the control group was 0.0376(0.0296,0.0629).The resistance change rate of the two groups of children was compared P< 0.05,adenoid hypertrophy had an effect on nasal respiratory airflow,and the nasal respiratory airflow in the sick group was smaller than that in the control group.(2)The size and age of nasal respiratory airflow(r=0.515,P<0.001)and BMI(r=0.248,P=0.027)were positively correlated,that is,the older the age or BMI was,the greater the nasal airflow was.There was no significant correlation with sex(P>0.05).(3)According to the degree of adenoid hypertrophy,there were 6 cases(10.9%)in the small adenoid group,17 cases(30.9%)in the medium adenoid group and 32 cases(58.2%)in the large adenoid group.The resistance change rate of small adenoid group was 0.0252(0.0210,0.0383),that of medium adenoid group was 0.0232(0.0141,0.0284),and that of large adenoid group was 0.0196(0.0163,0.0245).There was no significant difference in nasal respiratory airflow in children with different degrees of adenoid hypertrophy(P >0.05),the degree of adenoid hypertrophy could not be evaluated according to the size of nasal respiratory airflow.(4)According to the score of OSA-18 scale filled in by parents of children with children,the first three dimensions with the highest score rate were 63.51% influence on guardians,48.77% sleep disorders and 47.34% physical symptoms.(5)According to the total score of OSA-18 scale,the influence of adenoid hypertrophy on sleep and life quality of children was divided into mild group(23 cases(41.8%),moderate group(22 cases)(40%),severe group(10 cases)(18.2%).The resistance change rate of mild group was 0.0208(0.0185,0.0275),that of moderate group was 0.0225(0.0131,0.0299),and that of severe group was 0.0179(0.0164,0.0234).There was no significant difference in nasal respiratory airflow in children with different levels of influence(P>0.05),the influence degree of adenoid hypertrophy on sleep quality of life of children was not related to the size of nasal respiratory airflow,and the influence degree of adenoid hypertrophy on sleep quality of life of children could not be assessed according to the size of nasal respiratory airflow.Conclusion: In this experiment,a novel graphene/urethane nanocomposite material was prepared,which has the advantages of good electrical conductivity,high tensile strength and elongation at break,high sensitivity,short response time and durability,etc.The graphene/urethane nanoflexible strain sensor prepared by this material can be applied to the detection of nasal respiratory airflow size,and has the development potential of clinical application.The nasal airflow size was positively correlated with age and BMI,but had no significant correlation with sex.The size of nasal respiratory airflow can determine whether there is adenoid hypertrophy,but it cannot accurately evaluate the degree of adenoid hypertrophy and the effect of adenoid hypertrophy on sleep quality of life of children.It was found in the OSA-18 questionnaire that the symptoms of the children and the anxiety of the parents suggested the necessity of early diagnosis and treatment of adenoid hypertrophy.As a noninvasive objective examination method,nasal breath airflow detection can not independently diagnose adenoid hypertrophy,but it can provide certain reference value. |
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