A control method for an automatic airway opening position adjustment device

Abstract

The present invention discloses a control method for an automatic airway opening position adjustment device, the automatic airway opening position adjustment device comprising a horizontal base plate, a head support block, a back support plate, a neck support device, a headgear assembly and a PLC, wherein the neck support device is located between the head support block and the back support plate; the PLC controls the stroke of the electric cylinder according to the following equation: θ=1.235β+α, α=KX+B+C, wherein: θ is the position angle, which is the angle between the orthographic projection line of the line from the mandibular angle to the external auditory canal on the symmetry plane of the human body and the back branch; θ is a preset value, and the value range of θ is 90° to 100°. The control method for the automatic airway opening position adjustment device of the present invention adopts a self-defined position angle that combines the olfactory position and the slope position, and the recommended range of the position angle is verified by experiments, which can meet the airway opening requirements of most patients.

Description

Technical Field

[0001] The invention relates to a medical device, in particular to an airway opening position regulating device. Background Art

[0002] Opening the airway is the first step in endotracheal intubation, cardiopulmonary resuscitation, bronchoscopy, etc. The patient's body position during endotracheal intubation usually has three forms: simple backward position, sniffing position, and slope position. The simple backward position is when the head naturally tilts back. It is generally used in infants and young children. Some video laryngoscopes and other new airway devices can also be used. The simple backward position is as described in the instruction manual. Figure 1 The sniffing position refers to bending the neck with a pillow and then stretching the head backwards. Figure 2 As shown. The angle of neck flexion in the sniffing position is 35° to the horizontal plane, and the angle of face tilting back to the horizontal plane is 15°; to achieve this angle, the head should be raised 31-71mm (the average is 55mm). The sniffing position is the most studied and widely used position for opening the airway. The ramped position is to raise the patient's upper body to align the external auditory canal with the sternal angle while maintaining the sniffing position. The ramped position was proposed because the head elevation of obese patients alone cannot guarantee that they are in the sniffing position, because the anterior and posterior chest diameter of obese patients increases, so it is almost impossible to achieve a 35° neck flexion, unless the shoulders and neck are raised to a certain position so that the obese patient has the same oral-pharyngeal-laryngeal axis as the normal weight sniffing position. A rough reference standard for opening the airway in the ramped position is to align the external auditory canal with the sternal angle.

[0003] In order to solve the problem of opening the patient's airway quickly and accurately, the inventor first developed an automatic airway opening position adjustment device and applied for a patent for it. The patent number is ZL201910582372.2. The patented technology uses a tilt sensor to be set on the headgear. The PLC controls the electric cylinder to lift the neck support plate according to the detection data fed back by the tilt sensor, thereby automatically opening the patient's airway. In this patented technical solution, for patients with normal or thin body shape, the angle between the line connecting the patient's external auditory canal and the patient's mandibular angle and the horizontal plane is used as a reference benchmark, and a first tilt sensor is set on the headgear to detect the angle. This technology is based on the theory of olfactory position. For obese patients, the airway opening is based on the relative height position of the patient's external auditory canal and the patient's sternal angle as a reference benchmark, and a second tilt sensor is set on the headgear to detect the angle between the external auditory canal and the patient's sternal angle and the horizontal plane. This technology is based on the theory of slope position.

[0004] However, in further practice and research, the inventor found that the satisfaction of opening the patient's airway by using the sniffing position or the slope position alone was still insufficient. In addition, the automatic airway opening position adjustment device previously applied by the inventor required two tilt sensors to be installed on the headgear, so the structure of the headgear was complicated and the wearing comfort was poor. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a control method for an automatic airway opening position adjustment device, so as to combine the advantages of the olfactory position and the slope position to better meet the patient's airway opening requirements; and to simplify the headgear structure and improve the wearing comfort of the headgear.

[0006] The control method of the airway opening body position automatic adjustment device of the present invention comprises a horizontal bottom plate, a head support block, a back support plate, a neck support device, a headgear assembly and a PLC, wherein the neck support device is located between the head support block and the back support plate;

[0007] The horizontal bottom plate is provided with a straight guide rail, and the head support block is provided on the straight guide rail and slidably cooperates with the straight guide rail;

[0008] The neck support device comprises a neck support plate with a groove in the middle, a flexible neck limiting pad arranged in the groove, two guide columns fixed on the horizontal bottom plate and respectively slidingly matched with the left and right ends of the neck support plate up and down, a support arranged on the horizontal bottom plate, a lever hinged on the support in the middle, a bracket arranged on the horizontal bottom plate, and an electric cylinder arranged on the bracket with a telescopic rod facing vertically downward, the first end of the lever is located below the neck support plate, and the first end of the lever is provided with a first slide groove, the bottom of the neck support plate is provided with a first transmission pin passing through the first slide groove, the second end of the lever is provided with a second slide groove, and the end of the telescopic rod of the electric cylinder is provided with a second transmission pin passing through the second slide groove; the flexible neck limiting pad has an arc groove matched with the neck;

[0009] The front side edge of the back support plate is provided with a hinge shaft, the rear side edge of the back support plate is provided with a roller rolling on the horizontal bottom plate, the left and right sides of the neck support plate are respectively fixedly connected with a vertically downward connecting rod, and the lower end of the connecting rod is rotatably matched with the hinge shaft;

[0010] The headgear assembly comprises a headgear, a positioning plate arranged on the headgear, and a tilt sensor arranged on the positioning plate, wherein the positioning plate is used to locate the line connecting the patient's external auditory canal and the patient's mandibular angle;

[0011] The signal input end of the PLC is connected to the inclination sensor, and the signal output end of the PLC is connected to the electric cylinder;

[0012] The PLC controls the stroke of the electric cylinder according to the following equation:

[0013] θ=1.235β+α

[0014] α=KX+B+C

[0015] In the above formula:

[0016] θ is the body position angle, which is the angle between the orthographic projection line of the line from the mandibular angle to the external auditory canal on the human body symmetry plane and the dorsal branch; θ is a preset value, and the value range of θ is 90° to 100°;

[0017] β is the mandibular inclination angle, which is the Y-axis angle of the inclination sensor;

[0018] α is the angle between the back support plate and the horizontal bottom plate;

[0019] K is the lifting deviation coefficient of the neck support plate, and the value of K is fixed at 0.303;

[0020] X is the stroke of the electric cylinder;

[0021] B is the angle between the arc groove on the flexible neck limit pad and the horizontal bottom plate when the flexible neck limit pad is in the initial position, and the value of B is fixed at 7.5;

[0022] C is the position deviation, the default value is 0.

[0023] Beneficial effects of the present invention:

[0024] 1. The control method of the automatic airway opening posture adjustment device of the present invention adopts a customized posture angle that includes the airway opening angle generated by neck flexion and head backward extension and the airway opening angle generated by the patient lying on the back support board, that is, the posture angle combines the smelling position and the slope position, and the recommended range of the posture angle of 90° to 100° has been verified by experiments, which can meet the airway opening requirements of most patients.

[0025] 2. The control method of the airway opening body position automatic adjustment device of the present invention only needs to be provided with one tilt sensor on the headgear, so the wearing structure of the headgear is simplified and the headgear is more comfortable to wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a simple backward position;

[0027] Figure 2 It is a schematic diagram of the smelling position;

[0028] Figure 3 It is a schematic diagram of the three-dimensional structure of the automatic airway opening position adjustment device in the embodiment;

[0029] Figure 4It is a schematic diagram of the three-dimensional structure of the automatic airway opening position adjustment device in another embodiment from another perspective;

[0030] Figure 5 It is a schematic diagram of the structure of the head and neck being placed on the automatic airway opening position adjustment device;

[0031] Figure 6 is a schematic diagram of the angles in the equation. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] In the control method of the airway opening body position automatic adjustment device of this embodiment, the airway opening body position automatic adjustment device includes a horizontal base plate 1, a head support block 2, a back support plate 3, a neck support device, a headgear assembly and a PLC, and the neck support device is located between the head support block and the back support plate.

[0034] The horizontal bottom plate is provided with a straight guide rail 4, and the head support block is arranged on the straight guide rail and slidably cooperates with the straight guide rail.

[0035] The neck support device includes a neck support plate 5 with a groove in the middle, a flexible neck limiting pad 6 arranged in the groove, two guide columns 7 fixed on the horizontal bottom plate and respectively slidingly matched with the left and right ends of the neck support plate up and down, a support 8 arranged on the horizontal bottom plate, a lever 9 hinged on the support in the middle, a bracket 10 arranged on the horizontal bottom plate and an electric cylinder 11 arranged on the bracket with a telescopic rod facing vertically downward, the first end of the lever is located below the neck support plate, and the first end of the lever is provided with a first slide groove 12, the bottom of the neck support plate is provided with a first transmission pin 13 passing through the first slide groove, the second end of the lever is provided with a second slide groove 14, and the end of the telescopic rod of the electric cylinder is provided with a second transmission pin 15 passing through the second slide groove; the flexible neck limiting pad has an arc groove 16 matching the neck.

[0036] The front side of the back support plate is provided with a hinge shaft 17, the rear side of the back support plate is provided with a roller 18 rolling on the horizontal bottom plate, the left and right sides of the neck support plate are respectively fixedly connected with a vertical downward connecting rod 19, and the lower end of the connecting rod is rotatably matched with the hinge shaft.

[0037] The headgear assembly comprises a headgear 20, a positioning plate 21 arranged on the headgear and a tilt sensor 22 arranged on the positioning plate, wherein the positioning plate is used to locate the line between the patient's external auditory canal and the patient's mandibular angle.

[0038] The signal input end of the PLC is connected to the inclination sensor, and the signal output end of the PLC is connected to the electric cylinder.

[0039] The PLC controls the stroke of the electric cylinder according to the following equation:

[0040] θ=Aβ+α

[0041] α=KX+B+C

[0042] In the above formula:

[0043] θ is the body position angle, which is the angle between the orthographic projection line of the line from the mandibular angle to the external auditory canal on the human body symmetry plane and the dorsal branch; θ is a preset value, and the value range of θ is 90° to 100°.

[0044] β is the mandibular inclination angle, which is the Y-axis angle of the inclination sensor.

[0045] A is the angle conversion factor, and the value of A is fixed at 1.235. Since the Y-axis angle of the inclinometer is not on the symmetry plane of the human body, the Y-axis angle needs to be converted into the projection angle on the symmetry plane of the human body.

[0046] α is the back plate inclination angle, which is the angle between the back support plate and the horizontal bottom plate.

[0047] K is the lifting deviation coefficient of the neck support plate, and the value of K is fixed at 0.303, which is obtained through experiments.

[0048] X is the stroke of the electric cylinder.

[0049] B is the angle between the arc groove on the flexible neck limit pad and the horizontal bottom plate when the flexible neck limit pad is in the initial position, and the value of B is fixed at 7.5.

[0050] C is the position deviation, the default value is 0.

[0051] In a specific implementation, the PLC calculates the stroke X of the electric cylinder according to the preset angle θ, and calculates the number of pulses to be issued according to the stroke X, and sends a pulse signal to the electric cylinder according to the calculated number of pulses to control the stroke of the electric cylinder to reach X. During the change of the stroke of the electric cylinder, the angle α between the back support plate and the horizontal bottom plate and the mandibular inclination angle β will change.

[0052] The following is an experiment of using the method proposed in this embodiment to control the airway opening and body position automatic adjustment device to open the patient's airway.

[0053] A total of 360 patients who underwent electronic bronchoscopy or treatment in the Department of Respiratory and Critical Care Medicine of a tertiary hospital in Chongqing from January 4, 2021 to March 15, 2021 were selected by convenient sampling. The research assistant adjusted the position angle of the instrument to 90° (referred to as the instrument 90° group), 95° (instrument 95° group) or 100° (instrument 100° group) according to a computer-generated random sequence to open the airway of the subject. Then, a clinician who had been trained in advance and had rich experience in bronchoscopy or treatment used a bronchoscope to enter the airway from the subject's nose or mouth. When the bronchoscope saw the epiglottis and went straight to observe the subject's clearest glottal field of view, the bronchoscope image management system was used to collect and save the electronic image of the glottal field of view at this time. After the image acquisition is completed, the operating physician keeps the position and direction of the bronchoscope's operating lever unchanged, and the research assistant adjusts the remaining two angle values ​​according to the random results to collect the same process of electronic images of the glottis visual field, that is, each subject collects a total of 3 random electronic images of the glottis visual field. After completing this step, the research assistant no longer adjusts the angle value, and the remaining operations are performed by the operating physician according to the routine bronchoscopic diagnosis and treatment.

[0054] Secondly, the safety test phase starts from when the subject wears the head measurement and control device to the end of the bronchoscopic examination or treatment. Among them, after completing the effectiveness test process, the subject performs routine subsequent bronchoscopic diagnosis and treatment operations at the last random angle state, and continues to complete the safety verification of the instrument in this state. After the study, two research observers will use VAS scores to evaluate the degree of pain associated with the instrument in the subjects, and after the study, telephone follow-up will be conducted immediately, 0.5 hours, 1 hour, 3 hours, 6 hours, 12 hours, and 24 hours to observe whether the subjects have adverse reactions related to the instrument and the number of occurrences, such as scalp pain, forehead skin redness, scalp numbness, neck soreness, etc., and record the nature, degree, start time, duration, end time, corresponding treatment measures and the relationship between the adverse reaction and the instrument.

[0055] The Cormack-Lehane classification, referred to as the CL classification, is a classification of glottal visual field exposure first proposed by Cormack and Lehane in 1984. It is often used as a gold standard for objectively judging whether laryngoscopy, endotracheal intubation, and airway difficulty and its degree. In this study, the CL classification was used to judge the glottal visual field exposure of subjects under bronchoscopy after the application of instruments to open the airway, which was the main outcome indicator of effectiveness. The specific classification standards are as follows: Grade I, the glottis is completely exposed, and the anterior and posterior commissures can be seen; Grade II, the glottis is partially exposed, and only the posterior commissure can be seen; Grade III, only the tip of the epiglottis or the epiglottis can be seen, but the glottis cannot be exposed; Grade IV, neither the glottis nor the epiglottis can be exposed. CL grades of III or IV are considered to be difficult to expose the glottal visual field and belong to difficult airway. In this study, the results of all collected glottal electronic images were judged independently by three physicians with intermediate professional titles or above and rich endotracheal intubation experience (two anesthesiologists and one RICU physician). If the three doctors' judgment results are inconsistent, the final result will be determined by the head of the expert group. In addition, we also blinded these three doctors, and they did not know the order of each image acquisition and the corresponding subject identity information when judging the results. When judging the image results, there is only one subject's enrollment number and its corresponding glottal field of view image (the image is named 1 or 2 or 3) to protect patient privacy and avoid result bias.

[0056] The distribution of the three groups of mandibular inclination angle values, back plate inclination angle values, body position angle values, and back plate relative elevation values ​​(i.e., the stroke of the electric cylinder) actually measured by the airway opening position automatic regulator are shown in Table 1.

[0057] Table 1 Distribution of measurement values ​​of three groups of instruments

[0058]

[0059] The Kendall's W test analysis showed that the three clinicians had good consistency in the CL grading results of the three groups. The Kendall's W coefficients were all around 0.700 and the P values ​​were all less than 0.001 (see Table 2).

[0060] Table 2 Consistency test results of CL grading judgments of 3 groups by 3 physicians

[0061]

[0062] In the effectiveness trial phase of this experiment, a total of 216 subjects successfully completed three groups of tests. The incidence of difficult glottic visual field exposure (CL grade ≥ grade III) was 2.8% when the instrument was 90°, 4.2% when the instrument was 95°, and 2.3% when the instrument was 100°. All subjects successfully completed bronchoscopic examination or treatment surgery. Among the 216 subjects, 180 (83.3%) had a CL grade of grade I, 30 (13.9%) had a CL grade of grade II, 5 (2.3%) had a CL grade of grade III, and 1 (0.5%) had a CL grade of grade IV when the instrument was 90°; among them, 3 (1.4%) had a CL grade optimized from grade II to grade I when the instrument was 95°, and 8 (3.7%) had a CL grade optimized when the instrument was 100°; and when the instrument was increased from 95° to 100°, 5 (2.3%) subjects also had a CL grade improved. There was no statistically significant difference in the CL grading ratio among the three groups (2=1.942, P>0.05). The experimental results are shown in Table 3:

[0063] Table 3 Completion of the Cormack-Lehane classification of the three groups of tests (n=216)

[0064]

[0065] In addition, the CL grading results of 129 subjects who only completed one or two groups of the test were mostly grade I or II, as shown in Tables 4 and 5.

[0066] Table 4: Cormack-Lehane classification of patients who completed 1 group of tests (n=55)

[0067]

[0068] Table 5: Cormack-Lehane classification of patients who completed the two groups of tests (n=74)

[0069]

[0070] A total of 345 subjects completed the safety test in this experiment, of which 2 were lost due to loss of contact, so 343 were included in the statistical analysis. The overall compliance of the subjects was 99.4%, and the dropout rate was 0.6%. According to the research results, the duration of the safety test was 14.34±5.30min (range: 7-65min), and the 343 subjects did not report any instrument-related adverse reactions immediately, 0.5 hours, 1 hour, 3 hours, 6 hours, 12 hours, and 24 hours after the end of the study. The incidence of adverse reactions was 0, and the VAS scores were all 0 points.

[0071] Through experiments, it was found that when the airway was opened at three angles of 90°, 95° and 100° using the control method of the airway opening position automatic adjustment device in this embodiment under bronchoscope, the CL classification of most patients was grade I or II, indicating that the control method can effectively open the patient's airway and obtain a good glottal field of view, which is conducive to the smooth passage of the bronchoscope through the glottis into the lower respiratory tract and continuous maintenance of airway patency. In addition, no 343 subjects reported any adverse reactions related to the instrument within 24 hours of follow-up after the end of the experiment, and there was no concern about the size of the instrument angle in terms of safety.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A control method for an automatic airway opening position adjustment device, the automatic airway opening position adjustment device comprising a horizontal base plate, a head support block, a back support plate, a neck support device, a headgear assembly and a PLC, wherein the neck support device is located between the head support block and the back support plate; The horizontal bottom plate is provided with a straight guide rail, and the head support block is provided on the straight guide rail and slidably cooperates with the straight guide rail; The neck support device comprises a neck support plate with a groove in the middle, a flexible neck limiting pad arranged in the groove, two guide columns fixed on the horizontal bottom plate and respectively slidingly matched with the left and right ends of the neck support plate up and down, a support arranged on the horizontal bottom plate, a lever hinged on the support in the middle, a bracket arranged on the horizontal bottom plate, and an electric cylinder arranged on the bracket with a telescopic rod facing vertically downward, the first end of the lever is located below the neck support plate, and the first end of the lever is provided with a first slide groove, the bottom of the neck support plate is provided with a first transmission pin passing through the first slide groove, the second end of the lever is provided with a second slide groove, and the end of the telescopic rod of the electric cylinder is provided with a second transmission pin passing through the second slide groove; the flexible neck limiting pad has an arc groove matched with the neck; The front side edge of the back support plate is provided with a hinge shaft, the rear side edge of the back support plate is provided with a roller rolling on the horizontal bottom plate, the left and right sides of the neck support plate are respectively fixedly connected with a vertically downward connecting rod, and the lower end of the connecting rod is rotatably matched with the hinge shaft; The headgear assembly comprises a headgear, a positioning plate arranged on the headgear, and a tilt sensor arranged on the positioning plate, wherein the positioning plate is used to locate the line connecting the patient's external auditory canal and the patient's mandibular angle; The signal input end of the PLC is connected to the inclination sensor, and the signal output end of the PLC is connected to the electric cylinder; Features: The PLC controls the stroke of the electric cylinder according to the following equation: θ=1.235β+α α=KX+B+C In the above formula: θ is the body position angle, which is the angle between the orthographic projection line of the line from the mandibular angle to the external auditory canal on the human body symmetry plane and the dorsal branch; θ is a preset value, and the value range of θ is 90° to 100°; β is the mandibular inclination angle, which is the Y-axis angle of the inclination sensor; α is the angle between the back support plate and the horizontal bottom plate; K is the lifting deviation coefficient of the neck support plate, and the value of K is fixed at 0.303; X is the stroke of the electric cylinder; B is the angle between the arc groove on the flexible neck limit pad and the horizontal bottom plate when the flexible neck limit pad is in the initial position, and the value of B is fixed at 7.5; C is the position deviation, the default value is 0.

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