Sleep pillow design method based on profile fit degree and personal preference degree

Abstract

The invention relates to a sleep pillow design method based on profile fit degree and personal preference degree, and aims to provide a comfortable sleep pillow meeting individual requirements. The method comprises the following five steps of measuring, asking, calculating, determining and extracting: measuring the natural physiological curved surface shape and pressure value distribution of the head and neck of a human body; inquiring individual pillow height and hardness preference information; establishing a single-point compression state mechanical model of the pillow, and calculating an initial curved surface design shape of the pillow; determining each design element of the pillow; key shape surface parameters are extracted to serve as the basis of pillow classification and shaping. Starting from the individual reality of each user, the individual difference degree and the profile matching degree are comprehensively considered, and the design method of the comfortable sleep pillow better meeting the individual physiological needs is provided. According to the pillow designed according to the method, the shape surface of the pillow in a force balance state is highly matched with the shape of the natural physiological curved surface of the head and neck of an individual, the individual preference degree requirement is met, and scientific'pillow fixing according to people 'can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of bedding technology, specifically relating to a sleep pillow design method based on surface fit and personal preference. Background Technology

[0002] In modern society, people lead fast-paced lives and experience significant work pressure. With busy and stressful workdays, people are increasingly aware of the importance of good sleep for physical and mental health. Against this backdrop, a comfortable pillow has become a key factor in ensuring high-quality sleep. It can be said that a well-designed, soft, and comfortable pillow is not just a simple sleep product, but a companion that provides perfect support for the neck and head, relieves fatigue and stress, helps people enter deep sleep more quickly, improves sleep quality, and allows them to wake up refreshed and ready to face new challenges the next day. Therefore, in this fast-paced, high-pressure society, a comfortable pillow has become an important tool for modern people seeking high-quality sleep; it has become an indispensable part of modern life, helping people find balance amidst busyness and stress, and maintain health and vitality.

[0003] The design of pillow products in the existing technology mainly considers the following aspects: 1) Material Selection and Health Benefits: Pillow design and material selection are crucial for maintaining correct sleeping posture and reducing neck pressure. Pillow materials should be safe, non-toxic, and easy to clean and maintain to preserve a good sleep environment. Consumers are increasingly concerned about the health attributes of pillow materials. Latex and memory foam pillows are gradually becoming mainstream in the market due to their unique material properties and positive impact on human health. Latex pillows have natural antibacterial and anti-mite properties, as well as good breathability and support; memory foam pillows, through their unique slow rebound properties, can closely conform to the curves of the human body, effectively distributing pressure on the head and neck. Furthermore, with the increasing global awareness of environmental protection, consumers are demanding higher levels of environmental friendliness and sustainability in sleep products. Pillow designs are trending towards using formaldehyde-free, natural, and biodegradable materials to meet consumers' needs for environmental protection and health.

[0004] 2) Personalized needs of different groups: Different groups have significantly different needs for sleep products, which prompts manufacturers to continuously innovate and launch more diversified products to meet personalized needs. For example, adjustable height pillows are designed for children to protect their spinal health; while for the elderly, more emphasis is placed on the support and comfort of the pillow.

[0005] 3) Technology-enabled: Smart pillows, through built-in sensors and intelligent control systems, can monitor users' sleep status in real time and adjust parameters such as pillow height and firmness as needed to provide users with a more personalized sleep experience.

[0006] 4) Structural Design and Implementation: The pillow's shape adopts an ergonomic curve design, closely conforming to the contours of the head and neck to provide comfortable support. A groove is set in the center of the pillow to effectively reduce head pressure and improve sleeping posture. The raised design on both sides of the pillow provides stable lateral support and prevents stiff neck.

[0007] 5) Functional Features and Advantages Analysis: Based on ergonomic principles, the pillow's zoned support design divides the pillow into multiple zones, each providing varying levels of support to meet the needs of different sleeping positions. The adjustable pillow height allows for customization to ensure the cervical spine maintains its natural physiological curve during sleep.

[0008] The design trends and standards mentioned above reflect the main directions and market demands of current pillow product design. However, the current situation has created a "pillow-based" model, where each user has to adapt to a pillow purchased from the market, failing to meet the actual pillow needs of each individual. A truly comfortable pillow should be "personally oriented," meaning the pillow should be tailored to the natural physiological curvature of each individual's head and neck, perfectly matching the shape of the head and neck. However, current technical literature lacks relevant pillow design methods for reference. Summary of the Invention

[0009] The main objective of this invention is to provide a sleep pillow design method based on surface fit and personal preference, aiming to provide a comfortable pillow design method suitable for each individual based on their actual situation, thereby providing a comfortable sleep pillow that meets personalized needs.

[0010] To achieve the above objectives, this invention proposes a sleep pillow design method based on surface fit and personal preference, comprising the following steps: S1, sequentially measure the natural physiological curvature shape data and pressure value distribution data of the human head and neck; The pressure value distribution data is a set of pressure value data at various measurement points on the human head and neck. S2, query to obtain individual preferences for pillow height and firmness; S3. Establish a mechanical model of the pillow under single-point pressure. Based on the measurement data obtained in step S1 and the softness and hardness preference information obtained in step S2, calculate the initial shape and position of the pillow at a single measurement point, and then calculate the initial curved surface design shape of the pillow through a preset algorithm. The single-point pressure state mechanical model of the pillow is a force balance model that describes the pillow being in a force balance state after the human head and neck come into contact with the pillow under pressure at a certain measurement point; S4. Determine the height of the pillow based on the height preference information obtained in step S2, determine the surface shape profile of the pillow based on the initial curved surface design shape of the pillow calculated in step S3, and determine the softness and hardness of the pillow through material selection. S5. Extract the key surface parameters that describe the initial curved surface design shape of the pillow, and use these key surface parameters as the basis for guiding pillow classification and shaping.

[0011] Optionally, the single-point compression state mechanical model of the pillow described in step S3 adopts the following numerical analytical model: , In the formula, the subscript This indicates the number of a measurement point. Indicates measurement point The magnitude of the pressure exerted on the pillow surface by the human head and neck. Point The design stiffness of the pillow, For measurement points The initial shape and position of the pillow, and For measurement points The position of the pillow on the equilibrium plane is also the measurement point. Its position on the natural physiological curves of the human head and neck; The design stiffness of the pillow depends on the individual's preference for pillow firmness.

[0012] Optionally, the preset algorithm used in step S3 to calculate the initial surface design shape of the pillow includes one or more of the following: linear interpolation algorithm, cubic interpolation algorithm, polynomial fitting algorithm, and spline function fitting algorithm.

[0013] Optionally, the degree of matching between the pillow shape in a state of force equilibrium and the ideal pillow shape is measured by the degree of fit; the degree of fit is expressed as the root mean square error of the shape. The specific calculation formula is as follows: , In the formula, This indicates the total number of sections after dividing the pillow surface. This indicates the sequence number of the segmented units into which the pillow surface is divided. Indicates the first The projected area of ​​each block unit, Indicates the first The actual center of each block unit To the location, Indicates the first The ideal center of each block unit To position, symbol This represents the summation operation; Based on the aforementioned fit, the initial curved surface design shape of the entire pillow obtained in step S3 can be further optimized.

[0014] Optionally, the criterion for further surface optimization of the initial curved surface design shape of the entire pillow obtained in step S3 is to adopt the criterion of maximizing surface fit, wherein the criterion is to minimize the root mean square error of the surface. To optimize the objective, mathematical modeling and algorithm iteration are used to achieve the best match between the pillow shape in equilibrium and the natural physiological curvature of the human head and neck. The specific optimization process is as follows: Step S31, Data preparation and initialization: Input the measurement point data representing pressure distribution and physiological surface shape from step S1, the softness and hardness data and height type from step S2, and the initial surface data from step S3, and set the fit threshold and the number of pillow surface block units. Step S32, Surface Fitting and Error Calculation: The initial surface is smoothed using a spline function fitting algorithm to generate a continuous surface, and the current error value is calculated according to the fit formula. ; Step S33, Mechanical Model Feedback Adjustment: Optimize using Newton's iterative calculation method, while maintaining the user-specified height and stiffness type as constraints. make minimize; Step S34, Smoothness detection and verification: Use curvature analysis tools to check the continuity of the second derivative of the surface; Step S35, output the final shape: when If the threshold is reached and all constraints are satisfied, or if the number of iterations exceeds the upper limit, output the pillow shape optimization result.

[0015] Furthermore, the initial surface design shape of the entire pillow obtained in step S3 can be further optimized using the maximum pressure minimization optimization criterion. This optimization criterion is based on... To optimize the target and reduce the peak pressure distribution on the pillow surface, mathematical modeling and mechanical adjustments are used to prevent localized pressure concentration. Indicates measurement point The magnitude of the pressure exerted on the surface of the pillow by the human head and neck.

[0016] Furthermore, the initial surface design shape of the entire pillow obtained in step S3 can be further optimized using a pressure distribution uniformity optimization criterion. This optimization criterion aims to minimize the pressure standard deviation, thereby minimizing the dispersion of pressure values ​​on the pillow surface. Mathematical modeling is used to achieve a balanced pressure distribution in the head-neck contact area. The pressure standard deviation... The calculation formula is: ,in This represents the average pressure at all measurement points. This represents the total number of valid measurement points.

[0017] Optionally, step S1 includes the following sub-steps: S11, The shape of the natural physiological surface of the human head and neck is measured using a surface measurement device; The surface measurement device includes one or more of the following: an optical image photogrammetry device, a three-dimensional laser scanning device, a microwave sensing device, and a contact mechanical measurement device. S12, use the natural physiological surface shape obtained in sub-step S11 as the initial surface shape of the pressure measuring device; The pressure measuring device includes one or more of spring-based pressure measuring devices and magnetic force-based pressure measuring devices; S13, use a pressure measuring device to obtain pressure distribution data of the human head and neck.

[0018] Optionally, the pillow firmness type in step S2 includes soft, medium, and firm; the degree levels of the two firmness types, soft and firm, include slight, normal, and super firm; the degree levels of the medium firmness type include light, normal, and heavy firm; and the pillow height type includes low, normal, and high.

[0019] Optionally, the key surface parameters describing the initial curved surface design shape of the pillow in step S5 include: the depth, length, and overall curvature of the head curve segment; the depth, length, and overall curvature of the neck curve segment; the horizontal distance from the lowest point of the head curve segment to the highest point of the parietal bone; the vertical distance from the external occipital protuberance to the highest point of the parietal bone; and the horizontal distance from the highest point of the neck curve segment to the highest point of the parietal bone. Compared with existing conventional technologies, the beneficial technical effects that can be achieved by using the technical solution proposed in this invention are mainly reflected in the following aspects: Firstly, this invention starts from the individual reality of each user, comprehensively considers individual differences and surface matching, and provides a more comfortable pillow design method that meets individual physiological needs. The designed pillow has a high degree of conformity with the natural physiological curve of the user's head and neck under the force balance state, thereby optimizing the shape and performance of the pillow, which can significantly improve the comfort and quality of the user's sleep, while helping to reduce neck pain and relieve sleep fatigue, thus achieving the scientific "personalized pillow design". Secondly, the design method described in this invention ensures a high degree of conformity between the balanced state shape of the pillow after deformation under the action of the human head and neck and the natural physiological curve shape of the human head and neck. Therefore, it helps to support and protect the normal physiological curve of the human cervical spine, thereby promoting spinal health. Thirdly, the design method described in this invention incorporates two important factors at the design level: pillow height and firmness. The height factor takes into account the need for the degree of freedom of the human cervical spine to flex and extend (while the curved shape of the pillow takes into account the degree of freedom of the human cervical spine to tilt and flex). A good height can ensure smooth blood circulation. The firmness factor can reflect the different individual needs for pillow comfort.

[0020] Furthermore, the method described in this invention also scientifically classifies and shapes the inherently continuous and diverse pillow surfaces by finding the core key parameters that describe the curved shape of the pillow, thereby providing technical guidance for planning pillows with limited styles and designs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the sleep pillow design method based on surface fit and personal preference as described in this invention; Figure 2 This is a mechanical equilibrium model of a pillow under pressure at a single measurement point.

[0023] The reference numerals and their meanings in this invention are explained as follows: 1—The initial curved shape of the pillow; 2—The actual curved shape of the pillow after the head and neck are subjected to pressure; 3 - Pillow. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The design of a comfortable pillow should be based on ergonomic principles to ensure that its height, firmness, and shape match the natural physiological structure of the human body. A pillow designed in this way can best conform to the natural physiological curvature of each user's head and neck, providing better comfort and support, reducing spinal pressure, and preventing neck and shoulder pain. However, current pillow designs on the market mainly focus on material selection and application, functional division, technological enhancements, and general structural shape design, failing to truly achieve personalization and customization. This has created a "pillow-based" situation, where each user needs to adapt to a pillow purchased from the market, thus failing to meet the actual needs of each individual. In fact, the natural physiological curvature of the head and neck of every individual in the world is different. A truly comfortable pillow should adopt a "person-specific" design approach, meaning that the pillow should be determined based on the natural physiological curvature of each individual's head and neck, and its shape should perfectly match the shape of the human head and neck. Furthermore, regarding the question of what constitutes a truly comfortable sleep pillow and how a comfortable pillow should be designed, there is currently no unified understanding or truly scientific answer.

[0026] Therefore, in response to the above-mentioned current situation and technical problems, this invention proposes a sleep pillow design method based on surface fit and personal preference. The aim is to provide a comfortable pillow design method suitable for each individual based on their actual situation, thereby providing a comfortable sleep pillow that meets personalized needs.

[0027] See Figure 1 The flowchart shown illustrates the sleep pillow design method based on surface fit and personal preference described in this invention, which includes the following five steps S1 to S5, and can also be summarized as "measurement-questioning-calculation-determination-proposal": S1, sequentially measure the natural physiological curvature shape data and pressure value distribution data of the human head and neck; Step S1 specifically includes the following three sub-steps S11 to S13: S11, The shape of the natural physiological surface of the human head and neck is measured using a surface measurement device; There are many devices capable of measuring the shape of three-dimensional curved surfaces in space, mainly including devices based on optical image photogrammetry, devices based on three-dimensional laser scanning, devices based on microwave sensing, and contact mechanical measurement devices.

[0028] 1) Photogrammetry based on optical images: This device combines optical, mechanical, electronic, and computer image processing technologies. By taking pictures of the object being measured and analyzing the images using computer vision technology, it achieves accurate measurement of the object's dimensions.

[0029] 2) Measurement devices based on 3D laser scanning: 3D laser scanners measure distances by emitting lasers and receiving signals reflected from the surface of an object. They utilize the optical triangulation method, projecting a diffuse reflection image onto the surface being measured using a laser source, which is then imaged on an image sensor. The spatial coordinates of the measured point are then determined according to the principle of triangles.

[0030] 3) Microwave Sensing-Based Measurement Devices: The working principle of microwave sensors is based on radar principles. When microwaves encounter an object, they are reflected. By sending microwaves of a certain frequency and receiving the reflected microwaves, and analyzing the changes in the reflected microwaves (such as frequency, phase, intensity, etc.), information about the target object can be obtained, such as distance, speed, size, and shape.

[0031] 4) Contact-type mechanical measuring devices: Contact-type measuring instruments acquire measurement data by contacting the object being measured. Their principle is based on using the changes in the contact force between the measuring instrument and the object to reflect the characteristics of the object. Sensors are typically made of materials such as springs or strain gauges. When the measuring instrument contacts the object, the contact force exerted by the object causes the sensor to deform. These changes can be converted into electrical signals by electronic components. Patent document CN118168494A (application number: CN202410170782.7) discloses a rapid measuring device and application method for the shape of contact surfaces. Using this measuring device and method, the geometric contact surface shape and pressure value distribution of the human head and neck at different pitch angles in a supine position can be quickly obtained.

[0032] The above-mentioned measurement methods and devices can effectively and accurately measure the shape of the human head and neck, and are suitable for different application scenarios and needs.

[0033] S12, use the natural physiological surface shape obtained in sub-step S11 as the initial surface shape of the pressure measuring device; Pressure measuring devices are a type of device based on force sensors, used to measure the downward pressure formed on the head and neck of a person when they are in a natural lying position. Based on the type of sensor, pressure measuring devices mainly include spring-based pressure measuring devices and magnetic force-based pressure measuring devices.

[0034] The principle of a pressure measuring device based on a spring is to measure the magnitude of the force by utilizing the elastic deformation of the spring. That is, by taking advantage of the property that the spring deformation is proportional to the external force (Hooke's Law), the pressure is converted into mechanical displacement or electrical signal for measurement.

[0035] Magnetic pressure measurement devices work by measuring magnetic reaction force or displacement through the interaction between a magnetic module and a magnetically conductive component. A typical device, such as a magnetic force measuring instrument, combines hydraulic / electronic sensors to record the maximum force value.

[0036] S13, use a pressure measuring device to obtain pressure distribution data of the human head and neck.

[0037] Essentially, the human head and neck form a continuous curved surface, while pressure measuring devices can only measure a number of discrete points on a given set of measuring points. The more measuring points a device sets up, the more pressure data it can acquire, and the more accurate the measurement becomes, but the higher the cost also becomes. The pressure distribution data mentioned here refers to the set of pressure data at various measuring points on the human head and neck.

[0038] S2, query to obtain individual preferences for pillow height and firmness; Individual preferences for pillow firmness vary, influenced by factors such as sleeping posture, body characteristics, health status, personal preferences, and environment. Therefore, an ideal pillow design should accommodate these differences, providing appropriate support and comfort. Generally speaking, pillow firmness is categorized into three types: soft, medium, and firm. Soft and firm firmness levels include slight, moderate, and extra firm, while medium firmness levels include light, moderate, and heavy.

[0039] Taking latex pillows as an example, based on the above classification approach of softness and firmness types and levels, the following classification reference is given, as shown in Table 1.

[0040] Table 1. Pillow firmness classification and corresponding firmness values

[0041] In Table 1, the symbol D represents the density of the pillow, with the unit being kg / m³. Therefore, taking a latex pillow with a hardness value of 50D as an example means that its density is 50 kg / m³.

[0042] It is worth noting that if a pillow is too soft, the scalp will be under too much pressure, which is not conducive to blood circulation. It is also difficult to maintain a certain height and will not provide enough support for the neck, which can easily cause neck muscle fatigue and thus be detrimental to sleep. Conversely, if a pillow is too hard, the contact area with the head will be too small, resulting in excessive local pressure and causing discomfort to the head.

[0043] Besides firmness, pillow height is also a crucial factor, as a good height ensures proper blood circulation to the head. We generally consider the cervical spine to have six degrees of freedom in three-dimensional space, primarily involving movement in three planes: flexion / extension (forward / backward), lateral flexion (left / right), and rotation (horizontal). Specifically, this includes forward flexion, backward extension, left lateral flexion, right lateral flexion, left rotation, and right rotation. However, upon closer examination, we find that flexion / extension movements encompass two types: a head-nodding / lifting motion (tilting forward) and a forward flexion motion similar to extending the neck. The pillow's curvature affects the degree of cervical spine flexion / extension, while the pillow's height affects the degree of cervical spine flexion / extension. However, pillow height is not a single standard; it needs to be chosen considering age, sleeping posture, body type, and other factors.

[0044] Based on sleeping posture requirements, the pillow height range for supine positions is typically 6-12cm (about the height of a fist when compressed), while the height range for side-lying positions is 10-15cm (about the width of one shoulder). A personalized height can be determined using the formula: Pillow height ≈ (shoulder width - head width) ÷ 2 + 3 - 4 fingers. For example, if the shoulder width is 40cm and the head width is 20cm, the height would be approximately 10cm + 3 fingers (about 12cm).

[0045] As shown in Table 2, pillow height can be categorized into three types: low, normal, and high.

[0046] Table 2 Pillow Height Preference Categories and Corresponding Values

[0047] S3. Establish a mechanical model of the pillow under single-point pressure. Based on the measurement data obtained in step S1 and the softness and hardness preference information obtained in step S2, calculate the initial shape and position of the pillow at a single measurement point, and then calculate the initial curved surface design shape of the pillow through a preset algorithm. The mechanical model of the pillow under pressure is a force balance model that describes the pillow being in a state of force balance after the human head and neck come into contact with the pillow and pressure is applied; the ideal pillow shape is the natural physiological curve of the human head and neck.

[0048] refer to Figure 2 The mechanical equilibrium model of the pillow under compression shown is presented in this invention. The present invention establishes the following numerical analytical form of the pillow under compression mechanical model: , In the formula, the subscript This indicates the number of a measurement point. Indicates measurement point The magnitude of the pressure exerted on the pillow surface by the human head and neck. Point The design stiffness of the pillow, For measurement points The initial shape and position of the pillow, and For measurement points The position of the pillow on the equilibrium plane is also the measurement point. The position of the pillow on the natural physiological curvature of the human head and neck; the design stiffness of the pillow depends on the individual's preference for pillow firmness; and the pressure value of the human head and neck can be measured by the pressure measuring device described in step S1.

[0049] From the above formula, the formula for calculating the initial shape and position of the pillow at a single measurement point can be obtained as follows: , After obtaining the initial surface positions of the pillow at all measurement points, the initial curved surface design shape of the pillow can be calculated using a certain algorithm. Common algorithms or methods include linear interpolation, cubic interpolation, polynomial fitting, and spline function fitting. Taking linear interpolation as an example, it is an algebraic interpolation method based on approximating a curve with a straight line between two points. It constructs a straight line equation using the coordinates of two known points, thereby estimating the function value at any point within the interval. The interpolation result is calculated by weighting the distance between the two known points.

[0050] To further measure the accuracy of the designed pillow shape, the concept of fit is introduced, which describes the degree of matching between the pillow shape in equilibrium and the ideal pillow shape. Fit is expressed as the root mean square error of the shape. The specific calculation formula is as follows: , In the formula, This indicates the total number of sections after dividing the pillow surface. This indicates the sequence number of the segmented units into which the pillow surface is divided. Indicates the first The projected area of ​​each block unit, Indicates the first The actual center of each block unit To the location, Indicates the first The ideal center of each block unit To position, symbol This indicates a summation operation.

[0051] Root mean square error of the surface The smaller the value, the better the fit between the pillow shape in a state of force equilibrium and the ideal pillow shape.

[0052] By incorporating the concept of surface fit, the initial curved surface design shape of the entire pillow, calculated earlier, can be further optimized.

[0053] The optimization criterion adopts the maximization of surface fit criterion. This criterion emphasizes that the shape of the pillow in a force-balanced state must closely match the natural physiological curvature of the human head and neck, thereby minimizing the root mean square error of the shape between the pillow's shape in the balanced state and the natural physiological curvature of the human head and neck. With mathematical modeling and algorithm iteration as the core objective, the optimal match between the two is achieved.

[0054] The specific optimization process is as follows: Step S31, Data Preparation and Initialization: Input the measurement point data representing pressure distribution and physiological surface shape from step S1 { , }, Hardness data from step S2 and height type, and initial shape data And set parameters such as the fit threshold and the number of pillow surface segmentation units; here, the fit threshold is set. ≤1.5mm; Number of segmented units on the pillow surface =300.

[0055] Step S32, Shape Fitting and Error Calculation: High-order interpolation reconstruction algorithms, such as spline function fitting, are used to reconstruct the initial shape. Perform smoothing to generate a continuous surface. ;contrast With ideal surface Calculate the current error value according to the consistency formula. .

[0056] Note that the transition zone between the head and neck, such as the distance from the external occipital protuberance to the highest point of the parietal bone, needs to gradually change, with a rate of curvature change ≤ Therefore, it satisfies curvature continuity (second derivative continuity). Step S33, Mechanical Model Feedback Adjustment: With the user-specified height and stiffness type remaining constant as constraints, optimize the model using calculation methods such as Newton's iteration method or gradient descent method. make minimize; Note that pressure verification is performed on a single point simultaneously during the iteration process, based on the mechanical model. Check the pressure at each measuring point Is it uniform? If at a certain point... If the value exceeds ±20% of the average, adjust the local stiffness. or shape and position .

[0057] Step S34, Smoothness detection and verification: Use curvature analysis tools to check the continuity of the second derivative of the surface and eliminate abrupt change regions.

[0058] Step S35, output the final shape: when If the threshold is reached and all constraints are satisfied, or if the number of iterations exceeds the upper limit, output a smooth and continuous pillow-shaped surface result.

[0059] In addition to the above-mentioned optimization criteria for maximizing surface fit, the optimization process can also introduce optimization criteria such as minimizing maximum pressure and uniform pressure distribution.

[0060] The optimization criterion of minimizing maximum pressure is based on To optimize the target and reduce the peak value of pressure distribution on the pillow surface, mathematical modeling and mechanical adjustments are used to prevent local pressure concentration.

[0061] Pressure distribution uniformity aims to minimize the standard deviation of pressure, thereby minimizing the dispersion of pressure values ​​on the pillow surface. This is achieved through mathematical modeling to ensure a balanced pressure distribution in the head-neck contact area. The formula for calculating the standard deviation of pressure is as follows: , In the formula, This represents the average pressure at all measurement points. This represents the total number of valid measurement points.

[0062] S4. Determine the height of the pillow based on the height preference information obtained in step S2, determine the surface shape profile of the pillow based on the initial curved surface design shape of the pillow calculated in step S3, and determine the softness and hardness of the pillow through material selection. Based on the above steps, we have identified three important design elements for pillows: pillow height, pillow surface shape and contour, and pillow firmness.

[0063] S5. Extract the key surface parameters that describe the initial curved surface design shape of the pillow, and use these key surface parameters as the basis for guiding pillow classification and shaping.

[0064] Just as no two leaves are exactly alike, no two people have exactly the same natural physiological curvature of their head and neck. Strictly speaking, the most suitable pillow for each individual is also unique. This invention is designed based on the natural physiological curvature of each individual's head and neck; therefore, pillows designed according to the steps outlined above will undoubtedly be different. To ensure strong engineering feasibility and guidance in actual production, this embodiment extracts core parameter indicators from the inherently continuous yet diverse pillow shapes by identifying the core key parameters describing the pillow's curvature, thereby planning a limited number of pillow styles and designs, providing guidance for pillow classification and shaping.

[0065] See patent document CN119092044A (application number: CN202411073171.7), which discloses a method and system for recommending pillows based on the physiological curves of the head, neck, and shoulders. The key surface parameters used to describe the initial curved shape of the pillow include: the depth, length, and overall curvature of the head curve segment; the depth, length, and overall curvature of the neck curve segment; the horizontal distance from the lowest point of the head curve segment to the highest point of the parietal bone; the vertical distance from the external occipital protuberance to the highest point of the parietal bone; and the horizontal distance from the highest point of the neck curve segment to the highest point of the parietal bone. While these key surface parameters can describe and characterize the curved shape of the pillow to a certain extent, they are not exhaustive. In practice, more valuable parameters or indicators can be explored, thus providing a more intuitive and scientific basis and parameters for pillow classification and shaping.

[0066] The beneficial technical effects that can be achieved by utilizing the technical solution proposed by the present invention are mainly reflected in, but not limited to, the following aspects: Firstly, this invention starts from the individual reality of each user, comprehensively considers individual differences and surface matching, and provides a more comfortable pillow design method that meets individual physiological needs. The designed pillow has a high degree of conformity with the natural physiological curve of the user's head and neck under the force balance state, thereby optimizing the shape and performance of the pillow, which can significantly improve the comfort and quality of the user's sleep, while helping to reduce neck pain and relieve sleep fatigue, thus achieving the scientific "personalized pillow design". Secondly, the design method described in this invention ensures a high degree of conformity between the balanced state shape of the pillow after deformation under the action of the human head and neck and the natural physiological curve shape of the human head and neck. Therefore, it helps to support and protect the normal physiological curve of the human cervical spine, thereby promoting spinal health. Thirdly, the design method described in this invention incorporates two important factors at the design level: pillow height and firmness. The height factor takes into account the need for the degree of freedom of the human cervical spine to flex and extend (while the curved shape of the pillow takes into account the degree of freedom of the human cervical spine to tilt and flex). A good height can ensure smooth blood circulation. The firmness factor can reflect the different individual needs for pillow comfort.

[0067] Furthermore, the method described in this invention also scientifically classifies and shapes the inherently continuous and diverse pillow surfaces by finding the core key parameters that describe the curved shape of the pillow, thereby providing technical guidance for planning pillows with limited styles and designs.

[0068] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A method for designing a sleep pillow based on surface fit and personal preference, characterized in that, Includes the following steps: S1, sequentially measure the natural physiological curvature shape data and pressure value distribution data of the human head and neck; The pressure value distribution data is a set of pressure value data at various measurement points on the human head and neck. S2, query to obtain individual preferences for pillow height and firmness; S3. Establish a mechanical model of the pillow under single-point pressure. Based on the measurement data obtained in step S1 and the softness and hardness preference information obtained in step S2, calculate the initial shape and position of the pillow at a single measurement point, and then calculate the initial curved surface design shape of the pillow through a preset algorithm. The single-point pressure state mechanical model of the pillow is a force balance model that describes the pillow being in a force balance state after the human head and neck come into contact with the pillow under pressure at a certain measurement point; S4. Determine the height of the pillow based on the height preference information obtained in step S2, determine the surface shape profile of the pillow based on the initial curved surface design shape of the pillow calculated in step S3, and determine the softness and hardness of the pillow through material selection. S5. Extract the key surface parameters that describe the initial curved surface design shape of the pillow, and use these key surface parameters as the basis for guiding pillow classification and shaping.

2. The sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, The mechanical model of the pillow under single-point compression in step S3 adopts the following numerical analytical model: ， In the formula, the subscript This indicates the number of a measurement point. Indicates measurement point The magnitude of the pressure exerted on the pillow surface by the human head and neck. Point The design stiffness of the pillow, For measurement points The initial shape and position of the pillow, and For measurement points The position of the pillow on the equilibrium plane is also the measurement point. Its position on the natural physiological curves of the human head and neck; The design stiffness of the pillow depends on the individual's preference for pillow firmness.

3. The sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, The preset algorithm used in step S3 to calculate the initial surface design shape of the pillow includes one or more of the following: linear interpolation algorithm, cubic interpolation algorithm, polynomial fitting algorithm, and spline function fitting algorithm.

4. The sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, The degree of matching between the pillow's shape in a state of force equilibrium and the ideal pillow shape is measured by the degree of fit; the degree of fit is expressed as the root mean square error of the shape. The specific calculation formula is as follows: ， In the formula, This indicates the total number of sections after dividing the pillow surface. This indicates the sequence number of the segmented units into which the pillow surface is divided. Indicates the first The projected area of ​​each block unit, Indicates the first The actual center of each block unit To the location, Indicates the first The ideal center of each block unit To position, symbol This represents the summation operation; Based on the aforementioned fit, the initial curved surface design shape of the entire pillow obtained in step S3 can be further optimized.

5. The sleep pillow design method based on surface fit and personal preference as described in claim 4, characterized in that, The criterion for further surface optimization of the initial curved surface design shape of the entire pillow obtained in step S3 is the maximization criterion of surface fit, which is based on minimizing the root mean square error of the surface. To optimize the objective, mathematical modeling and algorithm iteration are used to achieve the best match between the pillow shape in equilibrium and the natural physiological curvature of the human head and neck. The specific optimization process is as follows: Step S31, Data preparation and initialization: Input the measurement point data representing pressure distribution and physiological surface shape from step S1, the softness and hardness data and height type from step S2, and the initial surface data from step S3, and set the fit threshold and the number of pillow surface block units. Step S32, Surface Fitting and Error Calculation: The initial surface is smoothed using a spline function fitting algorithm to generate a continuous surface, and the current error value is calculated according to the fit formula. ; Step S33, Mechanical Model Feedback Adjustment: Optimize using Newton's iterative calculation method, while maintaining the user-specified height and stiffness type as constraints. make minimize; Step S34, Smoothness detection and verification: Use curvature analysis tools to check the continuity of the second derivative of the surface; Step S35, output the final shape: when If the threshold is reached and all constraints are satisfied, or if the number of iterations exceeds the upper limit, output the pillow shape optimization result.

6. The sleep pillow design method based on surface fit and personal preference as described in claim 5, characterized in that, The criteria for further surface optimization of the initial curved surface design shape of the entire pillow obtained in step S3 can also be the maximum pressure minimization optimization criterion, which is based on... To optimize the target and reduce the peak pressure distribution on the pillow surface, mathematical modeling and mechanical adjustments are used to prevent localized pressure concentration. Indicates measurement point The magnitude of the pressure exerted on the surface of the pillow by the human head and neck.

7. The sleep pillow design method based on surface fit and personal preference as described in claim 5, characterized in that, The criteria for further surface optimization of the initial curved surface design shape of the entire pillow obtained in step S3 can also be the pressure distribution uniformity optimization criterion. This optimization criterion aims to minimize the pressure standard deviation, thereby minimizing the dispersion of pressure values ​​on the pillow surface. Through mathematical modeling, a balanced pressure distribution in the head-neck contact area is achieved. The pressure standard deviation... The calculation formula is ,in This represents the average pressure at all measurement points. This represents the total number of valid measurement points.

8. The sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, Step S1 includes the following sub-steps: S11, The shape of the natural physiological surface of the human head and neck is measured using a surface measurement device; The surface measurement device includes one or more of the following: an optical image photogrammetry device, a three-dimensional laser scanning device, a microwave sensing device, and a contact mechanical measurement device. S12, use the natural physiological surface shape obtained in sub-step S11 as the initial surface shape of the pressure measuring device; The pressure measuring device includes one or more of spring-based pressure measuring devices and magnetic force-based pressure measuring devices; S13, use a pressure measuring device to obtain pressure distribution data of the human head and neck.

9. A sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, The pillow firmness type mentioned in step S2 includes soft, medium and firm; the degree levels of the two firmness types include slight, normal and super, and the degree levels of the medium firmness type include light, normal and heavy; and the pillow height type includes low, normal and high.

10. A sleep pillow design method based on surface fit and personal preference as described in claim 1, characterized in that, The key surface parameters describing the initial curved surface design shape of the pillow in step S5 include: the depth, length, and overall curvature of the head curve segment; the depth, length, and overall curvature of the neck curve segment; the horizontal distance from the lowest point of the head curve segment to the highest point of the parietal bone; the vertical distance from the external occipital protuberance to the highest point of the parietal bone; and the horizontal distance from the highest point of the neck curve segment to the highest point of the parietal bone.

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