# Storage Method for Medical and Health Big Data Based on Distributed Sensor Network

Authors: Hui Chen; Zhao Song; Feng Yang
Journal: Journal of Sensors
 (2023)

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## Abstract

Monitoring and collecting medical data using embedded medical diagnostic devices with multiple sensors and sending these actual measured data to the corresponding health monitoring centers using multipurpose wireless networks to take necessary measures to coordinate with family medical service centers and regional medical service departments is a popular medical big data architecture. However, healthcare big data is characterized by large data volume, fast growth, multimodality, high value and privacy, etc. How to organize and manage it in a unified and efficient way is an important research direction at present. In response to the problems of low balance and poor security in the storage of data collected by distributed sensor networks in healthcare systems, we propose a distributed storage algorithm for big data in healthcare systems. The platform adopts Hadoop distributed file system and distributed file storage framework as the healthcare big data storage solution, and implements data integration, multidimensional data query and analysis mining components based on Spark-SQL data query tool, Spark machine learning algorithm library and its mining and analysis pipeline development, respectively. The distributed storage model of big data and three data storage levels are constructed using cloud storage architecture, and the data storage intensity as well as levels are calculated by high data access in the upper level, data connection in the middle level, and data archiving in the lower level according to the set known data granularity, odds, and elasticity to realize big data storage. It is experimentally verified that the above algorithm has high distribution balance and low load balance in the storage process.


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## Body

## 1. Introduction

In recent years, with the rapid development of information technology, the field of medical health and medical research is entering the era of big data, and the daily growth of medical health data has reached the terabyte level. The huge amount of medical and health data contains great value. Building a medical and health data storage platform to realize unified storage and retrieval of data is conducive to sharing data among different medical and health institutions [1–3]. Moreover, the addition of data analysis service function on the platform is conducive to the development of auxiliary diagnosis and treatment and disease prediction technology. Medical and health data is big data, which is characterized by complex data sources, diverse structures, huge scale, rapid growth, and multimodality. Among them, multimodality includes two-dimensional data, images, videos, text documents, etc. However, in the current healthcare service business, the real-time availability of data acquisition, the reliability of storage devices, and the accuracy of data analysis are still the three major problems that need to be solved.Traditional relational databases cannot store unstructured data and are limited by the performance of a single machine, which cannot meet the demand of data storage. Distributed technology is widely used in the field of storage with its advantages of low cost, high reliability, and large capacity, which provides a new idea for storing massive medical and health data. The technology stores, manages, and processes massive data in a distributed manner by connecting multiple common devices and supports the storage of unstructured data [4–7]. As a result, healthcare big data is usually stored in distributed file systems or nonrelational (NoSQL) databases, and the distributed parallel computing model improves the system data analysis to further optimize the query performance of the storage system. The advantages and disadvantages of the existing distributed medical data storage system are shown in Figure 1.Figure 1
Strengths and weaknesses of existing distributed medical data storage systems.Experts have conducted a lot of research and improvements for the business requirements of healthcare data storage system and the limitations of Hadoop system and summarized the improvement methods of Hadoop-based healthcare data storage system as follows. HDFS uses data blocks as data reading and writing units and stores metadata in the memory of NameNode, but since healthcare data contains a large amount of HDFS uses data blocks as data read and write units, and stores metadata in the memory of NameNode. In addition, the Hadoop replica storage policy makes it easy for nodes with frequent read and write operations to reach the load threshold and trigger the load balancing operation of the system several times. Therefore, by optimizing the small file processing strategy and improving the copy selection strategy of Hadoop, the performance optimization of the Hadoop-based medical health data storage system can be achieved [8–10]. The Hadoop distributed system has the advantages of low cost, high scalability, and high reliability, and is suitable for storing time-sensitive medical health data but cannot meet the demand of real-time storage. HDFS aims to achieve high throughput at the cost of high latency; HDFS aims to achieve high throughput at the cost of high latency and is not suitable for low latency read requests, but medical health data has more read and fetch operations, and the long response time will affect the user experience. How to combine MapReduce, Spark, and other big data analysis technologies for parallel processing of data sets is the key to analyze the value of data. There have been many healthcare data storage solutions based on improved Hadoop storage systems, and good research results have been achieved in system storage performance optimization, efficient retrieval, and data analysis [11].Since the reform and opening, medical and health care construction in China has gradually emerged, and its construction is divided by geography. As the concept of medical and health care is built based on medical and health care services, medical and health care services are continuously carried out under the promotion of the government, and medical and health care construction provides convenience for residents’ lives and greatly improves their quality of life.In recent years, the social service function of medical and health care in major cities is high, the construction of infrastructure has achieved leapfrog development, and a medical and health care service system covering 4 levels of city, district, street, and residence have been established. At present, the research on the probabilistic characteristics modeling of big data distributed storage for the regional distribution of medical and health density can be divided into two major aspects: the probabilistic density model of big data distributed storage with the characteristic probability distribution function simulating the regional distribution of medical and health density, and the fitting estimation model driven by the historical data of regional distribution of medical and health density. The former lacks accuracy and universality due to the disadvantages of many factors affecting the distributed storage of big data with health care density area distribution and large differences in spatial and temporal distribution, which makes it difficult to form a generalized application; while the latter uses the historical operational data of health care density area distribution as the sample base and builds the model of probabilistic characteristics of big data distributed storage with health care density area distribution by data-driven. The latter model is based on the historical data of health care density area distribution, and has better generalizability. Beta distribution is used to fit the prediction error of big data distributed storage with health care density area distribution, and then the distribution of prediction error of big data distributed storage with health care density area distribution is used to determine the size of energy storage capacity [12–15]. The t-distribution with shift factor and scaling factor is used to describe the big data distributed storage with regional distribution of medical health density, and then the model parameters are estimated using historical data samples. A third order Gaussian distribution function was used to fit the probability distribution of the longitudinal moments of the big data distributed storage of the regional distribution of health care density, and good results were achieved.The prediction errors of the big data distributed storage of health care health density regional distribution were modeled using exponential distribution and normal distribution functions, respectively, and then the parameters of the distribution functions were estimated using the great likelihood estimation and least squares method. However, the above-mentioned modeling of probabilistic properties of big data distributed storage of health care health density area distribution have the commonality of using a priori distribution models to simulate the probability density of big data distributed storage of health care health density area distribution, so there are two drawbacks: the effect of parameter estimation on sample data relies on the a priori definition set by human subjectivity, and it is difficult to guarantee if the assumptions of the a priori model are biased [16–18]. The convergence of the fitted model is difficult to guarantee if the assumptions of the prior model are biased; the differences in the spatial-temporal distribution of the distributed storage of big data with regional distribution of healthcare density make it necessary to use different probability density distributions for different regions, which does not meet the requirement of universal adaptation of modeling.Although the Hadoop-based approach for medical and health data storage system has an extremely practical value, it is not applicable to some specific application scenarios because the density region distribution of medical and health resources and patient groups are not considered. The optimal extraction of density region distribution in big data environment can effectively improve the data quality in big data environment. The optimal extraction of density region distribution needs to get the density value near each data quality sample, give the region where the samples are aggregated, and complete the optimal extraction of density region distribution. The traditional method first forms the original transaction data set and gives the distribution rules of the data, but neglects to give the region where the data samples are aggregated, resulting in low extraction accuracy.Time series-based method for optimal extraction of density region distribution in big data environment. The method first uses the time series model to identify the time series of each data state volume, classifies the density region distribution in the time series, uses the high-density clustering method to get the density value near each data quality sample, gives the region where the samples are aggregated, and introduces the label movement speed into the sliding window adaptive adjustment process to complete the optimal extraction of the density region distribution in the big data environment. Therefore, this paper proposes the big data distributed storage algorithm for medical and health system, constructs the big data distributed storage algorithm through cloud storage architecture, and considers the density region distribution through density estimation algorithm to achieve the balance between storage system and actual demand, guarantees the antiattack of stored data, and realizes the big data distributed encrypted storage.


## 2. Related Work

### 2.1. Traditional Medical Health Data Storage System

Currently, the construction of mature hospital systems mainly includes HIS (Hospital Information System), EMRS (Electronic Medical Record System), RIS (Radiology Information Management System), and PACS (Image Archiving and Communication System). The schematic diagram of the construction of inhospital medical and health storage system is shown in Figure2. Traditional healthcare data storage systems mostly use relational databases, such as MySQL and SQLServer, which organize data through a relational model and store each record in a two-dimensional table in the form of rows, but relational databases need to satisfy a predefined relational model and each record has a fixed data length [19, 20]. As the inhospital system is only for a single business or a single data type of the hospital, the amount of data stored and managed is relatively small, so the relational database can meet the demand.Figure 2
Schematic diagram of medical institution storage system construction.With the continuous development of network and information technology, the scale and complexity of medical and health data are getting larger and larger, which leads to the following limitations of using relational database for the storage of large-scale medical and health data: (1) medical and health data contain more unstructured data; however, the structure of relational database is relatively fixed and cannot be applied to the storage of unstructured data. (2) Relational database is limited by the storage capacity of single machine and cannot be applied to the storage scenario of medical and health care big data. Although the relational database supports distributed expansion, the installation and maintenance costs are high due to the complex rules of distributed relational database partitioning. (3) The scalability of relational database is poor, and it is difficult to realize data sharing among different medical and health institutions. (4) The read and write of relational database must go through SQL parsing, and the performance of concurrent read and write on large-scale data is weak. (5) The volume of data is too large, which makes it difficult for data analysis software to analyze data effectively and accurately. In summary, the traditional relational database can no longer meet the storage needs of terabytes and petabytes of medical and health data in the era of big data [21, 22].


### 2.2. Distributed Medical and Health Data Storage System

After a long development, the data storage system has gradually evolved from a stand-alone storage system to a storage system that supports distributed expansion. Subsequently, distributed solutions for relational databases and NoSQL databases that natively support distributed storage have emerged. This section introduces Hadoop distributed storage system and NoSQL database, respectively. Hadoop is a mainstream distributed system supporting massive data storage and processing, including Hadoop File System (HDFS), MapReduce, Hadoop Data Base (HBase), and other important components [23, 24]. Among them, HDFS is the data storage and management center of Hadoop system, with high fault tolerance, efficient writing, and other characteristics. The NameNode is responsible for managing the metadata and DataNode nodes of the file system, and the DataNode is the actual working node of the file system, which is responsible for storing and retrieving data and sending the stored block information to the NameNode periodically. The HDFS architecture diagram is shown in Figure 3.Figure 3
HDFS architecture diagram.MapReduce is a model for processing and generating large-scale datasets, which achieves parallel processing of massive datasets in a highly reliable and fault-tolerant way. MapReduce improves the cluster’s ability to handle massive data by decomposing tasks to be processed by multiple Hadoop runtime nodes when processing large datasets. For applications that require random reads, the data is stored in HBase, a column-oriented nonrelational database whose underlying data is stored in HDFS to ensure data reliability, and its integration with MapReduce ensures the efficiency of the system when analyzing large amounts of data.As shown in Figure3, HBase is composed of HMaster, HRegionServer, HRegion, and Zookeeper components. Among them, HMaster is the master server of HBase cluster and is responsible for allocating HRegionServer for HRegion; HRegionServer is responsible for providing data writing, deleting, and searching services for clients; HRegion is a subtable divided by row key, which is the smallest unit of storage and processing in HBase; ZooKeeper NoSQL database stores data without fixed structure, simple data organization, good scalability, and suitable for storing large amount of data. The database can be divided into columnar database, document database, and key-value database [25–27]. Among them, the document database represented by MongoDB supports storing a variety of structural data, and has powerful query function and indexing ability, which is suitable for the massive data application scenario with frequent reading and fetching operations.Distributed technology can realize the unified storage and query of medical and health data, but there are still some problems in the current research. For example, medical health data contains a large amount of patient privacy information, and none of the current storage solutions consider data privacy protection. Due to the high sensitivity of healthcare data, organizations usually use a centralized approach to manage the data; however, the management approach is not transparent enough, which can easily lead to data tampering and privacy leakage. These problems directly threaten data security and user privacy in healthcare, making it difficult to share data among organizations at all levels and unable to fully utilize the value of healthcare data. In recent years, with the continuous development of blockchain technology, it has become an effective means to secure data sharing. Using cryptographic knowledge, data can be secured from tampering, unforgeable, and decentralized transmission access. However, as an emerging technology, blockchain still lacks theoretical support for distributed system architecture and experimental testing for high concurrent read and write operations. Future research can focus on blockchain technology based on distributed architecture to realize a distributed medical and health care big data storage model based on privacy protection [28, 29].To make better use of medical and health information resources to make scientific decisions, it is necessary to dig deeper into the value of medical and health data. Current healthcare big data analysis technologies are focused on statistical analysis and decision-making, especially MongoDB-based healthcare data storage systems, with less research related to data analysis. Knowledge graph has emerged in the field of natural language processing and has become an effective organization form for presenting data knowledge. Using this technology to organize healthcare data helps to extract healthcare knowledge and realize healthcare knowledge reasoning, remote consultation, recommended medication, disease prediction, and other auxiliary diagnosis and treatment services.


### 2.3. Research Status of Density Region Distribution

For mining out high-density regions in data sources, the essence is the process of dividing a data object into subregions (or subsets) of different sizes. The objects in each subregion are highly like each other in terms of information, while not similar to the information of the objects in other subregions. And in the field of data mining, there are many density-based data mining algorithms that can be borrowed for mining out high-density data regions in data sources, such as the classical DBSCAN algorithm. However, the traditional density-based data clustering algorithms, when facing the data set with uneven density distribution, are often not good for the data set to region the data set according to the density distribution of the data. In addition, the traditional algorithm has redundant operations in object domain query, which requires domain query judgment for each sample point, yet it is not necessary to perform query judgment operations for all object domains in a determined high-density subset.Although the above method is of great practical value, it is not applicable to some specific application scenarios. For example, in exploring the changes of animal habits by collecting migration data of North American hoofed animals, the data is obtained by radio telemetry means with large positioning errors and sampling intervals, and large errors are introduced when extracting metadata features such as speed and curvature, resulting in extremely unreliable classification results. In addition, the trajectory data obtained by means of radar scanning, Wi-Fi indoor positioning, cellular positioning, Flicker photo location data, etc. have similar statistical characteristics. For this kind of data, if the trajectory data of different categories overlap severely in space, it is generally considered that its separability is not strong; on the contrary, if there is a certain degree of separation of trajectories in space, their location-related features can be fully explored [30].The two-dimensional space where the two-dimensional trajectory segments are located is divided, and the minimum description length (MDL) is used as the criterion for selecting the granularity of the division, and the rectangular homogeneous region containing only one type of trajectory is extracted as the feature. Compared with the trajectory pattern feature method, this method not only improves the classification accuracy of trajectories, but also enhances the training efficiency of the classifier. However, this method assumes that the significant regions are approximately rectangular in distribution, which is not always applicable in practice. In addition, to reduce the search complexity of the optimal classification, the method uses the projection tox- and y-axis to select the division points of each axis alternately, which is a limitation in the division of the trajectory cluster distribution. To solve this limitation, a strategy of spatial region merging is proposed to extract homogeneous regions; however, this method does not eliminate the limitation of rectangular region shape and still has strong limitations. In addition, Gaussian mixture model (GMM) is proposed to fit the distribution of trajectory segments in space, which eliminates the defects of region division method and extends the application to the problem of classifying trajectory data in 3D or even higher dimensions. However, the drawback of GMM method is that it introduces the number of Gaussian components K. Different values of K will affect the classification results: smaller values of K are not enough to describe the complex trajectory region distribution, and larger values of K may lead to training failure due to the complexity of the model. To more accurately portray the density distribution of the dataset, the region is divided according to the density distribution, and the concept of region and region area is introduced in the traditional density-based clustering algorithm, and the algorithm is improved to portray the density distribution of the dataset with the number of points per unit area.


## 2.1. Traditional Medical Health Data Storage System

Currently, the construction of mature hospital systems mainly includes HIS (Hospital Information System), EMRS (Electronic Medical Record System), RIS (Radiology Information Management System), and PACS (Image Archiving and Communication System). The schematic diagram of the construction of inhospital medical and health storage system is shown in Figure2. Traditional healthcare data storage systems mostly use relational databases, such as MySQL and SQLServer, which organize data through a relational model and store each record in a two-dimensional table in the form of rows, but relational databases need to satisfy a predefined relational model and each record has a fixed data length [19, 20]. As the inhospital system is only for a single business or a single data type of the hospital, the amount of data stored and managed is relatively small, so the relational database can meet the demand.Figure 2
Schematic diagram of medical institution storage system construction.With the continuous development of network and information technology, the scale and complexity of medical and health data are getting larger and larger, which leads to the following limitations of using relational database for the storage of large-scale medical and health data: (1) medical and health data contain more unstructured data; however, the structure of relational database is relatively fixed and cannot be applied to the storage of unstructured data. (2) Relational database is limited by the storage capacity of single machine and cannot be applied to the storage scenario of medical and health care big data. Although the relational database supports distributed expansion, the installation and maintenance costs are high due to the complex rules of distributed relational database partitioning. (3) The scalability of relational database is poor, and it is difficult to realize data sharing among different medical and health institutions. (4) The read and write of relational database must go through SQL parsing, and the performance of concurrent read and write on large-scale data is weak. (5) The volume of data is too large, which makes it difficult for data analysis software to analyze data effectively and accurately. In summary, the traditional relational database can no longer meet the storage needs of terabytes and petabytes of medical and health data in the era of big data [21, 22].


## 2.2. Distributed Medical and Health Data Storage System

After a long development, the data storage system has gradually evolved from a stand-alone storage system to a storage system that supports distributed expansion. Subsequently, distributed solutions for relational databases and NoSQL databases that natively support distributed storage have emerged. This section introduces Hadoop distributed storage system and NoSQL database, respectively. Hadoop is a mainstream distributed system supporting massive data storage and processing, including Hadoop File System (HDFS), MapReduce, Hadoop Data Base (HBase), and other important components [23, 24]. Among them, HDFS is the data storage and management center of Hadoop system, with high fault tolerance, efficient writing, and other characteristics. The NameNode is responsible for managing the metadata and DataNode nodes of the file system, and the DataNode is the actual working node of the file system, which is responsible for storing and retrieving data and sending the stored block information to the NameNode periodically. The HDFS architecture diagram is shown in Figure 3.Figure 3
HDFS architecture diagram.MapReduce is a model for processing and generating large-scale datasets, which achieves parallel processing of massive datasets in a highly reliable and fault-tolerant way. MapReduce improves the cluster’s ability to handle massive data by decomposing tasks to be processed by multiple Hadoop runtime nodes when processing large datasets. For applications that require random reads, the data is stored in HBase, a column-oriented nonrelational database whose underlying data is stored in HDFS to ensure data reliability, and its integration with MapReduce ensures the efficiency of the system when analyzing large amounts of data.As shown in Figure3, HBase is composed of HMaster, HRegionServer, HRegion, and Zookeeper components. Among them, HMaster is the master server of HBase cluster and is responsible for allocating HRegionServer for HRegion; HRegionServer is responsible for providing data writing, deleting, and searching services for clients; HRegion is a subtable divided by row key, which is the smallest unit of storage and processing in HBase; ZooKeeper NoSQL database stores data without fixed structure, simple data organization, good scalability, and suitable for storing large amount of data. The database can be divided into columnar database, document database, and key-value database [25–27]. Among them, the document database represented by MongoDB supports storing a variety of structural data, and has powerful query function and indexing ability, which is suitable for the massive data application scenario with frequent reading and fetching operations.Distributed technology can realize the unified storage and query of medical and health data, but there are still some problems in the current research. For example, medical health data contains a large amount of patient privacy information, and none of the current storage solutions consider data privacy protection. Due to the high sensitivity of healthcare data, organizations usually use a centralized approach to manage the data; however, the management approach is not transparent enough, which can easily lead to data tampering and privacy leakage. These problems directly threaten data security and user privacy in healthcare, making it difficult to share data among organizations at all levels and unable to fully utilize the value of healthcare data. In recent years, with the continuous development of blockchain technology, it has become an effective means to secure data sharing. Using cryptographic knowledge, data can be secured from tampering, unforgeable, and decentralized transmission access. However, as an emerging technology, blockchain still lacks theoretical support for distributed system architecture and experimental testing for high concurrent read and write operations. Future research can focus on blockchain technology based on distributed architecture to realize a distributed medical and health care big data storage model based on privacy protection [28, 29].To make better use of medical and health information resources to make scientific decisions, it is necessary to dig deeper into the value of medical and health data. Current healthcare big data analysis technologies are focused on statistical analysis and decision-making, especially MongoDB-based healthcare data storage systems, with less research related to data analysis. Knowledge graph has emerged in the field of natural language processing and has become an effective organization form for presenting data knowledge. Using this technology to organize healthcare data helps to extract healthcare knowledge and realize healthcare knowledge reasoning, remote consultation, recommended medication, disease prediction, and other auxiliary diagnosis and treatment services.


## 2.3. Research Status of Density Region Distribution

For mining out high-density regions in data sources, the essence is the process of dividing a data object into subregions (or subsets) of different sizes. The objects in each subregion are highly like each other in terms of information, while not similar to the information of the objects in other subregions. And in the field of data mining, there are many density-based data mining algorithms that can be borrowed for mining out high-density data regions in data sources, such as the classical DBSCAN algorithm. However, the traditional density-based data clustering algorithms, when facing the data set with uneven density distribution, are often not good for the data set to region the data set according to the density distribution of the data. In addition, the traditional algorithm has redundant operations in object domain query, which requires domain query judgment for each sample point, yet it is not necessary to perform query judgment operations for all object domains in a determined high-density subset.Although the above method is of great practical value, it is not applicable to some specific application scenarios. For example, in exploring the changes of animal habits by collecting migration data of North American hoofed animals, the data is obtained by radio telemetry means with large positioning errors and sampling intervals, and large errors are introduced when extracting metadata features such as speed and curvature, resulting in extremely unreliable classification results. In addition, the trajectory data obtained by means of radar scanning, Wi-Fi indoor positioning, cellular positioning, Flicker photo location data, etc. have similar statistical characteristics. For this kind of data, if the trajectory data of different categories overlap severely in space, it is generally considered that its separability is not strong; on the contrary, if there is a certain degree of separation of trajectories in space, their location-related features can be fully explored [30].The two-dimensional space where the two-dimensional trajectory segments are located is divided, and the minimum description length (MDL) is used as the criterion for selecting the granularity of the division, and the rectangular homogeneous region containing only one type of trajectory is extracted as the feature. Compared with the trajectory pattern feature method, this method not only improves the classification accuracy of trajectories, but also enhances the training efficiency of the classifier. However, this method assumes that the significant regions are approximately rectangular in distribution, which is not always applicable in practice. In addition, to reduce the search complexity of the optimal classification, the method uses the projection tox- and y-axis to select the division points of each axis alternately, which is a limitation in the division of the trajectory cluster distribution. To solve this limitation, a strategy of spatial region merging is proposed to extract homogeneous regions; however, this method does not eliminate the limitation of rectangular region shape and still has strong limitations. In addition, Gaussian mixture model (GMM) is proposed to fit the distribution of trajectory segments in space, which eliminates the defects of region division method and extends the application to the problem of classifying trajectory data in 3D or even higher dimensions. However, the drawback of GMM method is that it introduces the number of Gaussian components K. Different values of K will affect the classification results: smaller values of K are not enough to describe the complex trajectory region distribution, and larger values of K may lead to training failure due to the complexity of the model. To more accurately portray the density distribution of the dataset, the region is divided according to the density distribution, and the concept of region and region area is introduced in the traditional density-based clustering algorithm, and the algorithm is improved to portray the density distribution of the dataset with the number of points per unit area.


## 3. Methods

### 3.1. Model Structure

The distributed storage of medical and health care big data proposed in this paper is shown in Figure4. This architecture consists of application layer, storage layer, and platform layer. The application layer consists of clients of HIS system and PACS system, which are responsible for providing users with operation interface, information management, image viewing, and other functions. The storage layer is a two-level storage model of local side and cloud side, the local side consists of HIS server and PACS server, which can be built on the local server side and is responsible for storing and managing.Figure 4
Model structure.The local side consists of HIS server and PACS server, which can be built on the local server side and is responsible for storing and managing the structured information data and recent image data of the hospital; the cloud side is built by FastDFS large-scale distributed cluster, which is responsible for the permanent storage of long-term files. The platform layer is a virtual platform built on top of the infrastructure by virtualization technology, which facilitates the provision of cloud services through the rational and efficient use of server resources.


### 3.2. Distributed Sensor Network

Distributed sensor network-based medical health monitoring system is a networked physiological monitoring physiotherapy system for collecting users’ body status data, which should have the functions of automatic recording, continuous monitoring, warning notification, intelligent judgment, self-correction, and standard transmission. Noninvasive physiological signal monitoring system is an important part of the monitoring system, which consists of multiple sensors that measure medical data including important vital signs such as blood pressure, blood glucose, heart rate, blood oxygen concentration, and arterial oxygen pressure saturation. For example, a noninvasive wristwatch blood pressure monitor allows users to wear it around like a watch, monitor blood pressure, and record pulse rate 24/7 without discomfort for long periods of time. Over the Internet, medical monitoring data based on a distributed sensor network is transmitted by multiple complementary wireless networks to a specific health monitoring center, where it is integrated into the permanent electronic medical record of the designated user. As a result, the medical staff at the health monitoring center can monitor various vital signs of the user at any appropriate time, and if any abnormal physical signs are detected, the medical staff will give appropriate medical instructions before the condition deteriorates, and then take steps to treat the condition. The health monitoring center specialists can also accurately locate the user, consult with his or her home monitoring center doctor, and coordinate with local medical services using the fastest delivery method to take timely medical assistance. The goal of the health monitoring system is to monitor the health status of the user at anytime and anywhere. Therefore, the following two typical situations are illustrated: when the user is at home or near his residence, and when the user is far from home or in another city. Considering these two situations, the author proposes that the distributed health monitoring system, health monitoring center will be distributed to each region. In case 1, the user’s medical monitoring data will be sent to the home health monitoring center; in case 2, the medical monitoring data will be sent to the corresponding visiting health monitoring center.


### 3.3. Distributed Storage Algorithm

When data storage requirements are acquired by storage nodes, the distributed data storage continuously sends preservation requests. Therefore, through the storage capacity analysis and data storage hierarchy designed in this paper, if the demand of Equation (7) can be achieved after computing, the data is preserved, and if not, Equations (1)–(7) are repeatedly executed. At the same time, the data storage process is adjusted into three levels, firstly, the upper level completes data height access, the lower level realizes data archiving, and the middle level mainly takes over the connection between the upper and lower levels. Among them, the upper layer of the data storage process is mainly represented by the following Equations (1)–(7). If the adoption probability of distributed data is expressed through Px, the inverse relationship appears in the expectation of its adoption probability as EPx as well as the elastic expectation as ETx, so the elastic expectation of distributed data is calculated through
(1)EPx=λ−λ2ETx2−ETxETx.In Equation (1), the degree of obedience of the distributed data is described by A. If the result obtained from Equation (1) is negative, it is known that the blocked state is inversely proportional to the smooth state when the data is stored, and at this time, the distributed data storage is continued to be completed. If the result obtained is positive, it is necessary to control the preservation capacity during data storage and achieve continuous data storage by modifying the data granularity. Since the result obtained from Equation (1) will make the data storage smoothly affected and the calculated value is negative, if the data granularity is small, the result obtained from the calculation of Equation (1) may appear positive. Therefore, manipulating the data elasticity Tx by the granularity rate p can improve the congestion of data storage and reduce the degree of storage space being occupied. Since a negative correlation exists between Tx and p, it is known, based on this conclusion, that Tx can maintain its original value by means of Equation (2).
(2)Tx⇒p.The expected value ofETx⇒p can reach the time function, therefore, is described by Equation (3) as:
(3)ETx⇒p=∫ETx.Therefore, based on Equation (3), if at this stage we still set p to be the data preservation access granularity rate, i.e., the next moment Tx can be completed by the following
(4)Tx=∫ETx+ETx⇒p.Since the distributed storage has a limited bandwidth during the big data storage,Tx can be completely covered by the storage hierarchy, while the confirmed coverage association Δt corresponding to the random moment can be expressed by
(5)ΔTx=p∫ΔΔtΔ2−Tx2.Based on Equation (5), the big data distributed storage intensity index Δλ is described by
(6)Δλ=ETx−λ1−λ2ETx2−ETx.Based on the calculation of Equation (6), the calculation of data elasticity Tx and big data distributed storage gradient Δ can be completed by
(7)Tx=Δ1−Δ1−Δλ.With Equation (7), the process of distributed storage of data can be reached. Meanwhile, the final distributed storage of big data is described in the form ΔX via
(8)ΔX=Esentc·c·Px·Δλ·Tx.In the Equation (8), it is the result of the calculated preservation of the distributed storage of big data.


### 3.4. Density Area Distribution

In the big data environment, most of the original state data time series contain multiple feature data, so in the process of optimizing the extraction of feature data in the big data environment, it is necessary to use the time series model to divide all the collected data states into multivariate continuous time series, give the high-quality data state volume amplitude change law, extract the feature data state characteristics, and calculate the feature data on the time. The effect of the feature data on the time series fitting is calculated, and the residuals of the time series fitting of each data distribution state are obtained. The specific steps are detailed as follows: suppose, byαdfyy′ represents the number of each data state set in the big data environment, and Xth represents the value of the data state volume l at the moment h. Using Equation (9), all the collected data states are divided into a multivariate continuous time series
(9)rtghpp′=αdfyy′∗Xthpfgg′,where pfgg′ represents the autoregressive moving average function. Suppose ydfujj′ represents the high-quality data state change law, ω′ represents the type of change law, ofgij′ represents the time interval in which different data state quantities are periodically changed, and mfg′ represents the observation point of each data state quantity existing on the time series, using equation (10) to give the high quality data state quantity amplitude law.
(10)tdf′=mfg′×ofgij′ω′∓pdfpp′×ydfujj′∓κfg′where pdfpp′ represents the impulse function and κfg′ represents the delay operator. Suppose by gvbhjk′ represents the time series of high-quality data, the distribution of gvbhjk′ obeys the autoregressive moving average function represented by pfggg′, and rrdfgg represents the influence factor of the characteristic data, the characteristic data state characteristics are extracted using
(11)popll′=pfggg′∓rdfgggvbhjk′∓tdf′.In an observed time series, different time points are affected by different feature data. Suppose byZt′ and vjB represent the type of feature data, respectively, and kztvjB′ represents the number of feature data, the effect of feature data on the time fit is obtained using
(12)Esdpp′=kztvjB′×vjB±Zt′popll′×ujkk′∓rtghpp′,where ujkk′ represents the moment of feature data generation.


### 3.5. Data Processing

Because the total amount of collected data is huge and diverse, the platform needs to clean, transform, classify, integrate, and process the data and then store them in a distributed database. The built healthcare big data platform uses the distributed database SequoiaDB to store data, and the SequoiaDB distributed database contains data nodes, cataloging nodes, and coordination nodes. When an application sends an access request to the coordinating node, the coordinating node first calculates the optimal data node by communicating with the cataloging node and distributes the query task, and finally returns the query results of each data node to the application after aggregation.The data computing platform uses the Spark computing framework, which supports a variety of data storage models and can be combined with Hadoop to share storage resources and computation in a Hadoop cluster, and Spark can compute data that is accessed frequently and centrally and store such data in memory to improve access efficiency. Users submit data requests on the healthcare platform, and the platform analyzes the user input and presents the data. In addition to direct data list display, the data presentation method also provides data graphical display, coding the platform statistical classification of data into graphics, using the mainstream visualization technology html5, the introduction of chart drawing tool library chart.js, the data will be presented in the form of statistical chart reports.


## 3.1. Model Structure

The distributed storage of medical and health care big data proposed in this paper is shown in Figure4. This architecture consists of application layer, storage layer, and platform layer. The application layer consists of clients of HIS system and PACS system, which are responsible for providing users with operation interface, information management, image viewing, and other functions. The storage layer is a two-level storage model of local side and cloud side, the local side consists of HIS server and PACS server, which can be built on the local server side and is responsible for storing and managing.Figure 4
Model structure.The local side consists of HIS server and PACS server, which can be built on the local server side and is responsible for storing and managing the structured information data and recent image data of the hospital; the cloud side is built by FastDFS large-scale distributed cluster, which is responsible for the permanent storage of long-term files. The platform layer is a virtual platform built on top of the infrastructure by virtualization technology, which facilitates the provision of cloud services through the rational and efficient use of server resources.


## 3.2. Distributed Sensor Network

Distributed sensor network-based medical health monitoring system is a networked physiological monitoring physiotherapy system for collecting users’ body status data, which should have the functions of automatic recording, continuous monitoring, warning notification, intelligent judgment, self-correction, and standard transmission. Noninvasive physiological signal monitoring system is an important part of the monitoring system, which consists of multiple sensors that measure medical data including important vital signs such as blood pressure, blood glucose, heart rate, blood oxygen concentration, and arterial oxygen pressure saturation. For example, a noninvasive wristwatch blood pressure monitor allows users to wear it around like a watch, monitor blood pressure, and record pulse rate 24/7 without discomfort for long periods of time. Over the Internet, medical monitoring data based on a distributed sensor network is transmitted by multiple complementary wireless networks to a specific health monitoring center, where it is integrated into the permanent electronic medical record of the designated user. As a result, the medical staff at the health monitoring center can monitor various vital signs of the user at any appropriate time, and if any abnormal physical signs are detected, the medical staff will give appropriate medical instructions before the condition deteriorates, and then take steps to treat the condition. The health monitoring center specialists can also accurately locate the user, consult with his or her home monitoring center doctor, and coordinate with local medical services using the fastest delivery method to take timely medical assistance. The goal of the health monitoring system is to monitor the health status of the user at anytime and anywhere. Therefore, the following two typical situations are illustrated: when the user is at home or near his residence, and when the user is far from home or in another city. Considering these two situations, the author proposes that the distributed health monitoring system, health monitoring center will be distributed to each region. In case 1, the user’s medical monitoring data will be sent to the home health monitoring center; in case 2, the medical monitoring data will be sent to the corresponding visiting health monitoring center.


## 3.3. Distributed Storage Algorithm

When data storage requirements are acquired by storage nodes, the distributed data storage continuously sends preservation requests. Therefore, through the storage capacity analysis and data storage hierarchy designed in this paper, if the demand of Equation (7) can be achieved after computing, the data is preserved, and if not, Equations (1)–(7) are repeatedly executed. At the same time, the data storage process is adjusted into three levels, firstly, the upper level completes data height access, the lower level realizes data archiving, and the middle level mainly takes over the connection between the upper and lower levels. Among them, the upper layer of the data storage process is mainly represented by the following Equations (1)–(7). If the adoption probability of distributed data is expressed through Px, the inverse relationship appears in the expectation of its adoption probability as EPx as well as the elastic expectation as ETx, so the elastic expectation of distributed data is calculated through
(1)EPx=λ−λ2ETx2−ETxETx.In Equation (1), the degree of obedience of the distributed data is described by A. If the result obtained from Equation (1) is negative, it is known that the blocked state is inversely proportional to the smooth state when the data is stored, and at this time, the distributed data storage is continued to be completed. If the result obtained is positive, it is necessary to control the preservation capacity during data storage and achieve continuous data storage by modifying the data granularity. Since the result obtained from Equation (1) will make the data storage smoothly affected and the calculated value is negative, if the data granularity is small, the result obtained from the calculation of Equation (1) may appear positive. Therefore, manipulating the data elasticity Tx by the granularity rate p can improve the congestion of data storage and reduce the degree of storage space being occupied. Since a negative correlation exists between Tx and p, it is known, based on this conclusion, that Tx can maintain its original value by means of Equation (2).
(2)Tx⇒p.The expected value ofETx⇒p can reach the time function, therefore, is described by Equation (3) as:
(3)ETx⇒p=∫ETx.Therefore, based on Equation (3), if at this stage we still set p to be the data preservation access granularity rate, i.e., the next moment Tx can be completed by the following
(4)Tx=∫ETx+ETx⇒p.Since the distributed storage has a limited bandwidth during the big data storage,Tx can be completely covered by the storage hierarchy, while the confirmed coverage association Δt corresponding to the random moment can be expressed by
(5)ΔTx=p∫ΔΔtΔ2−Tx2.Based on Equation (5), the big data distributed storage intensity index Δλ is described by
(6)Δλ=ETx−λ1−λ2ETx2−ETx.Based on the calculation of Equation (6), the calculation of data elasticity Tx and big data distributed storage gradient Δ can be completed by
(7)Tx=Δ1−Δ1−Δλ.With Equation (7), the process of distributed storage of data can be reached. Meanwhile, the final distributed storage of big data is described in the form ΔX via
(8)ΔX=Esentc·c·Px·Δλ·Tx.In the Equation (8), it is the result of the calculated preservation of the distributed storage of big data.


## 3.4. Density Area Distribution

In the big data environment, most of the original state data time series contain multiple feature data, so in the process of optimizing the extraction of feature data in the big data environment, it is necessary to use the time series model to divide all the collected data states into multivariate continuous time series, give the high-quality data state volume amplitude change law, extract the feature data state characteristics, and calculate the feature data on the time. The effect of the feature data on the time series fitting is calculated, and the residuals of the time series fitting of each data distribution state are obtained. The specific steps are detailed as follows: suppose, byαdfyy′ represents the number of each data state set in the big data environment, and Xth represents the value of the data state volume l at the moment h. Using Equation (9), all the collected data states are divided into a multivariate continuous time series
(9)rtghpp′=αdfyy′∗Xthpfgg′,where pfgg′ represents the autoregressive moving average function. Suppose ydfujj′ represents the high-quality data state change law, ω′ represents the type of change law, ofgij′ represents the time interval in which different data state quantities are periodically changed, and mfg′ represents the observation point of each data state quantity existing on the time series, using equation (10) to give the high quality data state quantity amplitude law.
(10)tdf′=mfg′×ofgij′ω′∓pdfpp′×ydfujj′∓κfg′where pdfpp′ represents the impulse function and κfg′ represents the delay operator. Suppose by gvbhjk′ represents the time series of high-quality data, the distribution of gvbhjk′ obeys the autoregressive moving average function represented by pfggg′, and rrdfgg represents the influence factor of the characteristic data, the characteristic data state characteristics are extracted using
(11)popll′=pfggg′∓rdfgggvbhjk′∓tdf′.In an observed time series, different time points are affected by different feature data. Suppose byZt′ and vjB represent the type of feature data, respectively, and kztvjB′ represents the number of feature data, the effect of feature data on the time fit is obtained using
(12)Esdpp′=kztvjB′×vjB±Zt′popll′×ujkk′∓rtghpp′,where ujkk′ represents the moment of feature data generation.


## 3.5. Data Processing

Because the total amount of collected data is huge and diverse, the platform needs to clean, transform, classify, integrate, and process the data and then store them in a distributed database. The built healthcare big data platform uses the distributed database SequoiaDB to store data, and the SequoiaDB distributed database contains data nodes, cataloging nodes, and coordination nodes. When an application sends an access request to the coordinating node, the coordinating node first calculates the optimal data node by communicating with the cataloging node and distributes the query task, and finally returns the query results of each data node to the application after aggregation.The data computing platform uses the Spark computing framework, which supports a variety of data storage models and can be combined with Hadoop to share storage resources and computation in a Hadoop cluster, and Spark can compute data that is accessed frequently and centrally and store such data in memory to improve access efficiency. Users submit data requests on the healthcare platform, and the platform analyzes the user input and presents the data. In addition to direct data list display, the data presentation method also provides data graphical display, coding the platform statistical classification of data into graphics, using the mainstream visualization technology html5, the introduction of chart drawing tool library chart.js, the data will be presented in the form of statistical chart reports.


## 4. Experiments and Results

### 4.1. Experiment Setup

A simulation experiment is needed to verify the overall effectiveness of the distributed storage method for health care big data based on density area distribution. The experimental data comes from the internal data of multiple cities in a province in China. Experimental environment: 5 machines are used to correspond to the data stored in each cell. The configuration of each machine is: CPU is i5-2400, 3.1GHz; OS is Win10Ulti-mate, 10 T of available disk space, and 8 physical cores of the processor. A Hadoop 2.6.5 system was built in the cluster to provide HDFS file system for distributed storage of files, and YARN was used to manage the cluster. Meanwhile, Hive 2.1.1 was built on HDFS as the temporal data organization and query engine. Spark 2.1.1 platform was built on YARN, and Python 3.6 was used to develop system functions. All experiments were done by running Spark programs. Table1 describes the specific configuration information of the five NameNodes.Table 1
NameNode server parameters.
NameNode serverCPUMemoDiskBandwidthNameNodelFT150032GDDR4240GSSD1GNameNode2ARM32GDDR4240GSSD∗21GNameNode3ARM∗232GDDR4∗2240GSSD∗41GNameNode4E52620V4∗432GDDR4∗2240GSSD∗41GNameNode5E52620V4∗432GDDR4∗4240GSSD∗81GThe experimental metrics are the network node survival period after data fusion and the network energy consumption during the fusion process. Among them, the network node survival period: after distributed data fusion, it will be divided into different types of data nodes, and with the extension of time, there will be a large amount of data influx into each node, and the current data fusion node will be scattered, and the time between the current data fusion node is established and scattered is the network node survival period.We plot the training set and test set loss convergence and performance improvement during training in Figures5 and 6.Figure 5
Training set and test set loss convergence during training.Figure 6
Training set and test set performance improvement during training.


### 4.2. Experimental Results

When raw big data is stored, if there is an unbalanced distribution, it is easy to generate local hotspots, which makes larger loads appear in some nodes and makes empty loads appear continuously in some nodes at the same time. Therefore, based on the original big data distribution balance degree, the original big data distribution balance state of different algorithms is analyzed. The time required to store big data at different quantities for different algorithms is analyzed, and the analysis results are shown in Table2. According to Table 2, with the growth of data quantity, the storage spending time of three algorithms gradually increases, and when the data quantity is 2000 Mb, the storage spending time of massive spatial data cloud storage and query algorithm is the highest, reaching 67 s, and when the data quantity is 20000, the storage spending time of this algorithm remains the highest among three algorithms, 156 s, higher than the Hadoop-based big data. The storage algorithm 15 s, higher than the algorithm of this paper 84 s, the algorithm of this paper storage spending time is at least 26 s, so using the algorithm of this paper, can effectively reduce the big data storage spending time.Table 2
Different algorithms to store the time spent.
Amount of data/MbThis article algorithmHuge amount of spatial data cloud storage and query algorithmsHadoop-based big data storage algorithm2000266758400034726460003979788000478588100004988921200053949814000571071141600059132126180006514413920,00072156141The analysis of the ability to read/write data can effectively determine the real-time nature of the storage algorithm, and the analysis results are shown in Figures7 and 8by comparing different algorithms through data reading and writing operations in the case of different data volumes. According to Figures 7 and 8, the read data rates of the three algorithms are 79 Mb s-1, 46 Mb s-1, and 51 Mb s-1 when the data volume is 2000 Mb, and the read/write rates of the three algorithms are improved when the data volume is increasing, but when the data volume reaches 10000 Mb, the read data rate of the Hadoop-based big data storage algorithm remains the lowest among the three algorithms. The algorithm in this paper has the lowest read and write data rates of 93 Mb s-1 and 94 Mb s-1, respectively, at this data volume, which keeps the highest among the three algorithms, and the algorithm in this paper still keeps the highest read and write data rates at other data volumes, therefore, it shows that the algorithm in this paper has high read and write data rates and can realize faster distributed storage of big data.Figure 7
Comparison of read rates of different algorithms (Mb/s).Figure 8
Comparison of write rate of different algorithms (Mb/s).The utilization rate of density area distribution under different iterations is analyzed, and the utilization rate of density area distribution of different algorithms is derived by comparing three algorithms, and the analysis results are shown in Figure9. According to Figure 9, with the increase of iteration number, the utilization rate of data density area distribution of three algorithms increases, and the utilization rate of data density area distribution of this algorithm always remains above 90% between 100 and 600 iterations, which indicates that the utilization rate of data density area distribution of this algorithm is high.Figure 9
Density regional distribution utilization.


## 4.1. Experiment Setup

A simulation experiment is needed to verify the overall effectiveness of the distributed storage method for health care big data based on density area distribution. The experimental data comes from the internal data of multiple cities in a province in China. Experimental environment: 5 machines are used to correspond to the data stored in each cell. The configuration of each machine is: CPU is i5-2400, 3.1GHz; OS is Win10Ulti-mate, 10 T of available disk space, and 8 physical cores of the processor. A Hadoop 2.6.5 system was built in the cluster to provide HDFS file system for distributed storage of files, and YARN was used to manage the cluster. Meanwhile, Hive 2.1.1 was built on HDFS as the temporal data organization and query engine. Spark 2.1.1 platform was built on YARN, and Python 3.6 was used to develop system functions. All experiments were done by running Spark programs. Table1 describes the specific configuration information of the five NameNodes.Table 1
NameNode server parameters.
NameNode serverCPUMemoDiskBandwidthNameNodelFT150032GDDR4240GSSD1GNameNode2ARM32GDDR4240GSSD∗21GNameNode3ARM∗232GDDR4∗2240GSSD∗41GNameNode4E52620V4∗432GDDR4∗2240GSSD∗41GNameNode5E52620V4∗432GDDR4∗4240GSSD∗81GThe experimental metrics are the network node survival period after data fusion and the network energy consumption during the fusion process. Among them, the network node survival period: after distributed data fusion, it will be divided into different types of data nodes, and with the extension of time, there will be a large amount of data influx into each node, and the current data fusion node will be scattered, and the time between the current data fusion node is established and scattered is the network node survival period.We plot the training set and test set loss convergence and performance improvement during training in Figures5 and 6.Figure 5
Training set and test set loss convergence during training.Figure 6
Training set and test set performance improvement during training.


## 4.2. Experimental Results

When raw big data is stored, if there is an unbalanced distribution, it is easy to generate local hotspots, which makes larger loads appear in some nodes and makes empty loads appear continuously in some nodes at the same time. Therefore, based on the original big data distribution balance degree, the original big data distribution balance state of different algorithms is analyzed. The time required to store big data at different quantities for different algorithms is analyzed, and the analysis results are shown in Table2. According to Table 2, with the growth of data quantity, the storage spending time of three algorithms gradually increases, and when the data quantity is 2000 Mb, the storage spending time of massive spatial data cloud storage and query algorithm is the highest, reaching 67 s, and when the data quantity is 20000, the storage spending time of this algorithm remains the highest among three algorithms, 156 s, higher than the Hadoop-based big data. The storage algorithm 15 s, higher than the algorithm of this paper 84 s, the algorithm of this paper storage spending time is at least 26 s, so using the algorithm of this paper, can effectively reduce the big data storage spending time.Table 2
Different algorithms to store the time spent.
Amount of data/MbThis article algorithmHuge amount of spatial data cloud storage and query algorithmsHadoop-based big data storage algorithm2000266758400034726460003979788000478588100004988921200053949814000571071141600059132126180006514413920,00072156141The analysis of the ability to read/write data can effectively determine the real-time nature of the storage algorithm, and the analysis results are shown in Figures7 and 8by comparing different algorithms through data reading and writing operations in the case of different data volumes. According to Figures 7 and 8, the read data rates of the three algorithms are 79 Mb s-1, 46 Mb s-1, and 51 Mb s-1 when the data volume is 2000 Mb, and the read/write rates of the three algorithms are improved when the data volume is increasing, but when the data volume reaches 10000 Mb, the read data rate of the Hadoop-based big data storage algorithm remains the lowest among the three algorithms. The algorithm in this paper has the lowest read and write data rates of 93 Mb s-1 and 94 Mb s-1, respectively, at this data volume, which keeps the highest among the three algorithms, and the algorithm in this paper still keeps the highest read and write data rates at other data volumes, therefore, it shows that the algorithm in this paper has high read and write data rates and can realize faster distributed storage of big data.Figure 7
Comparison of read rates of different algorithms (Mb/s).Figure 8
Comparison of write rate of different algorithms (Mb/s).The utilization rate of density area distribution under different iterations is analyzed, and the utilization rate of density area distribution of different algorithms is derived by comparing three algorithms, and the analysis results are shown in Figure9. According to Figure 9, with the increase of iteration number, the utilization rate of data density area distribution of three algorithms increases, and the utilization rate of data density area distribution of this algorithm always remains above 90% between 100 and 600 iterations, which indicates that the utilization rate of data density area distribution of this algorithm is high.Figure 9
Density regional distribution utilization.


## 5. Conclusion

In the era of big data, the scale of medical and health data expands dramatically, and the data presents multimodal characteristics. The traditional relational database can no longer guarantee the efficient storage and fast response of massive data, and for this reason distributed storage technology provides a new idea for storing massive medical and health data. Based on the advantages of HDFS, HBase, and MapReduce, the Hadoop-based healthcare data storage system further optimizes the storage and query performance to realize a smart healthcare storage system that integrates high throughput, fast location, and efficient analysis. The distributed database based medical health data storage system can meet the demand for unified storage and fast response of multimodal medical health data and provides a platform support for subsequent multimodal data analysis and medical health data mining.In this paper, we study the distributed storage algorithm of medical and health care big data considering density area distribution, design the process of big data distributed storage through cloud storage architecture, and use the density area distribution algorithm to complete the distribution and decryption of the stored big data, so that the stored big data can play the maximum efficiency, and verify the storage capability of the algorithm in this paper through experiments. The load balance is lower, and the encryption is more resistant to attack. In the future research phase, we can continuously optimize the big data distributed storage algorithm so that it can be applied to various fields. In the future, we plan to conduct research on distributed medical and health data storage schemes for privacy data protection and medical and health knowledge inference.



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*Source: 8506485-2023-02-03.xml*