By using wearable sensors developed by H@H, patients’ physio‐pathological cardiovascular and respiratory parameters are acquired and transferred to a remote server. The gathered data is continuously monitored by an automatic processing system and accessible by the medical staff, who can take action in case of necessity.
Involving end-users since the first stages of the project was fundamental for the definition of user requirements. The rationale was to device a flexible and efficient system, taking into consideration both medical and patients’ needs and expectations: for the physicians the telemonitornig system can not be an excessive workload with respect to their regular activities, on the other side, the impact on the patient must be minimal. For these reasons, a system directly integrated with the Hospital Information System (HIS), based on an Operating Protocol (OP) was developed. The OP consists of a set of actions that the patient must follow during the monitoring. The OP can be customised depending on the patient’s needs and possible disease evolution when necessary. The actions are simple tasks like taking measurements or replying to simple questions.
The system has the typical client/server architecture (see Figure 1). The client side is located at the patient’s home and consists of a home gateway and a set of biomedical sensors. The server side, installed at the health service facilities, accepts and processes data from gateways making it available in the Hospital
The Bluetooth technology was chosen for the communication between the sensors and the gateway, due to the wide diffusion of available devices on the market. On the other side, ADSL is the primary transmission channel for data communication between the gateway and the server, while the mobile broadband (GSM/GPRS/UMTS) is used as a secondary data channel. Redundant access technologies ensure flexibility and fault tolerance. Furthermore alert messages are sent through SMSs directly to the physician, the patient’s relatives and the caregivers.
The sensing module consists of a set of wireless and wearable sensors to measure the main vital signs. The most significant vital parameters that a CHF patient has to measure are 3 leads ECG, SpO2, weight, blood pressure, chest impedance, respiration and posture. Table 1 shows the features of the sensor devices.
For it to be an asset for the implementation and to reduce project risks, the sensing module was divided into two possible configurations: basic and advanced. Basic partitioning is intended as the minimum set of requirements to achieve a complete and useful telemonitoring system. In the advanced configuration, additional features were considered in order to enlarge the type of CHF patients to be enrolled in the telemonitoring program.
The home gateway includes all the necessary computation and communication resources. The home gateway is responsible of the acquisition, management and forwarding of data on vital signs captured by the biomedical pool of sensors. The acquisition consists in handling all the sensor‐dependent communication protocols in order to receive specific data sets and extract their information content. Data management includes a first level of analysis, consisting of comparisons with thresholds in order to detect anomalies, and the permanent storage of data waiting to be transferred, so that power supply failures do not result in data loss. Collected data is made available also for local consultations. The transmission process allows flooding data into the patient’s Hospital Information System (HIS) record. The following list summarises all the gateway functionalities:
- Acquisition of data from wireless sensors;
- Data forwarding to a remote collection server using a safe and reliable connection;
- Reminder function, in order to help patients to follow the medical therapy and perform the planned measurements;
- Detection and management of emergency events, both coming from threshold comparison on incoming data or manually submitted by the patient through a selectable list of symptoms;
- Execution of an operating protocol customised according to the patient’s needs;
- System failure detection and management during data acquisition or data transmission to the server;
The gateway device is based on a netbook integrating all the computation and communication resources. In order to simplify the use of the gateway, the original keyboard of the netbook was replaced by a simpler keypad, designed as a membrane keybo.
Being a general purpose device, all the desired capabilities are implemented with a linux‐based multi threaded software platform directly running when the netbook is switched on. It results in a very modular architecture that ensures easy maintenance and upgrades, including future extensions with new sensors or the introduction of new communication standards. The gateway follows the operating protocol and executes the tasks as scheduled by the physician. When a planned activity time is reached, an alarm calls the patient’s attention and the system helps him to follow the therapy with messages and animations. To perform the reminder function, the system has an intuitive graphical user interface (see Figure 4) composed of three main areas: on the top the reminder textbox, a summary of the lasts measures on the left and an animation helper on the right.
Figure 4 – Screenshot of the home gateway
The graphical helper section strictly works with the reminder: the gateway helps the patient to interact with the system through textual messages and a set of animated images showing how to wear sensors to record required measures or how to use the input interface to select a symptom from the list. In order to minimise the patient effort, the measure acquisition simply consists in turning the related sensor on and waiting until the end of the measurement process. All involved sensor devices are able to establish a connection with the home gateway to transmit the relevant data. Moreover, extra protocol measures can be performed at any time, even if not established by the OP. After the reception of an extra protocol measure, the system asks the patient the reason of the measurement by selecting the symptom from a list.
The server side, installed at the health service facilities, accepts and processes data from the gateways making them available in the Hospital Information System. The H@H server is a web‐based application that receives data from all controlled gateways, providing a detailed process of analysis based on expert systems and finally updating the patient’s record in the HIS. It exports graphical interfaces that allow the clinicians to request and display: the data of a patient to detect early changes in vital signs, the historical data of a patient, monitoring the progress of the disease and to update the operating protocol. The server platform main functions are related to the patients management function, since their enrolment when the physician inserts the patient data and configures the OP on the basis of the patient’s needs. During the monitoring period the server collects patient measurements coming from the gateway. The physician can always access patient clinical data, comparing the patient health status at different times by means of measurement trends. The platform also highlights the alarms shown during the monitoring with respect to the OP established for that patient or simply reports symptoms manually indicated by the patient. If necessary, the physician can modify the OP at any time by producing an automatic and transparent update of the gateway.
As data exchanged between the gateway and the server involves the public Internet, the HTTPS protocol uses HTTP messages over an SSL channel established after certificate validation, fitting completely the requirements of confidentiality, authenticity and integrity for the data traffic and the web service interaction.
The request message sent by the home gateway at any transmission time contains all patient data (vital signs and events) mapped with HL7 CDA standard blocks, while the response includes the actual XML operating protocol description (see Figure above).
H@H Demonstration and results
A technical validation of the system has been implemented involving 30 patients with CHF disease in NYHA class III and IV, with an average age of 62 years and recently hospitalised for HF. The minimum period of monitoring was one month. A specific testing protocol and a questionnaire have been developed to gather patients, caregivers and physicians feedbacks and validate the system. The results show a very limited number of activity misses (<3%), mostly in the first days of monitoring, confirming also the capacity of such a system to improve the therapy compliance. Moreover, the number of false positive alarms is less than 5%. No connectivity and transmission problems, including data lost, occurred. All end‐users reported a positive feedback and good satisfaction level in the final questionnaire.Physicians reported that the use of this platform does not load up in a significant way their regular activity, but represents valid means to control at distance the evolution of the followed patients, thanks to the high quality of acquired signals and alarms detection capability. All physicians involved in the demonstration are definitively in favour of the adoption of the H@H system. 89% of patients report a very high satisfaction level, highlighting the friendliness of the solution and the easiness to follow the daily therapy.
The system was recently adopted by the ASL Arezzo in the framework “Progetto Domino” for the tele monitoring of patients affected by CHF and Broncho‐Pneumopathie Chronique Obstructive.
The Health at Home project (H@H) aims at solving societal problems related to the provision of healthcare services for elderly citizens affected by Chronic Hearth Failure (CHF), by enabling remote self-management of the patients and connecting in‐hospital care of the acute syndrome with out‐of‐hospital follow‐up. The new home care model should allow planning, controlling and monitoring of activities carried out by patients, caregivers, social and sanitary professionals, enabling the medical staff to monitor situations at distance and take action in case of necessity by the involvement of public and private health organisations. This new strategy will decrease the acting time in cases of destabilisation of CHF patients and will reduce avoidable hospital re‐admissions, resulting in an improved quality of life for the patient and in a cost reduction for the National Sanitary System.
Expected results and impact:
The H@H system is expected to enhance the quality of life of CHF patients (at present 14 million of European Citizens with an incidence of 3,6 million of new cases per year), to improve the effectiveness and cost management of specialised centres thus reducing costs for the public sanitary system. H@H ICT technologies have proved successful through an initial demonstration phase, while the clinical validity and the economic analysis for this new healthcare model has to be validated on a wider number of patients.
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