Abstract—Recently, efforts have been made to treat patients at home as much as possible. In many cases, the reason for the patient staying in hospital is not that he/she actually needs active medical care. Often, the principal reason for a lengthy stay in hospital is simply continual observation. This paper explains our experience and strategy to support the treatment of patients in their own home through the remote monitoring of physiological signals. The benefits of such remote monitoring are wide-ranging; the patient can continue to live their normal life, their risk of infection is reduced, costs are significantly decreased for the hospital, and clinician time is utilised more effectively. I. INTRODUCTION n recent years, the focus of health policy has shifted away from the provision of reactive, acute care towards preventive care outside hospital [1]. As models of care are redesigned, health economies are seeking to provide more and more care outside large acute centres. The drivers for this shift are two-fold; firstly, there is a quality of care issue and secondly there is a resource allocation issue. Being cared for in patient’s own home is a key aim of current UK government health policy [2] and that is driven by an imperative to provide better quality care to people without the need to disrupt their lives. Efforts have been made to avoid acute admissions and long lengths of stay in hospital. Emergency admissions and long lengths of stay are extremely costly and so health economies are looking at ways to prevent such occurrences. Investment in technologies that enable remote monitoring of would lead to long-term gains both in terms of hospital finances and patient care. This paper and system explained here is one such example which would significantly reduce lengths of stay amongst those patients who have had an acute episode but whose only medical requirements are for continual monitoring. This paper summarises the approach taken to this work and the technology behind it. II. METHODOLOGY We design a system whereby a group of sensors monitor and transmit medical signals. Sensors are tailored to a specific condition, so a patient who has suffered a heart attack, and is considered at risk of having a repeat attack, for example, would be fitted with Electro Cardiogram (ECG) sensors that monitor their heart activity, heart rate and so on. These sensors send signals to a terminal that is fitted in the This work was supported by a generous grant from the Modernisation Initiative with the support of the Guy’s and St Thomas’ Charity. R. Dilmaghani, M. Ghavami and H. Bobarshad are with the Electronic Engineering Department, King’s College London, Strand, London, WC2R 2LS, UK; e-mail: rezad@ ieee.org. patient’s home and then transmits them to the provider hospital. Clinicians are then able to monitor their patient’s condition, detect any abnormalities and take appropriate action (e.g. send an ambulance or contact the patient with advice). This system has particular benefits for patients who want to maintain their independence and for providers who are keen to closely monitor patients but have limited resources or space. III. THECHNOLOGICAL BACKGROUND There are three main sections in the system, each of which is explained below: the patient end where the medical signals are detected, the transmission whereby the signals are transmitted from the patient to the hospital via an access point and the hospital end where signals are received ready for interpretation by clinicians. The diagram of the whole system is shown in Figure 1. CP3000 micro-controller [3] is at the centre of the module at the patient end. This module is responsible for detecting medical signals from patient by using sensors, amplifying and digitising these signals then pre-processing the digital signal (i.e. data), formatting and transmitting the data to the module of access point within the home before being relayed to the module at the remote location (i.e. the hospital). This process is described in detail in the sections below. A. Patient End The module at the patient end consists of a CP3000 micro- controller and a variant number of sensors, depending on the patient’s condition, and an ‘access point’. Sensors are fitting to appropriate parts of the body, depending on their medical condition. For instance, a patient being monitored for a heart condition would have ECG sensors attached to the chest and a patient being monitored for stroke symptoms might have Electro-Encephalogram (EEG) and/or Electro- Myogram (EMG) sensors attached to the scalp and to various muscles in the body. These sensors are connected to the signal conditioning sub-module via very light cables. The heart of the signal conditioning sub-module is a Texas Instruments’ INA2322 Integrated Circuit (IC) [4], and a micro-power single-supply CMOS instrumentation amplifier with a very favourable CMRR of 60dB. The sub-module, which uses tiny surface-mount components in order to minimise noise and current draw, also consists of several operational amplifiers from two CMOS quad op-amp packages, together with a multitude of resistors and capacitors. The differential signals from the electrodes are amplified by INA2322 cored circuit while is also configured with a high-pass feedback filter to dynamically correct any DC shift that may occur over time. Its output is connected to a final operational amplifier which A New Paradigm for Telehealth Implementation R. Dilmaghani, Member, IEEE, M. Ghavami, Senior Member, IEEE, H. Bobarshad, Member, IEEE I 32nd Annual International Conference of the IEEE EMBS Buenos Aires, Argentina, August 31 - September 4, 2010 978-1-4244-4124-2/10/$25.00 ©2010 IEEE 3915