Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

A mobile feedback system for integrated E-health platforms to improve self-care and compliance of diabetes mellitus patients

Exploiting the full potential of telemedical systems means using platform based solutions: data are recovered from biomedical sensors, hospital information systems, care-givers, as well as patients themselves, and are processed and redistributed in an either centralized or, more probably, decentralized way. The integration of all these different devices, and interfaces, as well as the automated analysis and representation of all the pieces of information are current key challenges in telemedicine. Mobile phone technology has just begun to offer great opportunities of using this diverse information for guiding, warning, and educating patients, thus increasing their autonomy and adherence to their prescriptions. However, most of these existing mobile solutions are not based on platform systems and therefore represent limited, isolated applications. This article depicts how telemedical systems, based on integrated health data platforms, can maximize prescription adherence in chronic patients through mobile feedback. The application described here has been developed in an EU-funded R&D project called METABO, dedicated to patients with type 1 or type 2 Diabetes Mellitus.

Innovative self management system for guided cardiac rehabilitation

This paper describes the design and development of a system for cardio rehabilitation of patients that suffered a myocardial infarction. The proposed solution focuses on exercise prescriptions and the encouragement of healthy behaviors. The innovative strategy of the design takes into account health promotion models to provide safe, assistive exercise training sessions, personalized feedbacks, and educational contents.

Assessment of Bradykinesia in Parkinson's disease patients through a multi-parametric system

The aim of this paper is to describe and present the results of the automatic detection and assessment of bradykinesia in motor disease patients using wireless, wearable accelerometers. The current work is related to a module of the PERFORM system, a FP7 project from the European Commission, that aims at providing an innovative and reliable tool, able to evaluate, monitor and manage patients suffering from Parkinson's disease. The assessment procedure was carried out through a developed C# library that detects the activities of the patient using an activity recognition algorithm and classifies the data using a Support Vector Machine trained with data coming from previous test phases. The accuracy between the output of the automatic detection and the evaluation of the clinician both expressed with the Unified Parkinson's disease Rating Scale, presents an average value of [68.3 ± 8.9]%. A meta-analysis algorithm is used in order to improve the accuracy to an average value of [74.4 ± 14.9]%. Future work will include a personalized training of the classifiers in order to achieve a higher level of accuracy.

Integration of heterogeneous biomedical sensors into an ISO/IEEE 11073 compliant application

Current trends in healthcare technology include mobile-based applications. Relevant advances in the integration of vital signs monitoring devices with mobile platforms are widely reported nowadays. In this context, conceiving and designing an interoperable application is essential due to the growing necessity of integrating a huge and heterogeneous amount of biomedical data, coming from a wide range of devices and sensors. In this paper the key research issues associated with such integration are presented as well as a specific proposal to solve these problems. It is based on a middleware architecture for the integration of biomedical sensors with mobile devices, derived from the ISO/IEEE 11073 standards family. The application has been developed in the framework of an EU-funded R&D project called METABO.

A healthy lifestyle coaching-persuasive application for patients with type 2 diabetes

Losing weight can be one of the toughest objectives related to diabetes treatment, especially for Type 2 diabetes mellitus. This paper describes a tool to set goals to achieve lifestyle behavioral changes, and keep track of the benefits derived from these changes. This strategy leans on the capability of evaluating users' compliance to treatment, identifying key points where the lack of motivation causes therapy dropping, and on the better resources that physicians will have to adjust the treatments and the prescriptions.

A comprehensive motor symptom monitoring and management system: the bradykinesia case

The current work describes a methodology to automatically detect the severity of bradykinesia in motor disease patients using wireless, wearable accelerometers. This methodology was tested with cross validation through a sample of 20 Parkinson's disease patients. The assessment of methodology was carried out through some daily living activities which were detected using an activity recognition algorithm. The Unified Parkinson's Disease Rating Scale (UPDRS) severity classification of the algorithm coincides between 70 and 86% from that of a trained neurologist depending on the classifier used. These severities were calculated for 5 second segments of the signal with 50% of overlap. A bradykinesia profiler is also presented in this work. This profiler removes the overlap of the segments and calculates the confidence of the resulting events. It also calculates average severity, duration and symmetry values for those events. The profiler has been tested with a bogus dataset. Future work includes better training for the severity classifier with a larger sample and testing the profiler with real, longterm patient data in a projected pilot phase in three European hospitals.

A system to promote self-behaviors of patients with coronary heart disease

Personalized health devices are the novel paradigm to reduce healthcare costs and to improve the quality of health services. At the same time, health interventions and promotion of self behaviors generate benefits to healthcare and allow citizens to be more involved in their own health management. This paper describes the process followed in HeartCycle project to design education and coaching services to promote self-behaviors in a closed loop monitoring system for patients with coronary heart diseases that suffered a myocardial infarction.

"AmI for health: chronic disease management"

Several students of Bioengineering complain about the excess of theoretical classes and the difficulty to assimilate the subject taught. This work presents a strategy to mix theory and practice when teaching, thus motivating students to engage in their studies.

Gait assessment in Parkinson's disease patients through a network of wearable accelerometers in unsupervised environments

Parkinson's disease (PD) predominantly alters the motor performance of the affected individuals. In particular, the loss of dopaminergic neurons compromises the speed, the automaticity and fluidity of movements. As the disease evolves, PD patient's motion becomes slower and tremoric and the response to medication fluctuates along the day. In addition, the presence of involuntary movements deteriorates voluntary movement in advanced state of the disease. These changes in the motion can be detected by studying the variation of the signals recorded by accelerometers attached in the limbs and belt of the patients. The analysis of the most significant changes in these signals make possible to build an individualized motor profile of the disease, allowing doctors to personalize the medication intakes and consequently improving the response of the patient to the treatment. Several works have been done in a laboratory and supervised environments providing solid results; this work focused on the design of unsupervised method for the assessment of gait in PD patients. The development of a reliable quantitative tool for long-term monitoring of PD symptoms would allow the accurate detection of the clinical status during the different PD stages and the evaluation of motor complications. Besides, it would be very useful both for routine clinical care as well as for novel therapies testing.

Wearable and mobile system to manage remotely heart failure

Cardiovascular diseases (CVDs) account for 45% of all deaths in the western world according to the 2004 World Health Organization statistics report. Heart failure (HF), CVD's primary paradigm, mainly affects people older than 65. The European MyHeart Project's mission is to empower citizens to fight CVD by leading a preventative lifestyle and allowing early diagnosis. This paper presents the iterative design and development of the HF management system, part of MyHeart Project. The system daily measures vital body signals to assess HF. The methodology applied herein has involved stakeholders in an iterative process: concept validation, feasibility, efficiency, patients' experience, and patients' acceptance. The final solution allows patient self-management of their chronic condition.

User interaction design and development of a heart failure management system based on wearable and information technologies

In the Western World, cardiovascular diseases (CVD) are the leading source of death. Only in Europe, they cause 45% of all deaths. Besides heart failure, the paradigm of CVD, affects mainly people older than 65. Facing this reality, the European Union has funded MyHeart Project, whose mission is empowering citizens to fight CVD by means of a preventive lifestyle and an early diagnosis. This paper presents the design and development of the user interaction for a heart failure management system. This system consists on wearable and mobile technologies which monitors the vital body signals in a daily basis, providing a continuous assessment of this chronic disease.

Integration of telemedicine into emergency medical services

We developed an integrated model of telemedicine services in emergency medical care. The architecture was designed to support pre-hospital management. The experimental work was carried out with the collaboration of the emergency medical services (EMS) in Madrid. Two different study populations were defined: a control population using conventional EMS protocols and a population using the telemedicine system. The telemedicine system was based on a telepresence service; electrocardiograms and images were transmitted from the ambulance to the health emergency coordination centre. The cost of dealing with 100 patients using telemedicine was C6030 less than the cost of conventional care. The response times using telemedicine were significantly lower.

Theoretical efficiency of a televisiting service for home care support

We have made a theoretical study of the potential for televisiting. All journeys made by the home care support team in an area of Madrid were reviewed to study the possibility of using televisiting. During the year 2000 the team provided an average of seven home visits a day. The home visits took 30 min on average, and the journey time was 30 min for urban areas and 45 min in the suburbs. We estimated that two of each day s visits could be carried out by telemedicine, with a mean duration of 15 min each. A model was used to calculate the resource demands and the potential cost-savings of televisiting compared with traditional home care. Using televisiting, 62% more suburban oncology patients could be managed and a cost reduction of euro;6 per visit could be achieved after 10 weeks.

A telemedicine model for integrating point-of-care testing into a distributed health-care environment

Centralized testing demands costly laboratories, which are inefficient and may provide poor services. Recent advances make it feasible to move clinical testing nearer to patients and the requesting physicians, thus reducing the time to treatment. Internet technologies can be used to create a virtual laboratory information system in a distributed health-care environment. This allows clinical testing to be transferred to a cooperative scheme of several point-of-care testing (POCT) nodes. Two pilot virtual laboratories were established, one in Italy (AUSL Modena) and one in Greece (Athens Medical Centre). They were constructed on a three-layer model to allow both technical and clinical verification. Different POCT devices were connected. The pilot sites produced good preliminary results in relation to user acceptance, efficiency, convenience and costs. Decentralized laboratories can be expected to become cost-effective.

An assistive home care environment for people with special needs

We have developed a system for supporting people with special needs. It allows remote monitoring of electrocardiographic and other signals together with multimode environmental control. The multimodal approach allows users with disabilities to interact more with the home environment. Telemedicine devices were integrated into the system to provide a link to health services. The system provided support for the independent living of people with special needs. The pilot site was a rehabilitation service attached to the National Paraplegic Hospital of Toledo, Spain. During the six-week trial period, the system did not fail, nor was any unauthorized access reported. Twelve people with special needs and three staff evaluated aspects of the system on a scale from 0 to 9, on which higher scores indicated a positive assessment. The mean score for efficiency was 7.8, for satisfaction 8, for helpfulness 7.4, for controllability 7.2 and for learnability 8.

Multimedia telehomecare system using standard TV set

Nowadays, there are a very large number of patients that need specific health support at home. The deployment of broadband communication networks is making feasible the provision of home care services with a proper quality of service. This paper presents a telehomecare multimedia platform that runs over integrated services digital network and internet protocol using videoconferencing standards H.320 and H.323, and standard TV set for patient interaction. This platform allows online remote monitoring: ECG, heart sound, blood pressure. Usability, affordability, and interoperability were considered for the design and development of its hardware and software components. A first evaluation of technical and usability aspects were carried forward with 52 patients of a private clinic and 10 students in the University. Results show a high rate (mean = 4.33, standard deviation--SD = 1.63 in a five-points Likert scale) in the global perception of users on the quality of images, voice, and feeling of virtual presence.

User satisfaction with home telecare based on broadband communication

Home telecare services based on broadband communication were established in five locations in Europe. Two different types of telecare unit were developed: one based on a PC or set-top box containing a videoconferencing codec and another on off-the-shelf videoconferencing units. The participants in the project were 13 medical staff, 135 patients and 88 people informally caring for the patients. Questionnaires were used to evaluate user satisfaction with eight telecare services. Almost all participants rated the usability of the system as good or excellent. A total of 105 telecare sessions were scored by the medical staff. Overall, the quality of audio and video communication was judged satisfactory. For the patients and carers, the perceived quality of communication was also satisfactory and did not vary significantly between sites. The medical staff were reasonably satisfied with how the service supported them in their work. Except for the item about being able to support patients in a critical situation, medical staff agreed that an improved quality of health services was offered through telecare. All participants agreed that personal information was treated confidentially and that there was little risk in using the telecare services. The medical staff trusted the assessments they could make remotely while using the telecare system. Although the findings cannot be generalized due to the small number of telecare sessions and the relatively short duration of the experiment, the results encourage further research.

Modelling home televisiting services using systems dynamic theory

A quantitative model was developed to study the provision of a home televisiting service. Systems dynamic theory was used to describe the relationships between quality of care, accessibility and cost-effectiveness. Input information was gathered from the telemedicine literature, as well as from over 75 sessions of a televisiting service provided by the Severo Ochoa Hospital to 18 housebound patients from three different medical specialties. The model allowed the Severo Ochoa Hospital to estimate the equipment needed to support increased medical contacts for intensive cardiac and other patients.

Transmission trials with a support system for the treatment of cardiac arrest outside hospital

A mobile electrocardiogram (ECG) transmission system was developed which could transmit single-lead ECG data via GSM mobile telephony. Ambulance transmission trials comprised a total of 72 communications, of which 94% were successful. The system was able to redial up to a predetermined number of times until the GSM call was re-established (during the trials this value was set to five). The average number of GSM call tries was 1.3 per connection. The mean time required to establish a connection was 45 s; the minimum was 34 s, when only one attempt was needed to establish a GSM call. The average duration of ECG transmission between communication breakdowns was 5 min 12 s. When a link breakdown occurred, the user had to wait for an average of only 42 s to continue monitoring the signal.

Mobile technologies in the management of disasters: the results of a telemedicine solution

Nowadays a great number of applications are used to compile and transmit casualties and disasters information but there are many troubles associated with the technology as can be the communications reliability and the size and weight of the devices medical staff has to carry with. Telecommunication infrastructures support information movement among geographically dispersed locations. Recently a large family of little devices has appeared in the buyer's market. They are called Personal Digital Assistants and because of their physic and technical features, they are very useful in the emergency field. As for the communications reliability, many technologies have been developed in the last years but it is necessary to find a solution that can be used in whatever situation independently of the emergency circumstances. Facing this reality, the Spanish government funded REMAF, an ATYCA (Initiative of Support for the Technology, Security and Quality in the Industry) project. REMAF joined research groups (UPM), phone operators (Fundación Airtel Móvil) and end users (SAMUR) to build a disaster data management system conceived to use modern telemedicine systems to optimize the management in these situations, taking the advantage of the above mentioned mobile communication tools and networks.

Impact of a broadband interactive televisit/teleconsultation service for residential and working environments

The availability of health care attention at the point of need is one of the key benefits of telemedicine. Home environment and working place are the two scenarios selected in this article to evaluate the impact of a televisit and teleconsultation service. 31 users from four different medical and patient groups participated in this study supported by European Commission ATTRACT project. The experiences, carried out in Madrid and Valencia Spanish sites, benefited from interactive broadband access networks to provide cost-effective telecare services. Key areas analyzed encompass systems usability, clinical outcomes, patients quality of care and infoethic issues. Services advantages were verified and compared both from patients and medical staff points of view. Main benefits pointed out refer to displacement reduction, better communication doctor/patient, provision of comfort or friendliness, more precise therapy follow-up and increases in patients sense of well being.

Patient satisfaction with a home televisiting service based on interactive television over a cable network

Experience shows that high-quality audiovisual contact between remote health carers and patients facilitates a telemedicine service. However, the lack of broadband communication to the home usually prevents domestic televisiting. Deployment of cable networks in Spain has allowed the implementation of a home televisiting service designed for patients with chronic diseases. In a trial, 15 patients received televisits by three specialists and three nurses from the Severo Ochoa Hospital in Madrid. Five patients suffered from chronic pain, five were from the nephrology unit and five had been treated at the intensive-care unit after acute myocardial infarction. Each patient participated in three televisiting sessions, two provided by a specialist and the other by a nurse. The average length of a televisit was 12 min (range 5-21 min). The patients expressed their satisfaction with the service.

Using cable television networks for interactive home telemedicine services

Most recent cable television network infrastructures can be used to deliver broadband interactive telemedicine services to the home. These facilities allow the provision of social and health services like medical televisiting for elderly, disabled and chronically ill patients; health tele-education; and teleconsultation on demand. Large numbers of patients could benefit from these services. There is also the increasing European tendency to offer customized home-care services. These applications are being developed and validated by a pilot project in Madrid as part of the ATTRACT project of the European Commission. The long-term aim is to develop broadband applications on a large scale to support low-cost interactive home telemedicine services for both patients and institutions.

A home telecare management system

The increasing tendency to discharge chronic patients from hospital, as well as the growing expectation of improved quality of life for elderly and disabled people at home, was the original motivation for the development of a home telecare management system. The system allows a service centre to perform remote monitoring of biological signals and other data via the public telephone network, as well as to manage different emergency situations arising at home. The system is part of the FU-funded EPIC project (European Prototype for Integrated Care). It was tested in Belfast (Northern Ireland) and is currently being installed in Torre del Mar (Spain). This paper describes the system design and preliminary evaluation. The results indicate that the system operators find it highly acceptable in terms of efficiency, effectiveness, helpfulness, control and learnability. Integration of home telecare data with community-care information systems is essential if data captured at home are to be incorporated into the care process effectively.

A telemedicine system for remote cooperative medical imaging diagnosis

Telemedicine is changing the classical form of health care delivery, by providing efficient solutions to an increasing number of new situations: here we consider those which require some type of computer-supported cooperative work (CSCW) between health care professionals located in different clinical sites. This paper presents the design and development of a telemedicine system for remote computer-supported cooperative medical imaging diagnosis. The main and novel component of our system is a new CSCW distributed architecture, comprised by a collaborative toolkit to add audioconferencing, telepointing, window sharing, user's coordination and application synchronization facilities, either to existing or new medical imaging diagnosis applications. In comparison with existing CSCW products, mainly based on centralized architectures, our distributed toolkit is specially designed for telemedicine applications: to allow different levels of sharing between participants, to improve user feedback in highly interactive user interfaces, and to optimize the required communication bandwidth in order to implement a telemedicine CSCW application on almost any telecommunication network. This telemedicine CSCW system has been applied to build a cooperative medical imaging diagnosis application, in which two doctors, located in different hospitals, need to achieve a cooperative diagnosis on haemodynamic studies using cardiac angiography images. The design of the graphical user interface for this kind of telemedicine CSCW systems, a critical component which conforms any telemedicine application, is also addressed with a new methodological approach, to assure the system usability and final user acceptance. The telemedicine cardiac angiography pilot has been implemented, tested and evaluated within the Research Project 'FEST-Framework for European Services in Telemedicine' funded by EU AIM Programme.

Telehygiene system for preventive chronopharmacology in space

A remote computerized health care (telehygiene) system for space travel includes monitoring devices and pharmaceuticals aimed at the optimization of health and the environment. Early risk indicators are provided by dynamic characteristics of rhythms of several frequencies describing variation inside the physiologic range. These rhythm characteristics, assessed as one goes, can be updated and compacted as data accumulate by the use of chronobiologic software that resolves anticipated components of lower and lower frequency, thus providing summaries of data at intervals of differing length. At any time, harbingers of risk, including characteristics of circannual rhythms, can be retrieved in an instant. On their basis, early preventive action can be instituted for risk lowering and for delivery of timed treatment when needed. Preventive or curative health care in space and terrestrial spin-offs are the more effective the more of the chronome (time-structure) is resolved.

A hybrid knowledge based system for therapy adjustment in gestational diabetes

This poster describes a system to analyze self-monitoring data of gestational diabetic patients, for obtaining an assessment of their metabolic control with the final goal of supporting decision-making in therapy adjustment. The system is able to manage incomplete data and to make temporal reasoning under uncertainty, the two most important constraints when analyzing ambulatory monitoring data. Two different formalism have been used to represent and manage the knowledge: a dynamic Bayesian network and a production system based on rules. The outcomes provided by the whole system are: information on possible patient transgressions of the prescribed treatment and recommendations of treatment adjustments.

A telemedicine distributed system for cooperative medical diagnosis

Telemedicine is changing the classical form of health care delivery, dramatically increasing the number of new applications in which some type of distributed synchronous cooperation between health care professionals is required. This paper presents the design and development of a telemedicine distributed system for cooperative medical diagnosis based on two new approaches: 1) a distributed layered architecture specially designed to add synchronous computer supported cooperative work features either to new or existing medical applications; 2) the definition of a methodological procedure to design graphical user interfaces for telemedicine cooperative working scenarios. The cooperative work is supported by a collaborative toolkit that provides telepointing, window sharing, coordination and synchronization. Finally, we have implemented and installed the telemedicine system in clinical practice between two hospitals, providing teleconferencing facilities for cooperative decision support in haemodynamics studies. This specific implementation and a preliminary evaluation were accomplished under the Research Project FEST "Framework for European Services in Telemedicine" funded by the EU AIM Programme.

A pen-based system to support pre-operative data collection within an anaesthesia department

This paper describes the design and implementation of a pen-based computer system for remote preoperative data collection. The system is envisaged to be used by anaesthesia staff at different hospital scenarios where pre-operative data are generated. Pen-based technology offers important advantages in terms of portability and human-computer interaction, as direct manipulation interfaces by direct pointing, and "notebook user interfaces metaphors". Being the human factors analysis and user interface design a vital stage to achieve the appropriate user acceptability, a methodology that integrates the "usability" evaluation from the earlier development stages was used. Additionally, the selection of a pen-based computer system as a portable device to be used by health care personnel allows to evaluate the appropriateness of this new technology for remote data collection within the hospital environment. The work presented is currently being realised under the Research Project "TANIT: Telematics in Anaesthesia and Intensive Care", within the "A.I.M.--Telematics in Health CARE" European Research Program.

Effect of amiodarone on ventricular fibrillation and defibrillation thresholds in the canine heart under normal and ischemic conditions

The main goal of this project was to study the effect of amiodarone upon ventricular fibrillation and defibrillation thresholds (VFT and VDT) in the canine heart under normal and ischemic conditions. Both parameters were assessed in 11 dogs, each experiment consisting of three consecutive phases: (a) control, which resulted in VFT = 27.9 (S.D. = 15.5) and VDT = 43.9 (S.D. = 4.5); (b) drug, with VFT = 63.5 (S.D. = 32.8) and VDT = 57.8 (S.D. = 11.3), and (c) coronary occlusion, with VFT = 44.7 (S.D. = 21.6) and VDT = 57.1 (S.D. = 11.0). These values are overall means scaled to ventricular weight (microA/g for VFT and mA/g for VDT). Both VFT and VDT in (b) and (c) were, on the average, greater than in (a) and these differences were statistically significant (P less than 0.01, paired t-test). The animals were kept normothermic (37.3 degrees C, S.D. = 0.6) within normal values for the acid-base state. We concluded that amiodarone increased the VFT significantly. Similarly, it increased VDT. However, although the latter change was statistically significant, we believe it would not be important from a physiological or clinical point of view.

Transventricular simple-capacitor discharge defibrillation thresholds after coronary ligation and body hypothermia

Peak current defibrillation thresholds (PCDT), i.e., values with 50% probability of success, were determined after ligation of the left anterior descending coronary artery (LADCA) while, simultaneously, body temperature was slowly decreased until central venous temperature reached an average minimum of 22.8 degrees C (s.d. 3.1). In 14 dogs with over 166 successful defibrillations, the average time elapsed between the moment of ligation and the last defibrillation was 179.1 min. (s.d. 31.9), with an average PCDT of 53.6 mA g-1 of heart (s.d. 20.5). This value was compared by means of the unpaired Student's t test with three previous values obtained, respectively, under hypothermia with no occlusion (HNO), normo-thermia with coronary occlusion (NCO), and normothermia with no occlusion (NNO), that is, HNO 69.5 (s.d. 30.4), NCO 81.1 (s.d. 29.3), and NNO 89.5 (s.d. 32.8), all expressed in mA g-1 of heart. All three differences even after Bonferroni's correction, were statistically significant (P less than 0.3%). We concluded that, (1) defibrillation thresholds were decreased by coronary occlusion and by hypothermia, (2) the decrease due to hypothermia was greater than that due to coronary occlusion, (3) both decrements appeared as additive.

Effect of body hypothermia on transventricular simple-capacitor-discharge defibrillation thresholds

In 260 successful transventricular simple capacitor-discharge defibrillations performed on 20 mongrel dogs under conditions of body hypothermia, an overall average peak current threshold of 69.5 mA/g of heart (SD 30.4) was found. This value, when compared by means of the unpaired t test with previous data obtained under conditions of relative normothermia (89.5 mA/g of heart, SD 32.8, 346 defibrillations, 20 dogs) yielded a highly significant difference (P less than 0.1%). When comparing the deviation of the regression equation (current vs. temperature) from the horizontal line, the Snedecor F test gave also a high level of significance (P less than 1%). These results led to the conclusion that body hypothermia significantly reduces transventricular defibrillation thresholds. After normalizing the regression equations, this reduction was found to be on the average equal to 4.1%/degrees C (SD 1.4) for current and to 5.9%/degrees C (SD 1.4) for energy over the 20 dogs. In all animals, the coefficient of variation was greater for energy than for current (about twice as much), suggesting that current is a better descriptor of what is needed for electrical defibrillation. The transventricular impedance was rather constant, yielding an overall average of 28.5 omega (SD 6.0).