Biomedical subjects

P J Toussaint

Publications and source records attributed to P J Toussaint.

10 recordsLinked to original sources

PubMed2001

Integration of information systems: assessing its quality.

Due to organizational and technological changes the need for integrating information systems within healthcare institutions, has increased enormously. Although the technical means for systems integration have definitely matured, integration methodologies are still in their infancy. Two important questions regarding systems integration are hardly ever addressed in a systematic way: how to derive integration requirements, and how to check whether the requirements are met in a given integrated system. These two questions must be answered if we want to assess or improve the quality of integration of a given set of systems. In this article we present a nine-step method for deriving integration requirements from a business process model, and we assess the quality of integration of a given integrated system against these requirements. The method is demonstrated by elaborating two case studies from the health care domain.

Computer Simulation↗

PubMed2000

Sensorimotor organization in patients who have undergone hemispherectomy: a study with (15)O-water PET and somatosensory evoked potentials.

To identify cortical structures that subserve residual motor and sensory function in patients with congenital hemiparesis due to a porencephalic cyst, we examined, using [(15)O]H2O, PET and somatosensory evoked potentials (SEPs) in three patients with left-sided hemiparesis who had undergone hemispherectomy. Motor stimulation of the affected hand produced ipsilateral activation in the premotor area in all patients, the SMA in two patients, and SII in two patients. Vibrotactile stimulation resulted in activation of the ipsilateral SII in all subjects. Median nerve stimulation of the affected hand produced ipsilateral long-latency SEPs in fronto-centro-parietal areas, whereas stimulation of the non-affected hand produced normal early cortical potentials in the contralateral hemisphere. Our results suggest that residual function in the paretic hand is warranted through non-primary motor and sensory areas, and higher order associative areas in the intact hemisphere.

Adult↗

PubMed2000

A process view of medical practice by modeling communicative acts.

The need of an electronic patient record with a process view on medical care is widely acknowledged. Characteristics of DEMO (Dynamic Essential Modeling of Organizations) suggest that with this methodology an adequate process view of medical practice can be obtained. In applying DEMO to the care process of the emergency department at the University Medical Centre Utrecht, it was investigated if DEMO fulfilled our expectations. This practical application showed that DEMO yields an adequate process view by a clear and comprehensible view of the core processes, responsibilities, co-ordination of activities, and a clear description of causal and conditional relations between activities.

Computer Simulation↗

PubMed1998

Constructing an enterprise viewpoint: evaluation of four business modelling techniques.

Business process modelling is presented as an important first step in the process of designing a distributed system by integrating pre-existing components. The elements describing a business process are derived from the ODP-enterprise viewpoint language. One of the viewpoints distinguished in the Open Distributed Processing standard is the enterprise viewpoint. This viewpoint describes the organizational context in which the distributed system to be constructed will be used. In this paper we will review four business modelling techniques and their suitability for expressing the enterprise viewpoint is evaluated.

Computer Simulation↗

PubMed1997

L-arginine infusion increases basal but not activated cerebral blood flow in humans.

Nitric oxide is a potent vasodilator. Infusion of its precursor, L-arginine, results in increased cerebral blood flow (CBF) in experimental animals. We examined the effects of L-arginine infusion on CBF in humans using positron emission tomography and the quantitative H2(15)O method. Six subjects received 500 ml of 0.9% NaCl solution, and six subjects received an infusion of L-arginine (16.7 mg/kg/min; 500 mg/kg). Before and after the i.v. infusion, paired CBF measurements were performed at baseline and with vibrotactile stimulation of the right hand. In scans performed without vibrotactile stimulation, mean whole-brain CBF increased from 34.9 +/- 3.7 ml 100 g-1 min-1 to 38.2 +/- 4.4 ml 100 g-1 min-1. (9.5%; p < 0.005) after L-arginine infusion. The temporal pattern of CBF changes differed from that of plasma growth hormone and insulin levels and of arterial pH. In contrast, in the saline group, mean whole-brain CBF did not change significantly (35.8 +/- 5.9 ml 100 g-1 min-1 to 35.9 +/- 6.4 ml 100 g-1 min-1; 0.3%). Vibrotactile stimulation produced significant focal increases in CBF, which were unaffected by L-arginine infusion. L-arginine infusion was associated with an increase in plasma L-citrulline, a byproduct of nitric oxide synthesis.

Adult↗

PubMed1997

Migration towards a component based HIS architecture.

Computer Systems↗

PubMed1997

Supporting shared care for diabetes patients. The synapses solution.

In this paper we discuss the construction of a Federated Health Care Record server within the context of the European R&D project Synapses. We describe the system using the five ODP viewpoints. From an analysis of the business process to be supported by the distributed system (the shared care for diabetes patients) requirements for the server are derived.

Computer Communication Networks↗

PubMed1996

The complexity of transactions: a means for assessing interoperability.

Interoperability seems to be a major focal point of the activities within the Informatics Society in general, and the Medical Informatics society in particular. In both Europe and the USA standardization efforts are pursued in order to enable interoperability. However, even if the technical requirements are met, interoperability is sometimes not feasible because the message exchange needed is too complex. This complexity is influenced by at least three factors: the volume of the data to be exchanged, the functionality of the information exchange, and the communication standard adopted.

Computer Communication Networks↗

PubMedDate not supplied

Component-based development for supporting workflows in hospitals.

Changing requirements for health care information systems force the development of an open, modular architecture in which components can be integrated. This offers a flexible means for integrating different (heterogeneous) systems used by different users. Selecting the components to integrate, and determining the 'right way' to integrate them, necessitates a shift in focus towards the business process to be supported. The realization of such an open, modular architecture is a difficult task. It consists of breaking down existing systems in required components and integrating these and other components. Many authors on component-based development strategies focus attention on the technological issues of component integration (do we use CORBA, DCOM/OLE, or EDI?). This paper presents an approach for determining the required components, and the way they have to be integrated, based on an analysis of the business process to be supported, and the information systems currently used.

Computer Communication Networks↗

PubMedDate not supplied

Integrating information systems in medicine: a reference model for middleware.

This paper addresses the problem of integrating healthcare information systems, from a technological viewpoint. We propose to take the concept of an ¿integration service' as an elementary concept in discussing the problem of integration. We then propose a taxonomy for grouping integration services according to their functionality and their domain specificity. The use of this taxonomy for decomposing an integration problem into (less complex) sub-problems is demonstrated. Finally, a sequence of steps to be taken in solving an integration problem is discussed.

Computing Methodologies↗