Biomedical subjects

V Morice

Publications and source records attributed to V Morice.

11 recordsLinked to original sources

PubMed1995

Control theory as a conceptual framework for intensive care monitoring.

Monitoring patients hospitalized in hemato-oncology departments to undergo clinical protocols of therapy is a complex task. The main difficulty arises in the management of the oncology protocol as well as in the management of critical episodes of acute illness which frequently occur due to high toxicity of the used antimitotics. This problem of controlling a patient's condition can be conceptualized within the control theory paradigm as the task of controlling a process whose state changes over time and can deviate unacceptably from a normal range. Upon request of a French clinical department of hemato-oncology, we developed an intelligent patient monitor named SEPIA to assist clinicians in this task. Following the control theory analogy at the level of knowledge bases design, we have modeled the medical knowledge as control information to represent the medical actions, and state information is used as feedback control to characterize the patient's state. After a general presentation of SEPIA, the analogies between control theory actors and SEPIA's components are specified. The article then focuses on state variables representation. The data reduction process, activated as new data are given to the system, is described. A simulated running session is finally presented to illustrate the whole reasoning process.

Algorithms↗

PubMed1995

Real time monitoring in the control theory paradigm.

Monitoring patients hospitalized in hemato-oncology departments to undergo clinical protocols of therapy is a complex task. The main difficulty arises in the follow-up of the oncology protocol and in the management of critical episodes of acute illness which frequently occur due to the high toxicity of the antimitotics used. This problem can be conceptualized within the control theory paradigm as the task of controlling a process whose state can deviate unacceptably from a normal range. Following the control theory analogy at the level of knowledge bases design, we have modeled the medical knowledge as control information to represent the medical actions, and state information is used as a feedback control to readjust the command.

Aged↗

PubMed1995

A real time control architecture for continuously managing patients in a care unit.

The monitoring and treatment of patients in a care unit is a complex task in which even the most experienced clinicians can make errors. A hemato-oncology department in which patients undergo chemotherapy asked for a computerized system able to provide intelligent and continuous support in this task. One issue in building such a system is the definition of a control architecture able to manage, in real time, a treatment plan containing prescriptions and protocols in which temporal constraints are expressed in various ways, that is, which supervises the treatment, including controlling the timely execution of prescriptions and suggesting modifications to the plan according to the patient's evolving condition. The system to solve these issues, called SEPIA, has to manage the dynamic, processes involved in patient care. Its role is to generate, in real time, commands for the patient's care (execution of tests, administration of drugs) from a plan, and to monitor the patient's state so that it may propose actions updating the plan. The necessity of an explicit time representation is shown. We propose using a linear time structure towards the past, with precise and absolute dates, open towards the future, and with imprecise and relative dates. Temporal relative scales are introduced to facilitate knowledge representation and access.

Clinical Protocols↗

PubMed1987

Integrating management and expertise in a computerised system for hypertensive patients.

An expert system has been integrated to the data management system of the ARTEMIS programme for hypertensive patients. The patient database, which has been used since 1975, contains the medical records of about 20,000 patients. Information is interactively entered by physicians, nurses and secretaries on video display units. The computerised medical record has replaced the traditional handwritten medical record. The database management system is used to produce different summary reports (inpatient and outpatient care) and personalized recall letters which are mailed to the patients before their appointments. Suggestions provided by the expert system include additional information to be obtained (complementary patient interrogation, biological or radiological investigations, etc.), possible causes of hypertension, and medical prescriptions. The information base allows the description of both static knowledge (in the form of a semantic network) and dynamic knowledge (in the form of production rules). The inference system sequentially uses a combination of forward and backward chaining and performs both exact and approximate reasoning. The diagnostic performance of the expert system was evaluated in 100 cases of hypertension (50 of essential hypertension and 50 of secondary hypertension. Concordance between the diagnosis proposed by the expert system and the one proposed by the specialist was achieved in 92% of secondary hypertension cases and 88% of essential hypertension cases. It is suggested that the integration of data and knowledge management might enhance the overall acceptance by medical staff of a computerised system, and facilitate the validation of a knowledge base.

Database Management Systems↗

PubMed1986

[Testing an expert system for hypertension].

An Expert System (ES) has been connected to a database management system for the management and follow-up of hypertensive patients. The patient data base, called Artemis, contains approximately 18,000 medical records. About 90% of the initial informations used by the ES is contained in the medical records of the Artemis data base. The knowledge base consists of 870 rules. A first group of rules allows the description of knowledge structures (hierachies, graphs and mutual exclusions). The second group consists of production rules which describe the dynamic reasoning of the expert. The inference engine uses a combination of forward and backward chaining. The ES produce diagnostic hypotheses (possible causes of hypertension) and therapeutic suggestions before and after requiring additional information (patient supplementary interrogation, biological or radiological investigations). The evaluation of the diagnostic performance of the ES was made on 40 confirmed cases of secondary hypertension (SH) and 40 cases of essential hypertension (EH). The initial initial diagnosis, just after the forward chaining step, was correct in 17 cases of SH and 32 cases of EH. The final diagnosis proposed after several steps of forward and backward chaining was correct in 37 cases (92%) of SH and 36 (90%) of EH. Averages of 5 (EH) and 8 (SH) questions were formulated by the ES to reach the final diagnosis. The integration of the ES to the database is expected to facilitate the validation of the knowledge base and to enhance its overall acceptability. Whether or not such an integration will be useful and accepted as a complementary tool by physicians remains however an open question.

Decision Making, Computer-Assisted↗

PubMed1986

[The Landry-Guillain-Barré syndrome. Study of prognostic factors in 223 cases].

A retrospective study of 223 patients (111 men, 112 women, mean age 40.6 years) with the Landry-Guillain-Barre syndrome investigated vital or functional prognostic factors. Patients were first seen between 1963 and 1981, when 192 were noted to have cranial nerve disorders. Assisted ventilation was required in 152 cases, and 23 patients died, including 5 from cardiocirculatory dysautonomy. Plasma exchange was not used. Patients were divided into 3 groups as a function of the degree of maximum paralysis: group 1 (n = 63) patients had incomplete quadriplegia without assisted ventilation, group 2 (n = 93) incomplete quadriplegia with assisted ventilation, group 3 (n = 62) quadriplegia with or without assisted ventilation. Vital prognosis was related to the severity of neurologic disorders. Frequency of intercurrent complications, dysautonomic disorders and mortality increased with maximal severity of motor deficit. The 3 groups did not differ as a function of previous history, mode of onset of polyradiculoneuritis, duration of extension phase of paralysis, or CSF protein content at the first examination during the extension phase of the paralyses. It is therefore impossible at an early stage of the disease to predict future motor deficit. The cumulative percentage of patients who recovered a normal muscular force in limbs and cranial territories was 48 p. 100 after one year and 60 p. 100 after two years (actuarial values). The functional prognosis depends upon the degree of motor deficit at maximum paralysis and duration of the plateau phase. Probability of full muscular strength recovery was lower in group 3 and in those patients with a plateau phase duration longer than 2 weeks. Independently of groups, motility recovery rate was markedly higher in patients with a plateau phase duration of less than one week. Motility recuperation was independent of age, sex, duration of extension phase, CSF protein levels during the acute phase, and presence of autonomic nervous system disorders.

Adolescent↗

PubMed1984

Adjuvant immunotherapy with nonviable Mycobacterium smegmatis in resected primary lung carcinoma. A randomized clinical trial of 219 patients.

Two hundred and nineteen patients with resected lung carcinoma were randomized 3 weeks after surgery between two treatment arms: a control group (110 cases) and an immunotherapy group (109 cases). The immunostimulant was a nonviable saprophytic mycobacterium, M. smegmatis, given monthly by subcutaneous injection in four sites. The two groups were equivalent in terms of prognostic factors, including a nonsignificant difference favoring the control group based on the N (node) classification. This interim analysis was carried out on June 1, 1981. Treatment comparison by the log-rank test did not show any significant differences between these two groups in regards to disease-free interval and overall survival. There was no significant difference between the two groups after stratification of the comparison according to the N classification or adjustment with a subset of eight prognostic parameters through the Cox model. The initially expected difference (20% 1-year survival) will probably not be achieved, given these interim results, but patients will continue to be treated and followed-up according to the protocol as to allow further evaluation of this nonspecific immunotherapy.

Adult↗

PubMed1982

DISBAR: a program for two-group discriminant analysis on mixed variables after binary coding.

The program DISBAR is particularly adapted to medical data which often concern several measurements of different types (mixed variables) collected on patients divided into 2 groups according to a binary response variable such as survival or non-survival. DISBAR leads to a simple geometrical representation of the observations providing an easy allocation rule for a new case. The computer time required to run the program DISBAR is negligible in comparison with the one necessary to perform any other discriminant analysis of binary variables. DISBAR combines in practice computational facility with good results and easy interpretation.

Computers↗

PubMed1980

Two methods of discrimination on qualitative variables.

The methods of discrimination on qualitative variables are generally based on the estimation of density distribution in each group yk (k = 1, 2, ..., K). Two kinds of estimation are proposed and the correspondent computer program is presented. The results of a medical example are compared with those obtained by using a logistic model used by different authors when dealing with discrimination problems.

Computers↗

PubMed1980

[Maxillary cancer. A retrospective study of 239 cases (author's transl)].

A study of the distribution of these cancers demonstrated that they were mainly epidermoid carcinomas (144 cases), cylindromas (38 cases), and sarcomas. The series included 58% of male patients, but the percentage of women is high because of the predominance of muco-epidermoid epitheliomas and hematosarcomas in female patients. Age distribution was identical for both sexes. The period between the first sign and the diagnosis varied according to the histological type (5 months for epidermoid carcinoma, 10 months for the cylindromas, and 28 months for muco-epidermoid epitheliomas). The initial examination revealed the presence of palpable glands in 40% of the cases with epidermoid cancer of the gums, as against 25% of those with facial epidermoid carcinomas. Survival rate after 5 years was 33% for epidermoid cancer, 72% for cylindromas, and 15% for muco-epidermoid epitheliomas. For epidermoid carcinomas, survival was related to their size (56% for T1, 52% for T2, 30% for T3, and 16% for T4). No significant differences in relation to the site of the lesion were found. The incidence of glandular invasion is of the greatest importance. All N3 cases died within 30 months. In fact, two categories of patients can be conveniently distinguished; those with T1, T2, T3, NO who have an overall mean survival rate of 68% after two years, and all the other cases with a mean survival rate of 28%.

Adult↗

PubMed1979

The detection of doubtful data: the program DOUBT.

The problem of the detection of erroneous data has led us to define the 'doubtful patients' as patients who have a small density. Our program DOUBT computes the densities associated with each patient by using the method of n nearest neighbors. Then the program allows us to define a density limit, and chooses the patients who have a smaller density then the doubtful patients. The remaining patients may be classified by the program.

Computers↗