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Biomedical subjects

J Génin

Publications and source records attributed to J Génin.

At least 19 recordsLinked to original sources
PubMed1998

[Digital multi-filter auditory prosthesis: study of its efficiency in function of number of filters and their programming].

We designed a prototype of a 7-filter digital auditory prosthesis table prototype. For each of these filters frequency band width, amplification and compression were programmable in order to adapt these parameters to the deaf patient's audiometric particularities. We compared the hearing improvement it was possible to obtain either with the 3-analogue-filter auditory prosthesis Triton 3004 from Siemens, or with our prototype as a function of the number of filters (3, 4 or 7) and their frequency band width programmability. We tested 21 patients suffering from middle or severe neurosensory hearing loss. This study allows to demonstrate that to overpass the present analogue T004 device a 7 programmable-width-filter strategy seems to be the most appropriate. Further studies benefiting with material improvement of our prototype and finer audiometric adjustment of filter strategies as well as long term clinical studies have to be carried out.

Acoustic Stimulation↗
PubMed1997

Asynchronous interleaved stimulation (AIS): a new speech coding strategy for cochlear implant.

Cochlear implants use a fixed or F0 dependent stimulation rate, whatever the sound analysed (vowel or consonant) or procedure (fixed filters or FFT). We present a procedure which varies as a function of the input signal. This method is based on FFT analysis using a variable width analysis window. Short windows are applied on the transient part of the signal, providing poor frequency resolution but good time resolution; they permit us to accurately follow the speech signal in time during its fast temporal variations. Large windows are applied on the stationary parts of the signal, providing better frequency resolution but poor time resolution. Transient parts of the speech order this window switching; they are detected using the statistical properties of the FFT; moreover, the narrow windowing is coupled to an increase of the stimulation frequency. This strategy has been implemented using the DIGISONIC cochlear implant software, and clinically assessed in 6 regular cochlear implant users, on the basis of a consonant-vowel-consonant test. This Asynchronous-Interleaved-Stimulation (AIS) strategy provides the patients with better discrimination than fixed window FFT analysis. The coding protocol will be described and results presented.

Cochlear Implants↗
PubMed1990

[Presentation of the prototype of a fully implanted cochlear prosthesis].

Description of the prototype of a fully implanted cochlear implant demonstrating the feasibility of a prosthesis with no external component within the next few years. The battery is reloaded by means of electromagnetic induction, and the sound message is received by a subcutaneous microphone, which already has a satisfactory bandwitch and signal-to-noise ratio. This system can be generally applied to most types of permanent intracorporeal stimulation.

Cochlear Implants↗
PubMed1986

Cardiac metastases. Case report on an isolated cardiac metastasis of a myxoid liposarcoma.

This report describes an isolated case of cardiac metastasis of a myxoid liposarcoma that was successfully resected by surgery after clinical and ultrasound diagnosis. Although cardiac metastases are rarely diagnosed during patients' lifetimes, a search should be made for such lesions whenever cardiac disorders appear suddenly in cancer patients. Echocardiography appears to be one of the best investigative techniques for such purposes. Despite generally poor therapeutic results, surgical resection occasionally permits long periods of survival.

Adult↗
PubMed1984

Electrical characteristics of a set of electrodes.

A 12-electrode device has been implanted in the cochlea of a deaf human patient. The electrical impedances have been measured for sine-wave excitation at frequencies ranging from 100 to 3000 Hertz. Based on these results, an equivalent electrical circuit has been designed and its parameters computed. In addition, the patient's perception thresholds for sine-wave pulses at similar frequencies have been measured.

Auditory Perception↗
PubMed1983

[Primary chemotherapy in soft tissue sarcomas considered inoperable].

Fourteen adult patients with inoperable soft tissue sarcoma (with metastases in 4 cases) received chemotherapy as primary treatment. Nine cases were treated by CYVADIC (cyclophosphamide, vincristin, doxorubicin, DTIC) and five cases by DECAV (DTIC, cyclophosphamide, cis-platinum, doxorubicin, vindesine). An objective response was obtained in 7 cases (1 complete remission and 6 regressions greater than 50%) and stabilization in 4 cases. Seven patients became operable after 2 to 6 courses of chemotherapy and a complete resection could be performed in 6 cases. The duration of the response was 2 to 39 months. Toxicity with both combinations was acceptable. We conclude that chemotherapy can provide initial tumor reduction and permit subsequently less radical surgery.

Adolescent↗