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J R Ives

Publications and source records attributed to J R Ives.

8 recordsLinked to original sources
PubMed1979

Automatic recognition of inter-ictal epileptic activity in prolonged EEG recordings.

A method of automatic recognition and quantification of inter-ictal epileptic activity in the human EEG had previously been developed and tested using short recordings from awake subjects. This paper describes the adaptation of the method for use during overnight recordings in free-moving unattended patients, in combination with the already existing seizure monitoring system. EEG s were recorded from scalp and sphenoidal electrodes, using cable telemetry and a PDP-12 computer. The spike and sharp wave recognition method allowed the on-line analysis of 16 channels. A section of the 16-channel EEG including 1 sec before and 1 sec after each detected spike was saved on digital magnetic tape. Upon completion of the monitoring session, the tape was played back on the EEG machine, giving a discontinuous tracing of spike sections; this constituted a highly concentrated view of the inter-ictal epileptic activity, in traditional paper form. The spike sections were further analyzed by computer to determine and display on the computer terminal the spatial and temporal distributions of the epileptic activity, providing a complete synopsis of the recording. Several examples of the type of information available from this anslysis are discussed in detail. False detection rates are given for 34 six hour recordings, indicating a high vari ability in the performance, mainly because of artefacts. It is concluded that the final computer displays could only be trusted after visual inspection of the EEG sections provided on paper. The variety of morphologies of artefacts appeared to preclude a total automatic elimination.

Electroencephalography↗
PubMed1978

A long term time-lapse video system to document the patients spontaneous clinical seizure synchronized with the EEG.

A long term audio/video clinical seizure monitoring system is described which is complementary to a previously described EEG seizure monitoring system. The video unit is mobile and based on time-lapsed video recording techniques to extend the unattended continuous video recording of the patient to many days if necessary. The simultaneous coverage of the EEG and behavior of the patient particularly during his seizure has been very useful in the workup of intractable epileptic patients being considered for neurosurgical treatment.

Electroencephalography↗
PubMed1978

Update: chronic sphenoidal electrodes.

A technical modification in the type of material used in the chronic sphenoidal electrode previously described (Ives and Gloor 1977) has further improved their clinical use and benefit of the EEG work-up of epileptic patients. This procedure has become a routine investigation for all patients with suspected temporal lobe epilepsy at the Montreal Neurological Hospital.

Electrodes, Implanted↗
PubMed1977

Automatic noctural sleep sampling: a useful method in clinical electroencephalography.

The clinical usefulness of obtaining a sleep record in epileptic patients is well established. However, in many clinical EEG laboratories, it is difficult to obtain records at night during the patient's natural sleep. Thus, most sleep EEGs are recorded in the EEG laboratory during daytime and are induced by drugs. A 16 channel cable-telemetry system is described which automatically samples throughout the night the EEG of patients while sleeping in their room or ward without the aid of any medication. The electrodes and the cable-telemetry unit are applied to the patient in the afternoon and the system is checked. The patient is then instructed to plug the system into a wall box upon retiring and to disconnect it when he wakes up in the morning. The EEG samples are automatically written out during the night on one of the EEG machines located in the EEG laboratory to which the system is connected via spectral intra-hospital wiring. The duration of the samples and of the intervals separating them can be varied according to the circumstances. We have found this method to be very helpful in the investigation of epileptic patients, especially those considered for surgical treatment.

Electroencephalography↗
PubMed1977

New sphenoidal electrode assembly to permit long-term monitoring of the patient's ictal or interictal EEG.

A new sphenoidal wire electrode is described which greatly increases the clinical and diagnostic usefulness of sphenoidal electrode recordings. These very fine wire electrodes are easy to insert; they are comfortable and acceptable to the patient. In contrast to sphenoidal needle electrodes they expose the patient to no risk should he have a seizure during recording. These electrodes also allow one to extend the recording time to several days, thus increasing the chances of recording a spontaneous seizure, for instance while the patient's EEG is being recorded with a telemetry system. The extended recording time also allows for continuous automatic sampling of the interictal EEG over a period of several days. The quality and the reliability of the EEG record are also enhanced. The new sphenoidal electrodes have been used on over 100 patients and are now being used routinely on suspected temporal lobe epileptics recorded with conventional techniques, while 50 of the patients have also been recorded with a cable-telemetry seizure monitoring system which has captured 65 spontaneous seizures.

Electrodes, Implanted↗
PubMed1976

Seizure moitoring: a new tool in electroencephalography.

A seizure monitoring system, based on telemetry and computer techniques, has been developed to provide a reliable means of recording the patient's spontaneous seizures. It allows a patient's EEG to be monitored for hours or days with 16 channels of EEG from surface, sphenoidal or stereotaxically implanted depth electrodes, from any ward or room within the hospital. The EGG is delayed in time by up to 4 min by a mini-computer so that either the patient can push a button when he experiences his aura or others can push the button when they observe his seizure. Since the delayed EEG is written out, the preictal, ictal and postictal are recorded on paper, without many pages of uneventful interictal information. During the past 16 months, the seizure monitoring system has been used as a clinical service to examine patients with surface electrodes (42), sphenoidal wires (25) and depth electrodes (7) during 146 recording sessions for over 3200 h of monitoring time while over 200 seizures have been recorded.

Amplifiers, Electronic↗
PubMed1975

4-channel 24 hour cassette recorder for long-term EEG monitoring of ambulatory patients.

A 4-channel cassette recorder capable of continuously recording the EEG for 24 h on a C-120 cassette is currently in use at the Montreal Neurological Institute. We have done a limited study on 20 patients with over 2000 h of recording to evaluate the recording system, its limitations and its capabilities, and to develop methodology for its operations. The use of preamplifiers enables one to record the background EEG with a noise level of 3-5 muVpp on 4 channels continuously for 1 day. The electrodes can be hidden in the hair and the preamplifier under the collar, to allow the patient to carry on his normal activities at home and at work. Since the cassette and the batteries can be easily changed, the patient himself can prolong the recording for several days. The cassette can be played back as fast as 60 times on a Minograf EEG machine for compressed analysis or 20 times for more detailed write-out, to obtain a record equivalent to standard EEG recordings. The system was not designed to replace or compete with standard EEG recordings but when used on well defined clinical problems, or in specific research projects, it can enhance the diagnostic or research value of the EEG.

Ambulatory Care↗