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At least 199 records · Page 11Linked to original sources
PubMed1985

[Central alveolar hypoventilation as a complication of massive intracerebellar hemorrhage: report of a case treated by diaphragm pacing].

The author reported a case of central alveolar hypoventilation (Ondine's curse) which was treated by diaphragm pacing. A 59-year-old man was admitted because of sudden deep coma and tetraparesis. Neurological examination on admission showed miotic pupils with absent light reaction, no oculocephalic reflex, no corneal reflex and tetraparesis. Glasgow scale was evaluated to be E-1 V-1, and M-3 with total of 5 points. Computed tomography confirmed a large hematoma in the cerebellum with ventricular rupture. Immediately, a suboccipital craniectomy was performed and the hematoma was evacuated. His neurological condition was improved gradually within a month after the operation. He responded to verbal orders and moved all his limbs against gravity. His respiration, however, was irregular with a pattern of so-called "cluster breathing" followed by prolonged apnea, that was more pronounced in night. He was suffered from hypoxic hypercapnea and recurrent pneumonia. Therefore, authors decided to employ diaphragm pacing for management of central alveolar hypoventilation. A diaphragm pacemaker (radiofrequency induction) was implanted. A cuff electrode was put around the right phrenic nerve in the right thorax, and the receiver installed subcutaneously in the right anterior chest. Postoperative respiratory study showed ventilation on pacing with satisfactory blood gas and he became able to move around using a wheel chair. In 1966 Glenn demonstrated a new technique to move the diaphragm paced by a receiver through the phrenic nerve, triggered by radio wave from external device.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebellar Diseases↗
PubMedDate not supplied

Nuclear magnetic resonance imaging: methods and current status.

Nuclear magnetic resonance (NMR) is a new noninvasive tool for the imaging specialist. Images are produced, not with X rays, but through the use of radio waves that stimulate transitions between "spin states" of nuclei in a magnetic field. The time required for the nucleus to return to equilibrium gives information about the environment of that nucleus. In this way, tissue chemical abnormalities such as detection of carcinoma and elucidation of metabolic pathways can be determined in vivo. Clinical experience is being accumulated which seems to indicate a role for NMR in the diagnostic evaluation of patients.

Animals↗
PubMedDate not supplied

[Nuclear magnetic resonance and anesthesia].

Anesthesia for imaging by nuclear magnetic resonance presents special problems due to the effect of the large magnetic field and high frequency radio waves on monitoring and respiratory systems. These systems in turn affect image quality. Special materials should be designed specifically for this context or existing materials should be modified.

Anesthesia↗
PubMed1994

Electrosurgical injuries during laparoscopy: prevention and management.

Despite the fact that electrophysics and its application to surgery, in particular endoscopic surgery, is a discreet science, there is little attention paid to the applied principles of the physics involved when surgeons receive their formal training in the technical aspects of surgery. Most training programs consider the discipline of electrosurgery as a skill that is left to the 'hands on' exposure of the student, and that the skills and knowledge of the average professor have been awarded through a 'grandfather' process of credentials. As a result, many myths have been perpetuated over the past decades since William Bovie introduced the first electrosurgical diathermy machine using high frequency radio waves instead of heated instruments (cautery) to destroy human tissue. Electrogenerators, today, have become finely tuned instruments that offer many versatile variables for the contemporary surgeon to harness and deliver, in either a discreet or broad manner, to tissue to obtain a desired effect and outcome.

Electric Injuries↗
PubMed1998

[Treatment of intraepithelial cervical neoplasia with REP Radiosurgical Excision Procedure)].

Radiosurgical cervical excision has been performed in 59 patients affected by CIN of various stages. This non-traumatic method uses 3.8 MHz radio waves to cut and/or coagulate without postoperative pain and tissue destruction. The radiosurgical excision has been performed in local anesthesia by a loop electrode or microneedle according to the seat of the lesion. The therapy was "effective" in 98% of cases (58/59) whereas the "incomplete excision" of CIN was observed in 6.7% (4/59). Complications (postoperative and late bleeding) occurred in 3.2% of the patients (2/59). Therefore, the Radiosurgical Excision Procedure (REP) can be considered an easy technique in ambulatory surgery; this method is effective in the treatment of CIN with either therapeutic and economic advantages and guarantee the functional and anatomic integrity of the cervix.

Adult↗
PubMedDate not supplied

[Effect of geomagnetic disturbances on the blood coagulation system in patients with ischemic heart disease and prospects for correction with medication].

The goals of this investigation were to study the influence of geomagnetic activity on platelet aggregation, blood coagulation in venous blood. The geophysical information was provided by the Institute of Terrestrial Magnetism, Ionosphere and Radio Waves Propagation Russian Academy of Sciences. The most significant changes were obtained in increased platelets aggregation, blood coagulation during increased geomagnetic activity. All these effects may cause the development of angina pectoris. The using of acetyl acetylsalicylic enable decreased the negative effect of geomagnetic disturbances on patients with ischemic heart disease.

Adult↗
PubMed2004

Applications of a travelling wave-based radio-frequency-only stacked ring ion guide.

The use of radio-frequency (RF)-only ion guides for efficient transport of ions through regions of a mass spectrometer where the background gas pressure is relatively high is widespread in present instrumentation. Whilst multiple collisions between ions and the background gas can be beneficial, for example in inducing fragmentation and/or decreasing the spread in ion energies, the resultant reduction of ion axial velocity can be detrimental in modes of operation where a rapidly changing influx of ions to the gas-filled ion guide needs to be reproduced at the exit. In general, the RF-only ion guides presently in use are based on multipole rod sets. Here we report investigations into a new mode of ion propulsion within an RF ion guide based on a stack of ring electrodes. Ion propulsion is produced by superimposing a voltage pulse on the confining RF of an electrode and then moving the pulse to an adjacent electrode and so on along the guide to provide a travelling voltage wave on which the ions can surf. Through appropriate choice of the travelling wave pulse height, velocity and gas pressure it will be shown that the stacked ring ion guide with the travelling wave is effective as a collision cell in a tandem mass spectrometer where fast mass scanning or switching is required, as an ion mobility separator at pressures around 0.2 mbar, as an ion delivery device for enhancement of duty cycle on an orthogonal acceleration time-of-flight (oa-TOF) mass analyser, and as an ion fragmentation device at higher wave velocities.

Computer-Aided Design↗
PubMedDate not supplied

Improving productivity through the use of portable radios.

Orthopaedic practices are under increasing pressure to improve productivity in the ambulatory setting. Best practice use of portable radios or walkie-talkies help to achieve a near 50% reduction in patient visit time without reducing the time spent with the care provider. More patients may be seen or the same number in less time. Increased staff communication saves wasted steps and decreases the response time in patient emergencies. A variety of radios and accessory equipment may be needed to meet the needs of each user and to overcome any structural interference. Successfully instituting this practice change involves time-motion studies, assigning a project manager, and full leadership support. The emission of radio frequency waves by portable radios or their transmitting power may interfere with implanted pacemakers or external medical equipment. But the risk is low when radios are used away from individual patients.

Ambulatory Care↗
PubMed2004

Radio frequency continuous-wave and time-domain EPR imaging and Overhauser-enhanced magnetic resonance imaging of small animals: instrumental developments and comparison of relative merits for functional imaging.

Electron paramagnetic resonance (EPR) imaging in the continuous wave (CW) and time-domain modes, as well as Overhauser-enhanced magnetic resonance imaging in vivo is described. The review is based mainly on the CW and time-domain EPR instrumentation at 300 MHz developed in our laboratory, and the relative merits of these methods for functional in vivo imaging of small animals to assess hypoxia and tissue redox status are described. Overhauser imaging of small animals at magnetic fields in the range 10-15 mT that is being carried out in our laboratory for tumor imaging and the evaluation of tumor hypoxia based on quantitative evaluation of Overhauser enhancement is also described. Alternate approaches to spectral-spatial imaging using the transverse decay constants to infer in situ line widths and hence in vivo pO2 using CW and time-domain EPR imaging are also discussed. The nature of the spin probes used, the quality of the images obtained in all the three methods, the achievable resolution, limitations and possible future directions in small animal functional imaging with these modalities are summarized.

Algorithms↗
PubMed2000

Radio frequency radiation of millimeter wave length: potential occupational safety issues relating to surface heating.

Currently, technology is being developed that makes use of the millimeter wave (MMW) range (30-300 GHz) of the radio frequency region of the electromagnetic spectrum. As more and more systems come on line and are used in everyday applications, the possibility of inadvertent exposure of personnel to MMWs increases. To date, there has been no published discussion regarding the health effects of MMWs; this review attempts to fill that void. Because of the shallow depth of penetration, the energy and, therefore, heat associated with MMWs will be deposited within the first 1-2 mm of human skin. MMWs have been used in states of the former Soviet Union to provide therapeutic benefit in a number of diverse disease states, including skin disorders, gastric ulcers, heart disease and cancer. Conversely, the possibility exists that hazards might be associated with accidental overexposure to MMWs. This review attempts to critically analyze the likelihood of such acute effects as burn and eye damage, as well as potential long-term effects, including cancer.

Accidents, Occupational↗