Medical instrumentation最新文献

Much attention has been focused on the response to victims of injuries in the last two decades. During those twenty years, tremendous strides have been made in the medical community's ability to meet the needs of patients in the acute phase of treatment for traumatic injuries. Recent research has reflected these advances in treatment as well as equipment design and development that enable rapid response and access to the injured. Even with these modern miracles of treatment, injuries kill more citizens of the United States 1-34 yr of age than all diseases combined. Traumatic injury is the leading cause of death in people up to 44 yr of age. The emergency medical services community identifies the best "treatment" for traumatic injury as its prevention by means of pre-incident interventions that ultimately reduce the severity of the injury and the potential disablement of the victim.

Two approaches to intraoperative anesthetic gas monitoring exist today. Central, mass-spectrometer-based systems share cost and analyzer time among several remote locations. Stand-alone monitors are usually infrared analyzers and are dedicated to a single monitoring location. The advantages and disadvantages of each are due primarily to the shared versus dedicated approaches. Dedicated analyzers, while limited somewhat by infrared technology, offer uninterrupted, real-time analysis of anesthetic and respiratory gases. Central systems offer excellent monitoring but are limited to periodic updates of each monitored location. This article attempts a complete analysis of these and other factors affecting the use, reliability, and cost effectiveness of these two approaches to anesthesia gas monitoring.

These four examples of technology and its relationship to pre-hospital care will be reviewed: portable defibrillators, pneumatic antishock garment, 911 systems with computer-aided dispatch, and aeromedical transport.

Transrectal ultrasonic imaging of the prostate gland has proved a valuable tool in determining the stage of carcinoma of the prostate and in monitoring the effectiveness of endocrine and radiation therapies. Ultrasonography has been useful in prostatic biopsy, too, but there is debate over its routine use in patients with palpable prostatic abnormalities.

Anejaculation is a disorder that occurs infrequently in the general population, but it occurs in some cases of spinal cord injury and dissection of retroperitoneal lymph nodes for testicular cancer. It is associated with multiple sclerosis, transverse myelitis, and diabetes mellitus. Electroejaculation, which involves electrodes in a probe placed in the rectum, electrically stimulates emission of seminal fluid. Semen thus obtained can be used for artificial insemination if a patient and his spouse wish to become natural parents.

The importance of maintaining a low intravesical pressure during transurethral resection of the prostate has been demonstrated in studies of the relationship between bladder pressure and the amount of irrigating fluid absorbed during the procedure. Several methods of monitoring pressure are described, and the advantages and disadvantages of each are discussed.

Over the past 10 years, endourology and ureteroscopy have revolutionized the field of urinary endoscopy. No longer limited to cystoscopic examination of the lower genitourinary tract, endoscopy incorporates the upper tracts as well. With this surge in upper tract endoscopy has come a rise in the variety of medical instruments available to the endourologist. Beginning with rigid instruments that offered only a limited view, technology has advanced both flexible and rigid instruments that allow access to the entire urinary tract for examination and treatment. Lenses have been designed to give a clearer and wider view of the kidney and ureter, and forceps and graspers have been developed to treat the underlying pathologic conditions. Stents, wires, and nephrostomy tubes have been developed to keep the urinary system patent and readily accessible for reexamination. It is only through the continuous improvement of these instruments that endourology has advanced in the frontier of urologic surgery.

The effects of unilateral, low-frequency, neuromuscular stimulation on the circulation in skin of the lower extremities were studied in eight subjects with peripheral vascular disease and eight control subjects with normal peripheral vasculature. Sixty minutes of stimulation (at 2 Hz), of sufficient intensity to produce visible contraction of musculature, was applied through cutaneous electrodes placed over the common peroneal nerve and dorsum of the foot. Systolic and diastolic blood pressure, heart rate, bilateral great-toe photoplethysmographic waveform, and bilateral pedal skin temperature were recorded at 30-min intervals during stimulation and 30 min after stimulation. Mean differences in recordings before and after stimulation were then calculated for each parameter, showing in subjects with peripheral vascular disease significant increases of 5.3 +/- 2.1 mm and 0.5 +/- 0.1 degree C for ipsilateral photoplethysmographic waveform amplitude and pedal skin temperature, respectively. Mean differences for the remaining parameters were not significant. Recorded parameters in the control group did not change after stimulation. These results demonstrate that low-frequency, neuromuscular stimulation produces regional cutaneous vasodilation in subjects with peripheral vascular disease. No evidence of generalized vasodilation after neuromuscular stimulation was found.