Expert review of medical devices
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Expert Rev Med Devices · Sep 2005
ReviewDiaphragm pacers as a treatment for congenital central hypoventilation syndrome.
Congenital central hypoventilation syndrome is a rare syndrome present from birth, and is defined as the failure of automatic control of breathing. All patients with congenital central hypoventilation syndrome require life-long ventilatory support during sleep, although approximately a third of patients require ventilatory support 24 h per day. Diaphragm pacers offer a modality of ventilatory support that affords congenital central hypoventilation syndrome patients with maximal mobility for full-time ventilatory patients, and they may allow for a more normal lifestyle in the appropriate patient. ⋯ This stimulates the phrenic nerve resulting in a diaphragmatic contraction. Settings on the transmitter include respiratory rate and electrical voltage, and are adjusted to give enough tidal volume to allow for adequate oxygenation and ventilation. Therefore, diaphragm pacing is an attractive alternative mode of mechanically assisted ventilation for many patients with congenital central hypoventilation syndrome.
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Expert Rev Med Devices · Jul 2005
ReviewComputer-aided surgery of the paranasal sinuses and skull base.
Endoscopic sinus surgery is one of the most common surgical procedures in otolaryngology. However, the location of the orbit and intracranial contents in close proximity to the paranasal sinuses makes endoscopic sinus surgery potentially hazardous. Otolaryngologists have employed computer-aided surgery, or image-guided surgery, over the past two decades to enhance surgeon confidence, allow more thorough surgical dissections and possibly reduce the complication rate of endoscopic sinus surgery. ⋯ A number of institutional series noting surgeon experience with computer-aided surgery in the domain of paranasal sinus surgery are reviewed. Furthermore, the authors evaluate the utility of image-guidance technology beyond the paranasal sinuses and skull base, such as its use in surgery of the pituitary gland and pterygopalatine fossa, research and resident education. Finally, potential future applications of computer-aided surgery technology are discussed.
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The aim of this review is to report on studies of hydroxyapatite-coated external fixation pins as a solution to enhance pin fixation. In a highly loaded animal study, three tapered pin types were compared: Type A uncoated, Type B coated with hydroxyapatite and Type C coated with titanium. There was a 13-fold increase in the extraction torque of Type B pins compared with Type A, and a twofold increase compared with Type C pins. ⋯ Extraction torque of the hydroxyapatite-coated pins was higher than the extraction torque of the standard pins in both cancellous and cortical bone (p < 0.005). In a prospective, randomized clinical study of osteoporotic wrist fractures, extraction torque of the coated pins was higher than with standard pins (p < 0.0001). These studies demonstrate that with the use of hydroxyapatite-coated pins, no deterioration of pin fixation occurs, and that there is no significant pin loosening and infection, regardless of bone type and loading conditions.
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Expert Rev Med Devices · May 2005
ReviewCurrent state and future development of intracranial neuroendoscopic surgery.
Since the introduction of the modern, smaller endoscopes in the 1960s, neuroendoscopy has become an expanding field of neurosurgery. Neuroendoscopy reflects the tendency of modern neurosurgery to aim towards minimalism; that is, access and visualization through the narrowest practical corridor and maximum effective action at the target point with minimal disruption of normal tissue. Transventricular neuroendoscopy allows the treatment of several pathologies inside the ventricular system, such as obstructive hydrocephalus and intra-/paraventricular tumors or cysts, often avoiding the implantation of extracranial shunts or more invasive craniotomic approaches. ⋯ However, an endoscope may be used to assist microsurgery in virtually any kind of neurosurgical procedures (endoscope-assisted microsurgery), particularly in aneurysm and tumor surgery. Basic principles of optical imaging and the physics of optic fibers are discussed, focusing on the neuroendoscope. The three main chapters of neuroendoscopy (transventricular, endonasal transphenoidal and endoscope-assisted microsurgery) are reviewed, concerning operative instruments, surgical procedures, main indications and results.