Technological advances in diabetology

The understanding of diabetes mellitus has evolved constantly since ancient Egyptian times. Insulin administration is much easier today likewise urine testing and the monitoring of blood sugar levels. For more than 30 years, pancreas transplants and, over the last 15 years, the islets of Langerhans transplantation have offered new hope.     

Evaluation of selected sidewalk pavement surfaces for vibration experienced by users of manual and powered wheelchairs

BACKGROUND: Obstacles such as bumps, curb descents, and uneven driving surfaces cause vibrations that affect the wheelchair, and in turn, the wheelchair user. Chronic exposure can cause low-back pain, disk degeneration, and other harmful effects. Little research has been conducted to assess the vibrations experienced by wheelchair users. OBJECTIVE: The purpose of this study was to conduct an evaluation of the vibration exposure during electric-powered wheelchair driving and mechanical energy requirements for manual wheelchair propulsion over selected sidewalk surfaces. The goal was to determine the criteria for a wheelchair-pedestrian access route that does not require excessive propulsive work or expose wheelchair users to potentially harmful vibrations. METHODS: Ten unimpaired individuals participated in this study. Six sidewalk surfaces were tested. Measured variables included power of the acceleration per octave, mechanical work to propel over surfaces, peak acceleration, and frequency at which peak acceleration occurs. RESULTS: For both the manual and electric-powered wheelchair, at 1 m/s, significant differences were found in peak accelerations between the seat and footrest (P < 0.0001) and between the sidewalk surfaces (P = 0.004). The greatest risk for injury caused by shock and vibration exposure occurs at frequencies near the natural frequency of seated humans (4-15 Hz). The values for work required to propel over the surfaces tested were not statistically significantly different. Besides appearance and construction, the only distinguishing characteristic was surface roughness caused by the joints. CONCLUSION: When treating the poured concrete sidewalk as the standard, surfaces 2, 3, 5, and 6 compared most favorably in terms of vibration exposure, whereas surface 4 produced mixed results. Surfaces 2, 3, 5, and 6 yielded results that were similar to the poured concrete sidewalk and could be considered acceptable for wheelchair users. In conclusion, surfaces other than the traditional poured concrete can be used for pedestrian access routes without adding vibration exposure or reducing propulsion efficiency.     

Technological advances in laparoscopic aorto-occlusive surgery.

Minimally invasive surgery (MIS) has been recognized as increasingly beneficial to patients undergoing various cardiovascular surgical procedures. Cardiac applications with MIS techniques and technologies are being shown as beneficial in heart valve replacement and in coronary artery bypass. In vascular surgery, benefits are being reported for endoscopic saphenous vein harvesting as well as endoscopic ligation of incompetent perforators. Since 1993, applications of laparoscopy to aortic surgery have been reported. Until these reports, percutaneous interventional procedures have been the mainstay of MIS vascular work for aortoiliac disease. Reported laparoscopic techniques have ranged from laparoscopically assisted techniques to procedures performed completely laparoscopically. Several studies show that laparoscopic aortic surgery is feasible. These show the known advantages of MIS for patients, with decreased use of analgesics, shortened ileus, earlier ambulation, and shortened length of stay. Laparoscopy has been showing a growing role in the armamentarium of the modern vascular surgeon.     

Technological advances in the surgical management of trigeminal neuralgia

For years, many controversies have arisen on the surgical management of trigeminal neuralgia and neuropathy. The purpose of this paper is to review most of the current surgical techniques for the management of trigeminal neuralgia and present our position on the current management of these situations.     

Technological advances shed light on left ventricular cardiac disturbances in cystic fibrosis

Cystic fibrosis (CF), the most common autosomal recessive lethal disease in Caucasians, causes chronic pulmonary disease and can lead to cor pulmonale with right ventricular dysfunction. The presence of the cystic fibrosis transmembrane conductance regulator (CFTR) in cardiac myocardia has prompted debate regarding possible defective ion channel-induced cardiomyopathy. Clinical heart disease in CF is considered rare and is restricted to case reports. It has been unclear if this is due to the lack of physiological importance of CFTR in the heart, the relatively short lifespan of those with CF, or a technical inability to detect subclinical disease. Extensive echocardiographic investigations have yielded contradictory results, leading to the dogma that left ventricular defects in CF occur secondary to lung disease. In this review, we consider why studies examining heart function in CF have not provided clarity on this topic. We then focus on data from new echocardiographic and magnetic resonance imaging technology, which are providing greater insight into cardiac function in CF and demonstrating that, in addition to secondary effects from pulmonary disease, there may be an intrinsic primary defect in the CF heart. With advancing lifespans and activity levels, understanding the risk of cardiac disease is vital to minimizing morbidity in adults with CF.     

Technological advances in transurethral resection of the prostate: bipolar versus monopolar TURP

One of the most significant recent advancements in transurethral resection of the prostate (TURP) is the incorporation of bipolar technology. Bipolar circuitry allows TURP to be performed in a normal saline environment, which addresses a fundamental concern of conventional monopolar TURP (i.e., the use of hypo-osmolar irrigation). As a result, the risks of dilutional hyponatremia and transurethral resection (TUR) syndrome are eliminated, allowing for longer and safer resection. This review discusses the principles and applications of electrosurgery in conventional monopolar as well as new bipolar saline-based TURP systems. This review also addresses the positive impact on patient safety and resident training.     

The design of attendant propelled wheelchairs.

The attendant operated wheelchair is propelled by applying forces to handles at the rear of the chair. There are no published data to justify the design of pushing handles on existing wheelchairs. In Dundee, studies of pushing have been conducted in order to obtain subjective preferences for location and design of handles and an understanding of biomechanical factors associated with wheelchair pushing. Preferred positions for handles have been found to be in the region of 0.75 of shoulder height, 1.14 times shoulder width although deviations of +/- 5% in these values are still rated as acceptable. The preferred positions do not correspond to minimum levels of resultant force or with lowest levels of moment in any of the upper body joints. Moments occurring at the lower back are not substantially affected by handle position. The biomechanical analysis so far has not revealed why some handle positions are more comfortable for pushing than others. Further study, involving calculation of resultant moments (rather than just sagittal plane moments) at these joints and at the lower body joints, is a next step in attempting to find the indicators of discomfort. Transferring a patient from or to a wheelchair can be a difficult operation with risks of accidents to the patient through falling and risks to the attendant of strain, particularly to the back. Current footrests on wheelchairs are a major source of the problems during transfer. A new approach to footrest design is described which solves these difficulties by using a footrest that lowers onto the floor. This has other attractive features such as providing good stability and restraint of the chair during transfer.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evolution of powered surgical instruments

The history of powered surgical instruments has paralleled their need in surgery, particularly surgery involving hard tissue like bone or teeth. This development was of great importance, as the sophistication of procedures became more demanding, requiring the use of implants. The fields of neurosurgery, orthopaedics, otology, and dentistry have all played key roles in the development of the high-powered surgical instruments that are now used in every surgical and dental subspecialty. Power modalities that include pneumatic and electric sources along with the development of interchangeable accessories have revolutionized the surgical field, making procedures both safer and faster. Many physicians, dentists, and companies continue to contribute to this exciting and rapidly evolving industry.     

Osteonecrosis after powered core decompression

A 44-year-old man with alcohol-related osteonecrosis of his left femoral head, Ficat Stage 2, was treated by femoral head decompression. During this procedure the (1/4)-inch trephine driven by a power reamer became lodged in the femoral head and became hot to the touch. The trephine eventually was removed with difficulty after the decompression was completed. Four and a half years later, the patient continued to have progressive pain and difficulty ambulating. A radiograph at the time revealed a wide zone of symmetric increased density about the core decompression track. A total hip arthroplasty was done, yielding the femoral head and neck for study. Histologic sections of the femoral head and neck showed that the entire length of the core decompression track in the specimen was surrounded by 2.7 cm of unrepaired necrotic bone. The evidence suggests that extensive additional necrosis was produced iatrogenically during the core decompression with the powered trephine. Necrosis secondary to either heat generation or increased pressure along the trephine track is presented as possible mechanisms for this unusual finding.     

Upper limb strength in individuals with spinal cord injury who use manual wheelchairs

INTRODUCTION: Manual wheelchair users have been found to be at risk for secondary upper extremity injuries. PURPOSE: The primary goal of this study was to compare shoulder strength and muscle imbalance of individuals with paraplegia to case-wise matched unimpaired controls (UC). A secondary goal was to evaluate the impact of age and neurologic level of injury (NLI) on weight-normalized strength (WNS). METHODS: The SCI group (n = 28) and the UC group (n = 28) completed bilateral shoulder isokinetic strength testing in the sagittal, frontal, and horizontal plane at 60 degrees/second using the BioDex system. Strength ratios, an indicator of muscle imbalance, were also calculated. RESULTS: No significant difference was seen in shoulder strength or strength ratios between the SCI group and the UC group. However, NLI was significantly related to WNS on several planes in the SCI group. Therefore, we dichotomized the SCI group into equal groups based on an NLI. The Low-SCI group was significantly stronger than the High-SCI group in most planes (P < 0.05). The High-SCI group was significantly weaker than the UC in extension (P < 0.01) and a trend (P < 0.01) was seen in flexion, abduction, and external rotation. The Low-SCI group was significantly stronger in abduction than the UC. CONCLUSION: WNS at the shoulder correlated with NLI. It is likely that this is related to contributions of the trunk and abdominal muscles during testing, since proximal trunk strength aids in generating forces distally. This study and others of strength in individuals with paraplegia may overestimate shoulder strength.