Shuzo Asajima

Bio: Shuzo Asajima is an academic researcher from Shiga University of Medical Science. The author has contributed to research in topics: Functional electrical stimulation & Enthesis. The author has an hindex of 7, co-authored 10 publications receiving 184 citations.

Clinical outcomes of cervical spinal cord injuries without radiographic evidence of trauma

Abstract: We investigated 33 cervical spinal cord injury patients (25 males and eight females) without bony injury. Patients whose neurologic recovery had reached a plateau and who had evidence on imaging of persistent spinal cord compression were considered candidates for surgical decompression. When imaging did not show spinal cord compression or patients were maintaining a good neurologic recovery from the early days after injury, we pursued conservative treatment. Age at injury varied from 20 to 76 years (mean, 55.6). Average follow-up was 31 months. Twelve patients were treated conservatively (Group 1). Groups 2 and 3 had surgery. Group 2 (14 cases) had multi-level compression of spinal cord due to pre-existing cervical spine conditions such as ossification of posterior longitudinal ligament, cervical canal stenosis, and cervical spondylosis. Group 3 (7 cases) patients existed single-level compression of spinal cord by cervical disc herniations or spondylosis. We evaluated clinical results according to the Frankel classification, the American Spinal Injury Association (ASIA) scales and Japanese Orthopaedic Association (JOA) scores. Overall improvement of JOA and ASIA scores after treatment was 56.3 +/- 35.5% and 67.1 +/- 38.0%, respectively. Patients in Group 1 showed very good recovery after conservative treatment, with improvement of JOA and ASIA scores being 70.4 +/- 40.2% and 77.4 +/- 34.2%, respectively. The average interval between injury and operation was 4.3 +/- 4.4 months. The improvement of the surgically treated patients (Groups 2 and 3) in JOA and ASIA score was 48.2 +/- 30.7% and 61.2 +/- 39.6% respectively. We obtained good neurological recovery after operation, with significantly more improvement in Group 3 than in Group 2. No significant neurologic recovery had occurred preoperatively in these groups. In such patients operative intervention is essential for neurologic recovery.

A long-term follow-up study of cervical spondylotic myelopathy treated by "French window" laminoplasty.

Abstract: We investigated 30 patients with multilevel cervical spondylotic myelopathy (22 males and 8 females) treated by "French window" laminoplasties from 1979 to 1988. Patients averaged 62.6 years of age, and were followed an average of 5 years and 2 months. The average preoperative and postoperative Japanese Orthopaedic Association (JOA) scores were assessed, rising from the original 8.8 +/- 3.4 to 11.9 +/- 3.3 (p < 0.001). Patients were divided into two groups, demonstrating poor alignment and no malalignment after surgery. There was no statistical difference regarding improvement in the neurological examinations between these two groups. The "French window" laminoplasty achieved good clinical results in the management of cervical spondylotic myelopathy irrespective of whether or not alignment deteriorated in the postoperative period.

Rupture of the Achilles tendon in rheumatoid arthritis with histologic evidence of enthesitis. A case report.

Abstract: Spontaneous Achilles tendon rupture occurred in a 60-year-old man with a two-year history of sero-positive rheumatoid arthritis (RA). Histologic section of the ruptured Achilles tendon revealed the existence of rheumatoid granulation that consisted of lymphocytes, histiocytes, and small vascular proliferation within the tendon tissue. The enthesis of the tendon to the calcaneus also revealed lymphocyte infiltration in the bone marrow and rheumatoid granulation within the tendon. Throughout the course of his disease, the patient had not been treated with corticosteroids. These facts suggested that enthesis (attachment of tendon to bone) was one of the extraarticular sites of the rheumatoid inflammation and that enthesitis was a possible cause of Achilles tendon rupture in this RA patient.

Cuff actuator for adaptive holding condition around nerves

Abstract: A nerve stimulation technology is expected in the biomedical field. Above all, a functional electrical stimulation is studied in order to recover paralyzed functions. We have proposed a new nerve stimulation strategy and reported successful results. It is indispensable to guarantee a reliable contact between nerves and a stimulator for the nerve stimulation. Most of conventional stimulator, however, was a passive structure, so that it used to be not easy to obtain the desired contact. This paper presents a cuff actuator that allows an adaptive contact between nerves and the stimulator in order to solve the above problem. A trial towards an implantable device is also presented.

Traumatic bilateral locked facet at L4-5: report of a case associated with incorrect use of a three-point seatbelt.

Abstract: We present a case of traumatic L4-5 bilateral facet dislocation, without neurological deficit, in a 32-year-old female patient, as an unusual seatbelt injury caused by positioning the shoulder harness improperly under her armpit. Open reduction, posterior interbody fusion, and posterior segmental instrumentation were carried out. The aim of this report is to describe this rarely encountered condition and speculate regarding automotive shoulder harness misuse as a potential cause of bilateral locked facet at L4-5, and to emphasize the importance of multidirectional X-ray on first examination. The unusual L4-5 level facet interlocking was attributed to misuse of the automobile shoulder harness. We propose the importance of recognizing this injury and following up on such clues as transverse process fractures and/or widened posterior elements.

Method and apparatus for estimating a motion parameter

Abstract: A system for estimating motion parameters corresponding to a user. The system may generally include a receiver operable to receive a signal from an external source, an inertial sensor operable to be coupled with the user and arbitrarily oriented relative to the direction of user motion for generation of a signal corresponding to user motion, and a processing system in communication with the receiver and inertial sensor. The processing system can be operable to utilize the receiver signal to estimate a first parameter corresponding to a first motion parameter type, utilize the inertial sensor signal to estimate a second parameter corresponding to a second motion parameter type, generate a user-specific motion model to correlate the first parameter type and second parameter type using at least the first and second estimated parameters, utilize the inertial sensor signal to estimate a third parameter corresponding to the second parameter type, and utilize the motion model and the third parameter to estimate a fourth parameter corresponding to the first parameter type independent of the receiver signal.

Cervical laminoplasty: a critical review

Abstract: Object. The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multilevel anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the “postlaminectomy membrane.” Methods. The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients. All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20–80%). The authors of 23...

Elastic Inflatable Actuators for Soft Robotic Applications

Abstract: The 20th century's robotic systems have been made from stiff materials, and much of the developments have pursued ever more accurate and dynamic robots, which thrive in industrial automation, and will probably continue to do so for decades to come. However, the 21st century's robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfill the role of robotic link and actuator, where prime focus is on design and fabrication of robotic hardware instead of software control. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics, and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators. This article reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies, and on the other hand by a market pull from applications. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication, and applications.

Total Achilles tendon rupture. A review.

Abstract: There are only a few epidemiological studies on the incidence of Achilles tendon (AT) ruptures. These show an increase in incidence in the West during the past few decades. The main reason is probably the increased popularity of recreational sports among middle-aged people. Ball games constitute the cause of over 60% of AT ruptures in many series. The 2 most frequently discussed pathophysiological theories involve chronic degeneration of the tendon and failure of the inhibitory mechanism of the musculotendinous unit. There are reports of AT ruptures related to the use of corticosteroids, either systemically or locally, but the role of corticosteroids in large patient series is marginal. In addition, recent studies do not confirm earlier findings of blood group O dominance in patients with AT rupture.

Increased risk of achilles tendon rupture with quinolone antibacterial use, especially in elderly patients taking oral corticosteroids.

Abstract: for current exposure to quinolones, 2.4 (95% CI, 1.53.7) for recent exposure, and 1.4 (95% CI, 0.9-2.1) for past exposure. The OR of Achilles tendon rupture was 6.4 (95% CI, 3.0-13.7) in patients aged 60 to 79 years and 20.4 (95% CI, 4.6-90.1) in patients aged 80 years or older. In persons aged 60 years and older, the OR was 28.4 (95% CI, 7.0-115.3) for current exposure to ofloxacin, while the ORs were 3.6 (95% CI, 1.4-9.1) and 14.2 (95% CI, 1.6-128.6) for ciprofloxacin and norfloxacin, respectively. Approximately 2% to 6% of all Achilles tendon ruptures in people older than 60 years can be attributed to quinolones. Conclusions: Current exposure to quinolones increased the risk of Achilles tendon rupture. The risk is highest among elderly patients who were concomitantly treated with corticosteroids. Arch Intern Med. 2003;163:1801-1807