Search

This paper describes the development of a compact pneumatic valve that can obtain a high flow rate in a periodically pneumatically driven pipe-moving robot. Plumbing facilities around the world have fallen into disrepair in recent years. Pneumatically driven mobile robots are widely used as an inspection method due to the small inner diameter and complicated shape of the pipes. Various types of robots have been studied, such as earthworm, inchworm, and spiral tube robots. However, these robots are driven by existing pneumatic valve technologies, such as needle-type and solenoid valves, which limit the use of small mobile robots. Small pneumatic valves have a low flow rate, and the entire system is complicated because multiple air pressures are controlled by multiple electrical systems. Thus, focusing on the structure and periodic motion of the ball valve, we developed a pneumatic valve that can periodically apply pressure to multiple pneumatic actuators using only rotational motion with one degree of freedom. We also applied this pneumatic valve to a wave propagation robot and discussed the theoretical running speed of the robot with this valve.

This paper introduces a two-degree-of-freedom pipe selection mechanism using contraction and extension unit composed of single tube and a T branch experiment of an in-pipe mobile robot equipped with this mechanism. Household piping is used for gas transportation to each household. If the pipe is cracked or corroded due to long-term use, it becomes difficult to supply a stable gas. Therefore, inspection of household piping is necessary. The existing methods require a lot of time for the inspection or it is difficult to inspect the entire pipeline. Therefore, in this study we developed an inspection robot for home piping using a mobile robot. To date, the robots proposed have been able to bend in the direction along the pipeline, as the tip of the robot passively bends when passing through the curved pipe. However, at the branch pipe, there is no mechanism that actively bends the tip of the robot, and the pipe cannot be selected and moved in a specific direction. Therefore, this paper proposes the application of a small pipe selection mechanism combining a ball-point pen knock mechanism and a wire bending mechanism to an in-pipe mobile robot using the pressure difference of a single tube.

A 61-year-old female received intravenous injection of calcium chloride after common iliac artery bypass surgery. A red flare appeared at the site of the intravenous infusion on the left forearm and gradually progressed to induration. Seven weeks later, she was referred to the Department of Dermatology for management. Physical examination showed an indurated plaque measuring 13 × 65 mm in size, with linearly distributed ulcers covered by yellowish-white substance, surrounded by reddish skin. Laboratory tests showed no significant abnormalities including serum calcium, phosphate and thyroid hormones. Cultures were negative for microorganisms. Histopathological examination showed calcium deposition confined to the dermis. The lesion healed spontaneously within 2 months with scar formation. A review of the Japanese literature showed confinement of calcium deposits to the dermis in most of the reported cases. We speculate that the pathomechanism of dermal calcinosis includes needle-induced tissue injury with capillary destruction, leading to release of excess calcium between collagen fibers, and its binding to phosphate in the dermis and deposition as calcium phosphate crystals.

Patients with ostomy including urinary stoma often develop peristomal complications, especially skin damage. The patient in this case was a 69-year old female with a history of urothelial carcinoma of the bladder and left ureter who underwent transurethral resection of a bladder tumor, nephroureterectomy and cystectomy combined with ureterocutaneostomy. Later, she had recurrence of urothelial carcinoma in the remaining ureter that spread to the peristomal epidermis, with a skin appearance resembling Paget’s disease. We report this case based on its clinical significance since we believe it is the first description of this condition in the literature.

Close examination of a 67-year-old Japanese man, who complained of persistent nocturia, revealed that a semitransparent polypoid tumor had developed from the bladder neck to the prostatic urethra obstructing the internal urethral meatus, which resulted in excessive urinary retention and post-renal dysfunction. The tumor was resected by a transurethral procedure and a pathological examination of specimens revealed aggressive angiomyxoma (AAM) of the prostate. AAM usually develops in the intrapelvic and perineal organs of females. So far as we know, this is the second case of primary prostatic AAM reported in the English literature, and is the first case where the patient encountered urethral obstruction.

A 78-year old man was diagnosed with a left bleeding renal cyst from CT scan results. Serial CT scans revealed the left kidney mass to be increasing in size and a new lesion in the liver. Renal cell carcinoma with liver metastasis was diagnosed and a radical nephrectomy performed. The initial pathological diagnosis was a benign chronic hematoma. However, the liver mass increased in size and multiplied, while another mass emerged in the twelfth thoracic vertebra with spinal paralysis and was immediately removed. Pathological findings for that specimen showed malignancy of stromal cell origin but low atypia. The renal specimen was re-evaluated using whole cross-section analysis and immunohistochemistry, and diagnosed as a primary renal angiosarcoma. Recombinant interleukin-2 therapy was started immediately; however, the patient died of metastatic disease 13 months after the initial operation. Although contrast imaging depicted the primary lesion as a non-specific hematoma with little focal pooling, and low-grade cytological atypia was shown pathologically, the angiosarcoma was extremely aggressive.