With the maintenance, purchase and utilization analyzed, the medical engineer is oriented to enhancing the efficiency of the hospital and strengthening the construction of medical engineering department.

Objective To develop a hyperthermia temperature control system for the treatment of pelvic inflammatory disease. Methods Temperature was controlled by using PWM method based on a single chip computer. The system was heated by using heating wire. In the whole cycle of T, the heating wire's work time was divided into three different stages according to different temperature of system: in the lower temperature, the duty cycle of the heating wire's work time was 100%; when the system temperature entered to a certain stage, a control variable was obtained through the PID algorithm which was used to compare the difference between the current temperature and the temperature requirements. The control variable determined the duty cycle of the heating wire's work time: the more close to the temperature required for the temperature of system, the duty cycle of the heating wire's work time was more close to 0; if the temperature exceeded a predetermined value, then the heating wire would not heat in the whole cycle. Results The accuracy of the temperature control system was ?0.2 ℃, the overshoot of the temperature control system was ?0.3 ℃, and the response time of the temperature control system was 500 seconds. Conclusion The temperature control method has high precision, small overshoot, and the right response time, which can meet the requirements of constant temperature of hyperthermia treatment. Besides, it is simple and cheap.

Objective To investigate the CT angiography techniques of the pulmonary artery and aorta at a time.Methods Twenty-three patients who underwent the 64-slice spiral CT examinations of pulmonary and aortic angiography at a time were analyzed retrospec-tively (Group A).Also,13 cases whose pulmonary angiography showed normal (Group B)and 13 cases whose aortic angiography showed normal (Group C)enrolled in this study as control groups.The contrast media dose and the radiation dose were analyzed among three groups.The abnormal blood vessels were observed,and the CT values of the normal pulmonary artery and aorta and the number of the pulmonary 4,5 grade were compared among all groups.Results The contrast media dose in Group A was more than that in Group B or Group C,but less than the sum of that in Group B and Group C.The radiation dose in Group A was equivalent to that in Group C,which was obviously less than the sum of that in Group B and Group C.Six of 23 cases were accurately diagnosed as pul-monary embolism,1 case as pulmonary malformation,4 cases as aortic dissection whose true and false lumens clearly showed with contrast,5 cases as aortitis,and 10 cases as aortic atherosclerosis.For the cases whose angiography showed normal,there was no statistically significance of the number of the 4,5 grade of pulmonary artery and the CT values of pulmonary artery and the aorta compared with those of the control group (P >0.05 ).Conclusion The 64-slice spiral CT can be used to complete pulmonary and aortic angiography at a time,and the contrast media dose and the radiation dose can be reduced obviously.

Objective To analyze the angiography procedure,distribution of cerebral vascular lesions and complications of cerebral angiography in patients 75 years or older with cerebrovascular diseases.Methods A total of 83 consecutive patients 75 years or older (range 75-89 years) diagnosed as cerebral vascular diseases underwent cerebral angiography with a coverage of all arteries supplying blood to the whole brain including bilateral subclavian arteries between June 2003 and June 2009.The angiogram showed 61 patients (73.5%) with ischemic cerebralvascular diseases,22patients (26.5%) with hemorrhagic cerebralvascular diseases.Results The 78 (94.0%)angiographies were performed using transfemoral access.Composite curve catheters such as Simmons curve were selected in 11 (13.3%) angiographies.In patients with ischemic cerebralvascular diseases,159 stenotic lesions were detected,among which 107 (67.3%) lesions located at the anterior circulation and 52 (32.7%) lesions located at the posterior circulation;97 (61.0%) lesions were extracranial and 62 (39.0%) lesions were intracranial.The 9 unruptured aneurysms were incidentally detected in 8 patients.In patients with hemorrhagic cerebralvascular diseases,19 aneurysms were detected in 16 (72.6 % ) patients.Complications occurred in 5 (6.0 % ) patients:transient neurological complications occurred in 2 (2.4%) patients,hematoma at the puncture site occurred in 2 (2.4%)patients and uroschesis occurred in 1 (1.2%) patients.Conclusions As a kind of diagnostic technology,cerebral angiography is safe in patients 75 years or older with cerebral vascular diseases.The incidence of complications especially permanent neurological complications is low.

ObjectiveTo summarize the prevention and treatment of complications of carotid angioplasty and stenting (CAS) in the elderly. Methods88 cases (≥60 years) who underwent carotid angioplasty and stenting were collected from our hospital. The prevention and treatment of complications were analyzed retrospectively. ResultsNinety-two self-expanding stents were placed in the 88 cases and the technical success rate was 100%. The degree of stenosis was significantly improved from 82.6% to 13.2%. All patients were followed up for 3-12 months. Carotid sinus reaction was observed in 23 cases (26.1%) and it was more often in ≥70 years group than in 60～69 years group (P＜0.05). Meanwhile, compared with the distance ＞10 mm, Carotid sinus reaition was more often in the distance ≤ 10 mm between carotid bifurcation and maximum stenotic lesion (P＜ 0.05). Hypertension occurred in 6 cases, cerebral hyperperfusion syndrome in 4 cases including 1 case of cerebral hemorrhage. There were cases with cerebral ischemia in 1 case, cerebralvaseular spasm in 4 cases, acute renal insufficiency in 3 cases and ecchymosis and hematoma at the puncture site in 7 cases. There were 3 cases of transient ischemic attack, 1 case of myocardial infarction, 1 case of cerebral hemorrhage, 2 cases of mild neurological deficits and no death occurred during the period of follow-up. ConclusionsThere is higher risk for elderly patients undergoing CAS, but careful preoperative preparation and properly treatment may avoid the occurrence of complications.

Objective To explore the diagnosis, treatment strategies and clinical outcomes of spontaneous subarachnoid hemorrhage in elderly patients. Methods A total of 68 patients aged over 60 years presenting with spontaneous subarachnoid hemorrhage underwent cerebral angiography. And 72 intracranial aneurysms were detected in 60 patients, among whom 47 patients with 59 aneurysms underwent endovascular coil embolization, 6 aneurysms in 6 patients were clipped in microneurosurgery operation, and 7 patients chose conservative treatment. Results A total of 57 aneurysms (96.6%) were embolized successfully, among which 40 aneurysms (70.2%) reached dense occlusion and 17 aneurysms (29.8%) reached incomplete occlusion. Among 47 patients undergoing endovascular treatment, 39 patients (83.0%) were evaluated as good, 7 patients (14.9%) were moderately to seriously disabled according to Glasgow Outcome Scale when they were discharged, and one patient died. Conclusions Active treatment such as endovascular coil embolization can acquire good outcome in elderly patients with spontaneous subarachnoid hemorrhage, especially in elderly patients detected with aneurysms.

Objective Toinvestigatethetechnicalfeasibilityandefficacyofvertebralarteryorigin and adjacent subclavian artery stenosis treated with a single self-expandable stent implantation simultaneously. Methods Twenty-onepatientswithposteriorcirculationischemicsymptomsweretreatedwithasingle stent implantation for vertebral artery origin (stenosis rate≥70%)and adjacent subclavian artery stenosis (stenosis rate ≥50%)simultaneously. The head end of a single self-expandable open-cell stent was implanted into the middle or distal V1 segment of vertebral artery,and the caudal end was implanted at the proximal subclavian artery during procedure. At 6 -12 months after procedure they received followed-up with CTA and/or DSA. The clinical and image data of the patients were analyzed retrospectively. Results Allstentswereimplantedsuccessfully.Thevertebralarterystenosisratewasdecreasedfrom 87. 1 ± 5. 7% before procedure to 7. 4 ± 6. 4% and the subclavian artery stenosis rate was decreased from 61.9±8.4% to4.5±5.7% aftertheprocedure.Therewassignificantdifference(allP<0.05).No perioperative complications occurred. The in-stent restenosis (about 50%) was found in one patient (4.8%)during the follow-up and he did not have any relevant clinical symptoms. One patient (4. 8%) had recurrent vertigo at 6 months after procedure. CTA and DSA examinations revealed stent compression and vertebralarteryocclusion.Conclusion Asingleself-expandablestentimplantationforthetreatmentof vertebral artery origin and adjacent subclavian artery stenosis simultaneously is feasible and safe. The incidences of in-stent stenosis and stent compression are low.

This article is devoted to the design of a system for modulating intermediate frequency electrotherapy waveform output. Prescriptions with different output waveform combinations were produced using microcontroller unit (MCU). The rich output waveforms effectively improve tolerance of human adaptability and achieve a therapeutic effect.
Computer-Aided Design ; Electric Stimulation Therapy ; instrumentation ; Equipment Design ; Humans ; Microcomputers ; Software Design

Objective To investigate the clinical effect and feasibility of interventional treatment of cervical artery stenosis in the elderly patients aged 75 years and over. Methods The data of 60cases aged 75 years or over who underwent interventional treatment of the cervical arteriostenosis involving carotid artery (CA), vertebral artery (VA) or proximal segment of the subclavian artery (SCA) were analyzed retrospectively. The clinical manifestations, imaging characteristics,interventional managements and follow-up results were recorded. Results In this cohort, the mean age was (78. 9±3.7) years (range from 75 to 89). The 50 patients (93.3%) complained of cerebral ischemic symptoms, and all the patients had concurrent diseases or risk factors, including hypertension, diabetes mellitus, coronary heart disease (CHD), stroke history, and so on. Digital subtraction angiography (DSA) data showed 55 cases (91.7%) had 2 or more cerebral arteries with a stenosis exceeding 30%. Among all cases, 84 lesions were treated with 84 stents, with a technical success rate of 98.8%. After stenting, the percent diameter stenosis of lesions decreased from a mean of (80.8 ± 12.9) % to (7.1 ± 9.5 ) %. The periprocedural and 30-day postoperative neurological complication rate was 8. 3 %, resulting in a permanent complication rate of 5 %. Clinical improvement rate was 87.5%. During a follow-up period of (36.7±26. 3) months (range from 5 to 99), there were 4 deaths: 2 died from myocardial infarction, 1 died from brain metastases of lung cancer and 1 died from cerebral hemorrhage. Cerebral infarction recurred in 3 cases. Imaging follow-up in 78. 3% of patients for 66 stents, including ultrasound, CTA, MRA or DSA, showed that the general in-stent restenosis rate was 9. 1%, and the restenosis rate of VA, CA and SCA was 21.7% (5/23), 2.6%and 0, respectively. Conclusions The results of this series suggest that interventional treatment ofcervical artery stenosis in the elderly patients aged 75 years and over is effective and feasible. In our experience, clinical comprehensive management and skillful technique of the operator are equally important for the elderly patients aged 75 years and over with high incidence of concurrent diseases or risk factors.

OBJECTIVETo explore the feasibility, safety and efficacy of endovascular reconstructive treatment by multiple overlapping stents with or without coils.

METHODSTotally 17 patients of vertebrobasilar fusiform aneurysms treated by multiple overlapping stents with or without coils between September 2011 and September 2015 in Department of Neurosurgery, Beijing Hospital were retrospectively reviewed. There were 15 male and 2 female patients with mean age of (47±13) years. Clinical manifestations included subarachnoid hemorrhage in 5 patients, cerebral ischemia or infarction in the posterior circulation in 5 patients, mass effect accompanied with brainstem infarction in 1 patients, headache or dizziness in 4, and incidental findings in 2 patients. Aneurysm located in intracranial vertebral artery in 11 patients, vertebrobasilar junction in 2 patients, and basilar trunk in 4 patients. Mean aneurysmal size was 18.5 mm×8.0 mm(length×width).

RESULTSSole stenting with overlapping stents was performed in 8 patients, and overlapping stents with coils was applied in 9 patients. Post-procedural hemorrhage occurred in a patient with a giant basilar trunk fusiform aneurysm and led to death. The 16 surviving patients were clinically followed up for a mean of 21.1 months. One patient had a modified Rankin score of 4, and the other patients had a good recovery. Among 15 patients with a mean angiographic follow-up of 8.6 months, 9 patients had their aneurysms further thrombosed, 3 patients were stable, and 3 patients with a recurred aneurysm. Final complete occlusion was achieved in 7 patients.

CONCLUSIONReconstructive treatment by overlapping stents with or without coils is feasible and relative safe in vertebrobasilar fusiform aneurysms.

Adult ; Endovascular Procedures ; Female ; Humans ; Intracranial Aneurysm ; surgery ; Male ; Middle Aged ; Retrospective Studies ; Stents ; Subarachnoid Hemorrhage ; surgery ; Treatment Outcome ; Vertebral Artery ; pathology