The tilted supine position has been evaluated to be one of the significantly effective approaches to prevent bedsore of the patients in the bedridden state. Thus, it has deeply positive influences that in view of dynamics this study explores how the position works. Based on the anatomical theories, this study formulates the human dynamic model. Furthermore, the dynamic simulation of three usual postures in tilted supine position including lying on back, lying with one knee bent and lying with the upper and lower limb on one side lifted is carried out. Therefore, the changes of the three driving forces named as chest force, waist force and thigh force in the tilted supine position can be observed. In order to verify the validity of this simulation, this study obtains the electromyogram measurements of ectopectoralis, external obliques and thigh muscles which are respectively close to the chest, waist and thigh by conducting the human force measurements experiment. The result revealed that in terms of range and trend, the experimental data and simulation’s data were consistent. In conclusion, the changes of these muscles in the supine position movements are researched efficiently by both this experiment and the dynamic simulation. Besides, the result is crucially key to find the mechanism of human’s tilted supine position movements.
Objective To investigate the changes of respiratory mechanics in response to elevated respiratory central drive and their impacts on the inspiratory signals detection.Methods 10 normal volunteers were recruited for the study from the colleagues of the State Key Laboratory of Respiratory Disease. Rebreathing method was used to increase the end expiratory PCO2 ( PCO2 -ET) to the subject’s maximal tolerance in order to stimulate the increase of respiratory central drive. The changes of respiratory mechanics in response to elevated respiratory central drive and their impacts on the initiation signals of inspiration were observed.Results After re-breathing, the average maximal tolerated PCO2 -ET was ( 81. 2 ±6. 6) mm Hg. As the PCO2 -ET rising, electromyogram of diaphragmatic muscle ( RMSdi ) ,transdiaphragmatic pressure ( Pdi ) and tidal volume ( VT ) increased progressively while the time of respiratory cycle ( Ttot ) shorten gradually. As the PCO2 -ETlevel increased frombaseline [ PCO2 -ET( level-0) ] to the maximal level [ PCO2 -ET( level-4) ] , RMSdi increased from( 17. 17 ±12. 41) μV to ( 147. 99 ±161. 64) μV,Pdi and VT increased from ( 7. 5 ±1. 7) cmH2O and ( 0. 68 ±0. 27) L to ( 26. 13 ±11. 51) cm H2O and ( 2. 21 ±0. 37) L respectively, while Ttot shorten from ( 2. 91 ±0. 85) s to ( 1. 92 ±0. 39) s. These four parameters of respiratory mechanics, RMSdi, Pdi, VT and Ttot, were highly correlated linearly with PCO2 -ET ( r value was 0. 956, 0. 973,0. 956 and 0. 89 respectively, all P lt;0. 001) . At the start of inspiration, the first detectable signal was electromyogramof diaphragmatic muscle ( RMSdi) , followed by mouth pressure ( Pm)and inspiratory flow ( Flow) on time sequence. As the rising of PCO2 -ET, the time lag of Pmand Flow from RMSdi after the initiation of inspiration increased gradually. However, the time lag between Flow and Pm remained constant. Conclusions At the start of inspiration, the signal of RMSdi appears first as compared with Pm and Flow. As the rising of PCO2 -ET, the time lag of Pmand Flow fromRMSdi after the initiation of inspiration increased gradually, suggesting RMSdi is more sensitive inspiratory signal, which might be used for triggering of ventilator in order to improve the synchronization, especially in the situation of elevated respiratory central drive.
In this paper, the response of individual's physiological system under psychological stress state is discussed, and the theoretical support for psychological stress assessment research is provided. The two methods, i.e. the psychological stress assessment of questionnaire and physiological parameter assessment used for current psychological stress assessment are summarized. Then, the future trend of development of psychological stress assessment research is pointed out. We hope that this work could do and provide further support and help to psychological stress assessment studies.
ObjectiveTo investigate the clinical features of Hirayama disease (HD). MethodsWe analyzed the clinical manifestations and assistant examination results of one patient with HD diagnosed in November, 2010. In addition, we reviewed the related literatures. ResultsThe patient was a young man, and the main symptoms were bilateral hand weakness with muscular atrophy. The muscle bundles trembled when he stretched his fingers. The electromyography showed neurogenic damage of both the thenar muscles and the first interosseous muscles. Brain magnetic resonance imaging (MRI) showed normal; cervical spine flexion MRI showed thinning cervical spinal cord with spinal canal narrowing at C5-C7 plane. In addition, epidural fat gap widened at C4-T1 plane, and enhanced scan showed cord-like changes, patchy strengthening and blood flow void shadow. ConclusionWhen asymmetric distal upper limb muscle weakness with muscle atrophy appears in adolescents, HD should be considered. The combination of neuroelectrophysiological examination and cervical spine flexion MRI scan is helpful for diagnosis. Wearing cervical collar may slow disease progression.
OBJECTIVE: To investigate the feasibility of segmentation of latissimus dorsi on the basis of anatomy and electrophysiology. METHODS: Ten cadaveric latissimus dorsi was dissected according to the blood supply, nerve innervation. Electromyelogram (EMG) of latissimus dorsi of 13 healthy persons was recorded with superficial electrode plate in the motion of shoulder joint. The results of record were managed with statistic methods. Ten patients(including reconstruction of breast and repair of scar on elbow joint and on chest wall) were treated with the lateral inferior myocutaneous island flap. RESULTS: According to the medial and lateral vasculonervous branches, latissimus dorsi can be divided into the medial superior and lateral inferior segments. The clinical application of the segment achieved good results in reconstructing breast and in repairing scars on elbow and on chest wall. CONCLUSION: Latissimus dorsi can be divided into two segments and applied separately. The lateral inferior segment is more useful in shoulder motion.
Two cases of the femoral nerve injuriescaused by sport were reported. in one patient, the femoral nerve was overstretched during broadjump, and other was due to falling down duringskating in which the femoral nerve was compressedby the hematoma in the iliac fossa. The clinicalfeature showed paralysis of the anterior femoralmuscles and decreased skin sensation in both cases.Neurolysis of the femoral nerve and evacuation ofthe hematoma in the iliac fossa were conducted.The functions were recovered to normal after operation. The author pointed out that this kind of injury should be differentiated from the simple soft tissue injuries and the electromygram was helpful in the comfirmation of the diagnosis.
Thymoma complicated with polymyositis and myasthenia gravis is a rare case, which can be clearly diagnosed and given symptomatic treatment according to its own diagnostic criteria, imaging and laboratory examinations. This paper reports the clinical data of a thymoma patient with polymyositis and myasthenia gravis admitted to the Seventh Affiliated Hospital of Sun Yat-Sen University, and discusses the possible pathogenesis and treatment methods.
To evaluate the value of clinical application of examination of fibrillation potential amplitude, 110 patients, 97 males and 13 females, were examined and only the maximum fibrillation potential amplitudes were recorded in 420 muscles. The results showed that there was no significant difference between sexes, ages and sides. However, significant difference was evident between the groups of different frequency (1+ to 4+). The fibrillation potential amplitude was maximum at 3 to 4 months after denervation and still remained at relatively high level for years in certain patients. No significant difference was showed between the time groups in incomplete nerve injuries. Surgery did not affect the course of fibrillation potential amplitude change. It was suggested that the muscle cells sustained their property for years after denervation in some patients, thus it might explain that satisfactory result could be obtained from operative repair in some late cases. The changes of fibrillation potential amplitude might indicate that the changes from muscle denervation was still reversible and might be more accurate than traditional method of examination.