Least Squares Support Vector Machine Kalman Filter for Physiological Tremor Suppression in Minimally Invasive Surgical Robot

This paper studies the physiological tremor filtering in minimally invasive surgical robot.The surgeon􀆳s physiological tremor of the hand can cause the vibration of the tip of the surgical instrument,which may reduce operative accuracy and limit the application of surgical robots.Aiming at the vibration caused by physiological tremor of hand,we propose a Least Squares Support Vector Machine Kalman Filter(LSSVMKF),which can filter the tremor by estimating and modeling the tremor signal by Kalman filter and then superimposing it reversely in the control signal.When estimating and modeling the tremor signal,the filter uses the Least Squares Support Vector Machine(LS⁃SVM)to build the regression model of the constant parameters(Process Noise Covariance and Measurement Noise Covariance)of the traditional Kalman filter,which can dynamically adjust these parameters during the operation and improve the accuracy of Kalman filter.The simulation results show that the LSSVMKF can effectively filter out the tremor signal,thereby improving the accuracy of surgery.

Neuroprotective effect of angiotensin Ⅱ type 2 receptor during cerebral ischemia/reperfusion

Angiotensin Ⅱ type 2 receptor（AT2R） activation has been shown to protect against stroke,but its precise mechanism remains poorly understood.We investigated whether the protective effect of AT2 R against ischemia/reperfusion injury is mediated by the suppression of immune and inflammatory responses.Rat models of middle cerebral artery occlusion were intraperitoneally injected with physiological saline,the AT2 R agonist CGP42112（1 mg/kg per day） or antagonist PD123319（1 mg/kg per day）.In the CGP42112 group,AT2 R expression increased,the infarct area decreased,interleukin-1β and tumor necrosis factor-α expression decreased,and interleukin-10 expression increased compared with the saline group.Antagonisin AT2 R using PD123319 produced the opposite effects.These results indicate that AT2 R activation suppresses immune and inflammatory responses,and protects against cerebral ischemia/reperfusion injury.

Identifying specific RGC types may shed light on their idiosyncratic responses to neuroprotection

Retinal ganglion cells（RGCs）are located in the innermost layer of the retina and are the only retinal output neurons,conveying light information to the main retinorecipient target regions of the brain responsible for the image-and non-image-forming visual functions.There are well over twenty RGC types,each with its own dendritic morphology and physiological characteristics,

The Gray Mouse Lemur: A Model for Studies of Primate Metabolic Rate Depression

The use of daily torpor and/or of multi-day torpor bouts during a hibernation season are energy-saving survival strategies that have been well-studied for many years,particularly for small mammals living in seasonally-cold environments.Both phenomena are characterized by a regulated suppression of metabolic rate,