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Background: Currently, there are about twenty percent of the subjects who feel pain and become uncomfortable while they are in the middle of the process of bowel disease examination by colonoscopy. Within the examination, the attending physician needs the assistance of nurses to complete the operation, which is extremely inconvenient. And there is still the chance of being hurt or infected by corrosive intestinal juice. Therefore, how to improve the efficiency of diagnosis, ensure the safety of operation, and reduce the pain of patients are the current research hotspots in the field of colonoscopy. Objective: The study aimed to provide an overview of the existing colonoscopy robots and introduce their classification and characteristics. Methods: This paper reviews various productions and patents related to the colonoscopy robot. The structural characteristics, differences and applications of the typical colonoscopy robot are also introduced. Results: The auxiliary colonoscopy robot and the active flexible colonoscopy robot were compared and analyzed, and the typical characteristics were concluded. The main problems in colonoscopy robot’s development were analyzed, and the development trend is foreseen. The current and future research works on the productions and patents on colonoscopy robots are discussed. Conclusion: Colonoscopy robot is helpful for reducing the doctor’s efforts while performing labor operation. It gives a more clear vision and offers an excellent interactive interface to make man-machine conversation easy. With the continuous improvement of technology, especially in the field of artificial intelligence and imaging processing technology, colonoscopy robot has been found to be more stable, comfortable, humanized, intelligent and secure.

Background: According to "The World's Top Ten Chronic Diseases" published by the World Health Organization (WHO), Cervical Spondylosis, ranked second, has afflicted more youngsters and the number is still growing because of the popularity of smart devices and long-term office work. Surgical treatment is an invasive method with certain harm; in contrast, traction therapy, as a conservative treatment, can effectively relieve neck pain and oppressed nerves, which is widely accepted by doctors and patients. How to effectively guide and implement traction therapy has become a research hotspot in the field of cervical rehabilitation. Objective: To provide an overview of the existing cervical vertebra tractors and introduce their classification, characteristics, and development. Methods: This paper reviews the principles of traction therapy and various patents related to the cervical vertebra tractor. The structural characteristics, differentiations, and applications of existing cervical vertebra tractors are also introduced. Results: The existing cervical vertebra tractors are analyzed and compared, and the typical characteristics are concluded. The main problems in its development are analyzed, the development trend is foreseen, and the current and future research of the productions and patents on the cervical vertebra tractor are discussed. Conclusion: The cervical vertebra tractor is divided into a sitting and supine device according to the application of traction postural. The device can relieve the nerve, blood vessel, and spinal cord, relieve pain, and quickly relieve the symptoms of cervical spondylosis. However, the current treatment device exerts single axial traction, and the normal physiological curvature of the human cervical vertebra is similar to the shape of "C", which is not conducive to maintaining normal physiological curvature.

The purpose of this study was to assess the association of blood pressure (BP) measurements with the risk of cardiovascular disease (CVD) and examine whether central systolic BP (CSBP) predicts CVD better than brachial BP measurements (SBP and pulse pressure [PP]). Based on a cross-sectional study conducted in 2009-2010 with follow-up in 2016-2017 among 35- to 64-year-old subjects in China, we evaluated the performance of non-invasively predicted CSBP over brachial BP measurements on the first CVD events. Each BP measurement, individually and jointly with another BP measurement, was entered into the multivariate Cox proportional-hazards models, to examine the predictability of central and brachial BP measurements. Mean age of participants (n = 8710) was 50.1 years at baseline. After a median follow-up of 6.36 years, 187 CVD events occurred. CSBP was a stronger predictor for CVD than brachial BP measurements (CSBP, 1-standard deviation increment HR = 1.49, 95%CI: 1.31-1.70). With CSBP and SBP entering into models jointly, the HR for CSBP and SBP was 1.28 (1.04-1.58) and 1.22 (0.98-1.50), respectively. With CSBP and PP entering into models jointly, the HR for CSBP and PP was 1.51 (1.28-1.78) and 0.98 (0.83-1.15), respectively. For subgroup analysis, the association of CSBP with CVD was stronger than brachial BP measurements in women, those with hypertension and obesity. In the middle-aged Chinese population, noninvasively estimated CSBP may offer advantages over brachial BP measurements to predict CVD events, especially for participants with higher risk. These findings suggest prospective assessment of CSBP as a prevention and treatment target in further trials.

Background: In order to increase the accuracy of radiotherapy and to improve the patient's comfort, diverse structures of radiotherapy bed have been designed and improved constantly. Objective: To provide an overview of recent patents about radiotherapy bed and to introduce their characteristics and development. Methods: In this study, various representative patents related to the radiotherapy bed were reviewed. Additionally, the structural characteristics and applications of the typical radiotherapy bed were introduced. Results: The characteristics of different radiotherapy beds were analyzed and concluded. Moreover, the main problems concerning their development were analyzed, and the current and future developments of patents on radiotherapy bed were also discussed. Conclusion: Radiotherapy bed is an important part of radiotherapy system, which also determines the therapeutic outcomes of radiotherapy. Further improvements are required in the aspects of accuracy, comfort, flexibility and result stability of the radiotherapy bed. More invention should be laid on more patents on radiotherapy beds.

Background Prostate cancer is a common disease in men and has a relatively high mortality rate. However, the interventional medical equipment used for prostate biopsy and brachytherapy has always been a social concern. Methods To understand interventional medical equipment for prostate cancer, the structure of manual, semi-automatic and automatic medical equipment were considered as the mainline, while the corresponding research on these structures were the auxiliary lines. The characteristics and corresponding research status have been discussed. Results Interventional medical equipment for prostate cancer with different degrees of automation and its characteristics were determined, and the imaging principles and characteristics of computed tomography, transrectal ultrasound and magnetic resonance imaging have been briefly described. Conclusion Certain feasible research suggestions have been proposed for future development from the perspective of structure, accuracy and safety. These include flexible and compact robot structures, high-precision image recognition and guidance, accurate dose planning and monitoring, real-time imaging monitoring without delay, high-precision needle insertion strategy, master-slave control, virtual reality and remote control.

The clearance between two teeth is one of the most clinical manifestations of malocclusion. The open vertical loop is mostly used for the closing and opening of the clearance between two deformed teeth. The shape of the open vertical loop can greatly affect the orthodontic force. At present, the design of the open vertical loop depends entirely on the experience of the orthodontic doctors; this practice is ineffective and may easily hurt patients. To solve these problems, the orthodontic-force prediction model is established to help doctors calculate the orthodontic force generated by the open vertical loop using known parameters, such as the height and the clearance length. The structure of the open vertical loop is analysed, and the theory of the bending deformation of the equivalent beam is used for the analysis of the relationship between the orthodontic force and the effective parameters. The orthodontic-force measuring device of the open vertical loop with a one-dimensional force sensor was designed according to the characteristics of orthodontic force transmission. The orthodontic-force measuring experiments were conducted with open vertical loops of different parameters. Finally, the effective orthodontic-force prediction model of the open vertical loop was established by developing the correction factors in order to eliminate the errors. The average relative error rate of the theoretical value of the orthodontic-force prediction model ranged between 1.25 and 8.34%.

Background Image-guided brachytherapy (BT) robots can be used to assist urologists during seed implantation, thereby improving therapeutic effects. However, safety issues must be considered in the design of such robots, including their structure, mechanical movements, function, materials and actuators. Previous reviews focused on image-guided prostate BT robot technology (e.g., imaging and robot navigation technology and robot system introduction); however, this review is the first time that safety issues have been investigated as part of a study on low-dose-rate (LDR) prostate BT robots. Methods Multiple electronic databases were searched for LDR prostate BT robot articles published during the last 24 years (1996-2020), with a particular focus on two aspects of robots: safety in design and use. Results We retrieved a total of 26 LDR prostate BT robots. BT robots were divided into ultrasound, computed tomography, magnetic resonance imaging and fusion-guided systems. The conditions associated with each system were then analysed to develop a set of requirements for the safety of prostate BT robots. Recommendations are also provided for future BT robot development. Conclusions The transrectal approach for prostate seed implantation is safer than the traditional transperineal approach. Research into the control of a steerable needle by the urologists and robot, the needle deflection model, and robotic automated needle changing and seed injection equipment should be pursued in a future study.

Traditional hand-held ultrasound probe has some limitations in prostate biopsy. Improving the localization and accuracy of ultrasound probe will increase the detection rate of prostate cancer while biopsy techniques remain unchanged. This paper designs a manipulator for transrectal ultrasound probe, which assists doctors in performing prostate biopsy and improves the efficiency and accuracy of biopsy procedure. The ultrasound probe manipulator includes a position adjustment module that can lock four joints at the same time. It reduces operating time and improves the stability of the mechanism. We use the attitude adjustment module designed by double parallelogram RCM mechanism, the ultrasound probe can realize centering and prevent its radial motion. The self-weight balance design helps doctors operate ultrasound probe without weight. Using MATLAB to analyze the manipulator, the results show that the workspace of the mechanism can meet the biopsy requirements. And simulate the centering effect of the ultrasound probe when the attitude is adjusted at different feeding distances, the results show that the ultrasound probe is centering stability. Finally, the centering and joint interlocking tests of the physical prototype are completed. In this paper, a 7-DOF manipulator for transrectal ultrasound probe is designed. The mechanism is analyzed for kinematics, workspace analysis, simulation of centering effects, development of a physical prototype and related experimental research. The results show that the surgical demand workspace is located inside the reachable workspace of the mechanism and the joint locking of the manipulator is reliable.

Background The application of minimally invasive interventional breast surgery is becoming more and more widespread. The accurate puncture of breast cancer needs to solve the problems of tissue deformation and target displacement. Methods In this study, we analysed the process of leech blood absorption and developed a robotic needle insertion method based on bionic technology to improve the accuracy of breast cancer diagnosis and treatment. Among them, the design purpose of the sucker manipulator is to adjust and fix the breast tissue. We use uncalibrated visual servo to control soft tissue deformation. Results We compare the puncture effect of bionic needle puncture robot and common needle puncture on breast prosthesis and in vitro tissue. Experimental data shows that, compared with ordinary needle insertion, the robotic needle insertion method based on bionic technology greatly reduces the targeting error. Conclusions This method is expected to provide a safe and effective alternative to traditional puncture for breast cancer diagnosis and treatment.

Breast cancer is one of the most frequent cancers and a major cause of cancer death in women. In this article, the design and control of a novel magnetic resonance imaging-compatible breast intervention robot are proposed. The dimensions and tolerance of the robot system are considered, and a novel pitching mechanism is designed to achieve a dexterous operation in the limited space. The magnetic resonance imaging compatibility of the robot materials is tested. The nonmagnetic structure and compact Cartesian mechanism of the robot allow it to operate safely in a magnetic resonance imaging scanner. According to the robot’s structure, a kinematics analysis based on a coupled motions model is established. The workspace simulation analysis of the robot proves that it is suitable for the whole breast surgery. To control the needle insertion tasks, the overall control system in the form of “personal computer (PC) + single-chip micyoco (SCM)” is designed. Finally, the motion control experiment is carried out, and the robot positioning error is 0.37 mm, which proves that the breast intervention robot and its control system designed in this article can meet the requirements of breast intervention.

BACKGROUND Soft and flexible robots for medical applications are needed to change their flexibility over a wide range to perform tasks adequately. The mechanism and theory of flexibility has been a scientific issue and is of interest to the community. METHODS Recent advancements of bionics, flexible actuation, sensing, and intelligent control algorithms as well as tunable stiffness have been referenced when soft and flexible robots are developed. The benefits and limitations of these relevant studies and how they affect the flexibility are discussed, and possible research directions are explored. RESULTS The bionic materials and structures that demonstrate the potential capabilities of the soft medical robot flexibility are the fundamental guarantee for clinical medical applications. Flexible actuation that used to provide power, intelligent control algorithms which are the exact executors, and the wide range stiffness of the soft materials are the three important influence factors for soft medical robots. CONCLUSION Some reasonable suggestions and possible solutions for soft and flexible medical robots are proposed, including novel materials, flexible actuation concepts with a built-in source of energy or power, programmable flexibility, and adjustable stiffness.

The abnormal tooth arrangement is one of the most common clinical features of malocclusion which is mainly caused by the tooth root compression malformation. The second sequential loop is mostly used for the adjusting of the abnormal tooth arrangement. Now, the shape devise of orthodontic archwire depends completely on the doctor’s experience and patients’ feedback, this practice is time-consuming, and the treatment effect is unstable. The orthodontic-force of the different parameters of the second sequence loop, including different cross-sectional parameters, material parameters, and characteristic parameters, was compared and simulated for the abnormal condition of root compression deformity. In this paper, the analysis and experimental study on the unidirectional orthodontic-force were carried out. The different parameters of the second sequential loop are analyzed, and the equivalent beam deflection theory is used to analyze the relationship between orthodontic-force and archwire parameters. Based on the structural analysis of the second sequential loop, the device for measuring orthodontic force has been designed. The orthodontic force with different structural characteristics of archwire was compared and was measured. Finally, the correction factor was developed in the unidirectional orthodontic-force forecasting model to eliminate the influence of inherent error. The average relative error rate of the theoretical results of the unidirectional orthodontic-force forecasting model is between 12.6% and 8.75%, which verifies the accuracy of the prediction model.

Malocclusion is currently the third largest oral disease for harming people’s health. Fixed appliance technology is the most common and effective malocclusion orthodontic treatment method. And the elastic deformation of the second sequential loop generates orthodontic moment to treat the buccal-lingual tooth deformity. The shape of the second sequential loop can greatly affect the orthodontic moment. However, the design of the archwire depends entirely on the experience of the orthodontic doctors. This treatment is ineffective and may easily hurt patients. To solve these problems, the deflection equation of the second sequential loop around the buccal-lingual direction was obtained, the second sequential loop orthodontic moment prediction model was established to find the relation between the shape of the orthodontic archwire and the orthodontic moment to assist doctors design the proper orthodontic archwire. The orthodontic moment measuring device of the second sequential loop with a six-axis force/torque sensor was designed according to the characteristics of orthodontic moment transmission. The orthodontic moment measuring experiments were conducted with second sequential loops of different parameters. Finally, the effective orthodontic-moment prediction model of the second sequential loop was established by developing the correction factors in order to eliminate the errors. The relative errors between the prediction model and the experiment results ranged between 3.54%–8.72%. The orthodontic moment generating process is simulated through ANSYS. The relative errors between the prediction model and the simulation results ranged between 1.57%–7.08%. The experimental and simulation results verify the validity of the orthodontic moment prediction model of the second sequential loop.

Magnetic resonance imaging (MRI) is better than other imaging equipment in detecting tumors, and navigation for robotic breast intervention biopsy. However, material requirements for robots driving devices are demanding incredibly because of the environment. Given this problem, a novel double cable-conduit driving method is put forward in this paper, which can be used in MRI for breast intervention robots. Besides, lebus grooves are adopted to the driving wheels, which enable the system to realize remote-range and large-scale driving on the premise that the precision can be further enhanced. The driving characteristic of the novel cable-conduit is established. Moreover, the cable-conduit experimental data proves the results of theoretical deduction. Finally, the cable-conduit driving device is compensated, the average errors in the [Formula: see text], [Formula: see text], and [Formula: see text] directions of the needle tip entering the tissue are less than 2[Formula: see text]mm. The consequence verifies that it can meet the requirements for breast biopsy robot application under MR environment.

// Honglin Luo 1, 2, * , Huizan Yang 1, 3, * , Yong Lin 1, * , Yongde Zhang 1 , Chuanyan Pan 1 , Pengfei Feng 1 , Yanling Yu 1 and Xiaohan Chen 1 1 Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fishery Sciences, Nanning, P.R. China 2 Guangxi Medical University, Nanning, P.R. China 3 College of Animal Science and Technology, Guangxi University, Nanning, P.R. China * These authors have contributed equally to this work Correspondence to: Honglin Luo, email: 541365548@qq.com Xiaohan Chen, email: Chnxhn@163.com Keywords: long non-coding RNA; oreochromis niloticus ; macrophages; HSP70; Streptococcus agalactiae Received: June 22, 2017 Accepted: August 17, 2017 Published: September 30, 2017 ABSTRACT Objectives: To investigate the lncRNA profiling during tilapia peritoneal macrophages (TPMs) activation and discuss the relationship between lncRNA and mRNA. Materials and Methods: RNA sequencing was used to investigate the lncRNA and mRNA profiles of TPMs activation following stimulation with Streptococcus agalactiae (Sa) antigen, heat shock protein 70 (HSP70) and HSP70+Sa. The expressions of lncRNA and mRNA were confirmed by qPCR. 356 lncRNA, 10173 mRNA and 1782 transcripts of uncertain coding potential (TUCP) were differentially expressed by pairwise comparison. These lncRNAs were shorter in length, fewer in exon number and higher in expression levels as compared with mRNAs. 683 lncRNAs and 4320 mRNAs were co-located, while 316 lncRNAs and 9997 mRNAs were in co-expression networks. Seven mRNAs (ANKRD34A, FMODA, GJA3, CNTN5, BMP10, BAI2 and HS3ST6) were involved in both networks of LNC_00035 and LNC_000466. Differentially expressed genes were involved in signaling pathways, such as “phosphorylation”, “cytokine-cytokine receptor interaction”, “endocytosis” and “MHC protein complex”. LNC_000792, LNC_000215, LNC_000035 and LNC_000310, with cis and/or trans relationships with mRNAs, were also involved in ceRNA network. Conclusions: These results might represent the first identified expression profile of lncRNAs and mRNAs in tilapia macrophages activated by HSP70 and Sa.

A novel microsphere adsorbent based upon carboxymethyl cellulose sodium/prussian blue composite loaded with Lanthanum(III) (CMC/PB-La) was successfully synthesized via electrostatic ejection device for removal of cesium from contaminated water, and characterized by FT-IR, SEM, EDX and XPS. Influencing factors to adsorption cesium were investigated, including solution pH, adsorbent dosage, contact time, initial concentration, temperature and competing ions. Linear Freundlich isotherm was fitted satisfactorily to the adsorption data, and the adsorption kinetic data was fitted well with pseudo-second-order model. Moreover, the results of γ-irradiation experiments indicate that CMC/PB-La has good radiation stability.

Background The tilapia aquaculture industry is facing heavy economic losses due to Streptococcus agalactiae (S. agalactiae) infections. While progress has been made in past years, the lack of a high-quality tilapia genome and transcript annotations makes systematic and comprehensive exploration for a non-coding RNA regulatory network associated with the infection process unfeasible, and it stunts further research focused on disease defense and treatment. Herein, single molecular real time sequencing (SMRT-Seq) and RNA-seq data were utilized to generate a high-quality transcript annotation. In addition, Changes in mRNA and non-coding RNA expression were also analyzed during a S. agalactiae infection in tilapia. Findings In total, 16.79 Gb of clean data were obtained by sequencing on six SMRT cells, with 712,294 inserts (326,645 full-length non-chimeric reads and 354,188 non-full-length reads). A total of 197,952 consensus transcripts were obtained. Additionally, 55,857 transcript sequences were acquired, with 12,297 previously annotated and 43,560 newly identified transcripts. To further examine the immune response in Oreochromis niloticus following a S. agalactiae infection, a total of 470.62 Gb of clean data was generated by sequencing a library containing 18 S. agalactiae infected tilapia samples. Of the identified genes, 9911 were newly exploited, of which 7102 were functional annotated. Furthermore, 7874 mRNAs, 1281 long non-coding RNAs (out of 21,860 long non-coding RNAs), and 61 circular RNAs (out of 1026 circular RNAs) were found to be differentially expressed during infection, with the 1026 circRNAs not previously identified in tilapia. Moreover, k-means clustering and WGCNA analyses revealed that the immune response of tilapia to a S. agalactiae infection can be divided into three stages: cytokines driven rapid immune response, energy metabolism promotion, and the production of lysosomes and phagosomes. During this response, the head kidney and spleen have synergistic effects, while maintaining independent characteristics. Finally, lncRNA-mRNA (trans and cis), lncRNA-miRNA-mRNA, and circRNA-miRNA-mRNA regulatory networks were constructed and revealed that non-coding RNA is involved in the regulation of immune-related genes. Conclusions This study generated a greatly-improved transcript annotation for tilapia using long-read PacBio sequencing technology, and revealed the presence of a regulatory network comprised of non-coding RNAs in Nile tilapia infected with S. agalactiae.

MRI guided breast biopsy surgery is essential for the diagnosis and treatment of female breast diseases. It has great significance to research on the MRI-compatible breast biopsy robot, which can assist doctors to perform a breast biopsy surgery precisely in a narrow space of MRI scanner. In this paper, a novel MRI guided breast biopsy robot based on double shear fork mechanism is designed. The MRI compatibility and design requirements of breast biopsy robot are analyzed, and the structure design as well as space layout scheme for breast biopsy robot are proposed. The encircling breast fixation device, positioning mechanism based on double shear fork mechanism and biopsy mechanism are designed, and the virtual prototype model of breast biopsy robot is established. Besides, forward kinematics and inverse kinematics of the breast biopsy robot are analyzed, then the positioning mechanism based on double shear fork mechanism is analyzed by ANSYS/Workbench. Finally, the workspace range of the breast biopsy robot is solved by MATLAB/Simulink, which further verified the feasibility and rationality of the structure design of breast biopsy robot based on double shear fork mechanism.

Cancer represents a major threat to human health. Magnetic resonance imaging (MRI) provides superior performance to other imaging-based examination methods in the detection of tumors and offers distinct advantages in biopsy and seed implantation. However, because of the MRI environment, the material requirements for actuating devices for the medical robots used in MRI are incredibly demanding. This paper describes a novel double tendon-sheath transmission device for use in MRI applications. LeBus grooves are used in the original transmission wheels, thus enabling the system to realize long-distance and large-stroke transmission with improved accuracy. The friction model of the transmission system and the transmission characteristics model of the novel tendon-sheath structure are then established. To address the problem that tension sensors cannot be installed in large-stroke transmission systems, a three-point force measurement method is used to measure and set an appropriate preload in the novel tendon-sheath transmission system. Additionally, experiments are conducted to verify the accuracy of the theoretical model and multiple groups of tests are performed to explore the transmission characteristics. Finally, the novel tendon-sheath transmission system is compensated to improve its accuracy and the experimental results acquired after compensation show that the system satisfies the design requirements.

In the current prostate biopsy procedure, it is necessary for the doctor to hold the ultrasonic probe during the entire process. This increases the fatigue degree of the doctor, and the motion of the ultrasonic probe is more likely to cause damage to the anus of the patient. A medical device that can assist doctors in prostate scans and biopsy puncture devices was developed. We focused on the passive interlocking transrectal ultrasonic probe posture adjustment mechanism. Based on the posture adjustment mechanism, a passive interlocking transrectal ultrasound probe position and posture adjustment mechanism capable of assisting the doctor in prostate scanning and puncture intervention was designed. The passive interlocking posture adjustment mechanism with a seven-degree-of-freedom (DOF) interlocking mechanism was designed and can meet the requirements of doctors. The physical prototype of the passive interlocking transrectal ultrasonic probe posture adjustment mechanism was developed and commissioned. The locking torque and braking torque of the mechanism were measured. The results showed that the ultrasonic probe can achieve reliable locking and effectively meet the operation requirements.

Malocclusion is the third largest oral disease in the world. At present, the most effective treatment method for malocclusion is the fixed orthodontic technique based on orthodontic archwires. Robotic archwire bending can overcome the shortcomings of manual bending such as low efficiency and low precision. The three-dimensional digital expression and robot bending method of orthodontic archwire are studied to realize the orthodontic archwire bending using a robot. Tooth is identified by the doctors’ common method. The shape, position, and constraint relationship of orthodontic archwire in three-dimensional space are expressed by the Bessel curve. The bending of the archwire curve is realized by transmitting the archwire curve into the alternative lines. The planning method of forming points and the spatial angle planning method are proposed. The archwire bending experiment is carried out with the maxillary information of a patient. The error rate of the experimental and ideal values is between 2.94% and 6.74%. It can meet the physician’s basic requirements after simple modification. Therefore, it can be considered that the method of using discrete Bessel curve to carry out the control point planning and angle planning is suitable for the orthodontic archwire-bending robot system, which has certain feasibility and practicability in clinical treatment.

Breast cancer is one of the most common cancers and the principal cause of cancer death among women in the worldwide. Breast biopsy is a way to obtain tissue samples to determine if people suffer from breast cancer. Magnetic Resonance Imaging (MRI) can present the better performance in breast imaging than ultrasound or computed tomography, therefore a breast intervention robot for MRI guided biopsy of the breast was proposed in this paper. The structure of robot is nonmagnetic and thus the robot can operate safely within MRI scanner. Based on the study of the structure of the robot, the forward kinematics and inverse kinematics model of the robot was set up. According to the kinematics analysis and modeling, quintic polynomial interpolation methods were used in the trajectory planning of robot motion. Then the kinematics was also calculated by simulations. The simulation results showed that it can guarantee the continuous displacement, velocity and acceleration of joints. The smooth movement of the robot is vital to the physician, patient and robot itself, which helps to improve the safety of patient and the security of robot. Finally, the robot model was established and an experiment was carried out to prove that the robot runs smoothly and position accurately.

Needle insertion is the most common procedure of minimally invasive interventions. During insertion into a soft tissue, the needle with bevel tip can deflect due to the asymmetric forces acting on the tip of the needle. In this paper, a mechanics-based model is developed to predict the needle deflection. In the model, the needle is considered as a cantilever beam supported by a series of nonlinear springs each of which has stiffness different from each other. The value of stiffness can be calculated by cutting force acting on the needle tip. Based on the model and the analysis of cutting force and friction force, Rayleigh-Ritz method is used to estimate the amount of needle deflection. Experiment shows that the simulation model can accurately predict the deflection of the bevel-tipped needle.

Because of its excellent image quality, magnetic resonance imaging (MRI), as a new means of image guidance for breast biopsy robot, is used widely in clinical diagnostics and advanced breast research. However, the robot for MRI-guided biopsy is challenging due to the compatibility caused by strong magnetic field and very limited available space inside MR scanner. In this paper, a five degrees of freedom (DOF) robot is presented to perform biopsy in the breast with MRI guidance for the early detection of breast cancer. In an MR scanner (1.5T), the compatibility of copper, A4 non-magnetic stainless steel and POM, nylon, teflon is tested, and analyze the influence on the image of water model. Based on the analysis of available space, a 5 DOF robot which consists of 3-DOF Cartesian motions, 1-DOF rotation and 1-DOF insertion is designed, and the statics analysis of the robot is simulated using ANSYS. The results of statics analysis demonstrate that the robot meet the requirement of stiffness and precision.

Needle-based percutaneous prostate interventions include biopsy and brachytherapy and the former is the gold standard for the diagnosis of prostate cancer and the latter is often used in the treatment of prostate cancer. This paper introduces a novel robotic assistant system for prostate intervention and the system architecture and workflow are described, which is significant for the design of similar systems. In order to offer higher precision and better real-time performance, a Ultrasound (US)/Magnetic Resonance Imaging (MRI) fusion method is proposed to guide the procedures in this study. Moreover, image registration is a key step and a hot issue in image fusion, especially in multimodal image fusion. In this work, we adopt a novel registration method based on active demons and optic flow for prostate image fusion. To verify the availability of the system, we evaluate our approach of the US/MRI image fusion by using data acquired from six patients, and root mean square error (RMSE) for anatomical landmarks is 3.15[Formula: see text]mm. In order to verify the accuracy and validity of the system developed in this paper, a system experimental platform was built and used for bionic tissue puncture of prostate under the guidance of MR and Transrectal Ultrasound (TRUS) fusion images. The experimental results show that the deviations of the final actual needle points of the three target points on the bionic tissue model measured in the laboratory environment are less than 2.5[Formula: see text]mm.

Taking the lower maxillary incisors as an example and the orthodontic forces along the near–far middle direction, the orthodontic forces along the crown–root direction and the orthodontic moment around the tongue–cheek direction as loading condition, the biomechanical simulation of the tooth is carried out by the method of finite element simulation in this paper. The CT images of the skull are segmented and denoised by Mimics. The solid models of teeth, periodontal ligament (PDL), alveolar bone and brackets are established by Gomagic and Solidworks. The material characteristics of the PDL are defined by the two-order Ogden hyperelastic model. Taking the PDL capillary pressure as a criterion for orthodontic safety, combined with the stress response of PDL, the safe orthodontic force range of mandibular central incisors is obtained by ANSYS finite element software.

Background The traditional, manual method of reproducing the dental arch form is prone to numerous random errors caused by human factors. The purpose of this study was to investigate the automatic acquisition of the dental arch and implement the motion planning and synchronized control of the dental arch generator of the multi-manipulator tooth-arrangement robot for use in full denture manufacture. Methods First, the mathematical model of the dental arch generator was derived. Then the kinematics and control point position of the dental arch generator of the tooth arrangement robot were calculated and motion planning of each control point was analysed. A hardware control scheme is presented, based on the industrial personal computer and control card PC6401. In order to gain single-axis, precise control of the dental arch generator, we studied the control pulse realization of high-resolution timing. Real-time, closed-loop, synchronous control was applied to the dental arch generator. Experimental control of the dental arch generator and preliminary tooth arrangement were gained by using the multi-manipulator tooth-arrangement robotic system. Results The dental arch generator can automatically generate a dental arch to fit a patient according to the patient's arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways that drive the dental arch generator. The maximum value of single-point error is 1.83 mm, while the arc-width direction (x axis) is −33.29 mm. Conclusion A novel system that generates the dental arch has been developed. The traditional method of manually determining the dental arch may soon be replaced by a robot to assist in generating a more individual dental arch. The system can be used to fabricate full dentures and bend orthodontic wires. Copyright © 2012 John Wiley & Sons, Ltd.

To evaluate the potential impact of using atherosclerotic radial artery (RA) conduits as grafts in coronary artery bypass surgery, we examined the vasoconstrictor and electrophysiological properties of mildly and severely atherosclerotic RAs. Vasoconstrictor responses were measured in cannulated and pressurized (85 mmHg) RA segments and K + currents were measured in single smooth muscle cells. In the cannulated and pressurized vessel preparation, the pressure-induced dilation was attenuated in both the mildly and severely atherosclerotic RAs when compared to normal samples. Contractile responses to potassium chloride, thromboxane A 2 (TXA 2 ) analog U-46619 and to E-ring and F-ring isoprostanes were also attenuated. Smooth muscle cells (SMCs) from atherosclerotic arteries manifested significantly greater K + current density (76.6 ± 22.4 pA/pF) when compared to normal SMCs (18.6 ± 3.3 pA/pF). Our results show that vasocontractile properties of both mildly and severely atherosclerotic arteries are reduced when compared to normal RAs. A possible explanation for this could be decreased vascular compliance due to arterial stiffening and a substantial augmentation of K + currents in sclerotic smooth muscle cells. We conclude that caution should be exercised when using RA grafts with atherosclerotic lesions since they could significantly impact the clinical outcome of CABG surgery.

Application of robot to prosthodontics and orthodontics is a novel application of robot technology in medical field. This kind of robots can realize the manufacturing of complete or partial denture, dental implantology, and the bending of archwire. We have conducted a critical review on the development of application of robot in prosthodontics and orthodontics to identify the limitations of existing studies and clarify some promising research directions in this field. This paper is presented to summarize our findings and understanding. The main problems in its development are analyzed, the development trend is foreseen, and the future research is discussed.

The inhibitory pathway of 8-isoprostaglandin E(2) was investigated in murine renal arterial smooth muscle. K(+) current was augmented in a concentration-dependent fashion, with an average increase of 123+/-28% (n=6) following application of 10(-5) M 8-iso PGE(2). This augmentation was observed in the presence of 4-aminopyridine (4-AP, 10(-3) M) but not that of charybdotoxin (Ch Tx, 10(-7) M). Fluorimetric recordings showed marked concentration-dependent increase of cytosolic Ca(2+) levels by 8-iso PGE(2), while an enzyme-linked immunosorbent assay (ELISA)-based cyclic AMP assay showed increased cAMP levels by 10(-7) M 8-iso PGE(2) challenge. The isoprostane-induced augmentation was prevented by the ryanodine receptor blocker ruthenium red (10(-5) M) or the adenylate cyclase blocker SQ 22536 (10(-4) M). The protein kinase A (PKA) inhibitor H 89 (10(-5) M) inhibited resting K(+) currents (78+/-5%, n=5) but did not prevent 8-iso PGE(2) from augmenting the remaining K(+) current. We conclude that 8-iso PGE(2) enhances Ca(2+)-dependent K(+) currents in murine renal artery through a cAMP-dependent pathway which may involve internally sequestered Ca(2+).

In phenylephrine (1 μM)-precontracted rat superior mesenteric arteries (MA), hydrogen peroxide (H2O2, 0.3 and 1 mM) caused a biphasic response: a transient contraction followed by a relaxation. In the presence of thromboxane A2/prostaglandin H2 (TP) receptor antagonist (SQ 29548), the contractile component of the biphasic response was abolished. The relaxation response to H2O2 was smaller in spontaneously hypertensive rats (SHR) when compared with normotensive Wistar–Kyoto rats (WKY). The mechanisms for the attenuated relaxation to H2O2 in the SHR were studied. KCl (40 mM) prevented the relaxation response. Calcium-dependent K+ channel (KCa) blockers (tetraethylammonium chloride, TEA; iberiotoxin, and charybdotoxin) showed a greater inhibition of H2O2 relaxation in SHR than in WKY, whereas voltage-dependent K+-channel (Kv) blocker 4-aminopyridine was more effective in inhibiting the relaxation in WKY than in SHR. H2O2 (1 mM) greatly enhanced the frequency and intensity of the spontaneous transient outward K+ currents in SHR MA, and the effects of H2O2 were inhibited by iberiotoxin, while in WKY MA the K+ currents induced by H2O2 were mainly of the Kv type. The consequence of the activation of different types of K+ channel was that the net increase in mean outward K+ current density in response to H2O2 was smaller in SHR than in WKY, which may account for the attenuated relaxation response to H2O2 in the SHR. The contractile responses of MA to TEA, iberiotoxin, and charybdotoxin were greater in SHR than in WKY. In summary, an attenuated relaxation response to H2O2 was found in SHR MA when compared to WKY. In contrast to the activation of Kv channels in WKY, H2O2 markedly enhanced KCa activity in SHR, resulting in an attenuation of the increase in mean outward K+ current density in response to H2O2. These results suggest that alteration in K+ channel activation by reactive oxygen species may play a role in the development of hypertension in SHR. British Journal of Pharmacology (2004) 142, 143–149. doi:10.1038/sj.bjp.0705727

Existing animal models of femoral head osteonecrosis, while displaying varying levels of concordance with early histopathologic features of the human disorder, generally fail to progress to end-stage mechanical collapse. A new animal model of osteonecrosis is here introduced, utilizing the emu (Dromaius novaehollandie). These animals' bipedality and their high activity level represent a much more challenging biomechanical environment to the hip than seen in quadrupedal models of this disorder. Femoral head osteonecrosis was induced surgically, using a combination of ischemic (vessel ligation) and cryogenic (liquid nitrogen) insults. Of nineteen emus allowed free-roaming pen activity to study the natural history of such lesions, eighteen progressed to an osseous structural failure, sixteen of them developing incapacitating lameness at an average time point 11.75 weeks after the surgical insult. Histologically, the animals showed close concordance with both the early- and late-stage human pathology, in six cases even to the point of developing a crescent sign. Because of its large physical size and its consistent progression to mechanical collapse, the emu appears to offer a unique opportunity for the near-human-scale study of surgical interventions to forestall femoral head collapse. Toward this end, various directions for model refinement are outlined.

The successful application of robots in surgery and other medical fields prompts us that robots can also play an important role in oral restoration. The traditional way of complete denture manufacturing is manual and only high‐level dentists and skilled technicians can do this work well. But we believe that a robot can do this work better and more easily. Artificial teeth are very complicated in shape, and not easy to be grasped and manipulated accurately by a robot gripper. Aiming at improving our previous robot manufacturing system of complete dentures, we present a new method to perform teeth implanting. We improve the previous manufacturing procedure by adding several components in the operating process. By this method, the robot gripper only needs to grasp and implant intermediate blocks, which have very simple shapes and are easy to handle precisely. The 3D human‐machine tooth arrangement software performs the calculation of intermediate blocks’ positions and orientations. We perform the experiment of tooth arrangement for a patient, and obtain a pair of ideal tooth arches. A complete denture can be manufactured according to this result.

Epoxyeicosatrienoic acids (EETs) are released from endothelial cells and potently dilate small arteries by hyperpolarizing vascular myocytes. In the present study, we investigated the structural specificity of EETs in dilating canine and porcine coronary microvessels (50–140 μm ID) and activating large-conductance Ca2+-activated K+(BKCa) channels. The potencies and efficacies of EET regioisomers and enantiomers were compared with those of two EET homologs: epoxyeicosaquatraenoic acids (EEQs), which are made from eicosapentaenoic acid by the same cytochrome P-450 epoxygenase that generates EETs from arachidonic acid, and epoxydocosatetraenoic acids (EDTs), which are EETs that are two carbons longer. With EC50values of 3–120 pM but without regio- or stereoselectivity, EETs potently dilated canine and porcine microvessels. Surprisingly, the EEQs and EDTs had comparable potencies and efficacies in dilating microvessels. Moreover, 50 nM 13,14-EDT activated the BKCachannels with the same efficacy as either 11,12-EET enantiomer at 50 nM. We conclude that coronary microvessels and BKCachannels possess low structural specificity for EETs and suggest that EEQs and EDTs may thereby also be endothelium-derived hyperpolarizing factors.

A laboratory test was undertaken to evaluate the interfacial frictional characteristics of cortical and cancellous bone, as well as a novel porous tantalum biomaterial (Hedrocel®, Implex Corp.). Three sets of tests were conducted to measure the friction coefficients of (1) bovine cancellous bone against bovine cortical bone; (2) net-shape formed porous tantalum against bovine cortical and cancellous bone; and (3) electron-discharge-machine formed (EDM'd) porous tantalum against bovine cortical and cancellous bone. The bovine cortical bone was tested in three conditions: periosteum-intact, periosteum-denuded and surface-flattened. An inclined plane apparatus was used to determine the coefficients of friction. By gradually increasing the substrate tilt, the angle of slippage was determined, and the friction coefficient was calculated.The average friction coefficients of cancellous bone against periosteum-intact, periosteum-denuded and surface-flattened cortical bone were 0.91±0.14, 0.61± 0.07 and 0.58±0.06, respectively. Porous tantalum specimens prepared from a preshaped vitreous carbon skeleton, when tested against periosteum-intact, periosteum-denuded and surface-flattened cortical bone, and against cancellous bone, had average friction coefficients of 1.10±0.18, 0.82±0.15, 0.86±0.11, and 0.98±0.17, respectively. Porous tantalum specimens prepared by electron-discharge machining, when tested against periosteum-intact cortical bone, periosteum-denuded cortical bone and cancellous bone, had average friction coefficients of 1.75±0.33, 0.74±0.07, and 0.88±0.09, respectively. The friction coefficient of the porous tantalum material was very high in comparison to natural bone autografts or allografts, and to conventional orthopedic implant coating materials (sintered beads and wire mesh). Other factors being equal, this high-friction characteristic would be expected to translate into higher initial stability of a porous tantalum implant, as compared to natural bone grafts.

Segments of fibula commonly used as cortical bone grafts need to support functional loading at their host site. Since many such constructs require the fibula to carry appreciable bending loads, we undertook a series of flexural tests to determine how flexural rigidity of the fibula varies with longitudinal (or harvest) site and loading direction. Ten fresh-frozen human fibulas were tested in a 4-point bending fixture. The fibulas were tested at three longitudinal sites (centered at 1/4, 1/2 and 3/4 lengths) and in each of four anatomic directions (anterior, posterior, medial and lateral). There were consistent longitudinal and directional variations in flexural rigidity. The central site was about twice as stiff as the proximal and distal sites, for both the A-P and M-L directions (p < 0.05), indicating that the center of the fibula is the optimal site for harvesting grafts that will be subjected to severe bending. The A-P direction was stiffer in bending than the M-L direction, by 43%, 52%, and 86% for the proximal, central, and distal sites (p < 0.05 for the central and distal sites only), indicating that the choice of circumferential orientation of a fibular graft at the host site could have an appreciable influence on construct rigidity.

In the orthodontic treatment and manufacture of complete dentures, the most important steps are designing and generating a dental arch curve which adapts to the requirements of the patient according to their jaw arch form. The traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly generate a lot of errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi-manipulator tooth-arrangement robot, which can be used in full denture manufacturing. According to the work principle, motion planning method of the dental arch generator will be analysed. A collaborative simulation of the dental arch generator is realized based on Matlab and ADAMS. Controlled experimentation of the dental arch generator and preliminary tooth-arrangement experimentation are performed using the multi-manipulator tooth-arrangement robot system in order to verify the feasibility of the motion planning method and the technical route. It will lay an important theoretical foundation for quantitative research on oral restoration and also provide a way to standardize the manufacturing process of full dentures and orthodontic treatments.

Background The traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly bring numerous errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi-manipulator tooth-arrangement robot, which can be used in full denture manufacturing. Methods Based on the arc length constant theory, kinematics on dental arch generator is analyzed. The control pulse realization methods of high-resolution timing and CPU time-stamp timing are studied, and testing and comparative analysis of the control precision and stability of the two methods is carried out. Control experimentation of the dental arch generator and preliminary tooth-arrangement experimentation are performed using the multi-manipulator tooth-arrangement robot system. Results The dental arch generator can automatically generate a dental arch curve that fits a patient according to the patient's jaw arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways which drive the dental arch generator. The maximum value of single point error is 1.64 mm when the arc width direction (x-axis) is 37.25 mm. The experimental results indicate that the method of control pulse realized by high-resolution timing to achieve high precision coordinated motion control of dental arch generator of tooth-arrangement robot is feasible. The error analysis results indicate that the control strategy and technical route can fulfill the requirements for motion speed and location precision. Conclusion A novel system to generate the tooth arch curve has been developed. The traditional method of manually determining the dental arch may soon become obsolete in favour of the use of a robot to assist in generating a more standard tooth arch curve. The system can be used to manufacture a full denture. It will lay an important theoretical foundation for quantitative research of oral restoration, and also provide a way to standardize the manufacturing process of full denture. Copyright © 2010 John Wiley & Sons, Ltd.

We sought to investigate the effects of a variety of autacoids on Ca2+-handling in human airway fibroblasts. Primary cultured fibroblasts were loaded with the Ca2+-indicator dye fluo-4 and studied using confocal fluorimetric microscopy. ATP (10−5 M) evoked recurring Ca2+-waves . This fluorimetric change was greater and longer lasting within the nucleus of the cell than in the non-nuclear portion of the cytosol, and was only sometimes accompanied by a contraction. These responses were completely occluded by cyclopiazonic acid (10−5 M; depletes the internal Ca2+-store) or the phospholipase C inhibitor U73122 (10−6 M). Pretreatment of the cells with ryanodine (10−5 M), on the other hand, had no effect on the ATP-evoked responses. With respect to the receptor through which this response was exerted, we found it to be mimicked by UTP or ADP but not by adenosine or α,β-methylene-ATP, and to be blocked by the purinergic receptor blocker PPADS; interestingly, PPADS itself appeared to sometimes evoke a rise in [Ca2+]i on its own. ATP also evoked a membrane conductance change with characteristics of a non-selective cation current, markedly enhanced synthesis of the cytokine TGFβ and the matrix proteins fibronectin and collagen I; these changes in protein synthesis were blocked by PPADs and were partially reduced by ryanodine. We conclude that, in human pulmonary fibroblasts, ATP acts upon P2Y receptors to liberate internal Ca2+ through ryanodine-insensitive channels, leading to a Ca2+-wave which courses throughout the cell and triggers protein synthesis.This work was supported by the Canadian Institutes of Health Research

In contemporary brachytherapy procedures, needle placement at the desired target is challenging due to a variety of reasons. A robot-assisted brachytherapy system can improve the needle placement and seed delivery resulting in enhanced patient care. In this paper we present a 16 DOF (degrees-of-freedom) robotic system (9DOF positioning module and 7DOF surgery module) developed and fabricated for prostate brachytherapy. Techniques to reduce needle deflection and target movement have been incorporated after verifying with extensive experiments. Provisions for needle motion and force feedback have been included into the system for improving the robot control and seed delivery. Preliminary experimental results reveal that the prototype system is quite accurate (sub-millimeter) in placing brachytherapy needles.

We investigated K+ currents and their regulation by the sarcoplasmic reticulum in mesenteric arterial smooth muscle cells of the spontaneously hypertensive rat (SHR). Using perforated patch-clamp technique, we found the overall K+ current density was significantly lower in adult SHR compared to adult Wistar-Kyoto rats (WKY). The K+ currents were almost exclusively of large-conductance Ca2+-dependent (BK(Ca)) variety in SHR, but largely of voltage-gated (Kv) variety in WKY. Western blot assay showed parallel findings. These differences were not observed in pre-hypertensive rats. Depleting the intracellular Ca2+ store inhibited the K+ currents in adult SHR. Ryanodine augmented the K+ current at 1 microM, but suppressed it at 10 microM; 2-aminoethoxydiphenyl borate demonstrated concentration-dependent inhibition. We conclude that an alteration of membrane K+ channel composition has resulted in lower overall K+ current density. The changes in K+ current type may indicate an underlying defect in Ca2+-handling that predisposes smooth muscle cells to the hypertensive phenotype.

A laboratory study assessed the reliability of detecting radiolucencies at the prosthesis/cement interface in femoral components for total hip replacement. Radiolucencies (thicknesses=0.1, 0.3, 0.5 and 0.7 mm) were created by randomly masking non-tip Gruen zones (six per stem) in a group of 72 matte-finish femoral components. Only half of all Gruen zones were masked. The femoral components were reproducibly implanted in composite fiberglass replicate femurs. Anteroposterior and lateral radiographs taken using conventional techniques were then presented to 10 experienced readers, who scored each of 432 non-tip Gruen zones for radiolucency presence or absence. The series-average radiolucency detection rate was 47.1%, with a breakdown of 9.8%, 20.7%, 69.8% and 88.0% for radiolucency thicknesses of 0.1, 0.3, 0.5 and 0.7 mm, respectively. The false positive rate was 7.5%. The findings argue strongly that in many or most instances, initial cement–prosthesis debonding is not reliably detected from conventional plain film radiographs. Radiolucencies of at least 0.7 mm width are necessary to be accurately detectable by most viewers.

Intraoperative correction of patellar maltracking has traditionally involved the use of a lateral retinacular release. Problems, however, related to lateral retinacular release include increased postoperative pain and wound healing complications, compromised patellar blood flow, and longer rehabilitation. The purpose of this study was to assess the effect of patellar medialization in total knee arthroplasty. One hundred forty patients underwent total knee arthroplasty using the same components. Two groups of 70 patients each made up the study. Group 1 included patients whose patellar components were centralized on the patella, and group 2 consisted of patients in whom the patellar component was medialized to reproduce the patient's anatomic high point (ie, sagittal ridge). Lateral retinacular release was required in 45.5% of the patients in group 1 compared with 17% in group 2. The technique of patellar medialization is described.

RA samples were collected during the procedure (with preopera- tive patient consent) and shipped to the research laboratory in 0.9% saline solution on ice. Intraoperative visual inspection was used to determine the presence or absence of atherosclerotic plaques, which was then confirmed by light microscopic examination of the endothelium in the laboratory. Photographs of normal and sclerotic vessels were taken with a digital camera with a 1:2 macro lens. The arteries were immediately transferred to oxygenated Krebs solu- tion (4°C), and the connective tissue was removed. The smooth muscle strip was carefully dissected and dissociated in an enzyme tube containing collagenase (type F, 1 mg/mL) and elastase (type IV, 0.12 mg/mL). The tissues were incubated with the enzyme in a 37°C bath for 45 minutes and carefully triturated to liberate free smooth muscle cells. Electrophysiologic responses were tested in cells that were phase dense and appeared relaxed. Cell membrane potential was recorded at room temperature with current-clamp mode after a gigaohm seal was obtained. Potassium and calcium currents were also examined with voltage-clamp for kinetic and phar- macologic characterization (data not presented). Acquisition and analysis of data were accomplished with Axopatch 200B and pCLAMP8 software (Axon Instruments, Inc, Foster City, Calif). Results Three atherosclerotic arteries were found among 38 RA samples in the study. These arteries were obtained from patients with no contraindications to coronary artery bypass grafting. Fat plaques and loss of elasticity of arterial wall were used as the diagnostic criteria. The membrane potentials of normal RA range from 30 to 70 mV, compared with 10 to 35 mV in their sclerotic counterparts. The average membrane potentials of normal and atherosclerotic RA tissues were 50.0 7.8 mV (n 4) and 20.3 6.0 mV (n 3, P.05), respectively. One of the sclerotic tissues also exhibited spontaneous spikelike hyperpolar- izations (indicative of sporadic activation of calcium-dependent potassium ion currents); this type of activity was not seen in any of the normal tissues. The membrane potential recordings of both groups are shown in Figure 1.