Showing papers presented at "International Conference on Complex Medical Engineering in 2013"

Automatic eye-blink artifact removal method based on EMD-CCA

Abstract: This research proposes a new hybrid algorithm for automatic removal of eye blink artifact from EEG data based on empirical mode decomposition (EMD) and canonical correlation analysis (CCA). The validity and efficiency of the proposed algorithm is evaluated using correlation coefficient and signal-to-artifact ratio (SAR) and the proposed algorithm is also compared with other popular eye blink artifact removal techniques (CCA, ICA, EMD-ICA) on simulated EEG data of two channels. From the simulation results, the average correlation coefficients for the EEG channels are obtained as 0.908 and 0.864 respectively. The SAR of the EEG signal also improved from 2.2 dB to 6.0 dB after correction using our proposed method. Compared to other eye blink artifact removal techniques, our proposed method has two benefits. Firstly, no visual inspection is required to detect the eye blink artifact components. Secondly, computational assessment of corrected EEG waveforms reveals that the proposed algorithm retrieves the EEG data by removing the eye blink artifacts reliably.

Lung nodule detection using multi-resolution analysis

Abstract: The increase in number of smokers in the 20th century leads for lung cancer being the number one killer among cancer related deaths world-wide with an over-all survival rate of only 15% According to the latest World Health Organization report released on April 2011, Lung cancer is the number one killer among deaths related with cancer for men in Malaysia In most cases there are no symptoms or warning signs in the early stages of lung cancer It is often suspected initially from chest x-ray or Computed Tomography (CT) scans done to evaluate a cough or chest pain Several research work have been aimed at development of Computer Aided Diagnosis (CAD) systems which enhance early detection of lung cancer nodules This research work aims to develop a CAD system to detect pulmonary lung nodules from Low Dose CT (LDCT) scan images using template matching algorithm integrated with multi-resolution feature analysis technique in order to enhance the false positive detection rate 134 out of 165 nodules were correctly detected by our scheme That results in a detection rate of 81212%

Development of force analysis-based exoskeleton for the upper limb rehabilitation system

Abstract: With the development of exoskeleton rehabilitation robotic system, the biomechanics influence of device should be considered in rehabilitation training. This paper describes a novel upper limb exoskeleton rehabilitation device (ULERD) based on biomechanics, which can be used in rehabilitation of upper limb for hemiparalysis patients. This system is aimed at helping hemiparalysis patients recover motor function of upper limb and are suitable for variety of patients. This system is portable and wearable, which consists of exoskeleton device, haptic device (PHANTOM Premium), and computer. By using finite element software ANSYS, biomechanics influence of the exoskeleton device on the patient's upper limb in the rehabilitation training is explored. Based on it, the device can be optimization design to be cylindrical type and the activity angle range of the elbow joint of exoskeleton device is proposed from 30° to 90° in the training. These experiment results demonstrate this system that can prove an advance rehabilitation approach for hemiparalysis patients and the biomechanics impact of exoskeleton device should be reduced. In the future, this system will have a bright application prospect in the rehabilitation therapy field.

Epileptic seizure detection using the singular values of EEG signals

Abstract: A new technique based on Singular Value Decomposition (SVD) for the detection of epileptic seizures is proposed. The SVD is applied sequentially on a sliding window of one second width of EEG data and the r singular values are obtained and used to indicate sudden changes in the signals. EEG recordings of 4-paediatric patients with 20 seizures are used to validate the proposed algorithm and the preliminary results indicates good level of sensitivity by the singular values to the changes in the EEG signals due to epileptic seizure. This sensitivity can be used to develop more reliable seizure detector than the existing techniques.

A wearable navigation aid for blind people using a vibrotactile information transfer system

Abstract: In the present paper we describe different possibilities of vibrotactile stimulation of skin receptors for guiding visually impaired people. Different wearable low-budget prototypes were developed by integrating vibration motors as used in mobile phones. Various parameters for vibrotactile stimulation of skin receptors were evaluated. In addition a simple computer game was developed to simulate an environment with obstacles and to obtain the real-time reaction performance of test subjects. The prototypes were tested in a trial with obstacles in which blindfolded test persons were guided via a vibrating system controlled by a second test person. The prototypes were proven to be easy to use while no special training was required.

A novel type of catheter sidewall tactile sensor array for vascular interventional surgery

Abstract: In minimally invasive surgery, the surgeon is exposed to X-ray, threatening the surgeon's health due to depositing long. It is important to find a method instead of using X-ray during MIS. And the force feedback is the key factor for surgeon to operate this system successfully. In this paper, we developed a novel catheter sidewall tactile sensor array, which is based on a developed robotic catheter operating system with a master-slave structure. It can detect the force information between the catheter sidewall and the blood vessel in detail, and transmitting the detected force information to surgeon by using the robotic catheter system. The calibration work of single tactile sensor array element was done. We designed a LED lights array to indicate the tactile sensor array elements which sensor contacts the blood vessel wall, and we can obtain the wave profile of the contacting force from the PC. Experimental results show that the response of developed tactile sensor array is quit sensitive, and we can easily distinguish which sensor in the tactile sensor array is contacting blood vessel wall. Based on the experimental result, we know that the developed tactile sensor array is suitable for interventional vascular surgery.

EEG mean power and complexity analysis during complex mental task

Abstract: The aim of this study was to investigate the association between EEG measures (mean power and sample entropy) and complex mental reasoning task (IQ test). Six healthy university students participated voluntarily in the experiment. EEG was recorded at resting states (eye open and eye closed) and during performing IQ test and analyzed over 12 regions across the scalp. EEG mean power measure of delta and theta frequency significantly (p<;0.025) discriminated the IQ test from resting states at frontal regions and alpha frequency at parietal, occipital and parieto-occipital regions. Highly reduced mean power of beta frequency was found during IQ test at parietal, occipital and parieto-occipital regions as compared to frontal regions. Results of Sample Entropy (SE) showed high complexity in EEG signal during IQ test than resting state eye closed. Our findings showed high cortical activation and increased EEG complexity during IQ test than resting states.

The design and development of a lower limbs rehabilitation exoskeleton suit

Abstract: In this paper, we present the design and development of an exoskeleton suit for the lower limbs rehabilitation. The exoskeleton suit includes biomimetic framework, perception subsystem, controller, electrical motor driving system, and power supply subsystem. The framework is used to support the weight of the exoskeleton suit as well as wearer's body. Electrical motor driving system uses disc motor to drive knee joint and hip joint of exoskeleton suit. The perception subsystem mainly consists of sensors and transmission network, which gathers data about the body position and senses the intention of movement. The perception logic is based on events. Based on control algorithm, the controller sends signals to motor. In the paper, we detailed the design and implementation of each subsystem. The simulation results are given to demonstrate the feasibility and effectiveness of the designed lower limbs rehabilitation exoskeleton suit.

IPMC actuator-based a movable robotic venus flytrap

Abstract: Nature is a perfect model for a robot. Besides the insects and underwater animals, some carnivorous plants which are capable of rapid movement, such as mimosa, the venus fly trap, the telegraph plant, sundews and bladderworts, are of great interest for the biomimetic robot design. Carnivorous plants, such as Venus flytrap, can be turned on in a controlled manner to capture prey by using their trigger hairs as detecting sensors. In our previous research, we designed a robotic Venus flytrap by using two ionic polymer metal composite (IPMC) actuators and one proximity sensor. To enlarge its working area in real applications, we improved it by integrating biomimetic walking and rotating motions into the previous version. First, we proposed a conceptual structure of the improved robotic Venus flytrap which consisted of two IPMC lobes, one proximity sensor, and eight IPMC legs. Then, we developed a prototype movable robotic Venus flytrap and evaluated its walking and rotating speeds by using different applied signal voltages. At last, to reduce the gaps between two IPMC lobes, we improved the robotic flytrap by using three IPMC lobes. The experimental results showed a good performance.

Trot pattern generation for quadruped robot based on the ZMP stability margin

Abstract: Quadruped robot is expected to serve in complex conditions such as mountain road, grassland, etc., therefore we desire a walking pattern generation that can guarantee both the speed and the stability of the quadruped robot. In order to solve this problem, this paper focuses on the stability for the tort pattern and proposes trot pattern generation for quadruped robot on the basis of ZMP stability margin. The foot trajectory is first designed based on the work space limitation. Then the ZMP and stability margin is computed to achieve the optimal trajectory of the midpoint of the hip joint of the robot. The angles of each joint are finally obtained through the inverse kinematics calculation. Finally, the effectiveness of the proposed method is demonstrated by the results from the simulation and the experiment on the quadruped robot in BIT.

A novel VR-based upper limb rehabilitation robot system

Abstract: This paper presents a novel upper limb rehabilitation robot system based on virtual reality as many benefits of robots involved in upper limb rehabilitation for stroke are found out. The system has advantages of small size, less weight and interaction in rehabilitation. This system mainly consists of a haptic device called PHANTOM Premium, the upper limb exoskeleton rehabilitation device (ULERD) and a virtual reality environment. The impaired hand wears the ULERD, so the therapist can control and move the injured hand by PHANTOM Premium in tele-operation. With description of the system, the realization of virtual reality environment is implemented, which can potentially motivate patients to exercise for longer periods of time. Not only virtual images but also position and force information are sent to the doctors. This system aims to develop a light and interactive upper limb rehabilitation robot system which allows rehabilitation stations to be placed in a patient's home. And some exercise parameters evaluate the performance of patients. Experiment has been conducted to prove that it is accurate and convenient in the rehabilitation process. The development of this system can be a promising approach for further research in the field of tele-rehablitation science.

Mechanical design and kinematic analysis of a medical robot assisted maxillofacial surgery

Abstract: Since the intricate anatomical structure of the maxillofacial region and the limitation of surgical field and instrument, the current surgery is extremely high risk and difficult to implement. In contrast to traditional manual surgery, the paper introduces a multi-arm medical robot assisted the maxillofacial surgery using the optical navigation. The mechanical design was proposed gradually to satisfy the requirements of high precision, stability and safety in surgery, including the design of robot arm, wrist and the passive joint of the end-effector. In addition, the jacobian matrix with differential method and flexibility analysis based on condition number were displayed to describe the motion performance analysis of the medical robot. Finally the kinematic simulation with forward and inverse kinematics validates the stabile motion regarding displacement, velocity and acceleration, to express that it could be implied in clinic.

A novel approach for colon biopsy image segmentation

Abstract: Colon cancer is one of the leading causes of deaths worldwide. Traditionally, colon cancer is diagnosed using microscopic analysis of colon biopsy images. However, computer based diagnosis involves acquiring a biopsy image, segmenting the image into constituent regions, extracting features, and based on features identifying cancerous and non-cancerous regions. Image segmentation that is the core process in overall diagnosis is extremely challenging due to similar color distribution in various biological regions of histopathological images. Problem gets more complicated for homogenous images or images acquired under different conditions, particularly change in magnification factor. Several segmentation schemes, proposed for colon images, do not address these problems. In this research study, we propose an un-supervised colon biopsy image segmentation scheme that incorporates background knowledge of benign and malignant tissue organization. The scheme detects elliptical epithelial cells in four angular directions of 0°, 45°, 90°, 135°, and divides elliptic constituents into distinct `primitives'. It further makes use of the distribution as well as spatial relations of these `primitives' to define a homogeneity measure for identifying regions. Contrary to previous ones, the proposed scheme removes dependency on change in magnification and image type. Genetic algorithm (GA) has been employed to optimize several system parameters such as semi-major and semi-minor axis of ellipse, component area threshold to remove smaller components, and merge factor to merge two adjacent and similar regions. Algorithm has been tested on 100 colon biopsy images and improved segmentation accuracy has been observed when compared with segmentation results obtained using circular primitive based techniques.

A VR-based training system for vascular interventional surgery

Abstract: The Vascular Interventional Surgery(VIS) is a specialized surgical technique that permits vascular interventions through very small incisions. This minimizes the patients' trauma and permits a faster recovery compared to traditional surgery. However, the significant disadvantage of this surgery technique is its complexity; therefore, it requires extensive training before surgery. In this paper, we present a training system based on virtual reality technology for unskilled doctors with extremely similar environment in real vascular interventional surgery. This application allows generating realistic geometrical model of catheter and blood vessels, and enables surgeons to touch, feel and manipulate virtual catheter inside vascular model through the same surgical operation mode used in actual VIS. Finally, the experimental results show that the error rate is in an acceptable range and the system can be used for surgery training.

Food stamps: A reminiscence therapy tablet game for Chinese seniors

Abstract: During their aging process, many seniors are likely to develop mild cognitive impairment which could easily lead to Alzheimer's disease or dementia. Besides medication treatment, various reminiscence therapy methods have been proven to be effective in terms of enhancing the cognitive capacities of seniors, as well as improving their capabilities to participate in daily activities. This paper describes our design and implementation a reminiscence therapy game on Android tablet for Chinese seniors to help them maintain their memory capacities as well as their calculating abilities. To be more effective as a method of reminiscence therapy, we choose government food stamps that were mandated in China from 1960s to 1980s, as the backdrop of our game. With our experiment and further studies in the future, we aim to prove that this type of reminiscence therapy games can help seniors to maintain their memory capacity and postpone the development of potential Alzheimer's disease, and eventually dementia.

Performance evaluation on land of an amphibious spherical mother robot

Abstract: Various underwater microrobots were used widely to work in limited spaces in the last few years. However, for having compact structures, the robots had some limitations of locomotion velocity and enduring time. In order to solve these problems, we proposed a mother-son robot cooperation system. We designed a conceptual structure of a novel amphibious spherical robot as the mother robot to carry the microrobots as son robots for collaboration. The spherical mother robot was composed of a sealed hemispheroid, two openable quarter spherical shells, a plastic circular plate, a plastic shelf and four actuating units. Each unit consisted of a water jet propeller and two servo motors, each of which could rotate 90° in horizontal or vertical direction respectively. The robot could perform walking and rotating motions on land, as well as moving forward and backward, rotating, surfacing and diving motions in water. We developed the prototype mother robot and did the force analysis of each unit of the actuating system. Then we proposed three walking gaits for the robot and carried out the walking experiments on the tile floor to evaluate the performance of the walking motion, including stability and velocity. From the experimental results of walking and rotating motions, we got that under a frequency of 3.33 Hz in Gait 3 (duty factor β=0.67) we got a maximal walking velocity of 22.5 cm/s. Under a frequency of 1.56 Hz in Gait 2 (duty factor β=0.75), we achieved a maximal rotating velocity of 71.29 °/s.

CT image denoising based on sparse representation using global dictionary

Abstract: Low-dose CT (LDCT) images tend to be severely degraded by mottle and streak-like noise, and how to enhance image quality under low-dose CT scanning has attracted more and more attention. This work aims to improve LDCT abdomen image quality through a dictionary learning based de-noising method and accelerate the training time at the same time. The proposed method suppresses noise through reconstructing the image use only one dictionary. Experimental results show that the proposed method is effective in suppressing noise while maintaining the diagnostic image details with much more less time.

A SSVEP brain-computer interface with the hybrid stimuli of SSVEP and P300

Abstract: In this paper, to develop a hybrid brain-computer interface based on Steady State Visual Evoked Potential(SSVEP) and P300, we validate a SSVEP brain-computer interface (BCI) with the hybrid stimuli of SSVEP and P300, and analyze the effect of P300 visual stimuli on the classification accuracy of the SSVEP BCI. The hybrid stimuli include the SSVEP stimuli, which consist of twochessboardimagespresented on a LCD screen and flashing at particular frequencies, respectively, and the P300 stimuli, which include nine characters and locate between the SSVEP stimuli. We extract the fundamental frequencies and second harmonics of the frequencies of the SSVEP stimulifrom EEG data as features, andapply a Fisher's linear discriminant analysis to build the classifier. The experimental results from three subjects show that the SSVEP potentials can be elicited well under the hybrid stimuli of SSVEP and P300, and the P300 stimuli under the hybrid condition have no significant effect on the SSVEP BCI. This work laysa foundationfor developing a hybrid BCIbased on SSVEP and P300.

The research of hydraulic quadruped bionic robot design

Abstract: Based on the quadruped robot, this paper mainly studies the two directions of the content. The first part mainly introduces the mechanical structure design and the construction of the control system of the quadruped robot, completes the prototype design of the quadruped robot based on hydraulic power system. The second part studies a few experiments had be made in this thesis such as the marking time experiment, the squat experiment, the walking experiments, the trotting experiments.

Design of electronic blood pressure monitoring system based on mobile telemedicine system

Abstract: In this paper, a kind of non-invasive cuff blood pressure monitoring system is designed and presented. This device provides a useful system for people to measure their daily blood pressure and achieve early diagnosis of hypertension. The pressure signal is collected by the pressure senor and this proposed design includes a ZigBee wireless transmission module, in order to send BP data to the Information System in real time. In addition, the structure of the system is designed to a portable low power consumption device which is convenient to operate especially for senior citizens. This monitoring system can also be extended into the platform for mobile telemedicine system, including ECG and blood oxygen monitoring system.

Development of a spherical amphibious mother robot

Abstract: A variety kinds of underwater robots have been developed for the uses of underwater investigation and underwater operation. For those tasks in complicated or tiny underwater environments, some kinds of underwater microrobots have been developed. Thanks to the developments of smart actuators, microrobots realized relatively high performance within a compact structure. But problems in velocity and sustainable time limited their application. To solve this problem, we proposed a mother-son robot system, which include several microrobots as son robots, and an amphibious spherical robot as the mother robot. In this paper, a mother robot was proposed. It was designed to be able to walk on land, as well as move in water using a vectored water-jet mechanism. As the mother robot in the under-developing system, it also contained the space for transporting microrobots, and two openable hulls to protect the microrobots from the water currents and obstacles in water. A pressure sensor was used to determine whether robot was on land or in water, and measure the depth while in the underwater situation. To avoid obstacles, eight infrared distance sensors were used to detect obstacles in all the directions around the robot. In order to evaluate the robot's underwater performance, some experiments were conducted.

Design and analysis of a low actuation voltage electrowetting-on-dielectric device

Abstract: This paper presents an Electrowetting-on-Dielectric (EWOD) device with optimized insulating layers operated by low actuation voltage. The device consists of an electrode array on a silicon substrate, covered by a dielectric layer and a hydrophobic layer. To characterize the performance of the device, simulations are performed for the dielectric layer of Sio2 and the hydrophobic layer of Sio2, Su-8 and Parylene C at different voltages. The volume finite difference approach of the Coventorware software was used to carry out the simulations. Two different molar of di-ionized water droplet were considered in the simulations. It was observed that the device having the Sio2 dielectric layer and the Parylene C hydrophobic layer moved the 1M KCL (potassium chloride) droplet at the actuation voltage of 25V.

Characteristics evaluation of a pressure sensitive rubber-based tactile sensor

Abstract: Pressure sensitive rubber has been proposed to be used as the tactile sensor in robotic catheter system for MIS (minimally invasive surgery). The contact area in the blood vessels can not be clearly known within the current technical level. In this paper, supposing there are three different situations when the sensor contacts the blood vessel wall, including the contact area is one point, the contact area is part of the surface and the contact area is entire surface. This paper analyzes the strain based on FEA (finite element analysis) when the force loading area of pressure sensitive rubber is different. The linearity of pressure sensitive rubber is good on condition that the contact area is constant. Then we change the contact area to do more experiments and learn that the strain increases with the increase of the contact area. Keep contact area as a constant value, we can get an accurate calibration curve of pressure sensitive rubber. In this way, we evaluate the characteristics of the pressure sensitive rubber when it is used in robotic catheter system for MIS as a novel tactile sensor.

Development of a new kind of magnetic field model for wireless microrobots

Abstract: In the industrial field and medical application, a wireless microrobot may be used in the small space and medical practice. In this paper, we proposed a new kind of magnetic field model, which can generate a rotation magnetic field directly and drive a microrobot. In addition, we proposed a spiral wireless microrobot, which can work in narrow area such as blood vessels in application to microsurgery. The developed microrobot with a spiral structure can get very strong force to move and has the characteristics such as compact volume, completely symmetrical mechanical structure, quick response, cleaning the dirt adhering to the inner wall, and long distance movement. We can just change the characteristic of input current to control movement of the microrobot easily. It can move smoothly in water or other liquid medium and we are able to achieve wireless, high efficiency energy supply. Then through the theoretical analysis and software simulation of the rotation magnetic field model, we verify the feasibility of the new model and the motion characteristics of microrobot. It will be very useful for industrial application and microsurgery.

A force acquisition method in a catheter navigation system

Abstract: Endovascular intervention is expected to become increasingly popular in medical practice, both for diagnosis and for surgery. Accordingly, researches of robotic systems for endovascular surgery assistant have been carried out widely. Robotic catheter navigation systems are with advantages of higher precision, can be controlled remotely etc. However, the haptic feelings, the important function for propelling robotic catheter navigation system is immature. In the paper, a robotic catheter navigation system is proposed. The navigation system is designed to simulate the surgeon Os operating procedure. And the haptic feedback issue is concerned. A clamping force measure method is developed. Therefore, surgeons can carry out operation with their own skills. System implement and performance are presented.

Image processing-based measurement of volume for droplets in the microfluidic system

Abstract: This paper describes a new approach on the measurement of droplets volume in microfluidic system based on image processing. This approach successfully detects the diameter of a single droplet. Image processing via MATLAB is used to capture droplets volume in the microfluidic system. Compared with other methods, this approach has enormous advantages of real-time, simpleness and wide applications. Because of the demand of constant accurate flow in microfluidic system, the approach to measure volume of microfluid is in urgent need. The accuracy of the volume measurements is limited by the selected parameters of the image processing. During the experiment, the optimum parameters of the image processing are selected through repeated tests. The obtained results are in good agreement with the demand. The results show that microfluid can be controlled in quantitative. That makes an important application field of micro fluidic is in pharmacy, microchemistry, biochemistry and bioanalysis.

Simulation of the virtual reality based robotic catheter system

Abstract: Minimally Invasive Surgery (MIS) is a specialized surgical technique that permits vascular interventions through very small incisions and minimizes the patient's trauma and permits a faster recovery compared to traditional surgery. Telemedicine is one area where remotely controlled robots can have a major impact by providing urgent care at remote sites. However, the significant disadvantage of this surgery technique is complexity and it requires extensive training before surgery. The unavailability of force and tactile feedback the operator must determine the required action by visually examining the remote site and therefore limiting the tasks. In this paper, we present virtual reality simulators for training with force feedback in minimally invasive surgery which allows generating realistic physical-based model of catheter and blood vessels, and enables surgeons to touch, feel and manipulate virtual catheter inside vascular model through the same surgical operation mode used in actual MIS. In this paper, the design of the MIS VR system and initial experimental results are presented and the experimental results show that the error rate is in an acceptable range and the simulators can be used for surgery training.

Maxillofacial surgical robotic manipulator controlled by haptic device with force feedback

Abstract: Operation in the area of Maxillofacial section is very difficult and risky due to its complicated and random anatomical structure. Therefore, to resolve these types of surgical issues, a multi-arm medical robot is designed. This paper presents a system able to perform complex maxillofacial surgeries using 6-DOF surgical manipulator and haptic device with force feedback capability. Force sensor is placed on manipulator end-effector and force feedback responses are felt on Haptic device. This proposed system improves surgical accuracy and removes surgeon's tension during tele-operation. The prototype of the whole system is designed and tests are conceded out under the surveillance of optical tracking system. The results demonstrate the system accuracy and reliability with force feedback competency.

Hessian-based vessel enhancement combined with directional filter banks and vessel similarity

Abstract: Vessel enhancement in angiogram is an important preprocessing procedure for clinical diagnosis and further processing. Hessian-based methods have been widely used due to its elegant geometrical interpretations. But classical Hessian-based methods suffer the drawbacks of blurred vessel edges and intensity inhomogeneity, especially in vessel junction regions. In this paper, a new vessel enhancement method is proposed to address these problems. The input angiogram is first decomposed into several directional images and each of them is enhanced by traditional Hessian-based method. Then the enhanced direction images are recombined to generate final result. To improve contrast at vessel edges and intensity homogeneity in vessels, a vessel similarity measurement is proposed and used as weight coefficients in the recombination of enhanced directional images. It is calculated based on the intensity and curvature analysis of directional images. Qualitative and quantitative experiments performed on typical angiograms and retinal images in DRIVE database show that the proposed method has better performance than other two Hessian-based enhancement methods.

Barker coded excitation using LFM carrier for improving axial resolution in ultrasound imaging

Abstract: Improving the axial resolution of ultrasound imaging system can have broad clinical impact. In this paper, a novel Barker coded excitation uses LFM carrier (LFM-Barker coded excitation) instead of sinusoid carrier (Sinusoid-Barker coded excitation). Pulse compression scheme of LFM-Barker coded excitation is developed that consists of LFM mismatched filter, Barker matched filter and sidelobe suppression filter. In simulation, the axial resolution is almost doubled with a slight decrease of SNR gain of less than 1 dB using LFM-Barker coded excitation compared to Sinusoid-Barker coded excitation. The -6 dB mainlobe width is 0.6 μs and 1.5 μs, respectively. Maximum range sidelobe level is observed at -35 dB. Additionally LFM-Barker coded excitation is robust for frequency dependant attenuation of tissue. Simulation of B-mode images is carried out to demonstrate the advantage of LFM-Barker coded excitation system of good axial resolution.