Louis Phee

Energy sources and their development for application in medical devices

Electronic medical devices have become an indispensable part of modern healthcare. Currently, a wide variety of electronic medical devices are being used to monitor physiological parameters of the body, perform therapy and supplement or even entirely replace complex biological functions. Cardiac pacemakers, cardioverter-defibrillators and cochlear implants are a few examples of such medical devices. Proper functionality of these devices relies heavily on the continuous supply of a sufficient amount of electricity to them. In this sense, a reliable, safe and convenient method for the provision of energy is very crucial. Various approaches have been developed to fulfil the divergent and challenging energy requirements of medical devices. In this article, we present a brief overview of the energy requirements of medical devices and review the existing and emerging energy sources for application in these devices, particularly wearable and implantable devices.

Ultrasound Guided Robotic System for Transperineal Biopsy of the Prostate

We present a prototype of a robotic system for accurate and consistent insertion of a percutaneous biopsy needle into the prostate. The robot manipulates a transrectal ultrasound (TRUS) probe to collect a series of 2 dimensional (2D) images of the prostate, which are later used to create a 3D computer model of the organ. The urologist defines the needle’s entry point at the perineal wall and the biopsy points within the 3D model following a biopsy protocol or otherwise. The robotic system then calculates the required trajectory of the needle. The path of the needle going into the prostate can also be simulated with the 3D model before the actual insertion. Being satisfied with the predicted outcome, the urologist configures the robot accordingly and manually pushes the mechanically guided needle into the patient to take the biopsy. Cadaveric and human trials have validated the robot’s needle placement error to be less than 2.5mm. Our future work includes the integration of a cancer predictive modality into the system to increase the cancer detection rate. The robotic system could also be modified to accurately place foreign bodies into the prostate, which could improve therapeutic procedures such as Brachytherapy.

Flexible endoscopic robot

Abstract Natural orifice transluminal endoscopic surgery (NOTES) is a novel surgical procedure during which abdominal operations can be performed with an endoscope passed through a natural orifice through an internal incision in the stomach, vagina, bladder or colon. NOTES is still evolving and many barriers stand on its way before it can gain acceptance in modern surgical practice. Effective access to the peritoneal cavity, closure techniques of the natural orifice access sites, development of a multitasking platform to accomplish procedures and support for special orientation are only a handful of its known limitations. Although the endoscope and conventional tools are useful for simple procedures, many important and complicated procedures are currently not possible due to limitation of degree of freedom (DOF) of the end effectors. We have developed a Master and Slave Transluminal Endoscopic Robot (MASTER) with nine degrees of freedom (DOF) in end effectors, which are long and flexible so as to enhance endoscopic procedures and NOTES. Using MASTER we have successfully performed endoscopic sub-mucosal dissections (ESD) to segmental hepatectomies in animal models. Thus, the MASTER robotic system shows great potential to perform new surgical procedures that are otherwise not possible with conventional endoscopic tools.

Master-slave robotic system for therapeutic gastrointestinal endoscopic procedures.

Flexible endoscopy is used to inspect and treat disorders of the gastrointestinal (GI) tract without the need for creating an artificial opening on the patients body. Simple surgical procedures (like polypectomy and biopsy) can be performed by introducing a flexible tool via a working channel to reach the site of interest at the distal end. More technically demanding surgical procedures like hemostasis for arterial bleeding, or suturing to mend a perforation cannot be effectively achieved with flexible endoscopy. The proposed robotic system enables the endoscopist to perform technically demanding therapeutic procedures (currently possible only with open surgery) in conjunction with conventional flexible endoscopes. The robotic system consists of a master console and a slave. The latter is a cable driven flexible robotic manipulator that can be inserted into tool channel of existing endoscopes or attached in tandem to the endoscopes. Together with the real time endoscopic view, the endoscopist would be capable of performing more intricate and difficult surgical procedures

ULTRASOUND GUIDED ROBOTIC BIOPSY OF THE PROSTATE

In this paper, a prototype of a robotic system for accurate and consistent insertion of a percutaneous biopsy needle into the prostate is presented. A transrectal ultrasound (TRUS) probe is used to collect a series of two-dimensional (2D) images of the prostate. These images are used to create a 3D computer model of the organ which is used by the urologist to define the biopsy points within the prostate. The robotic system then calculates the required trajectory of the needle, which can be simulated on the computer. Following this, the robot is configured accordingly and the actual biopsy is performed. Cadaveric and human trials have validated the robots needle placement error to be less than 2.5 mm. Our future work includes the integration of a cancer predictive modality into the system to increase the cancer detection rate. The robotic system could also be modified to accurately place foreign bodies into the prostate, which could improve therapeutic procedures such as Brachytherapy.

Wireless capsule endoscopes for enhanced diagnostic inspection of gastrointestinal tract

Wireless capsule endoscopy has become a common procedure for diagnostic inspection of gastrointestinal tract. This method offers a less-invasive alternative to traditional endoscopy and provides the opportunity for exploring inaccessible areas of the small intestine. Current capsule endoscopes, however, move by peristalsis and are not capable of detailed and on-demand inspection of desired locations. Here, we propose and develop two wireless endoscopes with maneuverable vision systems to enhance diagnosis of gastrointestinal disorders. The vision systems in these capsules are equipped with mechanical actuators to adjust the position of the camera. This may help to cover larger areas of the digestive tract and investigate desired locations.

A HIFU robot for transperineal treatment of prostate cancer

Prostate cancer accounts for 29% of all cancers diagnosed in males in the United States. Present therapeutic procedures for prostate cancer are either invasive or minimally invasive. However, recent advances in technology (e.g. High Intensity Focused Ultrasound (HIFU)) allow the possibility of also non-invasive therapeutic procedures. This paper describes localizing the position of the prostate using an ultrasound probe. With this information, the robot can accurately manipulate a non-invasive therapeutic tool, such as HIFU, to an area of interest in the prostate via the transperineal route.

Software design of transperineal prostate needle biopsy robot

This paper focuses on introducing the software design of a robotic system for accurate and consistent insertion of a percutaneous biopsy needle into the prostate guided by transrectal ultrasound images. A set of software modules in the main computer system is designed to guide the urologist to control the biopsy robot and biopsy process. This system functionally undertakes the control of image acquisition, interaction with the urologist for prostate boundary delineation, puncture point planning and biopsy point definition on 2D image (ultrasound) slices. 3D visualization of the prostate surface, needle, biopsy point and needle trajectory is also performed by the software. The system calculates the required parameters of the needles trajectory and guides the urologist in maneuvering the robot to perform the biopsy. System performance and experimental results are presented at the end.

EFFICIENT 3D PROSTATE SURFACE DETECTION FOR ULTRASOUND GUIDED ROBOTIC BIOPSY

Prostate surface detection from ultrasound images plays a key role in our recently developed ultrasound guided robotic biopsy system. However, due to the low contrast, speckle noise and shadowing in ultrasound images, this still remains a difficult task. In the current system, a 3D prostate surface is reconstructed from a sequence of 2D outlines, which are performed manually. This is arduous and the results depend heavily on the users expertise. This paper presents a new practical method, called Evolving Bubbles, based on the level set method to semi-automatically detect the prostate surface from transrectal ultrasound (TRUS) images. To produce good results, a few initial bubbles are simply specified by the user from five particular slices based on the prostate shape. When the initial bubbles evolve along their normal directions, they expand, shrink, merge and split, and finally are attracted to the desired prostate surface. Meanwhile, to remedy the boundary leaking problem caused by gaps or weak boundaries, domain specific knowledge of the prostate and statistical information are incorporated into the Evolving Bubbles. We apply the bubbles model to eight 3D and four stacks of 2D TRUS images and the results show its effectiveness.