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Railroad crossings represent a significant danger in railroad transportation systems. Each year thousands of accidents occur that involve trains and other vehicles at unprotected railroad crossings, resulting in hundreds of fatalities and injuries. Additionally, derailments occur on average once every 6 h across the United States due to mechanical failures and improperly maintained track, endangering property and lives. The lack of electrical infrastructure in remote areas is a primary barrier impeding the installation of safety enhancements such as warning light systems and track health monitoring sensors that could reduce the frequency of such accidents. Providing on-demand power by harvesting energy from deflecting railroad track during the passage of trains is a promising approach compared with the cost of installing electrical power lines or the lack of robust solar and/or wind power solutions. This paper discusses the design and development of several power harvesting devices capable of scavenging power from the vertical deflection of railroad track. The design of a cam-based generator device driven by the train wheels is also discussed. Simulation and testing results on these devices are also presented in this paper.

Advances in endoscopic techniques for abdominal procedures continue to reduce the invasiveness of surgery. Gaining access to the peritoneal cavity through small incisions prompted the first significant shift in general surgery. The complete elimination of external incisions through natural orifice access is potentially the next step in reducing patient trauma. While minimally invasive techniques offer significant patient advantages, the procedures are surgically challenging. Robotic surgical systems are being developed that address the visualization and manipulation limitations, but many of these systems remain constrained by the entry incisions. Alternatively, miniature in vivo robots are being developed that are completely inserted into the peritoneal cavity for laparoscopic and natural orifice procedures. These robots can provide vision and task assistance without the constraints of the entry incision, and can reduce the number of incisions required for laparoscopic procedures. In this study, a series of minimally invasive animal-model surgeries were performed using multiple miniature in vivo robots in cooperation with existing laparoscopy and endoscopy tools as well as the da Vinci Surgical System. These procedures demonstrate that miniature in vivo robots can address the visualization constraints of minimally invasive surgery by providing video feedback and task assistance from arbitrary orientations within the peritoneal cavity.

Current laparoscopic surgical robots are expensive, bulky, and fundamentally constrained by the small entry incisions. A potential new approach to minimally invasive surgery is to place the robot completely within the patient. We have developed several such miniature mobile robots and conducted tests during animal surgeries. These robots can provide vision and task assistance to the surgeon without being constrained by the entry port. We used a mobile biopsy and camera robot to sample hepatic tissue from an anesthetized porcine animal model. This successful test demonstrated the capability of performing a single port laparoscopic biopsy procedure. In the future, a family of such robots could be remotely controlled and used to perform surgical procedures without the need for conventional laparoscopic tools.

Robotic laparoscopic surgery is evolving to include in vivo robotic assistants. The impetus for the development of this technology is to provide surgeons with additional viewpoints and unconstrained manipulators that improve safety and reduce patient trauma. A family of these robots have been developed to provide vision and task assistance. Fixed-base and mobile robots have been designed and tested in animal models with much success. A cholecystectomy, prostatectomy, and nephrectomy have all been performed with the assistance of these robots. These early successful tests show how in vivo laparoscopic robotics may be part of the next advancement in surgical technology.

This paper presents the results of tests that demonstrate the feasibility of using piezoelectric (PZT) ceramics to generate in vivo electrical energy for orthopedic implants. Sensors encapsulated within implants could provide in vivo diagnostic capabilities such as the monitoring of implant duty (i.e., walking) cycle, detecting abnormally asymmetric or high forces, sensing misalignment and early loosening, and early detection of wear. Early diagnosis of abnormalities or impending failure is critical to minimize patient harm. However, the routine use of sensors and microprocessors embedded within orthopedic implants for diagnostic and monitoring purposes has been limited by the lack of a long-term self-contained power source capable of lasting the expected 20-year implant lifetimes. By embedding PZT materials within orthopedic implants, a small amount of the mechanical energy generated during normal physical activity can be converted into useful electrical energy. This in vivo energy source can power embedded microprocessors and sensors for a broad range of biomedical uses. The current work investigates the application of this technology to total knee replacement (TKR) implants, but it is applicable to many other implanted biomedical devices.

Piezoelectric materials have long been used as sensors and actuators, however their use as electrical generators is less established. A piezoelectric power generator has great potential for some remote applications such as in vivo sensors, embedded MEMS devices, and distributed networking. Such materials are capable of converting mechanical energy into electrical energy, but developing piezoelectric generators is challenging because of their poor source characteristics (high voltage, low current, high impedance) and relatively low power output. In the past these challenges have limited the development and application of piezoelectric generators, but the recent advent of extremely low power electrical and mechanical devices (e.g., MEMS) make such generators attractive. This paper presents a theoretical analysis of piezoelectric power generation that is verified with simulation and experimental results. Several important considerations in designing such generators are explored, including parameter identification, load matching, form factors, efficiency, longevity, energy conversion and energy storage. Finally, an application of this analysis is presented where electrical energy is generated inside a prototype Total Knee Replacement (TKR) implant.

Laparoscopy reduces patient trauma, but also eliminates the surgeon's ability to directly view and touch the surgical environment. The long, rigid instruments and cameras typically used in laparoscopic surgery are constrained by the entry incision. This limits the ability to orient the tool tips arbitrarily, and prevents the optimal placement of the camera. These limitations generally restrict the application of laparoscopy to less complex procedures. Miniature in vivo robots are being designed to assist a surgeon during laparoscopic surgery. These in vivo robots, which are not constrained by entry incisions, will provide the surgeon with an enhanced field of view from arbitrary angles. These miniature camera robots were inserted through a small incision into an insufflated abdominal cavity of an anesthetized pig. The additional views, provided by the in vivo robots, allowed the surgeon to plan and place trocars safely and appropriately. The miniature robots provided additional camera angles that augmented surgical visualization and improved orientation, while abdominal procedures were performed. These successful prototype trials have demonstrated that in vivo miniature camera robots can provide surgeons with additional visual information that can increase procedural safety.

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of approximately 10(6) km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young--preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past approximately 10(5)-10(8) years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet--documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason--providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.

We use Python I, II, and III cosmic microwave background anisotropy data to constrain cosmogonies. We account for the Python beamwidth and calibration uncertainties. We consider open and spatially-flat-Lambda cold dark matter cosmogonies, with nonrelativistic-mass density parameter Omega_0 in the range 0.1--1, baryonic-mass density parameter Omega_B in the range (0.005--0.029) h^{-2}, and age of the universe t_0 in the range (10--20) Gyr. Marginalizing over all parameters but Omega_0, the combined Python data favors an open (spatially-flat-Lambda) model with Omega_0 simeq 0.2 (0.1). At the 2 sigma confidence level model normalizations deduced from the combined Python data are mostly consistent with those drawn from the DMR, UCSB South Pole 1994, ARGO, MAX 4 and 5, White Dish, and SuZIE data sets.

The use of miniature in vivo robots that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Previous work demonstrates that both mobile and fixed-based robots can successfully operate inside the abdominal cavity. A modular wireless mobile platform has also been developed to provide surgical vision and task assistance. This paper presents an overview of recent test results of several possible surgical applications that can be accommodated by this modular platform. Applications such as a biopsy grasper, stapler and clamp, video camera, and physiological sensors have been integrated into the wireless platform and tested in vivo in a porcine model. The modular platform facilitates rapid development and conversion from one type of surgical task assistance to another. These self-contained surgical devices are much more transportable and much lower in cost than current robotic surgical assistants. These devices could ultimately be carried and deployed by non-medical personnel at the site of an injury. A remotely located surgeon could use these robots to provide critical first response medical intervention.

A significant portion of railroad infrastructure exists in areas that are relatively remote. Railroad crossings in these areas are typically only marked with reflective signage and do not have warning light systems or crossbars due to the cost of electrical infrastructure. Distributed sensor networks used for railroad track health monitoring applications would be useful in these areas, but the same limitation regarding electrical infrastructure exists. This motivates the search for a long-term, low-maintenance power supply solution for remote railroad deployment. This paper describes the development of a mechanical device for harvesting mechanical power from passing railcar traffic that can be used to supply electrical power to warning light systems at crossings and to remote networks of sensors via rechargeable batteries. The device is mounted to and spans two rail ties such that it directly harnesses the vertical displacement of the rail and attached ties and translates the linear motion into rotational motion. The rotational motion is amplified and mechanically rectified to rotate a PMDC generator that charges a system of batteries. A prototype was built and tested in a laboratory setting for verifying functionality of the design. Results indicate power production capabilities on the order of 10 W per device in its current form. This is sufficient for illuminating high-efficiency LED lights at a railroad crossing or for powering track-health sensor networks.

One of the most limiting factors for distributed sensor networks used for railroad track health monitoring applications is the lack of a long-term, low-maintenance power supply. Most existing systems still require a change of battery, and remoteness of location and low frequency of maintenance can limit their practical deployment. In this paper we describe an investigation of two principal methods for harvesting mechanical power from passing railcars in order to supply electrical power to remote networks of sensors. We first considered an inductive voice coil device directly driven by vertical rail displacement. We then considered a piezoelectric device that is attached to the bottom of the rail and is driven by the longitudinal strain produced by rail bending due to passing railcars. Theoretical models of the behavior of these devices were integrated with an analytical model of rail track deflection to perform numerical simulations of both of these power scavenging techniques. Lab and field tests were also performed to validate the simulation results. Resulting values of average power production show promise for scavenging near the targeted level of 1 mW, and the field data matched well with the simulations.

Minimally invasive abdominal surgery (laparoscopy) results in superior patient outcomes as measured by less painful recovery and an earlier return to functional health compared to conventional open surgery. However, the difficulty of manipulating traditional laparoscopic tools from outside the patient’s body generally limits these benefits to patients undergoing procedures with relatively low complexity. The use of miniature in vivo robots that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Our previous work has demonstrated that mobile and fixedbased in vivo robots can successfully operate within the abdominal cavity and provide surgical vision and task assistance. All of these robots used tethers for power and data transmission. This paper describes recent work focused on developing a modular wireless mobile platform that can be used for in vivo sensing and manipulation applications. The robot base can accommodate a variety of payloads. Details of the designs and results of ex vivo and in vivo tests of robots with biopsy grasper and physiological sensor payloads are presented. These types of self-contained surgical devices are much more transportable and much lower in cost than current robotic surgical assistants. These attributes could ultimately allow such devices to be carried and deployed by non-medical personnel at the site of an injury. A remotely located surgeon could then use these robots to provide critical first response medical intervention irrespective of the location of the patient.Copyright © 2008 by ASME

Natural orifice transgastric endoscopic surgery promises to eliminate skin incisions and reduce postoperative pain and discomfort. Such an approach provides a distinct benefit as compared with conventional laparoscopy, in which multiple entry incisions are required for tools and camera. Endoscopy currently is the only method for performing procedures through the gastrointestinal tract. However, this approach is limited by instrumentation and the need to pass the entire scope into the patient. In contrast, an untethered miniature robot inserted through the mouth would be able to enter the abdominal cavity through a gastrotomy for exploration of the entire peritoneal cavity. In this study, the authors developed an endoluminal robot capable of transgastric abdominal exploration under esophagogastroduodenoscopic (EGD) control. Under EGD control, a gastrotomy was created, and the miniature robot was deployed into the abdominal cavity under remote control. Ultimately, future procedures will include a family of robots working together inside the gastric and abdominal cavities after their insertion through the esophagus. Such technology will help to reduce patient trauma while providing surgical flexibility.

A mobile in vivo camera robot was developed to provide the ability for a single port biopsy procedure. Such a robot can be inserted into the abdominal cavity through a standard trocar. The surgeon controls the robot using visual feedback from the on-board camera. Measurements were made to identify the forces required to successfully biopsy in vivo tissue, including clamping and tearing forces. The robot design was developed around these parameters and the need to traverse the abdominal environment using specially designed wheels. This mobility allows the biopsy robot to move to the area of interest to sample specific tissues. The lead-screw linkage system that actuated the graspers allows for large force production through careful mechanical design. In vivo testing of this system in a porcine (pig) model has been successful. The robot is capable of traversing the entire in vivo abdominal environment and has successfully been used to biopsy hepatic tissue. In addition, experimental analysis of the biopsy mechanism shows good results towards more elaborate tissue manipulation in the future

A mobile in vivo biopsy robot has been developed to perform a biopsy from within the abdominal cavity while being remotely controlled. This robot provides a platform for effectively sampling tissue. The robot has been used in vivo in a porcine model to biopsy portions of the liver and mucosa layer of the bowel. After reaching the specified location, the grasper was actuated to biopsy the tissue of interest. The biopsy specimens were gathered from the grasper after robot retraction from the abdominal cavity. This paper outlines the steps towards the successful design of an in vivo biopsy robot. The clamping forces required for successful biopsy are presented and in vivo performance of this robot is addressed.

Laparoscopy reduces patient trauma but limits the surgeon's ability to view or touch the surgical environment directly. The surgeon's ability to visualize and manipulate target organs can be improved using currently available external robotic systems. However, tool tip orientation and optimal camera placement remain limited because the robot instruments and cameras are still constrained by the entry incisions. Placing a robot completely within the abdominal cavity would provide an unconstrained platform that could provide an enhanced field of view from arbitrary angles and dexterous manipulators not constrained by the abdominal wall fulcrum effect. Several in vivo robots have been developed and successfully tested in a porcine model. These in vivo robots have been used to observe trocar and tool insertions and placement, and to provide additional camera angles that improved surgical visualization. Equipped with a grasper, such robots will provide task assistance. These in vivo robots will be much less expensive than the current generation of large external robotic surgical systems and will ultimately allow a surgeon to be a remote first responder irrespective of the location of the patient.

Today's laparoscopic tools impose severe ergonomic limitations and are constrained to only four degrees of freedom. These constraints limit the surgeon's ability to orient the tool tips arbitrarily, and can contribute to a variety of complications. Robots external to the patient have been used to aid in the manipulation of the tools and improve dexterity. However, these robots are expensive, bulky, and are used for only select procedures. In vivo robotic assistants have the potential to enhance the capabilities of the surgeon, reduce costs, and reduce patient trauma. The motion of these in vivo robots will not be constrained by the insertion incisions. Such assistants will need to attain optimal viewing angles by traversing the abdominal organs without causing trauma. This paper presents an experimental analysis of miniature in vivo robot wheels.

Laparoscopic techniques have allowed surgeons to perform operations through small incisions. However, the benefits of laparoscopy are still limited to less complex procedures because of losses in imaging and dexterity compared to conventional surgery. This project is developing miniature robots to be placed within the abdominal cavity to assist the surgeon. These remotely controlled in vivo robots provide the surgeon with an enhanced field of view from arbitrary angles as well as provide dexterous manipulators not constrained by small incisions in the abdominal wall.

Vidicon data for the intensities of Balmer and Paschen lines for n = 11 to 18 indicate a line ratio within 1σ of the theoretical value of 3.27, calculated with the assumptions of an optically thin atmosphere and angular momentum substates populated according to their statistical weights. The observed value is not consistent with the value of 8 reported in some early work, or with the model that higher angular momentum states have low populations.

Laparoscopy is abdominal surgery performed with long tools inserted through small incisions. The use of small incisions reduces patient trauma, but also eliminates the surgeon’s ability to directly view and touch the surgical environment. These limitations generally restrict the application of laparoscopy to less complex procedures. Large robots external to the patient have been used to aid in the manipulation of the tools and improve dexterity. This paper presents a theoretical and experimental analysis of miniature in vivo robots. The objective is to develop a wireless mobile imaging robot that can be placed inside the abdominal cavity during surgery. Such robots will allow the surgeon to view the surgical environment from multi-angles. The motion of these in vivo robots will not be constrained by the insertion incisions.Copyright © 2004 by ASME