Dr. Abdulrauf’s mission is to improve patient outcome during the most complicated neurosurgical operations using all the innovative tools available to him.
The Walter E. Dandy Neurosurgical Society is a premier forum for neurosurgical surgeons that provides education and training to surgeons on cutting-edge practices that improve patient outcomes. The president of the neurological society, Dr. Saleem Abdulrauf, is a leading neurosurgeon who has served more than 100 universities around the world and currently sits as the professor and chairman of the St. Louis University Department of Neurological Surgery and as Neurosurgeon-in-Chief at the St. Louis University Hospital. As part of Dr. Abdulrauf’s efforts, and the efforts of his department and the greater neurological community, to improve patient outcome during neurological surgery, the St. Louis Department of Neurological Surgery partnered with the St. Louis School of Engineering to begin quantifying how advanced manufacturing practices such as 3D printing will enhance the training and surgical practice for neurosurgeons. Their on-going study, which focuses on specifically undertaking the task of saving a patient experiencing a brain aneurysm, will compare 3D printing against traditional training methodologies such as cadavers (human, animal), foam models, and other conventional practices.
Challenge Dr. Abdulrauf’s mission is to improve patient outcome during the most complicated neurosurgical operations using all the innovative tools available to him.
“I personally perform a lot of brain aneurysm surgeries. It is a complex operation given the number of anatomical issues that we’re dealing with under the microscope. I knew if there was a way of simulating those complications before the operation using the same tools and under the same microscope we’d have a higher positive impact on the procedure outcome for the patient,” explains Dr. Abdulrauf.
Brain aneurysms are minutely different from patient to patient. During the operation, a surgeon is tasked with determining how to reach the aneurysm with minimal effect on surrounding tissue. The surgeon must calculate, in real time, the optimum angle to get into the area while factoring in the depth at which the aneurysm occurs and the size of the clip to close the aneurysm area.
“Every aneurysm is different in size, contour, and location. We have hundreds of clips sizes and types we can use and we’re typically making the decision on clip size during surgery. If I can make that decision beforehand by practicing on a model using the same tools and clips I plan to use in the final operation it really makes a difference during surgery,” explains Dr. Abdulrauf.
Developing a method to simulate an individual patient’s specific brain aneurysm presented a few challenges. Because the simulation would be most effective as a physical model that the surgeon could interact with and practice the procedure on, the models therefore needed to be a 1:1 scale of the patient’s brain. If the models could additionally mimic the feel and look of brain matter, so that surgeons could use the same equipment on the model as they would on the patient, it would be even more beneficial to surgeons.
Achieving simulation models with those parameters first requires an accurate high resolution map of the patient’s brain translated into a 3D CAD model. Next, a manufacturing method that is extremely fast is needed because patients will be suffering from the aneurysm in real time. Lastly, for the models to truly demonstrate potential as a future business model viable for doctors, a fast and a cost-effective production solution is required. Ideally, each model would be created as a one-off part unique to each patient’s particular brain abnormality. Therefore conventional production, with high costs for single tools that are dedicated to large volumes of identical parts, would not be sustainable for the low volume needs pertinent to a patient case-by-case creation.
Solution As one of the fastest and most cost effective production methods for one of a kind parts, 3D printing was on the top of the list to vet out as a viable solution for creating the brain models. From the selection of additive manufacturing technologies, PolyJet stood out as the most ideal 3D printing process because it is capable of meeting the time, cost, and material challenges Dr. Abdulrauf’s team faced. Additionally, PolyJet is one of the only 3D printing processes capable of printing a range of durometers into a single part, a significant boon to achieving the best feel for the skull of the model.
To create the models for the preliminary patients, scans of the patients’ brains were sent to the St. Louis University School of Engineering. The engineering students translated the scans into high resolution models which were exported as STL files compatible with 3D printing. Although the University had their own PolyJet machine, to achieve the quality and materials diversification necessitated by the project they chose to outsource the models. The team sent multiple CAD files of the brain, skull, and aneurysm to Stratasys Direct Manufacturing for printing. Together with Stratasys Direct Manufacturing, the engineering and medical students noted the critical area of the aneurysm. The Stratasys Direct Manufacturing team focused on maintaining flawless accuracy and detail on the aneurysm area throughout the entire production process.
Stratasys Direct Manufacturing was chosen as the 3D printing provider for the project for a few key reasons: its capacity, expertise, and dedicated anatomical department. The Stratasys Direct Manufacturing anatomical department based in Poway, California, is one of the leading innovators in revolutionary manufacturing methods throughout the field of anatomical training models. Some of their key achievements include providing 3D printing and urethane components for birthing simulators, dental, heart, bone, and kidney models. Stratasys Direct Manufacturing collaborated with the St. Louis University Department of Neurological Surgery to build the scans of the brains, aneurysm and skulls using PolyJet and urethane casting.
The two combined teams from Stratasys Direct Manufacturing and St. Louis University chose PolyJet Rigid VeroYellow for the skull and an overmolded TangoPlus material with a durometer of Shore 27A for the brain. The TangoPlus brain was built as a multi-functional piece. Initially, it served as the solid brain. Within the CAD design, the aneurysm was 3D printed according to the aneurysm pattern experienced by the actual patient. Finally, the skull was built with the inner support material that hugged the grooves and depressions of the sulci and gyri likeness of the patient’s brain. This support material served as the pattern for creating the inner brain matter. The interior of the TangoPlus brain was filled with a specially formulated gelatinous colloid material that mimics the feel of the spongey sulci and gyri in the brain. The urethane material filled in around the anatomically correct PolyJet printed aneurysm. The mixture cured within the TangoPlus and, with the aneurysm intact and in place according to the patient’s exact brain map, resulted in a completed, multi-material piece ready for operation.
Results These preliminary surgeries using a 3D printed model to simulate the procedure prior to operation provided valuable feedback for Dr. Abdulrauf and his team:
“I’ve done a lot of aneurysm operations in my career and I can confidently say that having the 3D printed model here has a very positive impact on the procedure results,” stated Dr. Abdulrauf. “The model has helped to identify and overcome surgical challenges, like optimum access to the aneurysm or the depth and angle of the approach, before surgery begins.”
With these preliminary positive results, the next move is to measure the success of 3D printed models through blind studies.
Dr. Abdulrauf has proposed a two arm study with resident neurosurgeons. All of the residents will be asked to perform a procedure on a cadaver. Half of the residents will receive a 3D printed model of the cadaver’s brain prior to surgery while the other half will prepare for the surgery without a 3D model. The two groups will then be compared. The assessors will be blind to which group received the 3D printed model. The success of one group over the other will be measured by time undertaken during the process, absence of errors, and the ability of the groups to keep the circumference of the surgery as minimally invasive into healthy tissue as possible. From this study, Dr. Abdulrauf hopes to quantify the use of 3D printed models in pre-surgical planning.
A second study will involve measuring the outcomes of patients who receive the traditional gold standard of care during surgery and patients who receive the gold standard plus their neurosurgeons receive a 3D printed model of their brain to practice on prior to surgery. The recovery time of patients and overall patient comfort post-surgery will be carefully monitored in both groups. By studying actual patient outcomes, Dr. Abdulrauf will gain measureable insight into the benefits of 3D printing for surgical procedures.
“The future of medicine is all based on measuring outcomes. The most important thing is quantifying what’s better for patients, and improving the lives of patients. To do that, we must know the absolute best measures we can take using the tools we have to improve their lives,” explains Dr. Abdulrauf. “We cannot thank Stratasys Direct Manufacturing enough for the work you’ve done. Having a heart in this kind of work always produces better results.”
Annual awards banquet acknowledges the team of accomplished distributors and agents throughout the U.S, Canada, Mexico, and South America, who represent Hurco.
Indianapolis, Indiana – Hurco Companies Inc. held its annual awards banquet in Indianapolis to acknowledge the team of accomplished distributors and agents throughout the USA, Canada, Mexico, and South America, who represent Hurco. The national meeting of Hurco distributor partners was held near Hurco’s Indianapolis headquarters at John Force Racing (JFR) to kick off the new partnership Hurco has established with the legendary NHRA team. Banquet attendees toured JFR’s 40,000-square-foot facility, including the Force American Made machine shop that features the latest Hurco CNC machines.
The winner of the Top Hurco Sales Representative Award was Gary Kittredge, of Brooks Associates , the full-service distributor that represents Hurco in New England. The other winners of the Hurco Top 5 Award were Jim Braun (#2) of Braun Machinery (Michigan), Mark Finnell (#3) of Reynolds Machinery (Ohio), Tim Navalta (#4) of Braun Machinery (Michigan), and Dennis Visser (#5) of Machinery Source (Illinois).
The distributorships were also recognized for their achievements in representing Hurco. The Top 5 Distributors from first to fifth were Braun Machinery (Michigan), Brooks Associates (Massachusetts), Reynolds Machinery (Ohio), Humston Machinery (Indiana), and a tie for fifth place, Stone Machinery (Minnesota), and Applied Machine Solutions (Georgia).
Humston Machinery won the Top Distributor Market Share Award and Top Distributor Growth went to Brooks Associates .
Hurco also welcomed new distributors Alta Enterprises (representing Hurco in western Pennsylvania) and CNC Solutions (representing Hurco in northern Calif.)
Motors and gearmotors ranging in torque from 0.04 to 8.5Nm released into its 24-Hour Pittman Express e-Commerce store.
Harleysville, Pennsylvania – Pittman a business unit of AMETEK Precision Motion Control, has released the EC044A and EC042B Series brushless motors into its 24-Hour Pittman Express e-Commerce store. Both EC044A and EC042B Series come with the new E30 encoder and PLG42S planetary gear that yield an outstanding level of performance in a truly compact assembly.
The EC044A is an economical 44mm brushless motor available in a range of lengths, windings and gear ratios to accommodate a range of user application requirements. Performance ranges from 0.04Nm (6oz-in) to 4Nm (600oz-in) of rated torque with rated speeds from 40rpm to 4,500rpm. Although stock gear ratios range from 4 – 100:1, optional ratios go to 512:1 yielding 14Nm of output.
The EC042B is the latest Pittman motor addition, effectively doubling rated torque in a smaller 42mm diameter. Performance ranges from 0.06Nm (9oz-in) to 8.8Nm (1,200oz-in) of rated torque with rated speeds from 40rpm to 4500rpm in stock solutions. The EC042B comes with the same options available in the EC044A in both stock and standard configurations.
The PittmanExpress e-Commerce store with 24-hour shipment offers a range of immediately available solutions. It is understood however, that one cannot predict all customer needs and as such also have the option of modifying motors to meet users’ unique requirements. Motors can be specified with a range of different windings, speeds, gear ratios and encoder outputs.
Brushless motor users should gear up for their next development project with new Pittman motor technology and go online to the PittmanExpress e-Commerce website at https://prototypes.haydonkerk.com to view the latest motor and gearmotor solutions available for immediate delivery.
About Pittman Pittman Motors is part of the AMETEK Precision Motion Control division. Pittman products are designed into a wide variety of high-tech motion applications, including lab automation, medical devices, communications equipment, semiconductor processing equipment, aerospace systems, and many other applications where precision motion is critical.
The Pittman motor line spans a wide variety of DC motor sizes and technologies, ranging from 10 mm-diameter brushless DC motors used in high-speed medical applications to large NEMA frame DC servo motors used in sophisticated automation equipment. Pittman also offers a wide variety of complementary products such as gearboxes, encoders, brakes, and drive systems.
Source: AMETEK Precision Motion Control
SABIC, PDI collaborate to help protect patients from infection.
Houston, Texas – SABIC, a global leader in thermoplastic technology, and PDI, a leader in infection prevention products and solutions for the healthcare industry, announced the results of a joint study on the environmental stress cracking resistance (ESCR) of SABIC’s materials used for medical device enclosures. The two companies evaluated how well SABIC’s industry-leading thermoplastics withstand repeated exposure to PDI’s Super Sani-Cloth wipes 1, one of the leading surface disinfectants widely used in the healthcare environment to help prevent healthcare-associated infections (HAIs). The study revealed that several of SABIC’s product technologies – including LEXAN EXL polycarbonate (PC) resin, XYLEX (PC/polyester blend) resin and VALOX polybutylene terephthalate (PBT) resin – deliver improved compatibility with PDI’s leading hospital-grade disinfectant. These and other products in SABIC’s robust portfolio of chemically resistant healthcare materials give manufacturers new options for designing medical equipment that maintains outstanding performance, while also addressing the disinfection demands of today’s healthcare environment.
PDI and SABIC collaborated to establish a testing procedure following ASTM D543 guidelines, and applied more stringent compatibility criteria compared to other benchmarks often used in the industry. SABIC has published the study findings in its updated and expanded brochure, Resistance + Durability: Chemical Resistance Performance Testing for Healthcare Materials. Also featured in the brochure is a new section, “Designing for ESCR,” which describes why following best practices in injection molding processing and designs can be instrumental in reducing molded-in stress, a key contributor to ESCR performance.
“Combatting HAIs is greatly important for hospitals, but if materials are not appropriately selected for the healthcare environment, the frequent application of cleaning chemicals can cause device enclosures to crack prematurely, which can lead to increased maintenance costs for healthcare providers,” said Cathleen Hess, Healthcare business leader for SABIC. “SABIC and PDI are committed to supporting the healthcare industry with information about compatibility between medical enclosure materials and commonly used disinfectants. Our joint study highlights the complex issue of environmental stress cracking, and provides valuable insights to help our customers make informed material selection decisions.”
According to the Centers for Disease Control and Prevention (CDC), “Although significant progress has been made in preventing some infection types, there is much more work to be done. On any given day, about one in 25 hospital patients has at least one healthcare-associated infection.”2 The World Health Organization (WHO) reported: “Hundreds of millions of patients are affected by health care-associated infections worldwide each year, leading to significant mortality and financial losses for health systems.”3
“With heightened emphasis on infection control in healthcare environments, medical devices are regularly subjected to repeated contact with hospital-grade disinfectants and, as a result, require exceptionally strong materials that are less vulnerable to environmental stress cracking,” said Cheryl Moran, senior director of Portfolio Management, PDI Infection Prevention. “By guiding manufacturers towards plastics that are better suited for the specific disinfecting requirements of each medical device, our study benefits both medical device manufacturers and healthcare providers, ultimately benefiting the patient, who can be protected from potential adverse events resulting from damaged or improperly disinfected equipment. Continuing our collaboration with SABIC and medical equipment manufacturers will enable even further insights as additional technologies emerge.”
Evaluating ESCR Environmental stress cracking is a complex problem that calls for in-depth knowledge of disinfectant and polymer chemistries and their compatibility, as well as part design and molding considerations. It is influenced by each aspect of the application development process, including, but not limited to, polymer morphology, chemical type and concentration, frequency of cleaning and residual stress in molded components. The new SABIC/PDI study evaluated the compatibility of select SABIC materials with PDI's Sani-Cloth wipes containing an alcohol/quaternary ammonium compound (QAC)-based disinfectant. This intermediate-level disinfectant provides broad-spectrum efficacy with a two-minute contact time.
Each medical device application requires a tailored approach to optimizing performance in today's hospital environment. SABIC's application and process development engineers are available to assist customers throughout the material selection, application development and molding process.
SABIC’s extensive portfolio of chemical resistant healthcare materials is available worldwide.
1 Manufactured and distributed in the U.S.
2 Healthcare-associated Infections (HAI) Progress Report. CDC website. http://www.cdc.gov/hai/surveillance/progress-report/index.html. Updated March 3, 2016.
3 Health care-associated infections fact sheet. World Health Organization. http://www.who.int/gpsc/country_work/gpsc_ccisc_fact_sheet_en.pdf.
Researchers at the University of Texas at Dallas have designed a wearable, flexible biosensor that can reliably detect and quantify glucose from very small amounts of human sweat. Photo credit: University of Texas at Dallas
Researchers at The University of Texas at Dallas are sweating the small stuff in their efforts to develop a wearable device that can monitor an individual's glucose level via perspiration on the skin.
This flexible, mechanically stable and disposable sensor (orange strip on hinge) can detect proteins in the blood that signal the onset of a heart attack.
Technology may aid diagnosis, monitoring
Blood-glucose monitoring devices have revolutionized the management of diabetes by making it easy for ordinary individuals to test their glucose levels at home.
But there are no similar consumer devices for cardiovascular disease, specifically for the quick and easy diagnosis of a heart attack.
“The onset of heart attack symptoms is usually gradual, over several minutes,” said Dr. Shalini Prasad, professor of bioengineering at UT Dallas. “But if you think you might be having a heart attack, every second counts to get a diagnosis and treatment.”
Prasad and biomedical engineering doctoral student Nandhinee Radha Shanmugam have developed a flexible, mechanically stable, disposable sensor for monitoring proteins circulating in the blood that are released from damaged heart muscle cells at the onset of a heart attack. Troponins can be found in the blood within about four hours after a heart attack, and for up to several days.
Low levels of troponin in capillary blood, such as that found in fingertips, correlates to higher levels in arterial blood, Prasad said. For this reason, the researchers focused on detecting ultralow concentrations of troponins with high accuracy in small volumes of blood drawn from a finger prick.
The key to the sensor’s performance is the way Prasad’s group incorporated nanostructures into the device’s zinc oxide electrodes. The nanostructures enhance the binding of the troponins to the electrode’s surface, making the device ultrasensitive.
“Our technique for growing these nanostructures on a variety of substrates opens up an entirely new and exciting research direction in the field of electrochemical biosensing for other biomolecules, like glucose, cholesterol and uric acid,” Prasad said.
The researchers recently described the technology in the online open-access journal Scientific Reports , part of Nature Publishing Group.
In a study recently published online in the journal Sensors and Actuators B: Chemical, Dr. Shalini Prasad, professor of bioengineering in the Erik Jonsson School of Engineering and Computer Science, and her co-authors demonstrated the capabilities of a biosensor they designed to reliably detect and quantify glucose in human sweat.
The team has previously demonstrated that their technology can detect cortisol in perspiration.
But for diabetics and those at risk for diabetes, self-monitoring of blood glucose, or blood sugar, is an important part of managing their conditions.
"Fitness trackers that monitor heart rate and step count are very popular, but wearable, non-invasive biosensors would be extremely beneficial for managing diseases," said Prasad, the Cecil H. and Ida Green Professor in Systems Biology Science.
Typical home-use blood glucose monitors require a user to obtain a small blood sample, usually through the prick of a finger and often several times a day. However, the UT Dallas textile-based sensor detects glucose in the small amount of ambient sweat on a person's skin.
"In our sensor mechanism, we use the same chemistry and enzymatic reaction that are incorporated into blood glucose testing strips," Prasad said. "But in our design, we had to account for the low volume of ambient sweat that would be present in areas such as under a watch or wrist device, or under a patch that lies next to the skin."
Prasad said that researchers who work with sweat often use a process called iontophoresis, which sends an electric current through the skin to generate enough perspiration for sensing experiments. However, because this method can lead to rashes and burns on the skin, the team sought an alternative that would work with small amounts of sweat.
Their design works with volumes of sweat less than a microliter, which is the approximate amount of liquid that would fit in a cube the size of a salt crystal.
The technology also provides a real-time response in the form of a digital readout.
Prasad and bioengineering doctoral student Rujuta Munje, lead author of the journal article, incorporated an off-the-shelf polymer-based textile material in their glucose sensor and used UT Dallas clean-room facilities to construct the electronic elements. The prototype is a small, flexible, rod-shaped device about an inch long.
"We used known properties of textiles and weaves in our design," Prasad said. "What was innovative was the way we incorporated and positioned the electrodes onto this textile in such a way that allows a very small volume of sweat to spread effectively through the surface."
Typical blood glucose testing strips also contain a molecule that ultimately amplifies the signal from the chemical reactions on the strip enough to register electronically on a monitoring device. But if used in a device that is worn next to the skin, those molecules can be irritating, Prasad said, which presented another challenge.
To ensure that such a tiny amount of sweat would generate a strong enough signal, Prasad and Munje modified the surface topography of the textile material.
"Our modifications allow this material to entrap glucose oxidase molecules, which effectively amplifies the signal," Prasad said. "We did it this way because we are thinking about possible commercialization – to make these, we need a fabrication process that is not complex."
Prasad and Munje also were able to account for the fact that the chemistry of a person's sweat changes throughout the day.
"Glucose is a tricky molecule to monitor because other factors can confound a signal," Prasad said. "For example, the pH, or acidity, of your sweat can vary greatly depending on the circumstances."
She noted that when individuals exercise or are under stress, the level of other compounds in their sweat, such as cortisol and lactic acid, change as well, and these can interfere with glucose detection.
"We have shown that with our technology, we address three critical issues: low volume of ambient sweat, interference from other compounds and pH swings," Prasad said
Prasad and Munje tested their prototype using samples of human sweat from donors.
While a consumer product based on the technology is still a few years away, the concept was developed with commercialization and scaled-up production in mind.
"At this point, we are thinking of this sensor as something you use for a day and toss out, and we believe it could easily be incorporated into existing consumer electronics platforms," Prasad said. "We're very excited about the potential for licensing this technology."
The research was supported by the Cecil H. and Ida Green endowed fellowship at UT Dallas.
Researchers at UT Dallas and elsewhere have investigated whether glucose found in other bodily fluids – such as urine and tears – might be used to track glucose levels, further eliminating the need for invasive blood draws. Google, for example, is investigating a smart contact lens designed to measure glucose levels in tears.
The Centers for Disease Control and Prevention estimate that 29 million people in the United States have diabetes and 86 million have prediabetes.