The human spine is composed of vertically stacked vertebrae that form a protective canal for the spinal cord. Instability of the spine caused by vertebral fractures, deformities and other spinal disorders often requires surgical intervention, in which two metal screws are placed into parts of the vertebrae called pedicles and joined at adjacent vertebral levels with metal rods. However, patients with osteoporosis (and thus poor bone quality) are susceptible to screw pullout during the procedure. At the same time, osteoporotic patients stand to gain the most from the procedure.
Rather than reinvent the effective and well-established procedure of pedicle screw fixation, this E-Team is aiming to rebuild the strength of screw fixation in the pedicles by shifting the forces experienced by weak inner bone to strong outer bone. They call this method Corticoplasty™, and the device used in this approach will act as an intermediary between the bone-screw interface and provide a strong interference fit for existing screws in osteoporotic patients.
Every day as clinicians perform their morning rounds, patients are asked whether they have been using their incentive spirometer, an inexpensive bedside device that promotes deep breathing with a visual feedback mechanism. Current clinical protocol suggests performing deep breathing exercises using the incentive spirometers ten times per hour as a preventative measure to reduce postoperative pulmonary complications that include atelectasis, pneumonia, and bronchitis. As a testimony to their efficacy, incentive spirometers are provided to every single patient who undergoes general anesthesia. Unfortunately, it’s impossible to tell if a patient has actually been using the spirometer, forcing clinicians to rely on patient memory, which is neither objective nor accurate in the post-operative period.
This E-Team is designing an electronic, disposable incentive spirometer that will quantify when a patient uses it. The device is designed to allow hospital staff to monitor patient usage and lung capacity performance—features not possible with current embodiments. Ultimately, the team hopes to expand into the full spirometry market to help diagnose non-hospitalized patients for conditions such as pneumonia.
For the past two years, The Center for Bioengineering Design, a Course and Program Grant-funded initiative at Johns Hopkins University, has provided bioengineering graduate students the tools and support to develop new medical devices.
One of the Center’s team design projects was recently given a licensing deal with Seguro Surgical, a Maryland company specializing in the commercialization of surgical instrumentation.
“SeguroSurgical’s…product line (the Lap-Pak) was borne out of one of our design team projects,” says instructor Robert Allen. The Lap-Pak is a device that cleanly and quickly repositions the bowel during a surgery.
Roughly 1.4 million lower extremity fractures, including 950,000 to the ankle, occur annually in the US. The majority of these musculoskeletal injuries require some type of physical therapy. Because the total cost involved in diagnosis, surgery, or rehabilitation of such injuries amounts to billions of dollars, this E-Team from John Hopkins University developed a low-cost foot sensor that aids patients in recovery.
Research shows that patients recover faster with limited weight-bearing programs, but gauging how much pressure to apply to the injury before doing harm is difficult. The team's foot sensor measured the pressure and alerted patients if they put too much pressure on their injury. Patients could adjust the pressure threshold according to the nature of the injury, the severity, and progress in rehabilitation.
The E-Team consisted of ten undergraduate students enrolled in a year-long biomedical engineering course sequence with skills in computer programming and computer, biomedical, and electrical engineering. The students worked under the umbrella of Homewood Biomedical Design Associates, a university-based corporation. An engineering professor worked with the team, along with an engineering lecturer, the clinical director of Physiotherapy Associates, and the president and founder of Venture Quest, Inc., a management firm.
This grant further supports the programs that make up the new Center for Bioengineering Design and Innovation at Johns Hopkins. Specifically, the grant helps with the development of a non-thesis option for the Masters program that will allow students to take on a design project for two years, starting as a design team leader in year one. It's hoped that the non-thesis Masters track will produce four Masters students per year, with funding from industry, donations, and other grants.
Over 400,000 premature births occur each year in the US, accounting for over $6 billion in annual health care spending. Statistics suggest that the number of premature births is rising, despite advances in prenatal care. Premature birth is associated with higher risk of maternal and infant death, and debilitating infant illnesses such as cerebral palsy, autism, mental retardation, and vision and hearing impairments. Currently, several tools on the market predict pre-term delivery, however the available diagnostic methods do not function early enough to safely and consistently administer labor-suppressing drugs.
This E-Team developed a cervical bioimpedance system that predicts the onset of birth early enough to safely administer preventative drugs. The system detects very subtle changes in cervical tissue composition, which indicate when the cervix is readying for childbirth. The system is composed of an electrode probe with a disposable sterile plastic tip containing the circuitry necessary to measure bioimpedance.
Update: the team has successfully licensed the technology (details not available).
This E-Team developed a new device designed for the early detection of acute renal failure (ARF). The device uses laser technology and Raman spectroscopy to provide data on metabolite excretion rates in near real-time (high levels of metabolite excretion are indicative of ARF). The device enables the detection of ARF in hospitalized patients up to 48 hours earlier than current detection methods. The detection of other biomarkers using this device is also possible, making the device useful in aiding with a number of clinical diagnoses.
ARF is seen in 5% of all hospitalized patients, and 4-15% of all patients who undergo cardiovascular surgery. It accounts for 30,000 deaths per year. Current detection methods are not effective in providing early detection of the disease, which is essential to effective treatment. By providing early detection capabilities, this device can give healthcare providers a jump start on effectively treating ARF.
This E-Team developed the EEG Keyboard, a Brain-Computer Interface (BCI) typewriter system capable of translating electroencephalogram signals generated from electrical activity in the brain into characters on a screen. Electrodes are attached to the user's scalp, and he or she chooses characters either by focusing on a certain row or column in a flashing six-by-six matrix or by staring at a region of the screen flashing at a certain known frequency. Initially the product was targeted at the Locked-In Syndrome (LIS) community--individuals with paralysis of all voluntary muscles in the body, leaving them virtually unable to communicate.
The E-Team consisted of two professors of biomedical engineering (one of which won the 2003 BCI competition), eight biomedical engineering undergraduates, and three faculty advisors: one from neurology, one from biomedical engineering, and one from business.
Each year, approximately 550,000 osteoporotic patients in the US suffer from compression fractures that require pedicle screws in order to reconstruct the spine. These patients are currently given pain management treatments instead of pedicle screws, however, because osteoporotic bone isn't strong enough to hold the screws in, or prevent them from falling out. This E-Team plans to solve the problem by developing a pull-out resistant pedicle screw. The novel design, based on a vertebral compression fracture treatment known as kyphoplasty, consists of a two-part screw involving a hollow capture chamber and a threaded inner screw. The hollow chamber is inserted into the vertebral body, then the inner screw is brought through the chamber into a wet cement adhesive. As the cement cures, the stickiness of the screw is enhanced, providing greater pull-out resistance.
People with ankle problems such as arthritis often wear supportive devices to help them walk. Traditionally ankle braces have been custom manufactured to meet specific patient needs, but in recent years there has been a movement toward prefabricated devices. While current prefabricated devices are capable of completely supporting the ankle, they often suffer from a lack of durability: the junction between the footplate and the upper support fails. Due to the high failure rates of existing products, physicians have voiced a need for a structurally sound and supportive ankle brace.
This E-Team is hoping to fill the need by designing a brace that incorporates the idea of recoil energy. The design includes a one-piece "sock" structure to allow for a greater fitting range, a resilient carbon-fiber foot-shin plate to provide the lever action that alleviates pressure at the ankle during walking, and stress distribution, particularly around the foot-plate strut joint that typically fails.