Real-time Plantar Force Demonstration System (2007-2008) The objective of this project was to develop a demonstration system that displays the real-time measurement of normal and shear components of the ground reaction force (GRF) occurring throughout the plantar loading and unloading portion of the gait cycle at multiple locations on the sole of the foot. This demonstration system allows for both normal and shear forces to be imparted by hand on a shoe-like plate. A sensor network is used to capture the real-time pressure measurement data and a computer displays the real-time pressure information in a concise and understandable format. One major task that was completed for this project was to integrate the sensor network and display computer to present real-time, accurate pressure data. This task was accomplished by converting the analog pressure measurements into digital values and multiplexing the results to an interface with the display computer. The successful project produces an easy-to-use demonstration system that provides accurate real-time measurements of ground reaction forces seen during plantar loading and unloading.

Cough Monitoring System (2007-2008) In some cases excessive coughing can be harmful to a person's health. Being able to monitor a patient's coughing, especially during the night, could help avoid long periods of harmful coughing. A portable battery-powered cough monitoring system was designed that records the time of occurrence of each cough from a patient over a period of up to 24 hours. The system is comprised of an analog microphone sensor, signal conditioning circuitry, a microcontroller and a USB computer interface for transferring recorded data to a PC for subsequent viewing and analysis. The microphone device is attached to the patient's throat in proximity of the cough, and its output signal is filtered, conditioned and tested with a threshold detector. When the threshold detector is triggered by a cough, the microcontroller then records the time of occurrence of the event. The detection threshold is manually set for desired sensitivity for each patient at the beginning of monitoring. If the patient’s rate of coughing exceeds a predetermined level, an alarm is generated to notify a nurse or other personnel that attention is needed.

Electronic Cardiac Arrhythmia Signal Generator (2006-07)  The normal human electrocardiogram (ECG) waveform has highly identifiable features that medical patient care personnel are trained to recognize. In the event of any physiological disturbance of the heart, noticeable changes are observed in the features of the ECG waveform. These disturbances are called “arrhythmias”. Many have been assigned specific names based on their appearance and experts can easily recognize them by their shape. In the research and development of ECG signal processing algorithms, it is important to test new software with specific cardiac arrhythmia waveforms to ensure their accurate detection. Therefore, a need exists for a signal generator which can produce custom synthesized analog cardiac arrhythmia waveforms for subsequent digitizing, analysis and research/development work by electrical engineering faculty and students at South Dakota State University. The objective of this project was to design an electronic cardiac arrhythmia signal generator that is capable of producing both a low level (nominal 1 mV) and a high level (1 V) analog electrocardiographic signal. This device is desired for use in research and development at SDSU. To design such a device, a microcontroller-based system was developed in which digitally stored cardiac signals are accessed and converted to analog cardiac signals. To convert the digital data into analog data, a digital to analog converter and low-pass analog filter are used. The analog signal is then converted to the desired output levels with a voltage divider circuit. The project has resulted in the fabrication of an easy to use, handheld electronic device that can be used by electrical engineering faculty and students at SDSU for research and educational purposes. It provides the following analog ECG waveforms: normal Lead II, Lead II Right Bundle Branch Block, normal Lead II with intermittent Premature Ventricular Contraction, normal Lead II with intermittent momentary Complete Atrial Block, and normal Lead I.

Wrist Proprioception Testing System (2006-07) Proprioception is defined as the ability to detect movement and position of a human body part. This project involved a research effort of the Motion Analysis Lab (Mayo Clinic) to study the proprioceptive role of mechanoreceptors, as well as the anterior and posterior interosseous nerves (AIN and PINI in the human wrist). The design objectives included finding the wrist's center of rotation as it is moved in flexion and extension, monitoring angular displacement of the wrist as it is moved in flexion and extension, and reducing mechanical vibrations involved with proprioception testing. Servo motor vibrations had to be damped in the laboratory's proprioception testing device, and two measurement systems needed to be developed. Damping was accomplished by fabricating a component with shock absorption characteristics. Measurement of angular displacement as well as locating the wrist's axis of rotation was carried out with electronic sensor assemblies and a monochromatic light source. LabVIEW was used to monitor the angular position, velocity, and acceleration of the wrist, but the software's real-time graphing did not accurately represent position and motion characteristics. Hence, angular displacement was monitored with a potentiometer mounted on the proprioception testing device. The potentiometer assembly included a potentiometer, a stationary attachment strapped to the forearm, a rotary attachment connected to the hand, a DC voltage supply, a data acquisition device, and mounting accessories. Locating the wrist's axis of rotation was accomplished with a rotational apparatus, a monochromatic light source, and a data acquisition system. This apparatus was mounted on the wrist proprioception testing device; the wrist is rotated several times in the assembly, and positional data is used to interpolate an axis of rotation. Marking the axis of rotation was carried out with one monochromatic light source, which marks the central axis of rotation for the proprioception testing device. The wrist's center is moved to coincide with the light beam before the start of proprioceptive testing.

Dialysis Cell Apparatus (2005-06) With the help of the Chemistry Dept. and Avera Research Institute, the group designed a functional apparatus that produces a medical-grade, low acidic gel used in patient care. The gel is produced from two liquids with varying acidity by manually mixing various quantities of bases and a buffer in a beaker to create the final product. The problems with this procedure include inconsistent mixtures as well as tedious and time consuming testing by laboratory technicians. The design objective was to produce an apparatus that controls the mixing of the base and buffer, with controllable flow rates, that yield a pressure within a predetermined range and accurately measure the pH of the final product. To accomplish this task, the apparatus uses peristaltic and high performance liquid chromatography pumps (HPLC), pressure transducers, a mixing chamber, an Analog-to-Digital Control module and associated software as well as pH electrodes. With modern sensors and data acquisition equipment, the apparatus allows researchers to consistently produce the gel product with little variation.

Acoustic Height Gauge (2005-06) During visits to the doctor's office, various physiological parameters of a patient are recorded, including height. Patient height is an important parameter for monitoring normal growth in adolescents and height loss in the case of degenerative bone diseases. Currently, most height measurements are made with a mechanical wall or scale-mounted caliper. However, these devices can introduce a degree of error that can hide short-term changes in patient height. Additionally, error can be introduced if the clinician is much shorter than the patient. Therefore, a device is needed for the accurate measurement of height where the measurement is independent of the environment and the person taking the measurement. A solution to this problem was to create a wall- or ceiling-mounted device that would measure and display height. The device must meet the following specifications. First, the device must measure over a range of three to eight feet, as most patients are within this height range. Second, the instrument must be able to measure within 1/4" to be comparable to current devices. Additionally, clinicians do not record a smaller resolution. Third, the device must be simple to use so that individuals who have little electronics experience can operate it with ease. To facilitate ease of use, the device should have a convenient wake-up power on feature. Overall, the design of this device includes an acoustic transducer, which is controlled by a microcontroller, where the measurements are displayed on an LCD screen. The acoustic transducer is mounted at a known height above the patient and is connected via cables to a ranging module, which controls the transducer and produces digital range information. A microcontroller controls both the ranging module and the LCD, as well as processes the received measurements from the transducer. An acoustic reflection from the top of the patient’s head is used to precisely measure his/her distance from the ranging transducer. This is subtracted from the known distance to the floor. Temperature and humidity variations in the speed of sound are compensated by a preliminary calibration ranging measurement from the ranging transducer to the floor (which is at a known distance).

Medication Reminder Bottle Cap (2004) There is a need for a product that utilizes a user-programmable clock and timing system to remind patients to take prescription medications. Physicians and pharmacists have expressed concern over patient compliance with prescription medications. Often this is not because of the willful disobedience of the patient, but due to forgetfulness and the busy schedules many people lead. Many of the current products on the market are costly and supply more features, such as locking and password protection, than many users need. The objective of this design project was to design an inexpensive alternative that provides audio and visual alarms to assist the user in prescription compliance. In fulfillment of this objective the Medication Bottle Cap is a small electronic device that replaces the cap on commonly used prescription bottles. The product snaps onto a 75 ml bottle and is approximately 2 inches in diameter. It features a clock display to show current time and three user programmable alarms. This allows the patient to be reminded of a medication three times daily.
Cardiac Heart Vector Display (2002-03) The heart beats as the result of an electrochemical current that starts in the upper right portion of the heart (at the sinoatrial node) and flows downward to the lower left portion of the heart, stimulating the cardiac muscles to contract, or “beat”. The cardiac vector is the angle of the path (in degrees) that the electric current follows from the upper right to the lower left portion of the heart. Changes in the cardiac vector can indicate physiological changes in the heart muscle or conduction system. The purpose of this project was to design, build and demonstrate a portable cardiac vector meter that displays the real-time cardiac vector (in degrees) for a patient. The completed electronic device determined the cardiac vector by comparing the real-time relative amplitude of a patient’s electrocardiogram (ECG) signal recorded from two different lead connections on the patient (Lead II, Lead III). The two ECG signals are amplified, conditioned and digitized for analysis by a microcontroller-based detection circuit. The microcontroller estimates the cardiac vector angle (within 5 degrees), and displays the value on a Liquid Crystal Display for medical personnel. The device may operate as a stand-alone unit, or could be integrated into a conventional cardiac monitor.
Handlebar Heart Rate Meter (2001-02) Today with an increased interest in maintaining good health through physical exercise, a need exists for a quick and easy way to detect the heart rate after exercise to ensure that the desired aerobic state has been reached. This challenge was met by students who designed a device for measuring a person’s heart rate using convenient, low cost technology, and can be used by anyone. The primary objective of the handlebar heart rate meter is to provide a portable, yet affordable device that quickly displays a person’s average heart rate when they simply grip the set of device handlebars. The handlebar heart rate meter detects the electrocardiogram (ECG) waveform through the handlebars. This waveform is converted to a pulse waveform whose frequency corresponds to the heart rate. This frequency is converted to a voltage level that is proportion to the person’s average heart rate and then displayed on the Liquid Crystal Display. In addition, a buzzer and flashing LED provide audio and visual indication of the heart beat. The handlebar heart rate meter is battery operated and has a response time of less than 5 seconds. The prototype of the handlebar heart rate meter was tested in parts successfully and met the need for a portable, low-cost device that can be used as a convenient method of measuring the heart rate.

“Breathe on Wheels” (2001-02) A patient transportation problem has arisen in health care faculties. Patients requiring the aid of a wheelchair and an oxygen concentrator pose a challenging task. An oxygen concentrator is a machine that delivers high quality oxygen to a patient. The device, which is on casters, is approximately 1.5’ x 1.5’ x 2.5’ and weighs about fifty pounds. It is difficult to maneuver the oxygen concentrator and wheelchair simultaneously because they are independent of each other. This cumbersome task leads to excessive body strain on the staff and slow transportation rates. The student team designed an attachment device that allows the staff to push the wheelchair and the concentrator as one unit. This universal design allows use of the device with a wide range of wheelchairs and concentrators. A prototype was built and tested at a local medical facility. Staff feedback allowed the student design team to analyze performance and make necessary improvements. The device will decrease staff medical problems while increasing transportation efficiency. Facility cost savings will result due to decreased staff medical bills and labor hours.
Digital Doppler Ultrasound Fetal Heart Rate Monitor (2001-02) Physicians frequently use a portable Doppler ultrasound device for monitoring fetal heart rates. One such device used by a physician in the region is the Imex Pocket Dop II Doppler ultrasound fetal heart rate monitor. The commercial unit provides only a Doppler audio tone of heart activity, played over a small speaker. The physician must correctly position the unit on the mother, count the fetal heart sounds in a given time interval, and manually compute the heart rate. The purpose of this project was to design an electronic add-on feature that converts the fetal heart sounds into average fetal heart rate, which is indicated on a Liquid Crystal Display (LCD). A small battery powered detection unit was designed, packaged and added to the unit, providing an accurate digital reading of fetal heart rate (+/- 1 Beat/Minute). A small red LED was added to blink for each detected fetal heart beat, providing positive heart beat information for a possibly hearing-impaired mother.
Voice-Activated Universal Remote Control (2000-01) Handicapped people often experience difficulty in controlling a television or VCR with the use of standard remote controls. The objective of this project was to develop a fully functional voice-activated universal remote control making it possible for disabled people to control a television or VCR in a hands free environment. The design implemented meets the necessary requirements of being voice-activated, performing basic TV/VCR operations, and operating from a battery-based power supply. The design solution consists of Voice Direct speech recognition technology, a standard microcontroller, and a universal remote control integrated circuit. The Voice Direct kit allows the unit to be voice-activated with greater than 99% accuracy. By using the kit in conjunction with the microcontroller, up to 60 words can be programmed. The microcontroller processes the data from the Voice Direct, and then feeds the universal remote control IC. The universal remote control IC contains all the codes for standard TVs and VCRs. The IC then outputs its signal to an infrared diode, hence controlling the TV or VCR using complete voice activation. The design solution is practical, viable, marketable, and possesses a true potential to enhance the quality of life for those in need. Home entertainment components that respond to voice commands show potential for commercialization, specifically the medical community. For example, independent-living quadriplegics could benefit from such devices. This method of control must have consistent word recognition, compatibility with various home electronics, and a diverse set of commands.

Handicap Access to a 4-Wheeler (2000-01) The use of 4-wheelers has gained significant popularity for chore type activities on farms and ranches and for use in other industries. Individuals with certain types of physical handicaps either have difficulty or are unable to get onto and/or operate 4-wheelers. Students developed a safe and efficient system that allows physically handicapped individuals to get onto and operate 4-wheelers. Emphasis was placed on access and operating system design that accommodates individuals with a wide range of physical disabilities. Affordability was another area of emphasis.
MediLift Patient Lifter (1999-2000) The MediLift project addressed the need in the medical industry to safely assist elderly or limited mobility patients onto an examination table. The task was previously performed manually by nurses and physician’s assistants allowing potential injury to occur to both the patients and the staff. The MediLift was designed by students to elevate patients approximately one foot above the floor to allow safe and easy access onto an examination table. The parameters that were set for this project included a strict budget, mobility of the apparatus and, most importantly, the unit’s capacity to safely lift humans. The MediLift consists of a steel frame with a ball screw, roller guides and an electric motor. The unit includes metal plating for the patient to stand on and removable rails for easy access and stability for the patient while the apparatus is in motion. The MediLift also has a wheel system incorporated into the design so that it may be used in more than one examination room. Anti-skid tape has also been included to further ensure the patient’s safety. The steel design ensures a safe, economical and practical lift.
PC-Controlled Blood Pressure and Temperature Measurement System (1998-99) Blood pressure and body temperature are important physiological parameters which can indicate the state of health. Only sophisticated electronic blood pressure measurement systems provide the convenience of automatic record keeping, which is helpful for accurate health assessment. Thus, there is a need to produce an easy-to-use, low cost blood pressure and body temperature measurement system which facilitates multiple-user record keeping. Components of this system include a blood pressure cuff and an oral temperature probe which interface with a personal computer through its parallel port. Users are able to take measurements and store the results for future analysis, guided by a Windows-based graphical interface software. The convenience of the measurements helps improve the awareness of a user’s general health and can detect various health disorders such as changes in or high blood pressure.