CleveMed Blogs

On New Years Eve 2009, Travis Pastrana found himself sitting in a rally car, mentally preparing to jump 269 feet across a body of water to break the world record for longest rally car jump. His instructions were clear: begin on the Pine Street Pier in Long Beach, California, take off on a ramp, fly approximately 50 feet above the water, and successfully land on a floating barge about 300 feet away. In the event of failure, he had a scuba tank, as well as rescue crews on the water.

CleveMed had the opportunity to use the BioRadio and BioCapture software to collect physiological data, as well as the car’s acceleration relative to free-fall, during Pastrana’s practice runs. Electrocardiogram (ECG) electrodes and a respiratory effort belt were attached to Pastrana, and the BioRadio was set up to measure G-forces in the car and characteristics such as heart rate and breathing rate were derived. The BioRadio monitored Pastrana’s entire jump, and physiological data collected provided fascinating information about the physiological response Pastrana experienced related to performing such a dangerous and adrenaline-filled stunt.

So, here’s the physiology of Travis Pastrana’s 269-foot jump:

As Pastrana sat waiting to accelerate forward his heart rate was elevated at approximately 107 beats per minute (bpm). His breathing patterns were relatively normal at this time, but his respiratory rate was also elevated.

As Pastrana began his approach, heart rate increased to 110 bpm. Additionally, right as he began to accelerate he took a very deep breath. After this initial breath Pastrana’s breathing was very shallow and rapid.

Upon reaching the end of the ramp where the rally car began its flight, Pastrana’s heart rate was 122 bpm. In addition, at the moment the car reached the edge of the ramp, Pastrana held his breath, and continued to hold it the entire time in the air. During this mid-air flight, Pastrana’s heart rate was approximately 130 bpm.

When the rally car landed on the opposite ramp, Pastrana exhaled deeply, and was quickly followed by a deep inhale and gradually slower respiration rates. In addition, when his rally car made impact with the ramp, Pastrana’s heart rate was 138 beats per minute. Once the car began decelerating, his heart rate gradually decreased until reaching the average normal resting heart rate. This physiological data is significant because it provides insight into the body’s reaction to extreme stress.

But other explanations for Pastrana’s physiological response could be attributed to the physical forces he experienced during his rally car’s flight. It was seen that as Pastrana began accelerating, his car was under approximately 1G of force, and at take-off it was as high as 5G’s. You can read about it here, from “The Physiology of a 269-foot Jump” as seen in BioRadio Research & Education Quarterly, Summer 2010. You can also see a screen-shot of Pastrana’s physiological data collected by BioRadio here!

In conclusion, BioRadio provided a clear image of the physiological response of an extreme sportsman. Even though Pastrana has been performing dangerous stunts for over a decade, it is evident that he still experiences stress and probably excitement during his jaw dropping stunts!

Last week, I wrote about the new GSR sensor that will expand BioRadio’s applications, and now it’s time to discuss, yet another new accessory that CleveMed is offering for the BioRadio: the skin temperature sensor.

In 1833 Michael Faraday noticed the resistance of silver sulfide decreased dramatically as temperature increased. This was the first documented observation of a compound that could be used as a thermistor. However, thermistors were difficult to produce and therefore commercial production did not begin until the 1930s with the technology vastly improving since then. The second new accessory integrated into the BioRadio is a skin/surface probe that can detect temperatures in the range of 70°F through 110°F. This probe, which is a thermistor, derives measurements based on a resistor whose resistance varies with changing temperature.

Thermistors can be used in a variety of applications relating to skin temperature measurements. First, it could be used to monitor dangerous physiological reactions, such as heat stroke in applications such as athletics and emergency workers. Next, thermistors could be used in a research setting involving the skin temperature of first responders, such as firefighters. If a new or improved material is developed for safety gear, the thermistor could be used to demonstrate the gear’s efficacy at shielding firefighters from heat. Similarly, thermistors could be used in the military to examine potential safety gear for personnel who are fighting in a war. Thermistors could also be used in sports medicine measurements, such as exploring the body’s ability to thermoregulate while performing a variety of strenuous activities for an extended period of time. Additionally, similar strategic experimental sensor placements could be executed in order to determine if and how certain behaviors, experiences, and actions affect body temperature. Such findings could provide a deeper understanding of mental and physiological processes that could ultimately be used for a variety of therapeutic and pharmacological interventions.

This post is an adaptation from “New GSR & Skin Temp Sensors Expand BioRadio Applications” as seen in BioRadio Research & Education Quarterly, Summer 2010.

CleveMed specializes in the manufacture of wireless, subject-worn physiological monitoring equipment. Within the Division of Research and Education systems, a number of wireless data acquisition devices are offered for a variety of applications.

BioCapture is a research system that uses the BioRadio, a wireless data acquisition device for physiological monitoring. The BioRadio can measure any combination of signals such as ECG, EMG, EEG, EOG, respiration, SpO2 and more. Data is telemetered to a receiver connected to a nearby PC. The information is displayed through the software and data can be exported for analysis in third party applications, such as LabView, Matlab or Excel. The BioCapture system is suitable for a number biomedical research applications.

CleveLabs is a laboratory course system that uses the same data acquisition device as BioCapture, the BioRadio. The software is different, in that it is tailored toward students as a laboratory teaching system focusing on engineering, physiology and clinical applications. Biomedical engineering, physiology, electrical & computer engineering and other departments can benefit from this technology. The system is very flexible and can be used in biomedical engineering labs and classrooms, biomedical research applications, physiology labs and research, and more.

KinetiSense is a wireless data acquisition system that measures three dimensional motion using accelerometers and gyroscopes. Linear acceleration and angular velocity are measured from different portions of the body and data is transmitted to a received connected to a nearby PC. The software displays and stores the data and some analysis features are included. An export utility is also included for easy export for custom analysis applications using programs such as LabView, Matlab or Excel.

CleveMed will be attending and exhibiting at the Gait and Clinical Movement Analysis Society’s (GCMAS) 14th Annual Meeting in Denver, Colorado. The meeting will be taking place March 9-14.

GCMAS is a society that is made up of orthopedic surgeons, neurologists, developmental pediatricians, physiatrists, physical and occupational therapists, kinesiologists, engineers and many others who are interested in human movement. The professional members of GCMAS are all interested in the advancement of scientific knowledge of gait and human movement analysis in both research and clinical settings.

CleveMed will be showcasing KinetiSense, a compact, lightweight, wireless system for measuring motion and electrical muscle activity (EMG). KinetiSense utilizes a small subject worn device that measures three degrees of linear acceleration and three degrees of angular velocity with accelerometers and gyroscopes. The device also has the option of two channels of EMG for a total of eight channels of data. KinetiSense can communicate in real time with a PC via a Bluetooth^™ radio link or data can be stored in memory. The small size and wireless aspect of the device make the system suitable for a number of research applications, including gait measurement, biomechanics, rehabilitation and any other situation in which movement monitoring and analysis is desired.

A second product on display will be BioCapture, a wireless data acquisition and research system. BioCapture uses the BioRadio 150, a wireless 12 channel programmable physiological monitor. The user can measure up to 8 channels of electrical muscle activity (EMG) on the available programmable inputs. Data is then sent in real time to a PC and displayed and stored using the BioCapture software interface. LabVIEW^™ and MATLAB^® drivers allow the user to write customized interfaces around the BioRadio 150 hardware for real-time acquisition or post processing. Data is also saved in standard ASCII file format for easy import into third party packages, making the system appropriate for a number of custom research applications.