CleveMed Blogs

CleveMed will soon be offering two new accessories for the BioRadio — galvanic skin response (GSR) and skin temperature sensors. These accessories further expand the possibilities of the BioRadio for research and educational applications. Ranging from psychology-related fields, in exploring connections between behavior and emotion, to sports medicine fields, in exploring the correlations between exercise and physiological response, these new accessories can provide valuable information for a broad range of applications. (This week, I will be writing about the new GSR sensor, and we’ll discuss the skin temperature sensor next week.)

In ancient China, a suspect would hold rice in the mouth during a prosecutor’s speech. If at the end the suspect could not successfully spit out all the rice, they were considered guilty. It was believed a lack of salivation was attributed to anxiety and therefore guilt. With today’s technology, there is no need for rice! Biomedical sensors can measure skin conductivity from the fingers and/or palms to provide a modern mechanism to measure emotions. The GSR sensor is highly sensitive to emotions in some people and can be used as a polygraph, or lie detector test. GSR has also been used as an index for those who need some measurable parameter of a person’s internal “state”. Physiologically, GSR quantifies sweat gland activity and changes in the sympathetic nervous system. Measured from the palm or fingertips, there are changes in relative conductance of a small electrical current between the electrodes. The activity of sweat glands in response to sympathetic nervous stimulation (increased sympathetic activation) results in an increase in conductance. There is a relationship between sympathetic activity and emotional arousal, although one cannot identify the specific emotion being elicited. Fear, anger, startle response, orienting response and sexual feelings are all among emotions which may produce similar GSR responses. This new accessory offers research labs and schools a new interface to use to provide insightful information about emotional response in a variety of applications.

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

I remember the story of a biomedical engineer I know. As an undergrad, he planned to graduate, leave school and enter the industry. In the last weeks of class, a professor brought in a patient with a high level spinal cord injury. He demonstrated how FES (functional electrical stimulation) could be used to control weak or paralyzed muscles. When he saw this paralyzed patient move his arms, he was hooked. He went on to graduate with a PhD in biomedical engineering with a focus on rehab engineering.

Biomedical Instrumentation 101: students learn circuit design, how to build an amplifier, data acquisition, signal processing, etc. The concepts are taught; but is there enough emphasis on how this information can be used in applications outside of the classroom? Education in these areas of engineering and physiology is important, but how it can be used in real world applications is just as critical.

CleveLabs is a lab course system that uses wireless data acquisition hardware and interactive software to teach engineering, data acquisition, digital signal processing and basic and advanced physiology. In addition to these customary topics, we also include a section of clinical applications: labs that demonstrate to students where they can apply all that they’ve learned. How about using electro-oculography (movement of the eye) to control the position of a dot on the screen, and control the color of the dot just by blinking? This shows how EOG can be used for computer cursor control, where blinking represents a click, for persons with high level spinal cord injuries. Or what about using electromyography (electrical muscle activity) from the biceps and wrist extensor muscles to control the elbow angle and hand grasp of a virtual robotic arm? This explains how the use of existing muscles can control a prosthetic limb. In addition, heart rate detectors are created, gait and stride time are measured, EEG is used to detect different states of alertness. CleveLabs goes beyond the traditional topics using clinical examples of biomedical engineering applications.

Where can real world examples, such as the story of my friend, take your students?

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.