Emily Haltiwanger

Wireless photoplethysmographic device for heart rate variability signal acquisition and analysis

The photoplethysmographic (PPG) signal has the potential to aid in the acquisition and analysis of heart rate variability (HRV) signal: a non-invasive quantitative marker of the autonomic nervous system that could be used to assess cardiac health and other physiologic conditions. A low-power wireless PPG device was custom-developed to monitor, acquire and analyze the arterial pulse in the finger. The system consisted of an optical sensor to detect arterial pulse as variations in reflected light intensity, signal conditioning circuitry to process the reflected light signal, a microcontroller to control PPG signal acquisition, digitization and wireless transmission, a receiver to collect the transmitted digital data and convert them back to their analog representations. A personal computer was used to further process the captured PPG signals and display them. A MATLAB program was then developed to capture the PPG data, detect the RR peaks, perform spectral analysis of the PPG data, and extract the HRV signal. A user-friendly graphical user interface (GUI) was developed in LabView to display the PPG data and their spectra. The performance of each module (sensing unit, signal conditioning, wireless transmission/reception units, and graphical user interface) was assessed individually and the device was then tested as a whole. Consequently, PPG data were obtained from five healthy individuals to test the utility of the wireless system. The device was able to reliably acquire the PPG signals from the volunteers. To validate the accuracy of the MATLAB codes, RR peak information from each subject was fed into Kubios software as a text file. Kubios was able to generate a report sheet with the time domain and frequency domain parameters of the acquired data. These features were then compared against those calculated by MATLAB. The preliminary results demonstrate that the prototype wireless device could be used to perform HRV signal acquisition and analysis.

A Web-based vital sign telemonitor and recorder for telemedicine applications

We describe a vital sign telemonitor (VST) that acquires, records, displays, and provides readings such as: electrocardiograms (ECGs), temperature (T), and oxygen saturation (SaO/sub 2/) over the Internet to any site. The design of this system consisted of three parts: sensors, analog signal processing circuits, and a user-friendly graphical user interface (GUI). The first part involved selection of appropriate sensors. For ECG, disposable Ag/AgCl electrodes; for temperature, LM35 precision temperature sensor; and for SaO/sub 2/ the Nonin Oximetry Development Kit equipped with a finger clip were selected. The second part consisted of processing the analog signals obtained from these sensors. This was achieved by implementing suitable amplifiers and filters for the vital signs. The final part focused on development of a GUI to display the vital signs in the LabVIEW environment. From these measurements, important values such as heart rate (HR), beat-to-beat (RR) intervals, SaO/sub 2/ percentages, and T in both degrees Celsius and Fahrenheit were calculated The GUI could be accessed through the Internet in a Web-page facilitating the possibility of real-time patient telemonitoring. The final system was completed and tested on volunteers with satisfactory results.

A Culturally Sensitive Diabetes Peer Support for Older Mexican-Americans

The purpose of this study was to determine if a peer-led diabetes support group intervention could improve adherence to recommendations for self-management in 42 Mexican-American elders with type 2 diabetes. This mixed-method pilot study occurred at a community-based diabetes education centre in Texas. The 10-week intervention programme was compared to usual care on five self-reported questionnaires and blood tests during four collection periods. Participants displayed statistically significant improvements in blood sugar, self-efficacy, transformational change and personal resources. Qualitative themes were derived from 30 focus group meetings, which were as follows: do not trust the system, choice + control = power and the social cost of diabetes. The results suggested a consultation role for occupational therapists in training peer leaders to learn to lead and manage community-based diabetes self-management programmes. Limitations were the sample size of the convenience sample, and the lack of qualitative analysis of the control group discussions. Future research should involve a study of expanded community-based social networks using experimental design.

A PDA-based flexible telecommunication system for telemedicine applications

Technology has been used to deliver health care at a distance for many years. Telemedicine is a rapidly growing area and recently there are studies devoted to prehospital care of patients in emergency cases. In this work we have developed a compact, reliable, and low cost PDA-based telecommunication device for telemedicine applications to transmit audio, still images, and vital signs from a remote site to a fixed station such as a clinic or a hospital in real time. This was achieved based on a client-server architecture. A Pocket PC, a miniature camera, and a hands-free microphone were used at the client site and a desktop computer running the Windows XP operating system was used as a server. The server was located at a fixed station. The system was implemented on TCP/IP and HTTP protocol. Field tests have shown that the system can reliably transmit still images, audio, and sample vital signs from a simulated remote site to a fixed station either via a wired or wireless network in real time. The Pocket PC was used at the client site because of its compact size, low cost and processing capabilities.

Application of nonlinear dynamics theory to neuro-occupation: A case study of alcoholism

Nonlinear dynamics systems theory, also referred to as chaos theory, is infiltrating the biomedical and social sciences, including the practice of occupational therapy. Consequently, the Neuro-occupation model has emerged for the treatment of different illnesses, in which a therapist strives to apply the benefits of this theory. This model provides occupational therapists with a method of anticipating the natural flux between underlying or hidden order and chaos in occupations, which allows individuals to function at their highest level. These occupations typically involve the interaction of numerous variables over time. By considering a nonlinear dynamics approach in illnesses such as alcoholism, occupational therapists may understand how meaningful occupations serve as a catalyst to facilitate change, which may assist in better understanding the effect of the therapeutic relationship with the clients they serve. This paper explains the nonlinear dynamics of the interventions in a single case study on alcoholism using the Neuro-occupation model.

Reduction of depressive symptoms in an elderly Mexican-American female with type 2 diabetes mellitus: a single-subject study.

The purpose of this study was to determine if occupation-based activities improve diabetes self-management and reduce depressive symptoms in an elderly Mexican-American woman with type 2 diabetes mellitus (T2DM). There have been no known studies showing occupational therapys role in self-care management of T2DM in people with depressive symptoms. The individual in this single-subject research was evaluated using glycosylated haemoglobin blood tests, four self-reported standardized questionnaires, participant reflective logs and clinical observations following an 8-week intervention. The participant improved on all measures, which were sustained 1 month after treatment ended. Clinical implications highlight a new role for occupational therapists providing early intervention in people with diabetes and depression for secondary prevention of complications of uncontrolled diabetes. Research suggestions include multiple single-subject studies showing occupational therapy contributions.

Experience of Mexican-American Elders with Diabetes: A Phenomenological Study

ABSTRACT  The purpose of this study was to gain insight about the lived experience of Mexican-American elders and the psychosocial issues that can impede or facilitate making the necessary lifestyle changes to adhere to a diabetes self-care regimen. As a phenomenological study, focus group discussions of male and female Mexican-Americans, ages 60–85, were conducted to capture their perspectives. Four themes emerged from the discussions which included (1) our social discomfort gets in the way of taking care of ourselves, (2) commonalities that bond us support us, (3) we do not have clear goals, and (4) we have lost control of our lives. Discussion how the experience of adapting to the demands of diabetes is ever changing and Mexican-American elders with diabetes may benefit at any stage of the adaptation process from supportive relationships that target psychosocial adjustment. Implications for occupational therapy practice, education, and research are discussed.

A user-friendly integrated software environment for heart rate variability analysis of sleep disordered breathing

We present an integrated software environment that enables sleep specialists to analyze, quantity and diagnose sleep disordered breathing based upon time-domain, frequency-domain, and nonlinear dynamics measurement measures of heart rate variability (HRV) signal. The integrated graphical user interface (GUT) and the signal processing algorithms were developed and implemented in MATLAB, This environment provides the facility to import or read sleep data (ECG, EEG, blood pressure, respiratory, oxygen saturation, etc.) under user control and displays them individually or collectively in a data window for visual inspection. It then enables the user to clip the length of data to be used in carrying out the analysis. Raw ECG data is preprocessed for reliable QRS detection and the HRV signal is derived following the guidelines of the Task Force of the European Society of Cardiology and the North American Society for Pacing and Electrophysiology, which is then displayed along with respiration signal in the analysis window. After this step time-domain, frequency- domain, and nonlinear dynamics analyses of the HRV signal are performed to extract sensitive measures used in detecting and diagnosing sleep disordered breathing. The computer analysis can then generate a complete report for the specialist and further statistical and/or automatic analyses. The system was developed and validated using data from the MIT-BIH Polysomnographic Database. After validation and reliability testing it was used to analyze sleep data for detection of sleep disordered breathing (SDB) in children. Data from normal and children diagnosed with SDB showed that the system could potentially distinguish between normal children and children suffering from sleep disordered breathing.

Life After Driving: A Community-Dwelling Senior's Experience

ABSTRACT Driving cessation may lead to sedentary lifestyles and isolation for seniors who are unprepared for the transition. This pilot study about cessation of driving used a case study design to explore the choices and adaptations of a 73-year-old nondriving senior, who lived alone. Interviews, a journal, and observations generated four themes: (a) when driving is no longer an option; (b) the value of others; (c) still active at home and in the community; and (d) difficulties with alternative transportation. The participant experienced inconveniences of driving cessation, but few negative consequences. She appeared to have a strong locus of control and felt fully responsible for her decision of not driving. She took responsibility for managing alternative transportation, had realistic expectations of the obstacles she might encounter with a plan in place for transitioning to nondriving, and the perception that her life had become less stressful and richer through her meaningful relationships with others.

Living with Cancer: Impact of Expressive Arts

This single case study explored the impact of participation in an expressive arts support group on a Caucasian female with lymphoma. The creative art process, a peer support group, and a five point data collection method were deployed. Four major themes emerged reflecting the impact of participation in the support group reshaping the occupational identity of the patient. This study combined the benefits of traditional support groups and expressive art activities, and demonstrated the holistic ability of occupational therapy to support a female cancer patient to reestablish her occupational identity as a catalyst to recovery.