skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Wireless Pressure Sensing Smart Stent for Enhanced Post-Endovascular Aneurysm Repair (EVAR) Surveillance
Continuous post-endovascular aneurysm repair (EVAR) surveillance is critical for patients who have undergone a stenting procedure. Despite its life-saving importance, studies have reported that patients gradually discontinue post-EVAR surveillance due to the significant burden associated with CT scans, X-rays, etc. Considering the importance and necessity of post-EVAR surveillance, we introduce a self-resonating flexible tube implanted in a standard clinically approved stent that enables wireless sensing of blood pressure inside an aneurysm through inductive coupling. To enable blood pressure monitoring outside the body, we designed and fabricated a spiral-type antenna, specifically crafted to capture the inherent resonance frequency of the self-resonating stent tube. To showcase the wireless pressure monitoring capability, a 3D-printed elastic model of an abdominal aortic aneurysm (AAA) was prepared. Our quantitative study validated the pressure-sensing capability with adequate sensitivity (up to 687.5 Hz/mmHg) when tissue was located between the stent and the external antenna. The wireless sensing also presents a consistent linear shift in resonance frequency across all tested measuring distances as the applied pressure ranges from 60 to 140 mmHg. The proposed self-resonating stent offers promising insights for improving post-EVAR surveillance.  more » « less
Award ID(s):
2326938 2306330
PAR ID:
10570911
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
IEEE
Date Published:
Journal Name:
IEEE Access
Volume:
12
ISSN:
2169-3536
Page Range / eLocation ID:
198123 to 198131
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Diagnosing hypertension or hemodialysis requires patients to carry a blood pressure (BP) monitoring device for 24 hours. Th erefore, wearing the wrist/arm-based BP monitoring device, in this case, has a signifi cant impact on users' daily activities. To address the problem, we developed eBP, an ear-worn device that measures blood pressure from inside the ear. Th rough the evaluation of 35 subjects, eBP can achieve the average error of 1.8 mmHg for systolic BP and -3.1 mmHg for diastolic BP with the standard deviation error of 7.2 mmHg and 7.9 mmHg, respectively. 
    more » « less
  2. The ability to monitor blood gases, namely oxy-gen and carbon dioxide, in real-time is of critical importance to clinicians in diagnosing and treating respiratory disorders. Transcutaneous monitors measure the partial pressure of carbon dioxide diffused from the skin. These monitors are noninvasive and capable of continuously monitoring carbon dioxide. Conventional transcutaneous carbon dioxide monitors require a heating element and large calibration equipment for reliable measurements. We propose a miniaturized transcutaneous carbon dioxide monitor based on a luminescence sensing film and dual lifetime referencing technique to assess the partial pressure of carbon dioxide within the 0-75 mmHg range, covering the clinically relevant range for healthy humans, 35-45 mmHg. We measured the partial pressure of carbon dioxide with less than ~1.6% error in the given range without any post-processing and heating. 
    more » « less
  3. Abstract BackgroundMillions of catheters for invasive arterial pressure monitoring are placed annually in intensive care units, emergency rooms, and operating rooms to guide medical treatment decision-making. Accurate assessment of arterial blood pressure requires an IV pole-attached pressure transducer placed at the same height as a reference point on the patient’s body, typically, the heart. Every time a patient moves, or the bed is adjusted, a nurse or physician must adjust the height of the pressure transducer. There are no alarms to indicate a discrepancy between the patient and transducer height, leading to inaccurate blood pressure measurements. MethodsWe present a low-power wireless wearable tracking device that uses inaudible acoustic signals emitted from a speaker array to automatically compute height changes and correct the mean arterial blood pressure. Performance of this device was tested in 26 patients with arterial lines in place. ResultsOur system calculates the mean arterial pressure with a bias of 0.19, inter-class correlation coefficients of 0.959 and a median difference of 1.6 mmHg when compared to clinical invasive arterial measurements. ConclusionsGiven the increased workload demands on nurses and physicians, our proof-of concept technology may improve accuracy of pressure measurements and reduce the task burden for medical staff by automating a task that previously required manual manipulation and close patient surveillance. 
    more » « less
  4. Frequent blood pressure monitoring is the key to diagnosis and treatments of many severe diseases. However, the conventional ambulatory methods require patients to carry a blood pressure (BP) monitoring device for 24 h and conduct the measurement every 10--15 min. Despite their extensive usage, wearing the wrist/arm-based BP monitoring device for a long time has a significant impact on users' daily activities. To address the problem, we developed eBP to measure blood pressure (BP) from inside user's ear aiming to minimize the measurement's impact on users' normal activities although maximizing its comfort level. The key novelty of eBP includes (1) a light-based inflatable pulse sensor which goes inside the ear, (2) a digital air pump with a fine controller, and (3) BP estimation algorithms that eliminate the need of blocking the blood flow inside the ear. Through the comparative study of 35 subjects, eBP can achieve the average error of 1.8 mmHg for systolic (high-pressure value) and -3.1 mmHg for diastolic (low-pressure value) with the standard deviation error of 7.2 mmHg and 7.9 mmHg, respectively. These results satisfy the FDA's AAMI standard, which requires a mean error of less than 5 mmHg and a standard deviation of less than 8 mmHg. 
    more » « less
  5. Background: Hypertension is a major risk factor for cardiovascular disease and requires long-term health treatment and ongoing monitoring to the extent that traditional management approaches may be limited in providing. Adopting appropriate digital tools like mobile health technology (mHealth) could be an effective strategy for improving the control and management of this public health burden. This pilot studyevaluated the feasibility of the AHOMKA care model at two tertiary hospitals in Ghana. Outcome measures were changes in systolic (SBP) and diastolic (DBP) blood pressure model acceptance by patients and health care providers.Objective: This study sought to assess the overall pattern of home blood pressure self-monitoring among participants from two teaching hospitals in southern Ghana, using mHealth.Methods: Participants attending two (2) cardiology clinics were recruited for this mixed-method pilot study over a period of eight (8) weeks. Following a longitudinal single-group approach, we conducted structured interviews at the baseline and end-line and used exports of the AHOMKA mHealth application, in-depth interviews and focus group discussions with patients and healthcare providers. Repeated measuresanalysis of variance was adopted to assess differences in SBP and DBP between baseline and end line.Results: This pilot study involved 27 participants with a mean of 50.4 ± 11.0 years-approximately 1:1 male-female participation. Mean SBP decreased by 11.6 mm Hg (95% CI = 15.0 to -8.2), from an average of 138.6 mmHg at baseline to 126.2 mmHg at endline. Average DBP was also significantly reduced by 3.0 mmHg (95% CI = -5.5 to -0.5), from an average of 87.0 mmHg at baseline to 83.0 mmHg at endline. Patients and healthcare providers were satisfied and optimistic about the AHOMKA care model.Conclusion: The encouraging trend in BP outcomes and high response rate from this pilot study provides evidence for further investigation involving the assessment of the effectiveness of the AHOMKA care model while culturally adapting the model to the Ghanaian context. In the spectrum of hypertension interventions, AHOMKA has the potential to ease the burden on the public health system 
    more » « less