Bioelectronic interfaces require electrodes that are mechanically flexible and chemically inert. Flexibility allows pristine electrode contact to skin and tissue, and chemical inertness prevents ...electrodes from reacting with biological fluids and living tissues. Therefore, flexible gold electrodes are ideal for bioimpedance and biopotential measurements such as bioimpedance tomography, electrocardiography (ECG), electroencephalography (EEG), and electromyography (EMG). However, a manufacturing process to fabricate gold electrode arrays on plastic substrates is still elusive. In this work, a fabrication and low‐temperature sintering (≈200 °C) technique is demonstrated to fabricate gold electrodes. At low‐temperature sintering conditions, lines of different widths demonstrate different sintering speeds. Therefore, the sintering condition is targeted toward the widest feature in the design layout. Manufactured electrodes show minimum feature size of 62 μm and conductivity values of 5 × 10 6 S m−1. Utilizing the versatility of printing and plastic electronic processes, electrode arrays consisting of 31 electrodes with electrode‐to‐electrode spacing ranging from 2 to 7 mm are fabricated and used for impedance mapping of conformal surfaces at 15 kHz. Overall, the fabrication process of an inkjet‐printed gold electrode array that is electrically reproducible, mechanically robust, and promising for bioimpedance and biopotential measurements is demonstrated.
Fabrication of inkjet‐printed flexible gold electrode arrays on plastic substrates is described, with a special focus on laser‐cut freestanding electrodes, low‐temperature sintering, and the methodology used for impedance mapping on conformal surfaces. Taking advantage of low‐cost and large‐area manufacturing techniques, these electrically reproducible and mechanically robust electrode arrays are promising for novel wearable biomedical sensing.
When pressure is applied to a localized area of the body for an extended time, the resulting loss of blood flow and subsequent reperfusion to the tissue causes cell death and a pressure ulcer ...develops. Preventing pressure ulcers is challenging because the combination of pressure and time that results in tissue damage varies widely between patients, and the underlying damage is often severe by the time a surface wound becomes visible. Currently, no method exists to detect early tissue damage and enable intervention. Here we demonstrate a flexible, electronic device that non-invasively maps pressure-induced tissue damage, even when such damage cannot be visually observed. Using impedance spectroscopy across flexible electrode arrays in vivo on a rat model, we find that impedance is robustly correlated with tissue health across multiple animals and wound types. Our results demonstrate the feasibility of an automated, non-invasive 'smart bandage' for early detection of pressure ulcers.
On page 1004, A. C. Arias and co‐workers demonstrate inkjet‐printed gold electrode arrays on plastic substrates—with a special focus on laser‐cut freestanding electrodes—that exhibit excellent ...mechanical compliance. Taking advantage of the low‐cost and large‐area manufacturing techniques, these mechanically flexible and chemically inert electrode arrays are promising for novel wearable medical sensing applications.
Impedance sensing device for monitoring ulcer healing in human patients Liao, Amy; Lin, Monica C.; Ritz, Lauren C. ...
2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC),
01/2015, Letnik:
2015
Conference Proceeding, Journal Article
Chronic skin wounds affect millions of people each year and take billions of dollars to treat. Ulcers are a type of chronic skin wound that can be especially painful for patients and are tricky to ...treat because current monitoring solutions are subjective. We have developed an impedance sensing tool to objectively monitor the progression of healing in ulcers, and have begun a clinical trial to evaluate the safety and feasibility of our device to map damaged regions of skin. Impedance data has been collected on five patients with ulcers, and impedance was found to correlate with tissue health. A damage threshold was applied to effectively identify certain regions of skin as "damaged tissue".
Using time-driven activity-based costing (TDABC), we examined resource allocation and costs for HIV services throughout Tanzania at patient and facility levels. This national, cross-sectional ...analysis of 22 health facilities quantified costs and resources associated with 886 patients receiving care for five HIV services: antiretroviral therapy, prevention of mother-to-child transmission, HIV testing and counseling, voluntary medical male circumcision, and pre-exposure prophylaxis. We also documented total provider-patient interaction time, the cost of services with and without inclusion of consumables, and conducted fixed-effects multivariable regression analyses to examine patient- and facility-level correlates of costs and provider-patient time. Findings showed that resources and costs for HIV care varied significantly throughout Tanzania, including as a function of patient- and facility-level characteristics. While some variation may be preferable (e.g., needier patients received more resources), other areas suggested a lack of equity (e.g., wealthier patients received more provider time) and presented opportunities to optimize care delivery protocols.
Mosaicism is increasingly recognized as a cause of developmental disorders with the advent of next-generation sequencing (NGS). Mosaic mutations of
have been associated with the widest spectrum of ...phenotypes associated with overgrowth and vascular malformations. We performed targeted NGS using 2 independent deep-coverage methods that utilize molecular inversion probes and amplicon sequencing in a cohort of 241 samples from 181 individuals with brain and/or body overgrowth. We identified
mutations in 60 individuals. Several other individuals (
= 12) were identified separately to have mutations in
by clinical targeted-panel testing (
= 6), whole-exome sequencing (
= 5), or Sanger sequencing (
= 1). Based on the clinical and molecular features, this cohort segregated into three distinct groups: (a) severe focal overgrowth due to low-level but highly activating (hotspot) mutations, (b) predominantly brain overgrowth and less severe somatic overgrowth due to less-activating mutations, and (c) intermediate phenotypes (capillary malformations with overgrowth) with intermediately activating mutations. Sixteen of 29
mutations were novel. We also identified constitutional
mutations in 10 patients. Our molecular data, combined with review of the literature, show that
-related overgrowth disorders comprise a discontinuous spectrum of disorders that correlate with the severity and distribution of mutations.
PDF
