Non-Invasive Wearable Patch Utilizing Seismocardiography for Peri-Operative Use in Surgical Patients.

OBJECTIVE: Optimizing peri-operative fluid management has been shown to improve patient outcomes and the use of stroke volume (SV) measurement has become an accepted tool to guide fluid therapy. The Transesophageal Doppler (TED) is a validated, minimally invasive device that allows clinical assessment of SV. Unfortunately, the use of the TED is restricted to the intra-operative setting in anesthetized patients and requires constant supervision and periodic adjustment for accurate signal quality. However, post-operative fluid management is also vital for improved outcomes. Currently, there is no device regularly used in clinics that can track patient's SV continuously and non-invasively both during and after surgery. METHODS: In this paper, we propose the use of a wearable patch mounted on the mid-sternum, which captures the seismocardiogram (SCG) and electrocardiogram (ECG) signals continuously to predict SV in patients undergoing major surgery. In a study of 12 patients, hemodynamic data was recorded simultaneously using the TED and wearable patch. Signal processing and regression techniques were used to derive SV from the signals (SCG and ECG) captured by the wearable patch and compare it to values obtained by the TED. RESULTS: The results showed that the combination of SCG and ECG contains substantial information regarding SV, resulting in a correlation and median absolute error between the predicted and reference SV values of 0.81 and 7.56 mL, respectively. SIGNIFICANCE: This work shows promise for the proposed wearable-based methodology to be used as an alternative to TED for continuous patient monitoring and guiding peri-operative fluid management.

Thromboresistance of Polyurethanes Modified with PEO-Silane Amphiphiles.

Surface-induced thrombosis is problematic in blood-contacting devices composed of silicones or polyurethanes (PUs). Poly(ethylene oxide)-silane amphiphiles (PEO-SA) are previously shown effective as surface modifying additives (SMAs) in silicones for enhanced thromboresistance. This study investigates PEO-SAs as SMAs in a PU at various concentrations: 5, 10, 25, 50, and 100 µmol g-1 PU. PEO-SA modified PUs are evaluated for their mechanical properties, water-driven surface restructuring, and adhesion resistance against a human fibrinogen (HF) solution as well as whole human blood. Stability is assessed by monitoring hydrophilicity, water uptake, and mass loss following air- or aqueous-conditioning. PEO-SA modified PUs do not demonstrate plasticization, as evidenced by minimal changes in glass transition temperature, modulus, tensile strength, and percent strain at break. These also show a concentration-dependent increase in hydrophilicity that is sustained following air- and aqueous-conditioning for concentrations ≥25 µmol g-1 . Additionally, water uptake and mass loss are minimal at all concentrations. Although protein resistance is not enhanced versus an HF solution, PEO-SA modified PUs have significantly reduced protein adsorption and platelet adhesion from human blood at concentrations ≥10 µmol g-1 . Overall, this study demonstrates the versatility of PEO-SAs as SMAs in PU, which leads to enhanced and sustained hydrophilicity as well as thromboresistance.

Thromboresistance of Silicones Modified with PEO-Silane Amphiphiles.

The antifouling properties of poly(ethylene oxide) (PEO)-silane amphiphiles as surface-modifying additives (SMAs) in a condensation cure silicone have been previously demonstrated against simple protein solutions. Comprising an oligo(dimethylsiloxane) tether (m = 13 or 30) and PEO segment (n = 8), sustained protein resistance was achieved even in the absence of a cross-linkable triethoxysilane group, particularly when comprising the longer tether. To probe their potential for thromboresistance, PEO-silane amphiphile SMAs were used to bulk-modify silicones and evaluated for adhesion resistance against whole human blood under both static and dynamic conditions. Both a cross-linkable (XL diblock, m = 13) and a non-cross-linkable (Diblock, m = 30) SMA were evaluated at various concentrations (5-50 µmol SMA/g silicone) in a condensation cure silicone. Under static conditions, silicones modified with either SMA at concentrations of 10 µmol/g or greater were effective in reducing adhesion of human fibrinogen and platelets. Dynamic testing further showed that modified silicones were able to reduce protein adsorption and thrombus formation. This occurred at 5 and 10 µmol/g for silicones modified with XL diblock, m = 13 and Diblock, m = 30 SMAs, respectively. Combined, these results indicate the effectiveness of PEO-silane amphiphiles as SMAs in silicone for improved thromboresistance.

Borderline personality features and integration of positive and negative thoughts about significant others.

Taking the bad with the good is a necessity of life, and people who readily integrate thoughts of their loved one's flaws with thoughts of their more positive attributes maintain more stable, satisfying relationships. Borderline personality disorder, however, is often characterized by interpersonal perceptions that fluctuate between extremes of good and bad. We used a timed judgment task to examine information processing about significant others in individuals high in borderline personality features relative to healthy individuals and those high in avoidant personality features. In Study 1, when judging traits of a liked significant other, same-valence facilitation by negative primes (judging negative traits faster than positive traits after a negative prime) was significantly stronger in the borderline features group than the other two groups, and was inversely associated with self-reports of integrated thoughts about significant others. In contrast, same-valence facilitation by positive primes (judging positive traits faster than negative traits after a positive prime) was significantly stronger in the avoidant features group than the other two groups, and inversely associated with self-esteem. No between-group differences in same-valence facilitation were statistically significant when participants judged traits of disliked significant others, liked foods, and disliked foods. In Study 2, same-valence facilitation by negative primes when judging traits of a liked significant other was significantly associated with less integrated positive/negative thoughts about that person in a 12-day diary. These results identify an implicit information-processing pattern relevant to interpersonal difficulties in borderline personality disorder. (PsycINFO Database Record

Effect of growth hormone replacement therapy on the quality of life in women with growth hormone deficiency who have a history of acromegaly versus other disorders.

OBJECTIVE: To compare the response in quality of life (QoL) to growth hormone (GH) replacement in women with GH deficiency (GHD) and a history of acromegaly with that in women with GHD of other causes. METHODS: Fifty-five women with GHD were studied: 17 with prior acromegaly and 38 with other causes of GHD. We compared two 6-month, randomized, placebo-controlled studies of GH therapy in women with hypopituitarism conducted with use of the same design-one in women with a history of acromegaly and one in women with no prior acromegaly. QoL was assessed with the following questionnaires: the QoL-Assessment of Growth Hormone Deficiency in Adults (AGHDA), the Symptom Questionnaire, and the 36-Item Short-Form Health Survey (SF-36). RESULTS: The 2 groups had comparable mean pretreatment age, body mass index, and QoL scores and comparable mean GH dose at 6 months (0.61 ± 0.30 versus 0.67 ± 0.27 mg daily). After 6 months of GH replacement therapy, women with GHD and prior acromegaly demonstrated a greater improvement in AGHDA score, four SF-36 sub-scales (Role Limitations due to Physical Health, Energy or Fatigue, Emotional Well-Being, and Social Functioning), and the Somatic Symptoms subscale of the Symptom Questionnaire than did women with GHD of other causes. Poorer pretreatment QoL was associated with a greater improvement in QoL after administration of GH. CONCLUSION: In this study, GH replacement therapy improved QoL in women with GHD and a history of acromegaly but not in women with GHD due to other hypothalamic and pituitary disorders. Further studies are needed to determine the long-term risks versus benefits of GH replacement in patients who develop GHD after definitive treatment for acromegaly.