Micro-optical force distribution sensing suitable for lump/artery detection.

Surgeons performing robotic-assisted surgical tasks need to establish the density and constituency of hidden tissue structures using only surgical tools. This is possible by integrating a miniaturized sensor into the end-effectors of robotic surgical systems. In this present work, optical microsystems technology is utilized to develop a miniature force-distribution sensor that can be integrated into surgical end-effectors. The sensing principle of the sensor is based on the mechanism of splice coupling. Since the device is fully optical, the sensor is magnetic-resonance compatible and is also electrically passive. The experimental results performed on the developed sensor confirm its ability to measure the distributed force information. Such information is used to detect different tissue structures such as lumps, arteries, or ureters during robotic-assisted surgical tasks.

Cost analysis and cost-effectiveness of NT-proBNP-guided heart failure specialist care in addition to home-based nurse care.

BACKGROUND: Heart failure management programmes have been shown to reduce re-hospitalizations. We recently investigated a new disease management programme comparing usual care (UC) to home-based nurse care (HNC) and a HNC group in which decision-making was based on NT-proBNP levels (BNC). As re-hospitalization is the main contributing economic factor in heart failure expenditures, we hypothesized that this programme might be able to reduce costs and could be conducted cost effectively compared to UC. METHODS: One hundred and ninety congestive heart failure patients, who were included in a randomized trial to receive UC, HNC or BNC at discharge, were analysed in a cost-effectiveness model. Different models were applied to perform analysis of all medical costs, and the costs per year survived were chosen as an effectiveness parameter. RESULTS: Per patient costs because of heart failure treatment in the UC and the BNC group were € 7109 ± 11,687 and € 2991 ± 4885 (P=0·027), respectively. Corrected for death as a competing risk, the costs in the UC group were € 7893 ± 11,734 and were reduced by BNC to €3148 ± 4949 (P=0·012). Considering costs because of all-cause re-hospitalizations, calculated costs per year survived after discharge were € 19,694 ± 26,754 for UC, € 14,262 ± 25 330 for HNC (P > 0·05) and € 8784 ± 14,728 for BNC (t-test-based contrast P=0·015). In all models calculated, HNC was cost neutral. CONCLUSIONS: NT-BNP-guided heart failure specialist care in addition to home-based nurse care is cost effective and cheaper than standard care, whereas HNC is cost neutral.

A major QTL controls susceptibility to spinal curvature in the curveback guppy.

BACKGROUND: Understanding the genetic basis of heritable spinal curvature would benefit medicine and aquaculture. Heritable spinal curvature among otherwise healthy children (i.e. Idiopathic Scoliosis and Scheuermann kyphosis) accounts for more than 80% of all spinal curvatures and imposes a substantial healthcare cost through bracing, hospitalizations, surgery, and chronic back pain. In aquaculture, the prevalence of heritable spinal curvature can reach as high as 80% of a stock, and thus imposes a substantial cost through production losses. The genetic basis of heritable spinal curvature is unknown and so the objective of this work is to identify quantitative trait loci (QTL) affecting heritable spinal curvature in the curveback guppy. Prior work with curveback has demonstrated phenotypic parallels to human idiopathic-type scoliosis, suggesting shared biological pathways for the deformity. RESULTS: A major effect QTL that acts in a recessive manner and accounts for curve susceptibility was detected in an initial mapping cross on LG 14. In a second cross, we confirmed this susceptibility locus and fine mapped it to a 5 cM region that explains 82.6% of the total phenotypic variance. CONCLUSIONS: We identify a major QTL that controls susceptibility to curvature. This locus contains over 100 genes, including MTNR1B, a candidate gene for human idiopathic scoliosis. The identification of genes associated with heritable spinal curvature in the curveback guppy has the potential to elucidate the biological basis of spinal curvature among humans and economically important teleosts.

Assessment of sleep health in collegiate athletes using the Athlete Sleep Screening Questionnaire.

STUDY OBJECTIVES: The objective of this study was to characterize sleep health in a large, diverse population of college athletes. The study utilized the Athletic Sleep Screening Questionnaire, a clinically validated questionnaire, designed to screen athletes for a clinically significant degree of poor sleep health, and to determine if they require intervention. METHODS: College athletes from 4 different National College Athletic Association institutions were surveyed using the Athletic Sleep Screening Questionnaire. Descriptive information including sex, sport, and college year was also collected. The Athletic Sleep Screening Questionnaire was scored according to prior clinically validated methods to determine a sleep difficulty score, clinical sleep problem category (none, mild, moderate, or severe), and need for assessment by a physician due to poor sleep health. RESULTS: A total of 1055 surveys were collected with a 95% response rate. Respondents were 36% female, 64% male, and included athletes competing in 15 different sports. Approximately 25% of participants were found to have a clinically meaningful problem with their sleep. Athletes entering their second or higher year of college were more likely to report worse sleep compared to those entering their first year (one-way analysis of variance, Kruskall-Wallis P < .001). CONCLUSIONS: A substantial portion of college athletes experience poor sleep health and would benefit from interventions aimed at improving sleep. The Athletic Sleep Screening Questionnaire appears to be a cost- and time-efficient way to evaluate sleep health in a large athletic population.

Levosimendan and prostaglandin E1 for uptitration of beta-blockade in patients with refractory, advanced chronic heart failure.

BACKGROUND: In advanced chronic heart failure (CHF) 20% of patients do not tolerate beta-blockers and 50% do not reach target doses. AIM: To test whether levosimendan or prostaglandin E1 (PGE1) can facilitate uptitration of beta-blockers in advanced CHF. METHODS AND RESULTS: Seventy-five advanced CHF patients (LVEF<35%, NYHA class IIIb or IV) intolerant to beta-blocker uptitration to target doses (10 mg bisoprolol/day) were randomised to a monthly 24 h infusion with levosimendan (n=39) or a chronic infusion with PGE1 (n=36) for 3 months. Bisoprolol was uptitrated following predefined criteria. At 12 weeks, bisoprolol dose increased from 4 mg to 10 mg in both groups. Heart failure worsening occurred in 29 levosimendan patients (74%) versus 16 PGE1 patients (44%, p=0.008). Uptitration was impossible in 9 levosimendan patients (23%) versus 2 PGE1 patients (6%, p=0.03). The combined endpoint of death or urgent heart transplantation or implantation of a ventricular assist device was reached by 12 levosimendan patients (31%) versus 4 PGE1 patients (11%, p=0.04). After 1 year, LVEF increased from 23+/-7% to 28+/-11% (p=0.0004), and BNP decreased from 994+/-806 to 659+/-564 pg/ml (p=0.03). CONCLUSION: Levosimendan and PGE1 facilitate uptitration of beta-blockers in previously intolerant CHF patients. PGE1 treatment allowed uptitration in more patients and resulted in a better clinical outcome compared to levosimendan. This approach increased LVEF and decreased BNP after 1 year.

Hybrid piezoresistive-optical tactile sensor for simultaneous measurement of tissue stiffness and detection of tissue discontinuity in robot-assisted minimally invasive surgery.

To compensate for the lack of touch during minimally invasive and robotic surgeries, tactile sensors are integrated with surgical instruments. Surgical tools with tactile sensors have been used mainly for distinguishing among different tissues and detecting malignant tissues or tumors. Studies have revealed that malignant tissue is most likely stiffer than normal. This would lead to the formation of a sharp discontinuity in tissue mechanical properties. A hybrid piezoresistive-optical-fiber sensor is proposed. This sensor is investigated for its capabilities in tissue distinction and detection of a sharp discontinuity. The dynamic interaction of the sensor and tissue is studied using finite element method. The tissue is modeled as a two-term Mooney­Rivlin hyperelastic material. For experimental verification, the sensor was microfabricated and tested under the same conditions as of the simulations. The simulation and experimental results are in a fair agreement. The sensor exhibits an acceptable linearity, repeatability, and sensitivity in characterizing the stiffness of different tissue phantoms. Also, it is capable of locating the position of a sharp discontinuity in the tissue. Due to the simplicity of its sensing principle, the proposed hybrid sensor could also be used for industrial applications.

Innovative optical microsystem for static and dynamic tissue diagnosis in minimally invasive surgical operations.

During conventional surgical tasks, surgeons use their tactile perception in their finger tips to sense the degree of softness of biological tissues to identify tissue types and to feel for any abnormalities. However, in robotic-assisted surgical systems, surgeons are unable to sense this information because only surgical tools interact with tissues. In order to provide surgeons with such useful tactile perception, therefore, a tactile sensor is required that is capable of simultaneously measuring contact force and resulting tissue deformation. Accordingly, this paper discusses the design, prototyping, testing, and validation of an innovative tactile sensor that is capable of measuring the degree of softness of soft objects such as tissues under both static and dynamic loading conditions and which is also magnetic resonance compatible and electrically passive. These unique characteristics of the proposed sensor would also make it a practical choice for use in robotic-assisted surgical platforms. The prototype version of this sensor was developed by using optical micro-systems technology and, thus far, experimental test results performed on the prototyped sensor have validated its ability to measure the relative softness of artificial tissues.

A piezoresistive tactile sensor for tissue characterization during catheter-based cardiac surgery.

BACKGROUND: Currently, most of mitral valve annuloplasty surgeries are performed by using open heart surgery. However, if such operation would be performed by using minimally invasive surgery via catheter-based techniques (CBT), it offers various advantages for both surgeons and patients. METHODS: Two piezoresistive force sensors are used in the structure of the tactile sensor, which can easily be miniaturized and integrated into surgical catheters. The tactile sensor was fabricated and tested to characterize different elastomers, as the phantom of cardiac tissues. Based on a developed finite element analysis (FEA) of the elastomers, the interaction between the sensor and those materials were modelled to validate the output of the sensor. RESULTS: The results of the mechanical and psychophysical tests confirm the capability of the proposed sensor to measure the relative hardness/softness of different soft tissues. CONCLUSIONS: The proposed tactile sensor will help surgeons to characterize different types of cardiac tissues and would facilitate the use of CBT to perform mitral valve annuloplasty.

N-terminal pro-B-type natriuretic peptide-guided, intensive patient management in addition to multidisciplinary care in chronic heart failure a 3-arm, prospective, randomized pilot study.

OBJECTIVES: This study was designed to investigate whether the addition of N-terminal pro-B-type natriuretic peptide-guided, intensive patient management (BM) to multidisciplinary care (MC) improves outcome in patients following hospitalization due to heart failure (HF). BACKGROUND: Patients hospitalized due to HF experience frequent rehospitalizations and high mortality. METHODS: Patients hospitalized due to HF were randomized to BM, MC, or usual care (UC). Multidisciplinary care included 2 consultations from an HF specialist who provided therapeutic recommendations and home care by a specialized HF nurse. In addition, BM included intensified up-titration of medication by HF specialists in high-risk patients. NT-proBNP was used to define the level of risk and to monitor wall stress. This monitoring allowed for anticipation of cardiac decompensation and adjustment of medication in advance. RESULTS: A total of 278 patients were randomized in 8 Viennese hospitals. After 12 months, the BM group had the highest proportion of antineurohormonal triple-therapy (difference among all groups). Accordingly, BM reduced days of HF hospitalization (488 days) compared with the hospitalization for the MC (1,254 days) and UC (1,588 days) groups (p < 0.0001; significant differences among all groups). Using Kaplan-Meier analysis, the first HF rehospitalization (28%) was lower in the BM versus MC groups (40%; p = 0.06) and the MC versus UC groups (61%; p = 0.01). Moreover, the combined end point of death or HF rehospitalization was lower in the BM (37%) than in the MC group (50%; p < 0.05) and in the MC than in the UC group (65%; p = 0.04). Death rate was similar between the BM (22%) and MC groups (22%), but was lower compared with the UC group (39%; vs. BM: p < 0.02; vs. MC: p < 0.02). CONCLUSIONS: Compared with MC alone, additional BM improves clinical outcome in patients after HF hospitalization. (BNP Guided Care in Addition to Multidisciplinary Care; NCT00355017).