scholarly journals Stiffness Modelling and Performance Evaluation of a Soft Cardiac Fixator Flexible Arm with Granular Jamming

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 303
Author(s):  
Likun Gao ◽  
Yanlin He ◽  
Hangwei Zhu ◽  
Guangkai Sun ◽  
Lianqing Zhu
Keyword(s):  
Artery Bypass ◽  
Variable Stiffness ◽  
Off Pump ◽  
Flexible Arm ◽  
Input Pressure ◽  
And Performance ◽  
Pump Coronary Artery Bypass ◽  
External Forces ◽  
Application Requirements ◽  
Soft Manipulator

To meet the practical application requirements of cardiac fixation during off-pump coronary artery bypass surgery, a soft cardiac fixator with a flexible arm was previously designed. To enable the soft cardiac fixator to adapt to uncertain external forces, this study evaluates the variable-stiffness performance of the flexible arm. First, the flexible arm was simplified as a soft silicone manipulator measuring 60 mm × 90 mm × 120 mm, which can actuate, soften, or stiffen independently along the length of the arm by combining granular jamming with input pressure. Then, the soft manipulator was modelled as a cantilever beam to analyse its variable-stiffness performance with granular jamming. Next, based on theoretical analysis and calculations, many experiments were conducted to evaluate the variable-stiffness performance of the soft manipulator. The experimental results demonstrated that the variable-stiffness performance is influenced by the flexible arm length, the size of the granules, and the input pressure.

Initial Report of Off-Pump Coronary Artery Bypass Surgery as Sole Therapy for Moderate Ischemic Mitral Regurgitation: Operative and Intermediate-Term Outcome

2005 ◽  
Vol 8 (2) ◽  
pp. 89 ◽  
Author(s):  
Kevin M. Harris ◽  
Avinash Reddy ◽  
Dorothee Aepplii ◽  
Betsy Wilson ◽  
Robert W. Emery
Keyword(s):  
Coronary Artery ◽  
Mortality Rate ◽  
Mitral Regurgitation ◽  
Coronary Artery Bypass Surgery ◽  
Bypass Surgery ◽  
Artery Bypass ◽  
Mortality Rates ◽  
Off Pump ◽  
Moderate Ischemic Mitral Regurgitation ◽  
Pump Coronary Artery Bypass

Background: Patients undergoing on-pump coronary artery bypass surgery (CAB) with coexistent moderate ischemic mitral regurgitation (IMR) have a significant mortality rate compared to patients without MR. The mortality rate is elevated both perioperatively (0%-12% mortality), as well as over a 1- and 2-year postoperative period (15%-25%). It is thought that some patients are best served by off-pump CAB (OPCAB); however, outcomes have not been reported for such patients with coexistent moderate IMR. Methods: We reviewed the independent database of patients undergoing OPCAB between 1995 and 2002 to find 989 patients, 17 (1.7%) of whom had moderate or moderately severe MR. Patients were contacted and clinical and echocardiographic data were obtained. Results: The patient group consisted of 11 men and 6 women (age, 65 15 years). The study group had a PA pressure of 52 14, creatinine of 1.6 0.7, and left ventricular ejection fraction of 43 18. Nine patients (53%) had advanced New York Heart Association (class III-IV) heart failure. Mortality rates perioperatively and at 1, 2, and 3 years were 0%, 6.25% (1/16), 12.5% (2/16), and 38% (4/8), respectively. At the time of this report, no patient had returned for a reparative procedure. Conclusion: In patients felt to be best served by OPCAB with ischemic MR, operative and intermediate mortality rates are remarkably similar to those previously reported for on-pump series. These data underscore the continued need to understand which patients undergoing CAB require mitral valve problems to be addressed at the time of surgery.

Routine Preoperative Insertion of IABP in High-Risk Off-Pump Coronary Artery Bypass Grafting

2005 ◽  
Vol 8 (2) ◽  
pp. 94 ◽  
Author(s):  
Hunaid A. Vohra ◽  
Norman P. Briffa
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Bypass Grafting ◽  
High Risk ◽  
Coronary Artery Bypass ◽  
Artery Bypass ◽  
Bypass Grafting ◽  
Artery Bypass Grafting ◽  
Off Pump ◽  
Beneficial Effects ◽  
Pump Coronary Artery Bypass

The beneficial effects of intraaortic balloon pump (IABP) in coronary artery bypass graft surgery with cardiopulmonary bypass have been reported. However, whether preoperative insertion of IABP in high-risk off-pump coronary artery bypass grafting (OPCAB) has any beneficial effects remains to be established. We report our experience of preoperative insertion of IABP in OPCAB.

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