MagScrew TAH: An Update

Weber, Stephan; Kamohara, Keiji; Klatte, Ryan; Luangphakdy, Viviane; Flick, Christine R.; Chen, Ji Feng; Casas, Fernando; Ootaki, Yoshio; Kopcak, Michael W.; Akiyama, Mitoshi; Hirschman, Gordon B.; Chapman, P. A.; Donahue, Arthur; Wetterau, William F.; Prisco, C. J.; Mast, R T; Sherman, Craig; Fukamachi, Kiyotaka; Smith, William A.

doi:10.1097/01.mat.0000187395.29817.36

Cited by 11 publications

(14 citation statements)

References 10 publications

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“…Improving upon this predecessor, the current system, the MagScrew TAH, has been under development in collaboration with Foster-Miller Technologies (Albany, NY, USA), Wilson Greatbatch (Clarence, NY, USA), and Whalen Biomedical (Somerville, MA, USA) since 2000. The system features of both pumps have been demonstrated in several reports (3,(7)(8)(9)(10)(11).…”

Section: Device Descriptionsmentioning

confidence: 91%

“…Therefore, left fill of greater than 90% leads to an increase in the beat rate, while fill of less than 90% causes a decrease in the beat rate. This setting produces preload-sensitive pump outputs according to a Frank-Starling response and has the advantages to minimize the LAP and to protect pulmonary function (7,10). A 15% SVL of the right pump relative to the left pump also functions to balance the RAP and LAP by compensating for both left side shunt flow and the difference of pump performance between the pulmonary and systemic circulations (8).…”

Section: Device Descriptionsmentioning

confidence: 98%

“…As a result, each blood pump has distinctive stroke volumes (CC-N-TAH, 60 mL; MagScrew TAH, 45 mL) and maximum beat rates (CC-N-TAH, 160 bpm; MagScrew TAH, 220 bpm), producing slightly different hemodynamic responses to various preloads. The major characteristics of the control mode technology in both the CC-N-TAH and MagScrew TAH are similar in the following aspects: (i) a passive filling pusher-plate pump; (ii) preload sensitivity resembling a Frank-Starling response; (iii) afterload insensitivity; (iv) a 15% stroke volume limit (SVL) of the right pump to balance the right atrial pressure (RAP) and the left atrial pressure (LAP); and (v) cross-linked gelatin coating on the blood-contacting surface and the use of bioprosthetic valves for excellent blood compatibility without a requirement for anticoagulation (3,(7)(8)(9)(10)(11).…”

Section: Device Descriptionsmentioning

confidence: 99%

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Hemodynamic and Metabolic Changes During Exercise in Calves With Total Artificial Hearts of Different Sizes yet Similar Output

Kamohara¹,

Weber²,

Klatte³

et al. 2007

Artificial Organs

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To evaluate the effects of downsizing of the total artificial heart (TAH), we compared the anaerobic threshold (AT) values in calves with two different types of TAH (Cleveland Clinic-Nimbus TAH and the downsized MagScrew TAH). Exercise studies were performed using a treadmill in 12 calves. During the exercise, parameters to obtain the AT were measured. To evaluate the determinants of the AT, a linear regression analysis was performed between AT and potential variables. AT values from 29 studies revealed no significant differences between the two different TAHs, with no significant differences in hemodynamic or oxygen metabolic parameters. AT values correlated well with pump flow/body weight (Q) multiplied by the hemoglobin level, regardless of the TAH used. In conclusion, downsizing of the original TAH design did not reduce AT without any significant differences in hemodynamic or oxygen metabolic parameters during exercise in calves.

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Section: Device Descriptionsmentioning

confidence: 91%

Section: Device Descriptionsmentioning

confidence: 98%

Section: Device Descriptionsmentioning

confidence: 99%

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Hemodynamic and Metabolic Changes During Exercise in Calves With Total Artificial Hearts of Different Sizes yet Similar Output

Kamohara¹,

Weber²,

Klatte³

et al. 2007

Artificial Organs

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“…The implantable battery enables tether free operation for up to 90 min at nominal conditions of flow 5-6 L/min, 100 mm Hg aortic pressure (AOP), and 20 mm Hg pulmonary arterial pressure (PAP). More details of the system are provided elsewhere (1)(2)(3)(4). The MagScrew TAH system includes two battery systems: (i) the IBP and (ii) the EBP.…”

Section: System Descriptionmentioning

confidence: 99%

Cycle Testing of the MagScrew Total Artificial Heart External Battery Pack

et al. 2007

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MagScrew total artificial heart (TAH) external battery pack (EBP) cycle bench testing was conducted on two Wilson Greatbatch (Clarence, NY, USA) lithium ion EBPs over a period of 22 months during continuous charge and discharge cycles under a simulated TAH system current requirement. A custom electronic load was developed to simulate the MagScrew current waveforms typically observed during nominal operation. These current load profiles were applied to the EBP under test during a voltage-defined discharge cycle. EBP endurance indicated a 240-min discharge cycle on a new battery diminishing linearly to 175 min after 800 cycles. A second linear trend started at this knee with 150 min of discharge time at 850 cycles until 10 min at 1600 cycles. Even at 1300 cycles, the EBP could still provide enough power for 60 min of nominal operation. In conclusion, the endurance performance of this EBP was satisfactory while exhibiting a predictable wear-out trend.

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“…To any of these drives, sensory feedback is an essential part of drive control. Commonly used sensor systems for the application in a TAH base upon eddy current sensors [4] or Hall sensors [5]. In pulsatile TAHs with hydraulic drives, pressure sensors give feedback for the drive control [6], [7].…”

Section: Introductionmentioning

confidence: 99%