Development of a wearable pneumatic total artificial heart system aimed at permanent use

研制了一种具有紧凑型可穿戴式气动驱动装置的可穿戴式气动全人工心脏（PTAH）系统。PTAH系统由左右隔膜式血泵和两个WPD单元组成。设计了两个适合解剖结构的血泵，它们的外壳由聚氨酯树脂制成。左右泵尺寸分别为95 × 68 × 49 mm和104 × 74 × 44 mm。左、右泵冲程体积分别为85、94毫升。WPD装置由无刷直流电动机、曲轴、气缸活塞、非圆齿轮和空气压力调节阀组成。驱动气压由气缸-活塞产生。非圆齿轮产生固定的收缩率。WPD装置的尺寸为20 × 8.5 × 20厘米，重量为1.8公斤。通过溢流式模拟循环试验，验证了PTAH系统的性能。采用左血泵，泵输出大于8l /min。在105bpm的泵速下，平均电力消耗约为20 W。在急性动物实验中对PTAH系统的基本性能进行了评价。左右泵被植入一头体重98公斤的小牛体内。两台固定收缩率为35%和44%的WPD装置分别用2m的空气软管与左、右血泵相连。心脏输出量为3.9 ~ 5.4 L/min，平均主动脉压为108 ~ 115 mmHg，泵速为60 ~ 100 bpm。每台WPD机组的平均耗电量根据发热率变化在5.3 ~ 17.6 W之间，效率估计在2% ~ 9%之间。

A wearable pneumatic total artificial heart (PTAH) system with compact wearable pneumatic drive (WPD) unit was developed. The PTAH system consists of left and right diaphragm-type blood pumps and two WPD units. Two blood pumps were designed to fit anatomy, and these had housing made of polyurethane resin. The sizes of the left and right pumps are 95 x 68 x 49 mm and 104 x 74 x 44 mm. The stroke volumes of the left and right pump are 85 and 94 ml, respectively. The WPD unit consists of a brushless DC motor, a crankshaft, a cylinder-piston, non-circular gears, and air pressure regulation valves. Driving air pressure is generated by the cylinder-piston. The non-circular gears generate the fixed systolic ratio. The size and weight of the WPD unit are 20 x 8.5 x 20 cm and 1.8 kg, respectively.The performance of the PTAH system was confirmed using an overflow-type mock circulation test. The pump output of more than 8 L/min using the left blood pump was achieved. The mean electric power consumption was approximately 20 W at 105bpm of pump rate.The fundamental performance of the PTAH system was evaluated in acute animal experiment. The left and right pumps were implanted in a calf weighing 98 kg. Two WPD units with fixed systolic ratio of 35 and 44% were connected to the left and right blood pumps with 2 m air hoses, respectively. The cardiac output ranged from 3.9 to 5.4 L/min at mean aorta pressures from 108 to 115 mmHg at pump rates from 60 to 100 bpm. The average electric power consumption in each WPD unit varied from 5.3 to 17.6 W according to the beating rate, and the efficiency was estimated from 2 to 9%.