Doppler blood flow detector for haemorrhoidal artery ligation

Haemorrhoidal artery ligation (HAL) is a novel noninvasive surgical treatment for haemorrhoids. The procedure entails precise identification of the superior rectal arteries supplying haemorrhoids using a Doppler transducer mounted on a proctoscope and a Doppler signal processor. To perform HAL the surgeon at Kasih Ibu General Hospital used medical device called Ultrasonic Blood Flow Detector KM-25 series from HADECO Co., Ltd. The problem is that the performance of the device has significantly degraded due to wear. The arterial sound produced by the device is also inherently indistinct when operated in operating room. The offered solution was to develop own receiver and proctoscope according the partner´s requirement. A prototype of the detector has been successfully developed and fully functional in the hospital. It consists of two major parts, i.e. proctoscope and the main unit. The proctoscope is a product of AMI GmbH, Austria. The prototype of the main unit consists of a receiver, a power amplifier, and a loudspeaker. Using specially designed 75 W RMS power amplifier, the average sound pressure level produced is 60 dBA in a spot within 1.5 meter from the loudspeaker. Within 6 month of evaluation period, it has been used to perform surgery on 27 patients mostly with grade III-IV haemorrhoids.