Implanted Medical RF Transceiver Chip - ZL 70101 - Zarlink

Based on its MICS technology platform, Zarlink Semiconductor build the ZL 70101 RF transceiver chip for use in monitoring base stations and implanted medical devices. This ultra low-power transceiver open more opportunity to create in-body communication systems to support advanced medical monitoring, diagnostic and therapeutic applications.

Zarlink ZL 70101 RF Transceiver Chip (Non Implanted Package)

The system is very flexible and supports several low power wakeup options. Extremely low power is achievable using the 2.45 GHz ISM Band Wakeup-receiver option. The high level of integration includes a Media Access Controller, providing complete control of the device along with coding and decoding of RF messages. A standard SPI interface provides for easy access by the application.

Zarlink MICS technology enable to create applications that store patient health data in the implanted medical device's memory, for further automatically transmitted wirelessly to a base station. The base station can then forward this patient data over the telephone or Internet to a physician’s office.

Zarlink ZL 70101 RF Transceiver Block Diagram

Key features of ZL 70101 RF transceiver chip:

• 402-405 MHz (10 MICS channels) and 433-434 MHz (2 ISM channels)
• MAC with error handling and flow control, typ < 1.5x10^-10BER.
• High data rate (800/400/200 kbps raw data rate)
• Extremely low power consumption (5 mA, continuous TX / RX, 1 mA low power mode) Ultra low power wakeup circuit (250 nA) Standards compatible (MICS, FCC, IEC)
• Very few external components (3 pcs + antenna matching)
• Standards compatible (MICS, FCC, IEC)

Typical Applications of ZL 70101 RF transceiver chip:

• Implantable Devices e.g.,  ICD’s, Neurostimulators, Pacemakers, Implantable Insulin Pumps, implantable physiological monitors and Bladder Control Devices
• Body area network, short range device applications using the 433 MHz ISM band.

Ultra low-power RF technology is also enabling a range of new diagnostics and therapies, including implanted devices used to monitor and treat diabetes, neurostimulators that alleviate chronic pain or lessen the debilitating effects of Parkinson's disease and dystonia, and gastric stimulators that may offer a viable alternative in the treatment of obesity.

The ZL70101 RF transceiver has defined two fundamental startup modes of operation:

• IMD Mode (IMD=Implantable Medical Device)
• Base Mode

When configured as an IMD, the transceiver is usually asleep and in a very low current state. The IMD may be woken up to initiate communications by using a 2.45 GHz link or directly by the IMD processor via the WU_EN pin. This flexibility leads to the following options for waking up an IMD transceiver for communication.

• IMD transceiver woken up by specially coded 2.45 GHz wakeup message using an ultra low power sniffing method
• IMD transceiver woken up to sniff 400 MHz link. The ZL70101 supports such a mode of operation although the 2.45 GHz wakeup system has lower power consumption
• IMD transceiver woken to send an emergency message in which case no clear channel assessment by the Basestation is required
• IMD transceiver woken up by a low frequency inductive link (as typically used in pacemakers/ICDs) or some alternative mechanism

In the IMD Mode,  ZL70101 RF transceiver incorporates a unique wake-up receiver that allows the integrated circuit to operate in an extremely low current 250 nA  sleep mode. This feature is essential, it helps to conserve battery life of the implanted device. Communication between implanted device and base station is initiated using a specially coded wake-up signal from the base station transmitter. The implanted medical device can also wake up the ZL70101 radio on detection of an emergency medical event. An emergency signal could then be sent to the base station, which in turn could directly alert paramedics. In full operation the ZL70101 RF transceiver typically consumes 5 mA of current.

ZL70101 includes a MAC that implements a high-reliability communication protocol which is compliant to current MICS standards. The MAC protocol includes Reed-Solomon forward error correction together with CRC error detection and retransmission.

The ZL70101 transceiver chip is available as implantable-grade wire-bondable die or in a 48-pin QFN package for the non-implanted or base station applications. The chip is fully supported by a reference system and application development kit. Full ZL70101 product information, including complete data sheet, design manual and pricing, is available for qualified customers.

Source: Zarlink  ZL 70101 Implanted Medical Transceiver Chip