Implantable medical device bus system and method

Abstract

A bus system is provided for implantable medical devices. The bus system provides for flexible and reliable communication between subsystems in an implantable medical device. The bus system facilitates a wide variety of communications between various subsystems. These various subsystems can include one or more sensing devices, processors, data storage devices, patient alert devices, power management devices, signal processing and other devices implemented to perform a variety of different functions.

1 . An implantable medical device bus system, comprising: 
 a streaming bus, the streaming bus includes a plurality of streaming data conductors, a data clock conductor, and a configuration clock conductor;    a plurality of bus interface circuits coupled to the streaming bus, each of the plurality of bus interface circuits coupled to a subsystem in an implantable medical device;    a streaming bus controller coupled to the streaming bus, the streaming bus controller multiplexes the streaming bus into a plurality of time slots per frame for transmitting streaming data on the streaming data conductors, the streaming bus controller selectively sending configuration clock signals on the configuration clock conductor with configuration data on the streaming data conductors between the streaming data on the streaming data conductors, the configuration data assigning time slots in the plurality of time slots to one or more of the subsystems in the implantable medical device.    
   
   
       2 . The implantable medical device bus system of  claim 1  wherein the configuration data assigns time slots in the plurality of time slots without disrupting the streaming data on the streaming data conductors.  
   
   
       3 . The implantable medical device bus system  claim 1  wherein the streaming bus controller sends a streaming bus data clock signal in each time slot to indicate the streaming data.  
   
   
       4 . The implantable medical device bus system  claim 1  wherein the streaming data comprises sensor data from a sensor on the implantable medical device.  
   
   
       5 . The implantable medical device bus system of  claim 1  wherein the streaming bus controller selectively sends an external streaming bus data clock to bus interface circuits in the plurality of bus interface circuits on an external integrated circuit, the external streaming bus data clock signaling only time slots assigned on the external integrated circuit.  
   
   
       6 . The implantable medical device bus system  1  wherein the implantable medical device comprises an implantable cardiac device, and wherein the streaming data comprises sensor data selected from the group of electrical data, ECG data, accelerometer data and pressure data.  
   
   
       7 . The implantable medical device bus system  1  wherein the bus interface circuits receive and recognize streaming data on the streaming data conductors based on time slot location in the plurality of time slots per frame.  
   
   
       8 . The implantable medical device bus system  1  wherein each of the plurality of bus interface circuits can be selectively assigned more than one time slot per frame to provide an increased data transmission rate.  
   
   
       9 . The implantable medical device bus system  1  wherein each of the plurality of bus interface circuits can be selectively configured to skip frames to provide a reduced data transmission rate.  
   
   
       10 . The implantable medical device bus system  1  wherein the streaming bus provides a precise bus latency by assigning a repeating at least one time slot in the plurality of timeslot to a subsystem in the implantable medical device.  
   
   
       11 . An implantable medical device bus system, comprising: 
 a message bus, the message bus including a plurality of message data conductors and a message data clock conductor;    a plurality of bus interface circuits coupled to the message bus, each of the plurality of bus interface circuits coupled to subsystem in an implantable medical device;    request line conductors, the request line conductors coupling the bus interface circuits into a series;    a message bus controller coupled to the message bus and the request line conductors, the message bus system arbitrating messages on the message bus by according to order of the series of transmitting bus interface circuits.    
   
   
       12 . The implantable medical device bus system of  claim 11  wherein the message data includes a header and a message body, the header sent from an initiating one of the plurality of bus interface circuits, and wherein a responding one of the plurality of bus interface circuits waits until an acknowledgement is received from at least one other of the plurality of bus interface circuits before sending the message body.  
   
   
       13 . The implantable medical device bus system  claim 12  wherein the initiating one of the plurality of bus interface circuits is the same as the responding one of the plurality of bus interface circuits in a write operation.  
   
   
       14 . The implantable medical device bus system  claim 12  wherein the initiating one of the plurality of bus interface circuits is different from the responding one of the plurality of bus interface circuits in a read operation.  
   
   
       15 . The implantable medical device bus system  claim 11  wherein the bus system further includes priority line conductors, the priority line conductors coupling to the bus interface circuits, and wherein the bus interface circuits can request precedence for transmitting on the priority line conductors.  
   
   
       16 . The implantable medical device bus system  claim 15  wherein priority line conductors includes an external priority line for requesting precedence for transmitting to subsystems on an external integrated circuit and an internal priority line for requesting precedence for transmitting only to subsystems within an integrated circuit.  
   
   
       17 . An implantable medical device bus system, comprising: 
 a streaming bus, the streaming bus including a plurality of streaming data conductors;    a plurality of streaming bus interface circuits coupled to the streaming bus, each of the plurality of streaming bus interface circuits coupled to a subsystem in an implantable medical device, the streaming bus interface circuits transmitting streaming data on the streaming bus in assigned time slots;    a message bus, the message bus including a plurality of message data conductors;    a plurality of message bus interface circuits coupled to the message bus, each of the plurality of message bus interface circuits coupled to subsystem in an implantable medical device, the message bus interface circuits sending message data on the message bus;    an event bus, the event bus including a plurality of event data conductors; and    a plurality of event bus interface circuits coupled to the message bus, each of the plurality of event bus interface circuits coupled to subsystem in an implantable medical device, the event bus interface circuits sending event data on the event bus, the event data having a limited data length.    
   
   
       18 . The implantable medical device bus system of  claim 17  further comprising a streaming bus controller coupled to the streaming bus, the streaming bus controller multiplexing the streaming bus into a plurality of time slots per frame for transmitting streaming data on the streaming data conductors, the streaming bus controller selectively sending configuration clock signals on a configuration clock conductor with configuration data on streaming data conductors between the streaming data on the streaming data conductors, the configuration data assigning time slots in the plurality of time slots to one or more of the subsystems in the implantable medical device.  
   
   
       19 . The implantable medical device bus system of  claim 17  further comprising a message bus request line conductors, the message bus request line conductors coupling the message bus interface circuits into a series, and further comprising a message bus controller coupled to the message bus and the request line controllers, the message bus system arbitrating messages on the message bus by according to order of the series of transmitting message bus interface circuits.  
   
   
       20 . The implantable medical device bus system of  claim 17  further comprising an event bus request line conductors, the event bus request line conductors coupling the event bus interface circuits into a series, and further comprising a event bus controller coupled to the event bus and the request line controllers, the event bus system arbitrating messages on the message bus by according to order of the series of transmitting event bus interface circuits.  
   
   
       21 . The implantable medical device bus system of  claim 17  wherein the assigned time slots in the streaming bus repeat by frame, and wherein the frame coincides with an event bus clock.  
   
   
       22 . The implantable medical device bus system of  claim 17  wherein the plurality of event bus interface circuits each include a data buffer, the data buffer large enough to store an entire event data.