Abstract: A method of determining desynchronization between a first implantable medical device and a second implantable medical device. The method includes receiving a synchronization query from the first device at the second device, that is transmitted in response to the first device detecting a predetermined transition of a first clock of the first device, the first clock having a first pulse rate. The method further includes determining a number of pulses of a second clock of the second device occurring between reception of the synchronization query and a predetermined transition of a third clock of the second device, the third clock having the first pulse rate. The second clock has a second pulse rate higher than the first pulse rate. The method further includes determining the desynchronization between the first device and the second device based on the determined number of pulses of the second clock.

Abstract: Systems, methods, and devices for activating an implantable medical device from a low-power sleep state are provided. One method includes receiving a wake-up signal at a receiver device from a transmitter device. The wake-up signal includes a series of pulses having a pulse pattern encoding a predetermined wake-up code. The wake-up signal is transmitted via intracorporeal communication of electrical pulses conducted by interstitial tissues of a patient's body. The method further includes extracting the wake-up code from the wake-up signal and determining whether the wake-up code corresponds to a stored wake-up value. The method further includes, in response to determining that the predetermined wake-up code corresponds to the stored wake-up value, switching at least one active circuit element of the receiver device from a lower-power sleep state into a higher-power operational state.

Abstract: A method of determining desynchronization between a first implantable medical device and a second implantable medical device. The method includes receiving a synchronization query from the first device at the second device, that is transmitted in response to the first device detecting a predetermined transition of a first clock of the first device, the first clock having a first pulse rate. The method further includes determining a number of pulses of a second clock of the second device occurring between reception of the synchronization query and a predetermined transition of a third clock of the second device, the third clock having the first pulse rate. The second clock has a second pulse rate higher than the first pulse rate. The method further includes determining the desynchronization between the first device and the second device based on the determined number of pulses of the second clock.

Abstract: A method for quantification of the desynchronization between the clocks of two medical devices communicating wirelessly, for example, by HBC signals. The devices are separately clocked by slow clocks (CLK1/32k, CLK2/32k) and include selectively activated fast clocks (CLK1/10M, CLK2/10M). The method comprises: a) on a predetermined transition (T1) of a slow clock, transmission by one device of a synchronization query signal (SYNC) to the other device, b) counting of the pulses of the activated fast clock to detect a predetermined transition (T3) of the first slow clock, then c) transmitting from the other device to the first device a response signal (D1) and d) upon reception of the response signal, computing a temporal shift (OFFSET) according to the result (D1, D2) of the counting of the pulses of the fast clock. Two fast clocks, one on each device, also can be used.

Abstract: Systems, methods, and devices for activating an implantable medical device from a low-power sleep state are provided. One method includes receiving a wake-up signal at a receiver device from a transmitter device. The wake-up signal includes a series of pulses having a pulse pattern encoding a predetermined wake-up code. The wake-up signal is transmitted via intracorporeal communication of electrical pulses conducted by interstitial tissues of a patient's body. The method further includes extracting the wake-up code from the wake-up signal and determining whether the wake-up code corresponds to a stored wake-up value. The method further includes, in response to determining that the predetermined wake-up code corresponds to the stored wake-up value, switching at least one active circuit element of the receiver device from a lower-power sleep state into a higher-power operational state.

Abstract: An autonomous active medical implantable device, with a power supply and a wake-up circuit that responds to receipt of specific pulses transmitted through the interstitial tissues of the body. A transmitter device (40) generates trains of modulated pulses applied to electrodes (22, 24), and a receiver (50) processes (e.g., filter, amplify and demodulate) pulses collected on electrodes (22?, 24?). The receiver circuits (50) are selectively activated from a dormant (sleep) state in which they are not powered by a power source (34), to an operational (active) state in which they are powered and able to process (e.g., filter, amplify and demodulate) the collected pulses. A specific wake-up pulse train, configured in a predetermined characteristic pulse pattern, triggers passive wake-up circuits (66) in the receiver (50) to switch the receiver circuits from the sleep state to the operational state.

Abstract: An active implantable medical device having wireless communication of data via electrical pulses conducted by the interstitial tissues of the body. This device (12, 14) includes a pair of electrodes (22, 24) and generates pulse trains consisting of a series of electrical pulses applied to the electrodes. The pulse train is modulated by digital information (data) that is produced by the device. A regulated current or voltage source (42) is used to generate (44, 48) current or voltage pulses to form the pulse train. Each current or voltage pulse is a biphasic pulse comprising a positive and negative alternation. The biphasic current or voltage modulated by the digital information, is injected between the electrodes (22, 24) and wirelessly communicated.

Abstract: A method for quantification of the desynchronization between the clocks of two medical devices communicating wirelessly, for example, by HBC signals. The devices are separately clocked by slow clocks (CLK1/32k, CLK2/32k) and include selectively activated fast clocks (CLK1/10M, CLK2/10M). The method comprises: a) on a predetermined transition (T1) of a slow clock, transmission by one device of a synchronization query signal (SYNC) to the other device, b) counting of the pulses of the activated fast clock to detect a predetermined transition (T3) of the first slow clock, then c) transmitting from the other device to the first device a response signal (D1) and d) upon reception of the response signal, computing a temporal shift (OFFSET) according to the result (D1, D2) of the counting of the pulses of the fast clock. Two fast clocks, one on each device, also can be used.

Abstract: An autonomous active medical implantable device, with a power supply and a wake-up circuit that responds to receipt of specific pulses transmitted through the interstitial tissues of the body transmitter device (40) generates trains of modulated pulses applied to electrodes (22, 24), and a receiver (50) processes (e.g., filter, amplify and demodulate) pulses collected on electrodes (22?, 24?). The receiver circuits (50) are selectively activated from a dormant (sleep) state in which they are not powered by a power source (34), to an operational (active) state in which they are powered and able to process (e.g., filter, amplify and demodulate) the collected pulses specific wake-up pulse train, configured in a predetermined characteristic pulse pattern triggers passive wake-up circuits (66) in the receiver (50) to switch the receiver circuits from the sleep state to the operational state.