Bivent

Bivent
Bi- ventricular programmable pulse generator

The pacemakers can be programmed with the range of values of the parameters that are detailed in Table 1.
TABLE 1
Pacing Modes DDD, DDI, DOO, VDD, VVI, VVT, VOO, AAI, AAT, AOO, ODO.
For Bi-Vent mode ( On-Off button)
Basic Pacing Rates From 30 to 132 ppm.
Maximum Rates From 60 to 147 ppm.
Post Pacing AV Delays
R ventricle
L ventricle		 From 63 to 281 ms, in steps of 15.625 ms.
From 63 to 281 ms, in steps of 15.625 ms.
Post Sensing AV Delays
R ventricle
L ventricle		 From 53 to 272 ms, in steps of 15.625 ms.
From 53 to 272 ms, in steps of 15.625 ms.
Rates of Change of the Post Sensing AV Delay From 30 to 132 ppm.
Blanking From 21 to 68 ms, in steps of 15.625 ms.
Atrial and right Ventricular Pulse Amp.
Left Ventricular pulse Amplitude		 2.5, 5.0 Volts.
5.0 volts
Atrial and ( R & L )Ventricular Pulse Widths From 0.1to 1.5 ms in steps of 0.1 ms.
Atrial and ‘R’ Ventricular Refractory Periods From 195 to 430 ms, in steps of 15.625 ms.
Refractory Period Post Premature Ventricular Event From 195 to 430 ms, in steps of 15.625 ms, or VA period.
Atrial Sensitivities 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0.
‘R’ Ventricular Sensitivities 1.0, 1.8, 2.6, 3.4, 4.2, 5.0, 5.8, 6.6.
Upper Rate Behavior Off, Wenckebach, 2:1 block.
Polarity Bipolar (output only in dual chamber mode i.e DDD , VDD)
Unipolar (output in dual chamber mode as well as in single chamber
i.e DDD , VDD, AAI, VVI etc…)
Weight 185g(incl. battery)
Atrial Pacing Polarity Unipolar OR Bipolar.
‘R’ & ‘L’ Ventricular Pacing Polarity Unipolar OR Bipolar.
Sensing Polarity Unipolar OR Bipolar.
Hysteresis 0%, 5%, 10%, 15%, 20% (single chamber modes)

Besides the information concerning the programmable parameters, it is also possible to obtain telemetry data about identification, battery status, statistics and marker pulses (see Table 2).

 TABLE 2
IDENTIFICATION Model and serial number.
BATTERY STATUS BOL OK, ERI, EOL.
STATISTICS Number of events (sensed and paced).
Being the pacemaker in the backup mode, number of given stimuli.
Amount of times that interference was detected and number of given stimuli.
MARKER PULSES Paced and sensed events.

 

PHYSICAL CHARACTERISTICS

The BI-VENT pacemakers are made with an hermetically sealed lithium-iodine battery (WG 8950 battery with an initial voltage of 2.8 V and a capacity of 1.58 Ah). Runs for 6.3 years at70 ppm for Atrium – 2.5V, 0.4ms, Right ventricle – 5 v , 0.4 ms & Left ventricle – 5 v, 0.4 ms for the channels 100% pacing.

For better protection of the components from organic fluids, the electronic circuit and the battery are perfectly isolated into an hermetic titanium can.

The BI- VENT size is 51 x 47 x 8,0 mm and its mass is 37 gm.

The connectors are made of stainless steel 316. The leads are fixed using screws that are adjusted with an Allen hex key. This key is included in the pacemaker blister.

FEATURES
In the next section, the features of the CHARAK DDD are described. In table 3, a list of these features is shown.

MAGNETIC RESPONSE Asynchronic mode
At BOL and OK: The period is 665 ms.
At ERI: The period is 705 ms.
AT EOL : The period is 1041 ms
BATTERY CHEMISTRY Lithium-Iodine WG 8950.
Initial voltage: 2.8 V.
Capacity: 1.58 Ah.
END-OF-SERVICE INDICATORS
ELECTIVE (ERI): Battery remaining capacity between 4 and 8% of the total.
When a magnet is applied, the period is incremented in 40 ms.
END OF LIFE (EOL): Battery remaining capacity under 4% of the total.
When a magnet is applied, the period is incremented in 335 ms.
PROTECTIONS When the pacemaker senses events with a rate exceeding 11 Hz:
a) if the programmed mode is DDD, DDI, or VDD, in presence of ventricular interference, it switches to VOO mode; in presence of Atrial interference, it switches to VVI mode.
b) if it is in a single chamber mode, it switches to an asynchronic mode.