A subcutaneous implantable cardioverter-defibrillator (S-ICD) comprising shocking electrodes configured to reduce the defibrillation threshold. The S-ICD may include a canister housing a source of electrical energy, a capacitor, and operational circuitry that senses heart rhythms and an electrode and lead assembly. The electrode and lead assembly may comprise a lead, at least one sensing electrode, and at least one shocking electrode. The at least one shocking electrode may extend over a length in the range of 50 to 110 millimeters and a width in the range of 1 to 40 millimeters.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) comprising shocking electrodes configured to reduce the defibrillation threshold. The S-ICD may include a canister housing a source of electrical energy, a capacitor, and operational circuitry that senses heart rhythms and an electrode and lead assembly. The electrode and lead assembly may comprise a lead, at least one sensing electrode, and at least one shocking electrode. The at least one shocking electrode may extend over a length in the range of 50 to 110 millimeters and a width in the range of 1 to 40 millimeters.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) comprising shocking electrodes configured to reduce the defibrillation threshold. The S-ICD may include a canister housing a source of electrical energy, a capacitor, and operational circuitry that senses heart rhythms and an electrode and lead assembly. The electrode and lead assembly may comprise a lead, at least one sensing electrode, and at least one shocking electrode. The at least one shocking electrode may extend over a length in the range of 50 to 110 millimeters and a width in the range of 1 to 40 millimeters.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) comprising shocking electrodes configured to reduce the defibrillation threshold. The S-ICD may include a canister housing a source of electrical energy, a capacitor, and operational circuitry that senses heart rhythms and an electrode and lead assembly. The electrode and lead assembly may comprise a lead, at least one sensing electrode, and at least one shocking electrode. The at least one shocking electrode may extend over a length in the range of 50 to 110 millimeters and a width in the range of 1 to 40 millimeters.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) is configured to induce a tachyarrhythmia by charging a high voltage capacitor to a voltage amplitude and delivering a series of pulses to a patient's heart by discharging the capacitor via an extra-cardiovascular electrode vector. Delivering the series of pulses includes recharging the high-voltage capacitor during an inter-pulse interval between consecutive pulses of the series of pulses.

An implantable medical device (IMD) includes a heterogeneous housing configured to receive and store one or more components of the IMD. The housing includes an intrinsically non-conductive and non-magnetic base material and at least one dopant with a property of at least one of electrical conductance and magnetic permeability. The base material and the dopant form a first region of the housing including a first skin depth and a second region of the housing including a second skin depth different than the first skin depth.

Systems and methods are provided for comparing a first number A.sup.bit with a second number B.sup.bit. A method includes receiving, from a first computing device associated with the first number A.sup.bit, a share a.sub.1.sup.bit and a share b.sub.1.sup.bit; receiving, from a second computing device associated with the second number B.sup.bit, a share a.sub.2.sup.bit and a share b.sub.2.sup.bit, wherein the first number A.sup.bit=a.sub.1.sup.bit+a.sub.2.sup.bit mod 2.sup.64 and wherein the second number B.sup.bit=b.sub.1.sup.bit+b.sub.2.sup.bit mod 2.sup.64. The first number A.sup.bit=a.sub.1.sup.bit XOR a.sub.2.sup.bit and the second number B.sup.bit=b.sub.1.sup.bit XOR b.sub.2.sup.bit. The XOR operation includes an XOR function that applies addition modulo 2 to corresponding pairs of bits of two strings. The method includes comparing, via a comparison function that compares numbers as modulo 2.sup.64, the first number A.sup.bit and the second number B.sup.bit to generate a shared output bit indicating which number is larger.

In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

A battle simulation system includes a limb immobilization device. The limb immobilization device is operative for immobilizing a limb of a user in response to receipt of the control signal indicating a hit to the limb of the user. The limb immobilization device may at least partially immobilize the limb. The immobilization may be voluntary or involuntary.

A battle simulation system includes a limb immobilization device. The limb immobilization device is operative for immobilizing a limb of a user in response to receipt of the control signal indicating a hit to the limb of the user. The limb immobilization device may at least partially immobilize the limb. The immobilization may be voluntary or involuntary.