Node.js Implementation:

class PaymentChannel {
    constructor(sender, receiver, balance) {
        this.sender = sender;
        this.receiver = receiver;
        this.balance = balance;
    }

    updateBalance(amount) {
        this.balance += amount;
    }
}

// Example usage:
const senderAddress = "sender_address";
const receiverAddress = "receiver_address";
const initialBalance = 10;

// Create a payment channel
const channel = new PaymentChannel(senderAddress, receiverAddress, initialBalance);

// Update the balance
channel.updateBalance(-5); // Deduct 5 from sender's balance
channel.updateBalance(5);  // Add 5 to receiver's balance

// Print updated balance
console.log(`Sender balance: ${channel.sender} BTC`);
console.log(`Receiver balance: ${channel.receiver} BTC`);