What can I do about an assault and battery committed by a policeman's wife if the police don't want to pursue the case?

Assault and battery are both civil and criminal matters.  The civil case (lawsuit) is separate from the criminal case.  If the cops aren't doing anything because the defendant is a cop's wife, you might want to try contacting the district attorney's office to try to have that office pursue the criminal case and prosecute the perpetrator.

As for the separate civil case, you can sue the cop's wife for assault and battery.  Assault is intentionally placing one in reasonable apprehension of an immediate battery without consent or privilege.  Assault does not require any physical contact; only the reasonable apprehension of immediate physical contact. 

Battery is the intentional harmful or offensive touching of the person of another without consent or privilege.

Your lawsuit would have separate causes of action (claims) for assault and battery.  If you received medical treatment, your damages (the amount you are seeking to recover in your lawsuit would be the medical bills.  You may also be able to recover compensation for pain and suffering.  Compensation for the medical bills is straight reimbursement.  Compensation for pain and suffering is an amount in addition to the medical bills. The medical reports will document the nature and extent of your injuries and will be used to determine compensation for pain and suffering.  Documentation of wage loss should also be included in your damages, if applicable. You should also consider punitive damages, which are a substantial amount to punish the defendant's intentional and malicious actions. 

You will need to file your lawsuit prior to the expiration of the applicable statute of limitations or you will lose your rights forever in the matter.