Extracorporeally controllable medical implant and method for operating same

• US 5,620,475 A
• Filed: 04/14/1995
• Issued: 04/15/1997
• Est. Priority Date: 04/25/1994
• Status: Expired due to Fees

• Current Assignee: Siemens Elema AB
• Original Assignee: Siemens Elema AB
• Inventors: Magnusson, Peter
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US08/421,780
• Time in Patent Office: 732 Days
• Field of Search: 607/30, 607/9
• US Class Current: 607/30
• CPC Class Codes: A61F 2250/0002 for data transfer
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/37254 Pacemaker or defibrillator security, e.g. to prevent or inhibit programming alterations by hackers or unauthorised individuals

Abstract

A medical implant contains a sensor for sensing extracorporeally, manually generated shockwaves and for generating electrical signals, a detector connected to the sensor that, dependent on the electrical signals, emits pulses to a control unit connected to the detector for controlling a function implementing stage. The control unit emits a function signal to the function stage for the implementation of a function of the implant corresponding to a sequence of one or more parameters with reference to two or more pulses in a shockwave sequence, said sequence being identified in the control unit. In a method for controlling a medical implant, shockwaves are manually generated in a sequence and pulses are respectively generated dependent on the shockwaves, a function signal is supplied to a function stage given every identified sequence of one or more parameters referred to two or more pulses and the implant function defined by the identified sequence is then implemented by the function stage.

Claims

1. A medical implant comprising:

an implantable housing;

function implementation means in said housing for implementing one of a plurality of functions relating to administration of therapy to a patient in whom said housing is implanted;

sensor means in said housing for sensing a series of extracorporeally generated shockwave pulses, said pulses having intervals therebetween, and for generating an electrical signal having a series of electrical pulses with respective intervals therebetween corresponding to the intervals between said shockwave pulses;

measuring means in said housing for measuring a duration of each interval in said electrical signal;

means in said housing for comparing the duration of each interval in said electrical signal, as measured by said measuring means, to each of a first predetermined time interval and a second predetermined time interval longer than said first predetermined interval, and for assigning each duration as being of said first predetermined time interval or of said second predetermined time interval and for producing an output interval sequence of first and second predetermined time intervals dependent on the comparison of the respective durations for all intervals in said electrical signal;

memory means in said housing for storing a plurality of interval sequences respectively corresponding to said plurality of functions;

means in said housing for comparing said output interval sequence to said interval sequences of said memory means for storing; and

means in said housing for, if coincidence exists between said output interval sequence and one of said plurality of interval sequences, controlling said function implementation means to implement the function corresponding to said one of said plurality of interval sequences.

3. A medical implant as claimed in claim 1 further comprising:

filter means in said housing, supplied with said electrical signal, for filtering said electrical signal by comparing said electrical pulses in said electrical signal to an adjustable threshold level and for generating a filtered electrical signal containing only pulses which exceed said threshold level.

4. A medical implant as claimed in claim 3 further comprising:

signal generator means in said housing connected to said sensor means and to said means for controlling said function implementation means, for causing said sensor means to emit an extracorporeally detectable signal identifying the function implemented by said function implementation means.

2. A medical implant as claimed in claim I further comprising:

means in said housing for comparing the respective durations of said intervals in said electrical signal to a predetermined threshold and, if all of said durations are below said predetermined time threshold, for determining a number of pulses in said electrical signal;

said memory means further comprising means for storing a plurality of numbers respectively corresponding to said functions; and

means for comparing the number of pulses in said electrical signal to said numbers in said memory means and for accepting said electrical signal as valid if the number of pulses in said electrical signal coincides with one of said numbers in said memory means.

5. A method for operating a medical implant implanted in a patient comprising the steps of:

extracorporeally generating a series of shockwave pulses in said patient, said pulses having intervals therebetween;

sensing said series of extracorporeally generated shockwave pulses in said medical implant generating an electrical signal having a series of electrical pulses with respective intervals therebetween corresponding to the intervals between said shockwave pulses;

measuring a duration in said medical implant of each interval in said electrical signal;

comparing, in said medical implant, the duration of each interval in said electrical signal to each of a first predetermined time interval and a second predetermined time interval longer than said first predetermined interval, and assigning each duration as being of said first predetermined time interval or of said second predetermined time interval and producing an output interval sequence of first and second predetermined time intervals dependent on the comparison of the respective durations for all intervals in said electrical signal;

storing a plurality of interval sequences in said medical implant respectively corresponding to a plurality of function relating to administration of therapy to said patient;

comparing, in said medical implant, said output interval sequence to said interval sequences stored in said medical implant; and

if coincidence exists between said output interval sequence and one of said plurality of interval sequences, implementing the function corresponding to said one of said plurality of interval sequences.

6. A method as claimed in claim 5 comprising the further steps of:

comparing, in said medical implant, the respective durations of said intervals in said electrical signal to a predetermined threshold and, if all of said durations are below said predetermined time threshold, determining a number of pulses in said electrical signal;

storing a plurality of numbers in said medical implant respectively corresponding to said functions; and

comparing, in said medical implant, the number of pulses in said electrical signal to said numbers in said memory means and accepting said electrical signal as valid if the number of pulses in said electrical signal coincides with one of said numbers in said memory means.

7. A method as claimed in claim 5 comprising the further steps of:

filtering said electrical signal in said medical implant by comparing said electrical pulses in said electrical signal to an adjustable threshold level and generating a filtered electrical signal containing only pulses which exceed said threshold level.

8. A method as claimed in claim 7 comprising the additional step of:

causing said sensor means to emit an extracorporeally detectable signal identifying the function implemented by said function implementation means.